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Hochholdinger F, Yu P. Molecular concepts to explain heterosis in crops. TRENDS IN PLANT SCIENCE 2024:S1360-1385(24)00215-2. [PMID: 39191625 DOI: 10.1016/j.tplants.2024.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 07/31/2024] [Accepted: 07/31/2024] [Indexed: 08/29/2024]
Abstract
Heterosis describes the superior performance of hybrid plants compared with their genetically distinct parents and is a pillar of global food security. Here we review the current status of the molecular dissection of heterosis. We discuss how extensive intraspecific structural genomic variation between parental genotypes leads to heterosis by genetic complementation in hybrids. Moreover, we survey how global gene expression complementation contributes to heterosis by hundreds of additionally active genes in hybrids and how overdominant single genes mediate heterosis in several species. Furthermore, we highlight the prominent role of the microbiome in improving the performance of hybrids. Taken together, the molecular understanding of heterosis will pave the way to accelerate hybrid productivity and a more sustainable agriculture.
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Affiliation(s)
- Frank Hochholdinger
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113 Bonn, Germany.
| | - Peng Yu
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113 Bonn, Germany; INRES, Institute of Crop Science and Resource Conservation, Root Functional Biology, University of Bonn, 53113 Bonn, Germany.
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Huang C, Cheng Y, Hu Y, Fang L, Si Z, Chen J, Cao Y, Guan X, Zhang T. Dynamic patterns of gene expressional and regulatory variations in cotton heterosis. FRONTIERS IN PLANT SCIENCE 2024; 15:1450963. [PMID: 39166253 PMCID: PMC11333441 DOI: 10.3389/fpls.2024.1450963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Accepted: 07/24/2024] [Indexed: 08/22/2024]
Abstract
Purpose Although the application of heterosis has significantly increased crop yield over the past century, the mechanisms underlying this phenomenon still remain obscure. Here, we applied transcriptome sequencing to unravel the impacts of parental expression differences and transcriptomic reprogramming in cotton heterosis. Methods A high-quality transcriptomic atlas covering 15 developmental stages and tissues was constructed for XZM2, an elite hybrid of upland cotton (Gossypium hirsutum L.), and its parental lines, CRI12 and J8891. This atlas allowed us to identify gene expression differences between the parents and to characterize the transcriptomic reprogramming that occurs in the hybrid. Results Our analysis revealed abundant gene expression differences between the parents, with pronounced tissue specificity; a total of 1,112 genes exhibited single-parent expression in at least one tissue. It also illuminated transcriptomic reprogramming in the hybrid XZM2, which included both additive and non-additive expression patterns. Coexpression networks between parents and hybrid constructed via weighted gene coexpression network analysis identified modules closely associated with fiber development. In particular, key regulatory hub genes involved in fiber development showed high-parent dominant or over dominant patterns in the hybrid, potentially driving the emergence of heterosis. Finally, high-depth resequencing data was generated and allele-specific expression patterns examined in the hybrid, enabling the dissection of cis- and trans-regulation contributions to the observed expression differences. Conclusion Parental transcriptional differences and transcriptomic reprogramming in the hybrid, especially the non-additive upregulation of key genes, play an important role in shaping heterosis. Collectively, these findings provide new insights into the molecular basis of heterosis in cotton.
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Affiliation(s)
- Chujun Huang
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Yu Cheng
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Yan Hu
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
- Hainan Institute of Zhejiang University, Sanya, China
| | - Lei Fang
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
- Hainan Institute of Zhejiang University, Sanya, China
| | - Zhanfeng Si
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Jinwen Chen
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Yiwen Cao
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
- Hainan Institute of Zhejiang University, Sanya, China
| | - Xueying Guan
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
- Hainan Institute of Zhejiang University, Sanya, China
| | - Tianzhen Zhang
- Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
- Hainan Institute of Zhejiang University, Sanya, China
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He C, Zhu B, Gao W, Wu Q, Zhang C. Study on Allele Specific Expression of Long-Term Residents in High Altitude Areas. Evol Bioinform Online 2024; 20:11769343241257344. [PMID: 38826865 PMCID: PMC11141219 DOI: 10.1177/11769343241257344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 05/07/2024] [Indexed: 06/04/2024] Open
Abstract
In diploid organisms, half of the chromosomes in each cell come from the father and half from the mother. Through previous studies, it was found that the paternal chromosome and the maternal chromosome can be regulated and expressed independently, leading to the emergence of allele specific expression (ASE). In this study, we analyzed the differential expression of alleles in the high-altitude population and the normal population based on the RNA sequencing data. Through gene cluster analysis and protein interaction network analysis, we found some changes occurred at the gene level, and some negative effects. During the study, we realized that the calmodulin homology domain may have a certain correlation with long-term survival at high altitude. The plateau environment is characterized by hypoxia, low air pressure, strong ultraviolet radiation, and low temperature. Accordingly, the genetic changes in the process of adaptation are mainly reflected in these characteristics. High altitude generation living is also highly related to cancer, immune disease, cardiovascular disease, neurological disease, endocrine disease, and other diseases. Therefore, the medical system in high altitude areas should pay more attention to these diseases.
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Affiliation(s)
- Chao He
- The General Hospital of Tibet Military Region, Lhasa, China
| | - Bin Zhu
- The General Hospital of Tibet Military Region, Lhasa, China
| | - Wenwen Gao
- The General Hospital of Tibet Military Region, Lhasa, China
| | - Qianjin Wu
- The General Hospital of Tibet Military Region, Lhasa, China
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4
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Shi TL, Jia KH, Bao YT, Nie S, Tian XC, Yan XM, Chen ZY, Li ZC, Zhao SW, Ma HY, Zhao Y, Li X, Zhang RG, Guo J, Zhao W, El-Kassaby YA, Müller N, Van de Peer Y, Wang XR, Street NR, Porth I, An X, Mao JF. High-quality genome assembly enables prediction of allele-specific gene expression in hybrid poplar. PLANT PHYSIOLOGY 2024; 195:652-670. [PMID: 38412470 PMCID: PMC11060683 DOI: 10.1093/plphys/kiae078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 02/29/2024]
Abstract
Poplar (Populus) is a well-established model system for tree genomics and molecular breeding, and hybrid poplar is widely used in forest plantations. However, distinguishing its diploid homologous chromosomes is difficult, complicating advanced functional studies on specific alleles. In this study, we applied a trio-binning design and PacBio high-fidelity long-read sequencing to obtain haplotype-phased telomere-to-telomere genome assemblies for the 2 parents of the well-studied F1 hybrid "84K" (Populus alba × Populus tremula var. glandulosa). Almost all chromosomes, including the telomeres and centromeres, were completely assembled for each haplotype subgenome apart from 2 small gaps on one chromosome. By incorporating information from these haplotype assemblies and extensive RNA-seq data, we analyzed gene expression patterns between the 2 subgenomes and alleles. Transcription bias at the subgenome level was not uncovered, but extensive-expression differences were detected between alleles. We developed machine-learning (ML) models to predict allele-specific expression (ASE) with high accuracy and identified underlying genome features most highly influencing ASE. One of our models with 15 predictor variables achieved 77% accuracy on the training set and 74% accuracy on the testing set. ML models identified gene body CHG methylation, sequence divergence, and transposon occupancy both upstream and downstream of alleles as important factors for ASE. Our haplotype-phased genome assemblies and ML strategy highlight an avenue for functional studies in Populus and provide additional tools for studying ASE and heterosis in hybrids.
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Affiliation(s)
- Tian-Le Shi
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Kai-Hua Jia
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
- Key Laboratory of Crop Genetic Improvement & Ecology and Physiology, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Ji’nan 250100, China
| | - Yu-Tao Bao
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Shuai Nie
- Rice Research Institute, Guangdong Academy of Agricultural Sciences & Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs & Guangdong Key Laboratory of New Technology in Rice Breeding, Guangzhou 510640, China
| | - Xue-Chan Tian
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Xue-Mei Yan
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Zhao-Yang Chen
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Zhi-Chao Li
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Shi-Wei Zhao
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Hai-Yao Ma
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Ye Zhao
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Xiang Li
- School of Agriculture, Ningxia University, Yinchuan 750021, China
| | - Ren-Gang Zhang
- Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China
| | - Jing Guo
- College of Forestry, Shandong Agricultural University, Tai’an 271000, China
| | - Wei Zhao
- Umeå Plant Science Centre, Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden
| | - Yousry Aly El-Kassaby
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Vancouver, Bc, V6T 1Z4, Canada
| | - Niels Müller
- Thünen-Institute of Forest Genetics, 22927 Grosshansdorf, Germany
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052 Ghent, Belgium
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0028, South Africa
- College of Horticulture, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiao-Ru Wang
- Umeå Plant Science Centre, Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden
| | - Nathaniel Robert Street
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-901 87 Umeå, Sweden
| | - Ilga Porth
- Départment des Sciences du Bois et de la Forêt, Faculté de Foresterie, de Géographie et Géomatique, Université Laval, Québec, QC G1V 0A6, Canada
| | - Xinmin An
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Jian-Feng Mao
- State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-901 87 Umeå, Sweden
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5
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Liu W, He G, Deng XW. Toward understanding and utilizing crop heterosis in the age of biotechnology. iScience 2024; 27:108901. [PMID: 38533455 PMCID: PMC10964264 DOI: 10.1016/j.isci.2024.108901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024] Open
Abstract
Heterosis, a universal phenomenon in nature, mainly reflected in the superior productivity, quality, and fitness of F1 hybrids compared with their inbred parents, has been exploited in agriculture and greatly benefited human society in terms of food security. However, the flexible and efficient utilization of heterosis has remained a challenge in hybrid breeding systems because of the limitations of "three-line" and "two-line" methods. In the past two decades, rapidly developed biotechnologies have provided unprecedented conveniences for both understanding and utilizing heterosis. Notably, "third-generation" (3G) hybrid breeding technology together with high-throughput sequencing and gene editing greatly promoted the efficiency of hybrid breeding. Here, we review emerging ideas about the genetic or molecular mechanisms of heterosis and the development of 3G hybrid breeding system in the age of biotechnology. In addition, we summarized opportunities and challenges for optimal heterosis utilization in the future.
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Affiliation(s)
- Wenwen Liu
- School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
- National Key Laboratory of Wheat Improvement, Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences in Weifang, Weifang, Shandong 261325, China
| | - Guangming He
- School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Xing Wang Deng
- School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
- National Key Laboratory of Wheat Improvement, Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences in Weifang, Weifang, Shandong 261325, China
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6
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Baldauf JA, Hochholdinger F. Molecular dissection of heterosis in cereal roots and their rhizosphere. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:173. [PMID: 37474870 PMCID: PMC10359381 DOI: 10.1007/s00122-023-04419-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 07/05/2023] [Indexed: 07/22/2023]
Abstract
Heterosis is already manifested early in root development. Consistent with the dominance model of heterosis, gene expression complementation is a general mechanism that contributes to phenotypic heterosis in maize hybrids. Highly heterozygous F1-hybrids outperform their parental inbred lines, a phenomenon known as heterosis. Utilization of heterosis is of paramount agricultural importance and has been widely applied to increase yield in many crop cultivars. Plant roots display heterosis for many traits and are an important target for further crop improvement. To explain the molecular basis of heterosis, several genetic hypotheses have been proposed. In recent years, high-throughput gene expression profiling techniques have been applied to investigate hybrid vigor. Consistent with the classical genetic dominance model, gene expression complementation has been demonstrated to be a general mechanism to contribute to phenotypic heterosis in diverse maize hybrids. Functional classification of these genes supported the notion that gene expression complementation can dynamically promote hybrid vigor under fluctuating environmental conditions. Hybrids tend to respond differently to available nutrients in the soil. It was hypothesized that hybrid vigor is promoted through a higher nutrient use efficiency which is linked to an improved root system performance of hybrids in comparison to their inbred parents. Recently, the interaction between soil microbes and their plant host was added as further dimension to disentangle heterosis in the belowground part of plants. Soil microbes influenced the performance of maize hybrids as illustrated in comparisons of sterile soil and soil inhabited by beneficial microorganisms.
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Affiliation(s)
- Jutta A Baldauf
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113, Bonn, Germany
| | - Frank Hochholdinger
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113, Bonn, Germany.
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7
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Chen J, Wang Z, Tan K, Huang W, Shi J, Li T, Hu J, Wang K, Wang C, Xin B, Zhao H, Song W, Hufford MB, Schnable JC, Jin W, Lai J. A complete telomere-to-telomere assembly of the maize genome. Nat Genet 2023:10.1038/s41588-023-01419-6. [PMID: 37322109 DOI: 10.1038/s41588-023-01419-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/05/2023] [Indexed: 06/17/2023]
Abstract
A complete telomere-to-telomere (T2T) finished genome has been the long pursuit of genomic research. Through generating deep coverage ultralong Oxford Nanopore Technology (ONT) and PacBio HiFi reads, we report here a complete genome assembly of maize with each chromosome entirely traversed in a single contig. The 2,178.6 Mb T2T Mo17 genome with a base accuracy of over 99.99% unveiled the structural features of all repetitive regions of the genome. There were several super-long simple-sequence-repeat arrays having consecutive thymine-adenine-guanine (TAG) tri-nucleotide repeats up to 235 kb. The assembly of the entire nucleolar organizer region of the 26.8 Mb array with 2,974 45S rDNA copies revealed the enormously complex patterns of rDNA duplications and transposon insertions. Additionally, complete assemblies of all ten centromeres enabled us to precisely dissect the repeat compositions of both CentC-rich and CentC-poor centromeres. The complete Mo17 genome represents a major step forward in understanding the complexity of the highly recalcitrant repetitive regions of higher plant genomes.
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Affiliation(s)
- Jian Chen
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China
| | - Zijian Wang
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China
| | - Kaiwen Tan
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China
| | - Wei Huang
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China
| | - Junpeng Shi
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China
| | - Tong Li
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China
| | - Jiang Hu
- Grandomics Biosciences, Wuhan, P. R. China
| | - Kai Wang
- Grandomics Biosciences, Wuhan, P. R. China
| | - Chao Wang
- Grandomics Biosciences, Wuhan, P. R. China
| | - Beibei Xin
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China
| | - Haiming Zhao
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China
| | - Weibin Song
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China
| | - Matthew B Hufford
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - James C Schnable
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Weiwei Jin
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China
| | - Jinsheng Lai
- State Key Laboratory of Maize Bio-breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, P. R. China.
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, P. R. China.
- Sanya Institute of China Agricultural University, Sanya, P. R. China.
- Hainan Yazhou Bay Seed Laboratory, Sanya, P. R. China.
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Zhou H, Deng XW, He H. Gene expression variations and allele-specific expression of two rice and their hybrid in caryopses at single-nucleus resolution. FRONTIERS IN PLANT SCIENCE 2023; 14:1171474. [PMID: 37287712 PMCID: PMC10242081 DOI: 10.3389/fpls.2023.1171474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/26/2023] [Indexed: 06/09/2023]
Abstract
Seeds are an indispensable part of the flowering plant life cycle and a critical determinant of agricultural production. Distinct differences in the anatomy and morphology of seeds separate monocots and dicots. Although some progress has been made with respect to understanding seed development in Arabidopsis, the transcriptomic features of monocotyledon seeds at the cellular level are much less understood. Since most important cereal crops, such as rice, maize, and wheat, are monocots, it is essential to study transcriptional differentiation and heterogeneity during seed development at a finer scale. Here, we present single-nucleus RNA sequencing (snRNA-seq) results of over three thousand nuclei from caryopses of the rice cultivars Nipponbare and 9311 and their intersubspecies F1 hybrid. A transcriptomics atlas that covers most of the cell types present during the early developmental stage of rice caryopses was successfully constructed. Additionally, novel specific marker genes were identified for each nuclear cluster in the rice caryopsis. Moreover, with a focus on rice endosperm, the differentiation trajectory of endosperm subclusters was reconstructed to reveal the developmental process. Allele-specific expression (ASE) profiling in endosperm revealed 345 genes with ASE (ASEGs). Further pairwise comparisons of the differentially expressed genes (DEGs) in each endosperm cluster among the three rice samples demonstrated transcriptional divergence. Our research reveals differentiation in rice caryopsis from the single-nucleus perspective and provides valuable resources to facilitate clarification of the molecular mechanism underlying caryopsis development in rice and other monocots.
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Affiliation(s)
- Han Zhou
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agriculture Sciences and School of Life Sciences, Peking University, Beijing, China
- Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Peking University Institute of Advanced Agricultural Sciences, Weifang, Shandong, China
| | - Xing Wang Deng
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agriculture Sciences and School of Life Sciences, Peking University, Beijing, China
- Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Peking University Institute of Advanced Agricultural Sciences, Weifang, Shandong, China
| | - Hang He
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agriculture Sciences and School of Life Sciences, Peking University, Beijing, China
- Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Peking University Institute of Advanced Agricultural Sciences, Weifang, Shandong, China
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9
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Epigenetic Changes Occurring in Plant Inbreeding. Int J Mol Sci 2023; 24:ijms24065407. [PMID: 36982483 PMCID: PMC10048984 DOI: 10.3390/ijms24065407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/01/2023] [Accepted: 03/10/2023] [Indexed: 03/18/2023] Open
Abstract
Inbreeding is the crossing of closely related individuals in nature or a plantation or self-pollinating plants, which produces plants with high homozygosity. This process can reduce genetic diversity in the offspring and decrease heterozygosity, whereas inbred depression (ID) can often reduce viability. Inbred depression is common in plants and animals and has played a significant role in evolution. In the review, we aim to show that inbreeding can, through the action of epigenetic mechanisms, affect gene expression, resulting in changes in the metabolism and phenotype of organisms. This is particularly important in plant breeding because epigenetic profiles can be linked to the deterioration or improvement of agriculturally important characteristics.
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10
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Dong X, Luo H, Yao J, Guo Q, Yu S, Zhang X, Cheng X, Meng D. Characterization of Genes That Exhibit Genotype-Dependent Allele-Specific Expression and Its Implications for the Development of Maize Kernel. Int J Mol Sci 2023; 24:ijms24054766. [PMID: 36902194 PMCID: PMC10002780 DOI: 10.3390/ijms24054766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/19/2023] [Accepted: 02/24/2023] [Indexed: 03/06/2023] Open
Abstract
Heterosis or hybrid vigor refers to the superior phenotypic traits of hybrids relative to their parental inbred lines. An imbalance between the expression levels of two parental alleles in the F1 hybrid has been suggested as a mechanism of heterosis. Here, based on genome-wide allele-specific expression analysis using RNA sequencing technology, 1689 genes exhibiting genotype-dependent allele-specific expression (genotype-dependent ASEGs) were identified in the embryos, and 1390 genotype-dependent ASEGs in the endosperm, of three maize F1 hybrids. Of these ASEGs, most were consistent in different tissues from one hybrid cross, but nearly 50% showed allele-specific expression from some genotypes but not others. These genotype-dependent ASEGs were mostly enriched in metabolic pathways of substances and energy, including the tricarboxylic acid cycle, aerobic respiration, and energy derivation by oxidation of organic compounds and ADP binding. Mutation and overexpression of one ASEG affected kernel size, which indicates that these genotype-dependent ASEGs may make important contributions to kernel development. Finally, the allele-specific methylation pattern on genotype-dependent ASEGs indicated that DNA methylation plays a potential role in the regulation of allelic expression for some ASEGs. In this study, a detailed analysis of genotype-dependent ASEGs in the embryo and endosperm of three different maize F1 hybrids will provide an index of genes for future research on the genetic and molecular mechanism of heterosis.
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Affiliation(s)
- Xiaomei Dong
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang 110866, China
| | - Haishan Luo
- College of Agronomy, Shenyang Agricultural University, Shenyang 110866, China
| | - Jiabin Yao
- College of Agronomy, Shenyang Agricultural University, Shenyang 110866, China
| | - Qingfeng Guo
- College of Agronomy, Shenyang Agricultural University, Shenyang 110866, China
| | - Shuai Yu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang 110866, China
| | - Xiaoyu Zhang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang 110866, China
| | - Xipeng Cheng
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang 110866, China
| | - Dexuan Meng
- College of Agronomy, Shenyang Agricultural University, Shenyang 110866, China
- Correspondence:
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11
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Wang P, Gu M, Yu X, Shao S, Du J, Wang Y, Wang F, Chen S, Liao Z, Ye N, Zhang X. Allele-specific expression and chromatin accessibility contribute to heterosis in tea plants (Camellia sinensis). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 112:1194-1211. [PMID: 36219505 DOI: 10.1111/tpj.16004] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Heterosis is extensively used to improve crop productivity, yet its allelic and chromatin regulation remains unclear. Based on our resolved genomes of the maternal TGY and paternal HD, we analyzed the contribution of allele-specific expression (ASE) and chromatin accessibility of JGY and HGY, the artificial hybrids of oolong tea with the largest cultivated area in China. The ASE genes (ASEGs) of tea hybrids with maternal-biased were mainly related to the energy and terpenoid metabolism pathways, whereas the ASEGs with paternal-biased tend to be enriched in glutathione metabolism, and these parental bias of hybrids may coordinate and lead to the acquisition of heterosis in more biological pathways. ATAC-seq results showed that hybrids have significantly higher accessible chromatin regions (ACRs) compared with their parents, which may confer broader and stronger transcriptional activity of genes in hybrids. The number of ACRs with significantly increased accessibility in hybrids was much greater than decreased, and the associated alleles were also affected by differential ACRs across different parents, suggesting enhanced positive chromatin regulation and potential genetic effects in hybrids. Core ASEGs of terpene and purine alkaloid metabolism pathways with significant positive heterosis have greater chromatin accessibility in hybrids, and were potentially regulated by several members of the MYB, DOF and TRB families. The binding motif of CsMYB85 in the promoter ACR of the rate-limiting enzyme CsDXS was verified by DAP-seq. These results suggest that higher numbers and more accessible ACRs in hybrids contribute to the regulation of ASEGs, thereby affecting the formation of heterotic metabolites.
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Affiliation(s)
- Pengjie Wang
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Mengya Gu
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Xikai Yu
- College of Agriculture, Guangxi University, Nanning, 530004, China
| | - Shuxian Shao
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Jiayin Du
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Yibin Wang
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Feiquan Wang
- College of Tea and Food Science, Wuyi University, Wuyishan, Fujian, 354300, China
| | - Shuai Chen
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Zhenyang Liao
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Naixing Ye
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Xingtan Zhang
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
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12
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Fu J, Zhang Y, Yan T, Li Y, Jiang N, Zhou Y, Zhou Q, Qin P, Fu C, Lin H, Zhong J, Han X, Lin Z, Wang F, He H, Wang K, Yang Y. Transcriptome profiling of two super hybrid rice provides insights into the genetic basis of heterosis. BMC PLANT BIOLOGY 2022; 22:314. [PMID: 35773646 PMCID: PMC9245205 DOI: 10.1186/s12870-022-03697-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/15/2022] [Indexed: 05/19/2023]
Abstract
BACKGROUND Heterosis is a phenomenon that hybrids show superior performance over their parents. The successful utilization of heterosis has greatly improved rice productivity, but the molecular basis of heterosis remains largely unclear. RESULTS Here, the transcriptomes of young panicles and leaves of the two widely grown two-line super hybrid rice varieties (Jing-Liang-You-Hua-Zhan (JLYHZ) and Long-Liang-You-Hua-Zhan (LLYHZ)) and their parents were analyzed by RNA-seq. Transcriptome profiling of the hybrids revealed 1,778 ~ 9,404 differentially expressed genes (DEGs) in two tissues, which were identified by comparing with their parents. GO, and KEGG enrichment analysis showed that the pathways significantly enriched in both tissues of two hybrids were all related to yield and resistance, like circadian rhythm (GO:0,007,623), response to water deprivation (GO:0,009,414), and photosynthetic genes (osa00196). Allele-specific expression genes (ASEGs) were also identified in hybrids. The ASEGs were most significantly enriched in ionotropic glutamate receptor signaling pathway, which was hypothesized to be potential amino acid sensors in plants. Moreover, the ASEGs were also differentially expressed between parents. The number of variations in ASEGs is higher than expected, especially for large effect variations. The DEGs and ASEGs are the potential reasons for the formation of heterosis in the two elite super hybrid rice. CONCLUSIONS Our results provide a comprehensive understanding of the heterosis of two-line super hybrid rice and facilitate the exploitation of heterosis in hybrid rice breeding with high yield heterosis.
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Affiliation(s)
- Jun Fu
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China
| | - Yilin Zhang
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Tianze Yan
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China
| | - Yanfeng Li
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China
| | - Nan Jiang
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China
| | - Yanbiao Zhou
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China
| | - Qunfeng Zhou
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China
| | - Peng Qin
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China
| | - Chenjian Fu
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China
| | - Haiyan Lin
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China
| | - Jing Zhong
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China
| | - Xue Han
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Zechuan Lin
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Fei Wang
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hang He
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
| | - Kai Wang
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China.
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China.
- Longping Hi-Tech (Sanya) Overseas Seed Industry R&D Co., Ltd, Sanya, 572099, China.
| | - Yuanzhu Yang
- Key Laboratory of Southern Rice Innovation & Improvement, Ministry of Agriculture and Rural Affairs, Hunan Engineering Laboratory of Disease and Pest Resistant Rice Breeding, Yuan Longping High-Tech Agriculture Co., Ltd, Changsha, 410128, China.
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China.
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, 410125, China.
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13
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Baldauf JA, Liu M, Vedder L, Yu P, Piepho HP, Schoof H, Nettleton D, Hochholdinger F. Single-parent expression complementation contributes to phenotypic heterosis in maize hybrids. PLANT PHYSIOLOGY 2022; 189:1625-1638. [PMID: 35522211 PMCID: PMC9237695 DOI: 10.1093/plphys/kiac180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/23/2022] [Indexed: 06/14/2023]
Abstract
The dominance model of heterosis explains the superior performance of F1-hybrids via the complementation of deleterious alleles by beneficial alleles in many genes. Genes active in one parent but inactive in the second lead to single-parent expression (SPE) complementation in maize (Zea mays L.) hybrids. In this study, SPE complementation resulted in approximately 700 additionally active genes in different tissues of genetically diverse maize hybrids on average. We established that the number of SPE genes is significantly associated with mid-parent heterosis (MPH) for all surveyed phenotypic traits. In addition, we highlighted that maternally (SPE_B) and paternally (SPE_X) active SPE genes enriched in gene co-expression modules are highly correlated within each SPE type but separated between these two SPE types. While SPE_B-enriched co-expression modules are positively correlated with phenotypic traits, SPE_X-enriched modules displayed a negative correlation. Gene ontology term enrichment analyses indicated that SPE_B patterns are associated with growth and development, whereas SPE_X patterns are enriched in defense and stress response. In summary, these results link the degree of phenotypic MPH to the prevalence of gene expression complementation observed by SPE, supporting the notion that hybrids benefit from SPE complementation via its role in coordinating maize development in fluctuating environments.
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Affiliation(s)
- Jutta A Baldauf
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113 Bonn, Germany
| | | | - Lucia Vedder
- Institute of Crop Science and Resource Conservation, Crop Bioinformatics, University of Bonn, 53115 Bonn, Germany
| | - Peng Yu
- Emmy Noether Group Root Functional Biology, Institute of Crop Science and Resource Conservation, University of Bonn, 53113 Bonn, Germany
| | - Hans-Peter Piepho
- Institute of Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany
| | - Heiko Schoof
- Institute of Crop Science and Resource Conservation, Crop Bioinformatics, University of Bonn, 53115 Bonn, Germany
| | - Dan Nettleton
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210, USA
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14
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Wan J, Wang Q, Zhao J, Zhang X, Guo Z, Hu D, Meng S, Lin Y, Qiu X, Mu L, Ding D, Tang J. Gene expression variation explains maize seed germination heterosis. BMC PLANT BIOLOGY 2022; 22:301. [PMID: 35718761 PMCID: PMC9208091 DOI: 10.1186/s12870-022-03690-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Heterosis has been extensively utilized in plant breeding, however, the underlying molecular mechanism remains largely elusive. Maize (Zea mays), which exhibits strong heterosis, is an ideal material for studying heterosis. RESULTS In this study, there is faster imbibition and development in reciprocal crossing Zhengdan958 hybrids than in their parent lines during seed germination. To investigate the mechanism of heterosis of maize germination, comparative transcriptomic analyses were conducted. The gene expression patterns showed that 1324 (47.27%) and 1592 (66.44%) of the differential expression genes between hybrids and either parental line display parental dominance up or higher levels in the reciprocal cross of Zhengdan958, respectively. Notably, these genes were mainly enriched in metabolic pathways, including carbon metabolism, glycolysis/gluconeogenesis, protein processing in endoplasmic reticulum, etc. CONCLUSION: Our results provide evidence for the higher expression level genes in hybrid involved in metabolic pathways acting as main contributors to maize seed germinating heterosis. These findings provide new insights into the gene expression variation of maize embryos and improve the understanding of maize seed germination heterosis.
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Affiliation(s)
- Jiong Wan
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Qiyue Wang
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Jiawen Zhao
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Xuehai Zhang
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Zhanyong Guo
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Desheng Hu
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Shujun Meng
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Yuan Lin
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Xiaoqian Qiu
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Liqin Mu
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Dong Ding
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China.
| | - Jihua Tang
- National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China.
- The Shennong Laboratory, Zhengzhou, 450002, China.
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15
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Liu W, Zhang Y, He H, He G, Deng XW. From hybrid genomes to heterotic trait output: Challenges and opportunities. CURRENT OPINION IN PLANT BIOLOGY 2022; 66:102193. [PMID: 35219140 DOI: 10.1016/j.pbi.2022.102193] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 12/19/2021] [Accepted: 01/23/2022] [Indexed: 06/14/2023]
Abstract
Heterosis (or hybrid vigor) has been widely used in crop seed breeding to improve many key economic traits. Nevertheless, the genetic and molecular basis of this important phenomenon has long remained elusive, constraining its flexible and effective exploitation. Advanced genomic approaches are efficient in characterizing the mechanism of heterosis. Here, we review how the omics approaches, including genomic, transcriptomic, and population genetics methods such as genome-wide association studies, can reveal how hybrid genomes outperform parental genomes in plants. This information opens up opportunities for genomic exploration and manipulation of heterosis in crop breeding.
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Affiliation(s)
- Wenwen Liu
- School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Yilin Zhang
- School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Hang He
- Peking University Institute of Advanced Agricultural Sciences, 699 Binhu Road, Xiashan Ecological and Economic Development Zone, Weifang, Shandong, 261325, China
| | - Guangming He
- School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
| | - Xing Wang Deng
- School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China; Peking University Institute of Advanced Agricultural Sciences, 699 Binhu Road, Xiashan Ecological and Economic Development Zone, Weifang, Shandong, 261325, China.
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16
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Wang X, Ke L, Wang S, Fu J, Xu J, Hao Y, Kang C, Guo W, Deng X, Xu Q. Variation burst during dedifferentiation and increased CHH-type DNA methylation after 30 years of in vitro culture of sweet orange. HORTICULTURE RESEARCH 2022; 9:uhab036. [PMID: 35039837 PMCID: PMC8824543 DOI: 10.1093/hr/uhab036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 01/18/2022] [Accepted: 10/15/2021] [Indexed: 06/14/2023]
Abstract
Somaclonal variation arising from tissue culture may provide a valuable resource for the selection of new germplasm, but may not preserve true-to-type characteristics, which is a major concern for germplasm conservation or genome editing. The genomic changes associated with dedifferentiation and somaclonal variation during long-term in vitro culture are largely unknown. Sweet orange was one of the earliest plant species to be cultured in vitro and induced via somatic embryogenesis. We compared four sweet orange callus lines after 30 years of constant tissue culture with newly induced calli by comprehensively determining the single-nucleotide polymorphisms, copy number variations, transposable element insertions, methylomic and transcriptomic changes. We identified a burst of variation during early dedifferentiation, including a retrotransposon outbreak, followed by a variation purge during long-term in vitro culture. Notably, CHH methylation showed a dynamic pattern, initially disappearing during dedifferentiation and then more than recovering after 30 years of in vitro culture. We also analyzed the effects of somaclonal variation on transcriptional reprogramming, and indicated subgenome dominance was evident in the tetraploid callus. We identified a retrotransposon insertion and DNA modification alternations in the potential regeneration-related gene CLAVATA3/EMBRYO SURROUNDING REGION-RELATED 16. This study provides the foundation to harness in vitro variation and offers a deeper understanding of the variation introduced by tissue culture during germplasm conservation, somatic embryogenesis, gene editing, and breeding programs.
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Affiliation(s)
- Xia Wang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University,
No. 1, Shizishan Street, Wuhan 430070, China
| | - Lili Ke
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University,
No. 1, Shizishan Street, Wuhan 430070, China
| | - Shuting Wang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University,
No. 1, Shizishan Street, Wuhan 430070, China
| | - Jialing Fu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University,
No. 1, Shizishan Street, Wuhan 430070, China
| | - Jidi Xu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University,
No. 1, Shizishan Street, Wuhan 430070, China
| | - Yujin Hao
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University,
No. 1, Shizishan Street, Wuhan 430070, China
| | - Chunying Kang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University,
No. 1, Shizishan Street, Wuhan 430070, China
| | - Wenwu Guo
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University,
No. 1, Shizishan Street, Wuhan 430070, China
| | - Xiuxin Deng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University,
No. 1, Shizishan Street, Wuhan 430070, China
| | - Qiang Xu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University,
No. 1, Shizishan Street, Wuhan 430070, China
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17
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McReynolds MR, Dash L, Montes C, Draves MA, Lang MG, Walley JW, Kelley DR. Temporal and spatial auxin responsive networks in maize primary roots. QUANTITATIVE PLANT BIOLOGY 2022; 3:e21. [PMID: 37077976 PMCID: PMC10095944 DOI: 10.1017/qpb.2022.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 08/23/2022] [Accepted: 08/26/2022] [Indexed: 05/03/2023]
Abstract
Auxin is a key regulator of root morphogenesis across angiosperms. To better understand auxin-regulated networks underlying maize root development, we have characterized auxin-responsive transcription across two time points (30 and 120 min) and four regions of the primary root: the meristematic zone, elongation zone, cortex and stele. Hundreds of auxin-regulated genes involved in diverse biological processes were quantified in these different root regions. In general, most auxin-regulated genes are region unique and are predominantly observed in differentiated tissues compared with the root meristem. Auxin gene regulatory networks were reconstructed with these data to identify key transcription factors that may underlie auxin responses in maize roots. Additionally, Auxin-Response Factor subnetworks were generated to identify target genes that exhibit tissue or temporal specificity in response to auxin. These networks describe novel molecular connections underlying maize root development and provide a foundation for functional genomic studies in a key crop.
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Affiliation(s)
- Maxwell R. McReynolds
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa50011, USA
| | - Linkan Dash
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa50011, USA
| | - Christian Montes
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa50011, USA
| | - Melissa A. Draves
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa50011, USA
| | - Michelle G. Lang
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa50011, USA
- Corteva Agriscience, Johnston, Iowa50131, USA
| | - Justin W. Walley
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa50011, USA
- Authors for correspondence: D. R. Kelley and J. W. Walley, E-mail: ;
| | - Dior R. Kelley
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa50011, USA
- Authors for correspondence: D. R. Kelley and J. W. Walley, E-mail: ;
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18
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Wu J, Sun D, Zhao Q, Yong H, Zhang D, Hao Z, Zhou Z, Han J, Zhang X, Xu Z, Li X, Li M, Weng J. Transcriptome Reveals Allele Contribution to Heterosis in Maize. FRONTIERS IN PLANT SCIENCE 2021; 12:739072. [PMID: 34630491 PMCID: PMC8494984 DOI: 10.3389/fpls.2021.739072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 09/06/2021] [Indexed: 06/13/2023]
Abstract
Heterosis, which has greatly increased maize yields, is associated with gene expression patterns during key developmental stages that enhance hybrid phenotypes relative to parental phenotypes. Before heterosis can be more effectively used for crop improvement, hybrid maize developmental gene expression patterns must be better understood. Here, six maize hybrids, including the popular hybrid Zhengdan958 (ZC) from China, were studied. Maize hybrids created in-house were generated using an incomplete diallel cross (NCII)-based strategy from four elite inbred parental lines. Differential gene expression (DEG) profiles corresponding to three developmental stages revealed that hybrid partial expression patterns exhibited complementarity of expression of certain parental genes, with parental allelic expression patterns varying both qualitatively and quantitatively in hybrids. Single-parent expression (SPE) and parent-specific expression (PSE) types of qualitative variation were most prevalent, 43.73 and 41.07% of variation, respectively. Meanwhile, negative super-dominance (NSD) and positive super-dominance (PSD) types of quantitative variation were most prevalent, 31.06 and 24.30% of variation, respectively. During the early reproductive growth stage, the gene expression pattern differed markedly from other developmental stage patterns, with allelic expression patterns during seed development skewed toward low-value parental alleles in hybrid seeds exhibiting significant quantitative variation-associated superiority. Comparisons of qualitative gene expression variation rates between ZC and other hybrids revealed proportions of SPE-DEGs (41.36%) in ZC seed DEGs that significantly exceeded the average proportion of SPE-DEGs found in seeds of other hybrids (28.36%). Importantly, quantitative gene expression variation rate comparisons between ZC and hybrids, except for transgressive expression, revealed that the ZC rate exceeded the average rate for other hybrids, highlighting the importance of partial gene expression in heterosis. Moreover, enriched ZC DEGs exhibiting distinct tissue-specific expression patterns belonged to four biological pathways, including photosynthesis, plant hormone signal transduction, biology metabolism and biosynthesis. These results provide valuable technical insights for creating hybrids exhibiting strong heterosis.
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Affiliation(s)
- Jianzhong Wu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
- Institute of Forage and Grassland Sciences, Heilongjiang Academy of Agricultural Sciences, Harbin, China
| | - Dequan Sun
- Institute of Forage and Grassland Sciences, Heilongjiang Academy of Agricultural Sciences, Harbin, China
| | - Qian Zhao
- Institute of Crop Cultivation and Tillage, Heilongjiang Academy of Agricultural Sciences, Harbin, China
| | - Hongjun Yong
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Degui Zhang
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhuanfang Hao
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhiqiang Zhou
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jienan Han
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaocong Zhang
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhennan Xu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xinhai Li
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Mingshun Li
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jianfeng Weng
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
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19
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Zhang W, Luo C, Scossa F, Zhang Q, Usadel B, Fernie AR, Mei H, Wen W. A phased genome based on single sperm sequencing reveals crossover pattern and complex relatedness in tea plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:197-208. [PMID: 33118252 DOI: 10.1111/tpj.15051] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/19/2020] [Accepted: 10/22/2020] [Indexed: 05/27/2023]
Abstract
For diploid organisms that are highly heterozygous, a phased haploid genome can greatly aid in functional genomic, population genetic and breeding studies. Based on the genome sequencing of 135 single sperm cells of the elite tea cultivar 'Fudingdabai', we herein phased the genome of Camellia sinensis, one of the most popular beverage crops worldwide. High-resolution genetic and recombination maps of Fudingdabai were constructed, which revealed that crossover (CO) positions were frequently located in the 5' and 3' ends of annotated genes, while CO distributions across the genome were random. The low CO frequency in tea can be explained by strong CO interference, and CO simulation revealed the proportion of interference insensitive CO ranged from 5.2% to 11.7%. We furthermore developed a method to infer the relatedness between tea accessions and detected complex kinship and genetic signatures of 106 tea accessions. Among them, 59 accessions were closely related with Fudingdabai and 31 of them were first-degree relatives. We additionally identified genes displaying allele specific expression patterns between the two haplotypes of Fudingdabai and genes displaying significantly differential expression levels between Fudingdabai and other haplotypes. These results lay the foundation for further investigation of genetic and epigenetic factors underpinning the regulation of gene expression and provide insights into the evolution of tea plants as well as a valuable genetic resource for future breeding efforts.
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Affiliation(s)
- Weiyi Zhang
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Cheng Luo
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China
| | - Federico Scossa
- Max-Planck-Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm, 14476, Germany
- Council for Agricultural Research and Economics, Research Center for Genomics and Bioinformatics, Via Ardeatina 546, Rome, 00178, Italy
| | - Qinghua Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China
| | - Björn Usadel
- Institute for Biological Data Science, Heinrich Heine University, Düsseldorf, Germany
- Institute of Bio- and Geosciences, IBG-4: Bioinformatics, CEPLAS, Forschungszentrum Jülich, Leo-Brandt-Straße, Jülich, 52425, Germany
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm, 14476, Germany
- Center of Plant Systems Biology and Biotechnology, Plovdiv, 4000, Bulgaria
| | - Hanwei Mei
- Shanghai Agrobiological Gene Center, Shanghai, 201106, China
| | - Weiwei Wen
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
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20
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Li Z, Zhou P, Della Coletta R, Zhang T, Brohammer AB, H O'Connor C, Vaillancourt B, Lipzen A, Daum C, Barry K, de Leon N, Hirsch CD, Buell CR, Kaeppler SM, Springer NM, Hirsch CN. Single-parent expression drives dynamic gene expression complementation in maize hybrids. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:93-107. [PMID: 33098691 DOI: 10.1111/tpj.15042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/27/2020] [Accepted: 10/02/2020] [Indexed: 06/11/2023]
Abstract
Single-parent expression (SPE) is defined as gene expression in only one of the two parents. SPE can arise from differential expression between parental alleles, termed non-presence/absence (non-PAV) SPE, or from the physical absence of a gene in one parent, termed PAV SPE. We used transcriptome data of diverse Zea mays (maize) inbreds and hybrids, including 401 samples from five different tissues, to test for differences between these types of SPE genes. Although commonly observed, SPE is highly genotype and tissue specific. A positive correlation was observed between the genetic distance of the two inbred parents and the number of SPE genes identified. Regulatory analysis showed that PAV SPE and non-PAV SPE genes are mainly regulated by cis effects, with a small fraction under trans regulation. Polymorphic transposable element insertions in promoter sequences contributed to the high level of cis regulation for PAV SPE and non-PAV SPE genes. PAV SPE genes were more frequently expressed in hybrids than non-PAV SPE genes. The expression of parentally silent alleles in hybrids of non-PAV SPE genes was relatively rare but occurred in most hybrids. Non-PAV SPE genes with expression of the silent allele in hybrids are more likely to exhibit above high parent expression level than hybrids that do not express the silent allele, leading to non-additive expression. This study provides a comprehensive understanding of the nature of non-PAV SPE and PAV SPE genes and their roles in gene expression complementation in maize hybrids.
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Affiliation(s)
- Zhi Li
- Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Peng Zhou
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Rafael Della Coletta
- Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Tifu Zhang
- Jiangsu Provincial Key Laboratory of Agrobiology, Institute of Germplasm Resources and Biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Alex B Brohammer
- Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Christine H O'Connor
- Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Brieanne Vaillancourt
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Anna Lipzen
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Chris Daum
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Kerrie Barry
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Natalia de Leon
- Department of Agronomy, University of Wisconsin, Madison, WI, 53706, USA
| | - Cory D Hirsch
- Department of Plant Pathology, University of Minnesota, Saint Paul, MN, 55108, USA
| | - C Robin Buell
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Shawn M Kaeppler
- Department of Agronomy, University of Wisconsin, Madison, WI, 53706, USA
| | - Nathan M Springer
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Candice N Hirsch
- Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA
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21
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Zhang X, Qi Y. Single-Parent Expression of Anti-sense RNA Contributes to Transcriptome Complementation in Maize Hybrid. FRONTIERS IN PLANT SCIENCE 2020; 11:577274. [PMID: 33343593 PMCID: PMC7744309 DOI: 10.3389/fpls.2020.577274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/30/2020] [Indexed: 06/12/2023]
Abstract
Anti-sense transcription is increasingly being recognized as an important regulator of gene expression. But the transcriptome complementation of anti-sense RNA in hybrid relative to their inbred parents was largely unknown. In this study, we profiled strand-specific RNA sequencing (RNA-seq) in a maize hybrid and its inbred parents (B73 and Mo17) in two tissues. More anti-sense transcripts were present in the hybrid compared with the parental lines. We detected 293 and 242 single-parent expression of anti-sense (SPEA) transcripts in maize immature ear and leaf tissues, respectively. There was little overlap of the SPEA transcripts between the two maize tissues. These results suggested that SPEA is a general mechanism that drives extensive complementation in maize hybrids. More importantly, extremely high-level expression of anti-sense transcripts was associated with low-level expression of the cognate sense transcript by reducing the level of histone H3 lysine 36 methylation (H3K36me3). In summary, these SPEA transcripts increased our knowledge about the transcriptomic complementation in hybrid.
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22
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Dai X, Xu Z, Liang Z, Tu X, Zhong S, Schnable JC, Li P. Non-homology-based prediction of gene functions in maize (Zea mays ssp. mays). THE PLANT GENOME 2020; 13:e20015. [PMID: 33016608 DOI: 10.1002/tpg2.20015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 12/22/2019] [Accepted: 02/12/2020] [Indexed: 06/11/2023]
Abstract
Advances in genome sequencing and annotation have eased the difficulty of identifying new gene sequences. Predicting the functions of these newly identified genes remains challenging. Genes descended from a common ancestral sequence are likely to have common functions. As a result, homology is widely used for gene function prediction. This means functional annotation errors also propagate from one species to another. Several approaches based on machine learning classification algorithms were evaluated for their ability to accurately predict gene function from non-homology gene features. Among the eight supervised classification algorithms evaluated, random-forest-based prediction consistently provided the most accurate gene function prediction. Non-homology-based functional annotation provides complementary strengths to homology-based annotation, with higher average performance in Biological Process GO terms, the domain where homology-based functional annotation performs the worst, and weaker performance in Molecular Function GO terms, the domain where the accuracy of homology-based functional annotation is highest. GO prediction models trained with homology-based annotations were able to successfully predict annotations from a manually curated "gold standard" GO annotation set. Non-homology-based functional annotation based on machine learning may ultimately prove useful both as a method to assign predicted functions to orphan genes which lack functionally characterized homologs, and to identify and correct functional annotation errors which were propagated through homology-based functional annotations.
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Affiliation(s)
- Xiuru Dai
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 273100, China
- Quantitative Life Sciences Initiative, Center for Plant Science Innovation, and Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Zheng Xu
- Department of Mathematics and Statistics, Wright State University, Dayton, OH, 45435, USA
| | - Zhikai Liang
- Quantitative Life Sciences Initiative, Center for Plant Science Innovation, and Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Xiaoyu Tu
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Silin Zhong
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - James C Schnable
- Quantitative Life Sciences Initiative, Center for Plant Science Innovation, and Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Pinghua Li
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 273100, China
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23
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Luo Z, Qian J, Chen S, Li L. Dynamic patterns of circular and linear RNAs in maize hybrid and parental lines. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2020; 133:593-604. [PMID: 31784779 DOI: 10.1007/s00122-019-03489-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/22/2019] [Indexed: 06/10/2023]
Abstract
Hybrid vigor, also known as heterosis, has been widely utilized in agronomic production of maize (Zea mays L.) and other crops. However, the molecular mechanisms underlying heterosis are still not fully understood. To provide a more complete understanding of the transcriptomic dynamics associated with heterosis, we collected a comprehensive set of sequence data on linear mRNA transcripts and circular RNAs (circRNAs) from seedling leaves of two widely used maize inbred lines and their F1 hybrid at the V4 growth stage. We detected over 25,000 expressed genes with more than 1200 circRNAs that showed dramatic and distinct variations in expression level across the three genotypes. Although most linear and circular transcripts exhibited additive expression in the hybrid, the expression of circRNAs was more likely to be nonadditive. Interestingly, the levels of linear transcripts and their corresponding circRNAs from the same loci showed a significant relationship and coordinated expression mode across all three genotypes. Notably, in the hybrid, allele-specific expression of linear transcripts was significantly associated with the expression of circRNAs from the same locus, suggesting potential regulatory cross talk between linear and circular transcripts. Our study provides a deeper understanding of dynamic variations for both the linear and circular transcriptome in a classical hybrid triplet of maize.
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Affiliation(s)
- Zi Luo
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jia Qian
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China
| | - Sijia Chen
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lin Li
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.
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24
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Baldauf JA, Vedder L, Schoof H, Hochholdinger F. Robust non-syntenic gene expression patterns in diverse maize hybrids during root development. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:865-876. [PMID: 31638701 DOI: 10.1093/jxb/erz452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 09/30/2019] [Indexed: 06/10/2023]
Abstract
Distantly related maize (Zea mays L.) inbred lines exhibit an exceptional degree of structural genomic diversity, which is probably unique among plants. This study systematically investigated the developmental and genotype-dependent regulation of the primary root transcriptomes of a genetically diverse panel of maize F1-hybrids and their parental inbred lines. While we observed substantial transcriptomic changes during primary root development, we demonstrated that hybrid-associated gene expression patterns, including differential, non-additive, and allele-specific transcriptome profiles, are particularly robust to these developmental fluctuations. For instance, differentially expressed genes with preferential expression in hybrids were highly conserved during development in comparison to their parental counterparts. Similarly, in hybrids a major proportion of non-additively expressed genes with expression levels between the parental values were particularly conserved during development. Importantly, in these expression patterns non-syntenic genes that evolved after the separation of the maize and sorghum lineages were systemically enriched. Furthermore, non-syntenic genes were substantially linked to the conservation of all surveyed gene expression patterns during primary root development. Among all F1-hybrids, between ~40% of the non-syntenic genes with unexpected allelic expression ratios and ~60% of the non-syntenic differentially and non-additively expressed genes were conserved and therefore robust to developmental changes. Hence, the enrichment of non-syntenic genes during primary root development might be involved in the developmental adaptation of maize roots and thus the superior performance of hybrids.
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Affiliation(s)
- Jutta A Baldauf
- Institute for Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Bonn, Germany
| | - Lucia Vedder
- Institute for Crop Science and Resource Conservation, Crop Bioinformatics, University of Bonn, Bonn, Germany
| | - Heiko Schoof
- Institute for Crop Science and Resource Conservation, Crop Bioinformatics, University of Bonn, Bonn, Germany
| | - Frank Hochholdinger
- Institute for Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Bonn, Germany
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25
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Cuello C, Baldy A, Brunaud V, Joets J, Delannoy E, Jacquemot MP, Botran L, Griveau Y, Guichard C, Soubigou-Taconnat L, Martin-Magniette ML, Leroy P, Méchin V, Reymond M, Coursol S. A systems biology approach uncovers a gene co-expression network associated with cell wall degradability in maize. PLoS One 2019; 14:e0227011. [PMID: 31891625 PMCID: PMC6938352 DOI: 10.1371/journal.pone.0227011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 12/09/2019] [Indexed: 11/18/2022] Open
Abstract
Understanding the mechanisms triggering variation of cell wall degradability is a prerequisite to improving the energy value of lignocellulosic biomass for animal feed or biorefinery. Here, we implemented a multiscale systems approach to shed light on the genetic basis of cell wall degradability in maize. We demonstrated that allele replacement in two pairs of near-isogenic lines at a region encompassing a major quantitative trait locus (QTL) for cell wall degradability led to phenotypic variation of a similar magnitude and sign to that expected from a QTL analysis of cell wall degradability in the F271 × F288 recombinant inbred line progeny. Using DNA sequences within the QTL interval of both F271 and F288 inbred lines and Illumina RNA sequencing datasets from internodes of the selected near-isogenic lines, we annotated the genes present in the QTL interval and provided evidence that allelic variation at the introgressed QTL region gives rise to coordinated changes in gene expression. The identification of a gene co-expression network associated with cell wall-related trait variation revealed that the favorable F288 alleles exploit biological processes related to oxidation-reduction, regulation of hydrogen peroxide metabolism, protein folding and hormone responses. Nested in modules of co-expressed genes, potential new cell-wall regulators were identified, including two transcription factors of the group VII ethylene response factor family, that could be exploited to fine-tune cell wall degradability. Overall, these findings provide new insights into the regulatory mechanisms by which a major locus influences cell wall degradability, paving the way for its map-based cloning in maize.
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Affiliation(s)
- Clément Cuello
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Aurélie Baldy
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Véronique Brunaud
- Institute of Plant Sciences Paris-Saclay, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Gif-sur-Yvette, France
- Institute of Plant Sciences Paris-Saclay, CNRS, INRA, Université Paris-Diderot, Sorbonne Paris-Cité, Gif-sur-Yvette, France
| | - Johann Joets
- Génétique Quantitative et Evolution—Le Moulon, INRA, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Gif-Sur-Yvette, France
| | - Etienne Delannoy
- Institute of Plant Sciences Paris-Saclay, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Gif-sur-Yvette, France
- Institute of Plant Sciences Paris-Saclay, CNRS, INRA, Université Paris-Diderot, Sorbonne Paris-Cité, Gif-sur-Yvette, France
| | - Marie-Pierre Jacquemot
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Lucy Botran
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Yves Griveau
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Cécile Guichard
- Institute of Plant Sciences Paris-Saclay, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Gif-sur-Yvette, France
- Institute of Plant Sciences Paris-Saclay, CNRS, INRA, Université Paris-Diderot, Sorbonne Paris-Cité, Gif-sur-Yvette, France
| | - Ludivine Soubigou-Taconnat
- Institute of Plant Sciences Paris-Saclay, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Gif-sur-Yvette, France
- Institute of Plant Sciences Paris-Saclay, CNRS, INRA, Université Paris-Diderot, Sorbonne Paris-Cité, Gif-sur-Yvette, France
| | - Marie-Laure Martin-Magniette
- Institute of Plant Sciences Paris-Saclay, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Gif-sur-Yvette, France
- Institute of Plant Sciences Paris-Saclay, CNRS, INRA, Université Paris-Diderot, Sorbonne Paris-Cité, Gif-sur-Yvette, France
- UMR MIA-Paris, AgroParisTech, INRA, Université Paris-Saclay, Paris, France
| | | | - Valérie Méchin
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Matthieu Reymond
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Sylvie Coursol
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
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26
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Penning BW, Shiga TM, Klimek JF, SanMiguel PJ, Shreve J, Thimmapuram J, Sykes RW, Davis MF, McCann MC, Carpita NC. Expression profiles of cell-wall related genes vary broadly between two common maize inbreds during stem development. BMC Genomics 2019; 20:785. [PMID: 31664907 PMCID: PMC6819468 DOI: 10.1186/s12864-019-6117-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 09/20/2019] [Indexed: 11/23/2022] Open
Abstract
Background The cellular machinery for cell wall synthesis and metabolism is encoded by members of large multi-gene families. Maize is both a genetic model for grass species and a potential source of lignocellulosic biomass from crop residues. Genetic improvement of maize for its utility as a bioenergy feedstock depends on identification of the specific gene family members expressed during secondary wall development in stems. Results High-throughput sequencing of transcripts expressed in developing rind tissues of stem internodes provided a comprehensive inventory of cell wall-related genes in maize (Zea mays, cultivar B73). Of 1239 of these genes, 854 were expressed among the internodes at ≥95 reads per 20 M, and 693 of them at ≥500 reads per 20 M. Grasses have cell wall compositions distinct from non-commelinid species; only one-quarter of maize cell wall-related genes expressed in stems were putatively orthologous with those of the eudicot Arabidopsis. Using a slope-metric algorithm, five distinct patterns for sub-sets of co-expressed genes were defined across a time course of stem development. For the subset of genes associated with secondary wall formation, fifteen sequence motifs were found in promoter regions. The same members of gene families were often expressed in two maize inbreds, B73 and Mo17, but levels of gene expression between them varied, with 30% of all genes exhibiting at least a 5-fold difference at any stage. Although presence-absence and copy-number variation might account for much of these differences, fold-changes of expression of a CADa and a FLA11 gene were attributed to polymorphisms in promoter response elements. Conclusions Large genetic variation in maize as a species precludes the extrapolation of cell wall-related gene expression networks even from one common inbred line to another. Elucidation of genotype-specific expression patterns and their regulatory controls will be needed for association panels of inbreds and landraces to fully exploit genetic variation in maize and other bioenergy grass species.
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Affiliation(s)
- Bryan W Penning
- Department of Botany & Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA.,Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA.,, Present Address: USDA-ARS, Wheat Quality Research Unit, 1680 Madison Avenue, Wooster, OH, 44691, USA
| | - Tânia M Shiga
- Department of Botany & Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA.,Present Address: Departamento de Alimentos e Nutrição Experimental, FCF-USP F, 3091-3647 / 3091-3007, Av. Prof. Lineu Prestes, 580 - BL-14 CEP 05508-000, Butantã, Sâo Paulo, SP, Brazil
| | - John F Klimek
- Department of Botany & Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA
| | - Philip J SanMiguel
- Genomics Core Facility, Purdue University, 170 South University Street, Purdue University, West Lafayette, IN, 47907, USA
| | - Jacob Shreve
- Bioinformatics Core Facility, Purdue University, 155 South Grant Street, West Lafayette, IN, 47907, USA.,, Present Address: Department of Internal Medicine, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH, 44195, USA
| | - Jyothi Thimmapuram
- Present Address: Departamento de Alimentos e Nutrição Experimental, FCF-USP F, 3091-3647 / 3091-3007, Av. Prof. Lineu Prestes, 580 - BL-14 CEP 05508-000, Butantã, Sâo Paulo, SP, Brazil.,Bioinformatics Core Facility, Purdue University, 155 South Grant Street, West Lafayette, IN, 47907, USA
| | - Robert W Sykes
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.,, Present Address: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM, Los Alamos, NM, 87545, USA
| | - Mark F Davis
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Maureen C McCann
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA.,Purdue Center for Plant Biology, West Lafayette, USA
| | - Nicholas C Carpita
- Department of Botany & Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA. .,Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA. .,Purdue Center for Plant Biology, West Lafayette, USA.
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Heterotic patterns of primary and secondary metabolites in the oilseed crop Brassica juncea. Heredity (Edinb) 2019; 123:318-336. [PMID: 30911141 DOI: 10.1038/s41437-019-0213-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 02/23/2019] [Accepted: 03/11/2019] [Indexed: 02/01/2023] Open
Abstract
Heterosis refers to the superior performance of F1 hybrids over their respective parental inbred lines. Although the genetic and expression basis of heterosis have been previously investigated, the metabolic basis for this phenomenon is poorly understood. In a preliminary morphological study in Brassica juncea, we observed significant heterosis at the 50% flowering stage, wherein both the growth and reproduction of F1 reciprocal hybrids were greater than that of their parents. To identify the possible metabolic causes or consequences of this heterosis, we carried out targeted LC-MS analysis of 48 primary (amino acids and sugars) and secondary metabolites (phytohormones, glucosinolates, flavonoids, and phenolic esters) in five developmental tissues at 50% flowering in hybrids and inbred parents. Principal component analysis (PCA) of metabolites clearly separated inbred lines from their hybrids, particularly in the bud tissues. In general, secondary metabolites displayed more negative heterosis values in comparison to primary metabolites. The tested primary and secondary metabolites displayed both additive and non-additive modes of inheritance in F1 hybrids, wherein the number of metabolites showing an additive mode of inheritance were higher in buds and siliques (52.77-97.14%) compared to leaf tissues (47.37-80%). Partial least regression (PLS) analysis further showed that primary metabolites, in general, displayed higher association with morphological parameters in F1 hybrids. Overall, our results are consistent with a resource-cost model for heterosis in B. juncea, where metabolite allocation in hybrids appears to favor growth, at the expense of secondary metabolism.
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Patterns of genome-wide allele-specific expression in hybrid rice and the implications on the genetic basis of heterosis. Proc Natl Acad Sci U S A 2019; 116:5653-5658. [PMID: 30833384 PMCID: PMC6431163 DOI: 10.1073/pnas.1820513116] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Utilization of heterosis has greatly increased productivity of many crops globally. Allele-specific expression (ASE) has been suggested as a mechanism for causing heterosis. We performed a genome-wide analysis of ASE in three tissues of an elite rice hybrid grown under four conditions. The analysis identified 3,270 genes showing various patterns of ASE in response to developmental and environmental cues, which provides a glimpse of the ASE landscape in the hybrid genome. We showed that the ASE patterns may have distinct implications in the genetic basis of heterosis, especially in light of the classical dominance and overdominance hypotheses. The genes showing ASE provide the candidates for future studies of the genetic and molecular mechanism of heterosis. Utilization of heterosis has greatly increased the productivity of many crops worldwide. Although tremendous progress has been made in characterizing the genetic basis of heterosis using genomic technologies, molecular mechanisms underlying the genetic components are much less understood. Allele-specific expression (ASE), or imbalance between the expression levels of two parental alleles in the hybrid, has been suggested as a mechanism of heterosis. Here, we performed a genome-wide analysis of ASE by comparing the read ratios of the parental alleles in RNA-sequencing data of an elite rice hybrid and its parents using three tissues from plants grown under four conditions. The analysis identified a total of 3,270 genes showing ASE (ASEGs) in various ways, which can be classified into two patterns: consistent ASEGs such that the ASE was biased toward one parental allele in all tissues/conditions, and inconsistent ASEGs such that ASE was found in some but not all tissues/conditions, including direction-shifting ASEGs in which the ASE was biased toward one parental allele in some tissues/conditions while toward the other parental allele in other tissues/conditions. The results suggested that these patterns may have distinct implications in the genetic basis of heterosis: The consistent ASEGs may cause partial to full dominance effects on the traits that they regulate, and direction-shifting ASEGs may cause overdominance. We also showed that ASEGs were significantly enriched in genomic regions that were differentially selected during rice breeding. These ASEGs provide an index of the genes for future pursuit of the genetic and molecular mechanism of heterosis.
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Zhou P, Hirsch CN, Briggs SP, Springer NM. Dynamic Patterns of Gene Expression Additivity and Regulatory Variation throughout Maize Development. MOLECULAR PLANT 2019; 12:410-425. [PMID: 30593858 DOI: 10.1016/j.molp.2018.12.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 12/14/2018] [Accepted: 12/18/2018] [Indexed: 05/26/2023]
Abstract
Gene expression variation is a key component underlying phenotypic variation and heterosis. Transcriptome profiling was performed on 23 different tissues or developmental stages of two maize inbreds, B73 and Mo17, as well as their F1 hybrid. The obtained large-scale datasets provided opportunities to monitor the developmental dynamics of differential expression, additivity for gene expression, and regulatory variation. The transcriptome can be divided into ∼30 000 genes that are expressed in at least one tissue of one inbred and an additional ∼10 000 ″silent" genes that are not expressed in any tissue of any genotype, 90% of which are non-syntenic relative to other grasses. Many (∼74%) of the expressed genes exhibit differential expression in at least one tissue. However, the majority of genes with differential expression do not exhibit consistent differential expression in different tissues. These genes often exhibit tissue-specific differential expression with equivalent expression in other tissues, and in many cases they switch the directionality of differential expression in different tissues. This suggests widespread variation for tissue-specific regulation of gene expression between the two maize inbreds B73 and Mo17. Nearly 5000 genes are expressed in only one parent in at least one tissue (single parent expression) and 97% of these genes are expressed at mid-parent levels or higher in the hybrid, providing extensive opportunities for hybrid complementation in heterosis. In general, additive expression patterns are much more common than non-additive patterns, and this trend is more pronounced for genes with strong differential expression or single parent expression. There is relatively little evidence for non-additive expression patterns that are maintained in multiple tissues. The analysis of allele-specific expression allowed classification of cis- and trans-regulatory variation. Genes with cis-regulatory variation often exhibit additive expression and tend to have more consistent regulatory variation throughout development. In contrast, genes with trans-regulatory variation are enriched for non-additive patterns and often show tissue-specific differential expression. Taken together, this study provides a deeper understanding of regulatory variation and the degree of additive gene expression throughout maize development. The dynamic nature of differential expression, additivity, and regulatory variation imply abundant variability for tissue-specific regulatory mechanisms and suggest that connections between transcriptome and phenome will require expression data from multiple tissues.
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Affiliation(s)
- Peng Zhou
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Candice N Hirsch
- Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN 55108, USA
| | - Steven P Briggs
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nathan M Springer
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA.
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30
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Extensive intraspecific gene order and gene structural variations between Mo17 and other maize genomes. Nat Genet 2018; 50:1289-1295. [PMID: 30061735 DOI: 10.1038/s41588-018-0182-0] [Citation(s) in RCA: 233] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Accepted: 06/05/2018] [Indexed: 12/24/2022]
Abstract
Maize is an important crop with a high level of genome diversity and heterosis. The genome sequence of a typical female line, B73, was previously released. Here, we report a de novo genome assembly of a corresponding male representative line, Mo17. More than 96.4% of the 2,183 Mb assembled genome can be accounted for by 362 scaffolds in ten pseudochromosomes with 38,620 annotated protein-coding genes. Comparative analysis revealed large gene-order and gene structural variations: approximately 10% of the annotated genes were mutually nonsyntenic, and more than 20% of the predicted genes had either large-effect mutations or large structural variations, which might cause considerable protein divergence between the two inbred lines. Our study provides a high-quality reference-genome sequence of an important maize germplasm, and the intraspecific gene order and gene structural variations identified should have implications for heterosis and genome evolution.
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31
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Liang Z, Schnable JC. Functional Divergence between Subgenomes and Gene Pairs after Whole Genome Duplications. MOLECULAR PLANT 2018; 11:388-397. [PMID: 29275166 DOI: 10.1016/j.molp.2017.12.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 11/28/2017] [Accepted: 12/12/2017] [Indexed: 05/20/2023]
Abstract
Gene loss following whole genome duplication (WGD) is often biased, with one subgenome retaining more ancestral genes and the other sustaining more gene deletions. While bias toward the greater expression of gene copies on one subgenome can explain bias in gene loss, this raises the question to what drives differences in gene expression levels between subgenomes. Differences in chromatin modifications and epigenetic markers between subgenomes in several model species are now being identified, providing an explanation for bias in gene expression between subgenomes. WGDs can be classified into duplications with higher, biased gene loss and bias in gene expression between subgenomes versus those with lower, unbiased rates of gene loss and an absence of detectable bias between subgenomes; however, the originally proposed link between these two classes and whether WGD results from an allo- or autopolyploid event is inconsistent with recent data from the allopolyploid Capsella bursa-pastoris. The gene balance hypothesis can explain bias in the functional categories of genes retained following WGD, the difference in gene loss rates between unbiased and biased WGDs, and how plant genomes have avoided being overrun with genes encoding dose-sensitive subunits of multiprotein complexes. Comparisons of gene expression patterns between retained transcription factor pairs in maize suggest the high degree of retention for WGD-derived pairs of transcription factors may instead be explained by the older duplication-degeneration-complementation model.
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Affiliation(s)
- Zhikai Liang
- Plant Science Innovation & Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68503, USA
| | - James C Schnable
- Plant Science Innovation & Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68503, USA.
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32
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Lai X, Yan L, Lu Y, Schnable JC. Largely unlinked gene sets targeted by selection for domestication syndrome phenotypes in maize and sorghum. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:843-855. [PMID: 29265526 DOI: 10.1111/tpj.13806] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 11/27/2017] [Accepted: 12/04/2017] [Indexed: 05/14/2023]
Abstract
The domestication of diverse grain crops from wild grasses was a result of artificial selection for a suite of overlapping traits producing changes referred to in aggregate as 'domestication syndrome'. Parallel phenotypic change can be accomplished by either selection on orthologous genes or selection on non-orthologous genes with parallel phenotypic effects. To determine how often artificial selection for domestication traits in the grasses targeted orthologous genes, we employed resequencing data from wild and domesticated accessions of Zea (maize) and Sorghum (sorghum). Many 'classic' domestication genes identified through quantitative trait locus mapping in populations resulting from wild/domesticated crosses indeed show signatures of parallel selection in both maize and sorghum. However, the overall number of genes showing signatures of parallel selection in both species is not significantly different from that expected by chance. This suggests that while a small number of genes will extremely large phenotypic effects have been targeted repeatedly by artificial selection during domestication, the optimization part of domestication targeted small and largely non-overlapping subsets of all possible genes which could produce equivalent phenotypic alterations.
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Affiliation(s)
- Xianjun Lai
- Center for Plant Science Innovation and Department of Agronomy and Horticulture, University of Nebraska-Lincoln, NE, 68588, USA
- Maize Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Lang Yan
- Center for Plant Science Innovation and Department of Agronomy and Horticulture, University of Nebraska-Lincoln, NE, 68588, USA
- Laboratory of Functional Genome and Application of Potato, Xichang College, Liangshan, 615000, China
- College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Yanli Lu
- Maize Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - James C Schnable
- Center for Plant Science Innovation and Department of Agronomy and Horticulture, University of Nebraska-Lincoln, NE, 68588, USA
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Baldauf JA, Marcon C, Lithio A, Vedder L, Altrogge L, Piepho HP, Schoof H, Nettleton D, Hochholdinger F. Single-Parent Expression Is a General Mechanism Driving Extensive Complementation of Non-syntenic Genes in Maize Hybrids. Curr Biol 2018; 28:431-437.e4. [PMID: 29358068 DOI: 10.1016/j.cub.2017.12.027] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 12/08/2017] [Accepted: 12/13/2017] [Indexed: 12/11/2022]
Abstract
Maize (Zea mays L.) displays an exceptional degree of structural genomic diversity [1, 2]. In addition, variation in gene expression further contributes to the extraordinary phenotypic diversity and plasticity of maize. This study provides a systematic investigation on how distantly related homozygous maize inbred lines affect the transcriptomic plasticity of their highly heterozygous F1 hybrids. The classical dominance model of heterosis explains the superiority of hybrid plants by the complementation of deleterious parental alleles by superior alleles of the second parent at many loci [3]. Genes active in one inbred line but inactive in another represent an extreme instance of allelic diversity defined as single-parent expression [4]. We observed on average ∼1,000 such genes in all inbred line combinations during primary root development. These genes consistently displayed expression complementation (i.e., activity) in their hybrid progeny. Consequently, extreme expression complementation is a general mechanism that results on average in ∼600 additionally active genes and their encoded biological functions in hybrids. The modern maize genome is complemented by a set of non-syntenic genes, which emerged after the separation of the maize and sorghum lineages and lack syntenic orthologs in any other grass species [5]. We demonstrated that non-syntenic genes are the driving force of gene expression complementation in hybrids. Among those, the highly diversified families of bZIP and bHLH transcription factors [6] are systematically overrepresented. In summary, extreme gene expression complementation extensively shapes the transcriptomic plasticity of maize hybrids and might therefore be one factor controlling the developmental plasticity of hybrids.
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Affiliation(s)
- Jutta A Baldauf
- Institute for Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Friedrich-Ebert-Allee 144, 53113 Bonn, Germany
| | - Caroline Marcon
- Institute for Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Friedrich-Ebert-Allee 144, 53113 Bonn, Germany
| | - Andrew Lithio
- Department of Statistics, Iowa State University, 2438 Osborne Dr., Ames, IA 50011-1210, USA
| | - Lucia Vedder
- Institute for Crop Science and Resource Conservation, Crop Bioinformatics, University of Bonn, Katzenburgweg 2, 53115 Bonn, Germany
| | - Lena Altrogge
- Institute for Crop Science and Resource Conservation, Crop Bioinformatics, University of Bonn, Katzenburgweg 2, 53115 Bonn, Germany
| | - Hans-Peter Piepho
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, Fruwirthstraße 23, 70599 Stuttgart, Germany
| | - Heiko Schoof
- Institute for Crop Science and Resource Conservation, Crop Bioinformatics, University of Bonn, Katzenburgweg 2, 53115 Bonn, Germany
| | - Dan Nettleton
- Department of Statistics, Iowa State University, 2438 Osborne Dr., Ames, IA 50011-1210, USA
| | - Frank Hochholdinger
- Institute for Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Friedrich-Ebert-Allee 144, 53113 Bonn, Germany.
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Hochholdinger F, Yu P, Marcon C. Genetic Control of Root System Development in Maize. TRENDS IN PLANT SCIENCE 2018; 23:79-88. [PMID: 29170008 DOI: 10.1016/j.tplants.2017.10.004] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 10/21/2017] [Accepted: 10/25/2017] [Indexed: 05/21/2023]
Abstract
The maize root system comprises structurally and functionally different root types. Mutant analyses have revealed that root-type-specific genetic regulators intrinsically determine the maize root system architecture. Molecular cloning of these genes has demonstrated that key elements of auxin signal transduction, such as LOB domain (LBD) and Aux/IAA proteins, are instrumental for seminal, shoot-borne, and lateral root initiation. Moreover, genetic analyses have demonstrated that genes related to exocytotic vesicle docking, cell wall loosening, and cellulose synthesis and organization control root hair elongation. The identification of upstream regulators, protein interaction partners, and downstream targets of these genes together with cell-type-specific transcriptome analyses have provided novel insights into the regulatory networks controlling root development and architecture in maize.
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Affiliation(s)
- Frank Hochholdinger
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113 Bonn, Germany.
| | - Peng Yu
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113 Bonn, Germany
| | - Caroline Marcon
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113 Bonn, Germany
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Forestan C, Farinati S, Aiese Cigliano R, Lunardon A, Sanseverino W, Varotto S. Maize RNA PolIV affects the expression of genes with nearby TE insertions and has a genome-wide repressive impact on transcription. BMC PLANT BIOLOGY 2017; 17:161. [PMID: 29025411 PMCID: PMC5639751 DOI: 10.1186/s12870-017-1108-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 10/04/2017] [Indexed: 05/09/2023]
Abstract
BACKGROUND RNA-directed DNA methylation (RdDM) is a plant-specific epigenetic process that relies on the RNA polymerase IV (Pol IV) for the production of 24 nucleotide small interfering RNAs (siRNA) that guide the cytosine methylation and silencing of genes and transposons. Zea mays RPD1/RMR6 gene encodes the largest subunit of Pol IV and is required for normal plant development, paramutation, transcriptional repression of certain transposable elements (TEs) and transcriptional regulation of specific alleles. RESULTS In this study we applied a total RNA-Seq approach to compare the B73 and rpd1/rmr6 leaf transcriptomes. Although previous studies indicated that loss of siRNAs production in RdDM mutants provokes a strong loss of CHH DNA methylation but not massive gene or TEs transcriptional activation in both Arabidopsis and maize, our total RNA-Seq analysis of rpd1/rmr6 transcriptome reveals that loss of Pol IV activity causes a global increase in the transcribed fraction of the maize genome. Our results point to the genes with nearby TE insertions as being the most strongly affected by Pol IV-mediated gene silencing. TEs modulation of nearby gene expression is linked to alternative methylation profiles on gene flanking regions, and these profiles are strictly dependent on specific characteristics of the TE member inserted. Although Pol IV is essential for the biogenesis of siRNAs, the genes with associated siRNA loci are less affected by the pol IV mutation. CONCLUSIONS This deep and integrated analysis of gene expression, TEs distribution, smallRNA targeting and DNA methylation levels, reveals that loss of Pol IV activity globally affects genome regulation, pointing at TEs as modulator of nearby gene expression and indicating the existence of multiple level epigenetic silencing mechanisms. Our results also suggest a predominant role of the Pol IV-mediated RdDM pathway in genome dominance regulation, and subgenome stability and evolution in maize.
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Affiliation(s)
- Cristian Forestan
- Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell’Università 16, 35020 Legnaro, PD Italy
| | - Silvia Farinati
- Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell’Università 16, 35020 Legnaro, PD Italy
| | | | - Alice Lunardon
- Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell’Università 16, 35020 Legnaro, PD Italy
- Present Address: Department of Biology and Huck Institutes of the Life Sciences, Penn State University, University Park, Pennsylvania, PA 16802 USA
| | | | - Serena Varotto
- Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell’Università 16, 35020 Legnaro, PD Italy
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Zhang Y, Ngu DW, Carvalho D, Liang Z, Qiu Y, Roston RL, Schnable JC. Differentially Regulated Orthologs in Sorghum and the Subgenomes of Maize. THE PLANT CELL 2017; 29:1938-1951. [PMID: 28733421 PMCID: PMC5590507 DOI: 10.1105/tpc.17.00354] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/05/2017] [Accepted: 07/18/2017] [Indexed: 05/19/2023]
Abstract
Identifying interspecies changes in gene regulation, one of the two primary sources of phenotypic variation, is challenging on a genome-wide scale. The use of paired time-course data on cold-responsive gene expression in maize (Zea mays) and sorghum (Sorghum bicolor) allowed us to identify differentially regulated orthologs. While the majority of cold-responsive transcriptional regulation of conserved gene pairs is species specific, the initial transcriptional responses to cold appear to be more conserved than later responses. In maize, the promoters of genes with conserved transcriptional responses to cold tend to contain more micrococcal nuclease hypersensitive sites in their promoters, a proxy for open chromatin. Genes with conserved patterns of transcriptional regulation between the two species show lower ratios of nonsynonymous to synonymous substitutions. Genes involved in lipid metabolism, known to be involved in cold acclimation, tended to show consistent regulation in both species. Genes with species-specific cold responses did not cluster in particular pathways nor were they enriched in particular functional categories. We propose that cold-responsive transcriptional regulation in individual species may not be a reliable marker for function, while a core set of genes involved in perceiving and responding to cold stress are subject to functionally constrained cold-responsive regulation across the grass tribe Andropogoneae.
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Affiliation(s)
- Yang Zhang
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Daniel W Ngu
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Daniel Carvalho
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Zhikai Liang
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Yumou Qiu
- Department of Statistics, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Rebecca L Roston
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - James C Schnable
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
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37
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Samayoa LF, Malvar RA, Butrón A. QTL for Maize Midparent Heterosis in the Heterotic Pattern American Dent × European Flint under Corn Borer Pressure. FRONTIERS IN PLANT SCIENCE 2017; 8:573. [PMID: 28469629 PMCID: PMC5395649 DOI: 10.3389/fpls.2017.00573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/29/2017] [Indexed: 05/18/2023]
Abstract
Despite the importance of heterosis and the efforts to comprehend this phenomenon, its molecular bases are still unknown. In this study, we intended to detect Quantitative trait loci (QTL) for mid-parent heterosis under infestation with the Mediterranean corn borer (MCB, Sesamia nonagrioides Lef.) using a North Carolina design III approach with a RIL population derived from a European flint inbred (EP42) × American dent inbred (A637) cross. QTL for heterosis of kernel yield have been positioned in regions corresponding to previously identified QTL for the same trait in different backgrounds. These results reinforce the high congruency of genes controlling heterosis across populations, even when populations have been developed from different heterotic patterns. A high percentage of genetic variation for mid-parent heterosis (Z2) for kernel yield could not be explained. Furthermore, genomic regions involved in heterosis for yield and plant height were not found despite the high genetic correlation between Z2 transformations for kernel yield and plant height. The moderate power in detecting QTL for mid-parent heterosis suggests that many genes with low augmented dominance effects contribute to the genetic architecture of mid-parent heterosis; dominance and additive-additive epistatic effects could also contribute to heterosis. However, results from this and previous studies suggest that the region 8.03-8.05 deserves special attention in future works in order to fine map loci involved in mid-parent heterosis for yield.
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Affiliation(s)
| | | | - Ana Butrón
- Misión Biológica de Galicia, CSICPontevedra, Spain
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Choo-Wosoba H, Datta S. Analyzing clustered count data with a cluster specific random effect zero-inflated Conway-Maxwell-Poisson distribution. J Appl Stat 2017; 45:799-814. [PMID: 31080303 DOI: 10.1080/02664763.2017.1312299] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
In recent years, data analysis techniques have been developed in biological and medical research areas with different types of count distributions. In particular, zero-inflated versions of parametric count distributions have been used to model excessive zeros that are often present in these assays. Perhaps, the most common count distribution which has been used for analyzing such data is the Poisson distribution. However, a Poisson distribution, having a single underlying parameter, cannot cope with any other data dispersion pattern besides equidispersion. A negative binomial distribution is capable of modeling overdispersed, but not underdispersed data. However, a Conway-Maxwell-Poisson (CMP) distribution (Conway, R. W., and Maxwell, W. L., 1962) can handle not only overdispersion but also underdispersion. We show with an illustrative data set on next generation sequencing of maize hybrids that both underdispersion and overdispersion can be present in genetic data. Furthermore, if count data consists of clustered observations, one of the most efficient statistical technique is to introduce a cluster specific random effect term. Once again, the maize hybrids data presents such a situation. We develop inference procedures for a zero-inflated CMP regression that incorporates a cluster specific random effect term. Unlike, the Gaussian models, the underlying likelihood is computationally challenging. We use a numerical approximation via a Gaussian quadrature to circumvent this issues. A test for checking zero-inflation has also been developed in our setting. Finite sample properties of our estimators and test have been investigated by extensive simulations. Finally, the statistical methodology has been applied to analyze the maize data mentioned before.
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Affiliation(s)
- Hyoyoung Choo-Wosoba
- Department of Bioinformatics and Biostatistics, University of Louisville, Louisville, KY 40202, U.S.A
| | - Somnath Datta
- Department of Biostatistics, University of Florida, Gainesville, FL 32611, U.S.A
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Hey S, Baldauf J, Opitz N, Lithio A, Pasha A, Provart N, Nettleton D, Hochholdinger F. Complexity and specificity of the maize (Zea mays L.) root hair transcriptome. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2175-2185. [PMID: 28398587 PMCID: PMC5447894 DOI: 10.1093/jxb/erx104] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Root hairs are tubular extensions of epidermis cells. Transcriptome profiling demonstrated that the single cell-type root hair transcriptome was less complex than the transcriptome of multiple cell-type primary roots without root hairs. In total, 831 genes were exclusively and 5585 genes were preferentially expressed in root hairs [false discovery rate (FDR) ≤1%]. Among those, the most significantly enriched Gene Ontology (GO) functional terms were related to energy metabolism, highlighting the high energy demand for the development and function of root hairs. Subsequently, the maize homologs for 138 Arabidopsis genes known to be involved in root hair development were identified and their phylogenetic relationship and expression in root hairs were determined. This study indicated that the genetic regulation of root hair development in Arabidopsis and maize is controlled by common genes, but also shows differences which need to be dissected in future genetic experiments. Finally, a maize root view of the eFP browser was implemented including the root hair transcriptome of the present study and several previously published maize root transcriptome data sets. The eFP browser provides color-coded expression levels for these root types and tissues for any gene of interest, thus providing a novel resource to study gene expression and function in maize roots.
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Affiliation(s)
- Stefan Hey
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
| | - Jutta Baldauf
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
| | - Nina Opitz
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
| | - Andrew Lithio
- Department of Statistics, Iowa State University, Ames, IA 50011-1210, USA
| | - Asher Pasha
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada
| | - Nicholas Provart
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada
| | - Dan Nettleton
- Department of Statistics, Iowa State University, Ames, IA 50011-1210, USA
| | - Frank Hochholdinger
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
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Hao M, Li A, Shi T, Luo J, Zhang L, Zhang X, Ning S, Yuan Z, Zeng D, Kong X, Li X, Zheng H, Lan X, Zhang H, Zheng Y, Mao L, Liu D. The abundance of homoeologue transcripts is disrupted by hybridization and is partially restored by genome doubling in synthetic hexaploid wheat. BMC Genomics 2017; 18:149. [PMID: 28187716 PMCID: PMC5303294 DOI: 10.1186/s12864-017-3558-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 02/07/2017] [Indexed: 11/10/2022] Open
Abstract
Background The formation of an allopolyploid is a two step process, comprising an initial wide hybridization event, which is later followed by a whole genome doubling. Both processes can affect the transcription of homoeologues. Here, RNA-Seq was used to obtain the genome-wide leaf transcriptome of two independent Triticum turgidum × Aegilops tauschii allotriploids (F1), along with their spontaneous allohexaploids (S1) and their parental lines. The resulting sequence data were then used to characterize variation in homoeologue transcript abundance. Results The hybridization event strongly down-regulated D-subgenome homoeologues, but this effect was in many cases reversed by whole genome doubling. The suppression of D-subgenome homoeologue transcription resulted in a marked frequency of parental transcription level dominance, especially with respect to genes encoding proteins involved in photosynthesis. Singletons (genes where no homoeologues were present) were frequently transcribed at both the allotriploid and allohexaploid plants. Conclusions The implication is that whole genome doubling helps to overcome the phenotypic weakness of the allotriploid, restoring a more favourable gene dosage in genes experiencing transcription level dominance in hexaploid wheat. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3558-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ming Hao
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Aili Li
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Tongwei Shi
- Biomarker Technologies Corporation, Beijing, 101300, China
| | - Jiangtao Luo
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Lianquan Zhang
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Xuechuan Zhang
- Biomarker Technologies Corporation, Beijing, 101300, China
| | - Shunzong Ning
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Zhongwei Yuan
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Deying Zeng
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Xingchen Kong
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Xiaolong Li
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Hongkun Zheng
- Biomarker Technologies Corporation, Beijing, 101300, China
| | - Xiujin Lan
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Huaigang Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, 810001, China
| | - Youliang Zheng
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Long Mao
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Dengcai Liu
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China. .,Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, 810001, China.
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Liu S, Zheng J, Migeon P, Ren J, Hu Y, He C, Liu H, Fu J, White FF, Toomajian C, Wang G. Unbiased K-mer Analysis Reveals Changes in Copy Number of Highly Repetitive Sequences During Maize Domestication and Improvement. Sci Rep 2017; 7:42444. [PMID: 28186206 PMCID: PMC5301235 DOI: 10.1038/srep42444] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/10/2017] [Indexed: 12/15/2022] Open
Abstract
The major component of complex genomes is repetitive elements, which remain recalcitrant to characterization. Using maize as a model system, we analyzed whole genome shotgun (WGS) sequences for the two maize inbred lines B73 and Mo17 using k-mer analysis to quantify the differences between the two genomes. Significant differences were identified in highly repetitive sequences, including centromere, 45S ribosomal DNA (rDNA), knob, and telomere repeats. Genotype specific 45S rDNA sequences were discovered. The B73 and Mo17 polymorphic k-mers were used to examine allele-specific expression of 45S rDNA in the hybrids. Although Mo17 contains higher copy number than B73, equivalent levels of overall 45S rDNA expression indicates that transcriptional or post-transcriptional regulation mechanisms operate for the 45S rDNA in the hybrids. Using WGS sequences of B73xMo17 doubled haploids, genomic locations showing differential repetitive contents were genetically mapped, which displayed different organization of highly repetitive sequences in the two genomes. In an analysis of WGS sequences of HapMap2 lines, including maize wild progenitor, landraces, and improved lines, decreases and increases in abundance of additional sets of k-mers associated with centromere, 45S rDNA, knob, and retrotransposons were found among groups, revealing global evolutionary trends of genomic repeats during maize domestication and improvement.
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Affiliation(s)
- Sanzhen Liu
- Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA
| | - Jun Zheng
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China
| | - Pierre Migeon
- Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA
| | - Jie Ren
- Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA
| | - Ying Hu
- Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA
| | - Cheng He
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China
| | - Hongjun Liu
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Taian 271018, P.R. China.,College of Life Sciences, Shandong Agricultural University, Taian 271018, P.R. China
| | - Junjie Fu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China
| | - Frank F White
- Department of Plant Pathology, University of Florida, Gainesville, FL, 32611, USA
| | | | - Guoying Wang
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China
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Marcon C, Paschold A, Malik WA, Lithio A, Baldauf JA, Altrogge L, Opitz N, Lanz C, Schoof H, Nettleton D, Piepho HP, Hochholdinger F. Stability of Single-Parent Gene Expression Complementation in Maize Hybrids upon Water Deficit Stress. PLANT PHYSIOLOGY 2017; 173:1247-1257. [PMID: 27999083 PMCID: PMC5291719 DOI: 10.1104/pp.16.01045] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 12/18/2016] [Indexed: 05/24/2023]
Abstract
Heterosis is the superior performance of F1 hybrids compared with their homozygous, genetically distinct parents. In this study, we monitored the transcriptomic divergence of the maize (Zea mays) inbred lines B73 and Mo17 and their reciprocal F1 hybrid progeny in primary roots under control and water deficit conditions simulated by polyethylene glycol treatment. Single-parent expression (SPE) of genes is an extreme instance of gene expression complementation, in which genes are active in only one of two parents but are expressed in both reciprocal hybrids. In this study, 1,997 genes only expressed in B73 and 2,024 genes only expressed in Mo17 displayed SPE complementation under control and water deficit conditions. As a consequence, the number of active genes in hybrids exceeded the number of active genes in the parental inbred lines significantly independent of treatment. SPE patterns were substantially more stable to expression changes by water deficit treatment than other genotype-specific expression profiles. While, on average, 75% of all SPE patterns were not altered in response to polyethylene glycol treatment, only 17% of the remaining genotype-specific expression patterns were not changed by water deficit. Nonsyntenic genes that lack syntenic orthologs in other grass species, and thus evolved late in the grass lineage, were significantly overrepresented among SPE genes. Hence, the significant overrepresentation of nonsyntenic genes among SPE patterns and their stability under water limitation might suggest a function of these genes during the early developmental manifestation of heterosis under fluctuating environmental conditions in hybrid progeny of the inbred lines B73 and Mo17.
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Affiliation(s)
- Caroline Marcon
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Anja Paschold
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Waqas Ahmed Malik
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Andrew Lithio
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Jutta A Baldauf
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Lena Altrogge
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Nina Opitz
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Christa Lanz
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Heiko Schoof
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Dan Nettleton
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Hans-Peter Piepho
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.)
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
| | - Frank Hochholdinger
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics (C.M., A.P., J.A.B., N.O., F.H.) and Crop Bioinformatics (L.A., H.S.), University of Bonn, 53113 Bonn, Germany;
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, 70599 Stuttgart, Germany (W.A.M., H.-P.P.);
- Department of Statistics, Iowa State University, Ames, Iowa 50011-1210 (A.L., D.N.); and
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany (C.L.)
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Mei W, Liu S, Schnable JC, Yeh CT, Springer NM, Schnable PS, Barbazuk WB. A Comprehensive Analysis of Alternative Splicing in Paleopolyploid Maize. FRONTIERS IN PLANT SCIENCE 2017; 8:694. [PMID: 28539927 PMCID: PMC5423905 DOI: 10.3389/fpls.2017.00694] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 04/18/2017] [Indexed: 05/19/2023]
Abstract
Identifying and characterizing alternative splicing (AS) enables our understanding of the biological role of transcript isoform diversity. This study describes the use of publicly available RNA-Seq data to identify and characterize the global diversity of AS isoforms in maize using the inbred lines B73 and Mo17, and a related species, sorghum. Identification and characterization of AS within maize tissues revealed that genes expressed in seed exhibit the largest differential AS relative to other tissues examined. Additionally, differences in AS between the two genotypes B73 and Mo17 are greatest within genes expressed in seed. We demonstrate that changes in the level of alternatively spliced transcripts (intron retention and exon skipping) do not solely reflect differences in total transcript abundance, and we present evidence that intron retention may act to fine-tune gene expression across seed development stages. Furthermore, we have identified temperature sensitive AS in maize and demonstrate that drought-induced changes in AS involve distinct sets of genes in reproductive and vegetative tissues. Examining our identified AS isoforms within B73 × Mo17 recombinant inbred lines (RILs) identified splicing QTL (sQTL). The 43.3% of cis-sQTL regulated junctions are actually identified as alternatively spliced junctions in our analysis, while 10 Mb windows on each side of 48.2% of trans-sQTLs overlap with splicing related genes. Using sorghum as an out-group enabled direct examination of loss or conservation of AS between homeologous genes representing the two subgenomes of maize. We identify several instances where AS isoforms that are conserved between one maize homeolog and its sorghum ortholog are absent from the second maize homeolog, suggesting that these AS isoforms may have been lost after the maize whole genome duplication event. This comprehensive analysis provides new insights into the complexity of AS in maize.
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Affiliation(s)
- Wenbin Mei
- Department of Biology, University of Florida, GainesvilleFL, USA
| | - Sanzhen Liu
- Department of Agronomy, Iowa State University, AmesIA, USA
- Department of Plant Pathology, Kansas State University, ManhattanKS, USA
| | - James C. Schnable
- Department of Agronomy and Horticulture, University of Nebraska–Lincoln, LincolnNE, USA
| | - Cheng-Ting Yeh
- Department of Agronomy, Iowa State University, AmesIA, USA
| | - Nathan M. Springer
- Department of Plant Biology, Microbial and Plant Genomics Institute, University of Minnesota, Saint PaulMN, USA
| | - Patrick S. Schnable
- Department of Agronomy, Iowa State University, AmesIA, USA
- Center for Plant Genomics, Iowa State University, AmesIA, USA
| | - William B. Barbazuk
- Department of Biology, University of Florida, GainesvilleFL, USA
- Genetics Institute, University of Florida, GainesvilleFL, USA
- *Correspondence: William B. Barbazuk,
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Qi J, Sun G, Wang L, Zhao C, Hettenhausen C, Schuman MC, Baldwin IT, Li J, Song J, Liu Z, Xu G, Lu X, Wu J. Oral secretions from Mythimna separata insects specifically induce defence responses in maize as revealed by high-dimensional biological data. PLANT, CELL & ENVIRONMENT 2016; 39:1749-1766. [PMID: 26991784 PMCID: PMC5295635 DOI: 10.1111/pce.12735] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/06/2016] [Indexed: 05/13/2023]
Abstract
Attack from insect herbivores poses a major threat to plant survival, and accordingly, plants have evolved sophisticated defence systems. Maize is cultivated as a staple crop worldwide, and insect feeding causes large production losses. Despite its importance in agriculture, little is known about how maize reacts to insect herbivory. Taking advantage of advances in sequencing and mass spectrometry technology, we studied the response of maize to mechanical wounding and simulated Mythimna separata (a specialist insect) herbivory by applying its oral secretions (OS) to wounds. In comparison to the responses induced by mechanical wounding, OS elicited larger and longer-lasting changes in the maize transcriptome, proteome, metabolome and phytohormones. Specifically, many genes, proteins and metabolites were uniquely induced or repressed by OS. Nearly 290 transcription factor genes from 39 families were involved in OS-induced responses, and among these, more transcription factor genes were specifically regulated by OS than by wounding. This study provides a large-scale omics dataset for understanding maize response to chewing insects and highlights the essential role of OS in plant-insect interactions.
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Affiliation(s)
- Jinfeng Qi
- Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Guiling Sun
- Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Lei Wang
- Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Chunxia Zhao
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Christian Hettenhausen
- Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Meredith C. Schuman
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Leipzig 04103, Germany
| | - Ian T. Baldwin
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany
| | - Jing Li
- Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Juan Song
- Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Zhudong Liu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China
| | - Guowang Xu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Xin Lu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Jianqiang Wu
- Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Corresponding author: Jianqiang Wu, Phone/Fax: +86-871-65229562,
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Baldauf JA, Marcon C, Paschold A, Hochholdinger F. Nonsyntenic Genes Drive Tissue-Specific Dynamics of Differential, Nonadditive, and Allelic Expression Patterns in Maize Hybrids. PLANT PHYSIOLOGY 2016; 171:1144-55. [PMID: 27208302 PMCID: PMC4902609 DOI: 10.1104/pp.16.00262] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 04/18/2016] [Indexed: 05/21/2023]
Abstract
Distantly related maize (Zea mays) inbred lines display an exceptional degree of genomic diversity. F1 progeny of such inbred lines are often more vigorous than their parents, a phenomenon known as heterosis. In this study, we investigated how the genetic divergence of the maize inbred lines B73 and Mo17 and their F1 hybrid progeny is reflected in differential, nonadditive, and allelic expression patterns in primary root tissues. In pairwise comparisons of the four genotypes, the number of differentially expressed genes between the two parental inbred lines significantly exceeded those of parent versus hybrid comparisons in all four tissues under analysis. No differentially expressed genes were detected between reciprocal hybrids, which share the same nuclear genome. Moreover, hundreds of nonadditive and allelic expression ratios that were different from the expression ratios of the parents were observed in the reciprocal hybrids. The overlap of both nonadditive and allelic expression patterns in the reciprocal hybrids significantly exceeded the expected values. For all studied types of expression - differential, nonadditive, and allelic - substantial tissue-specific plasticity was observed. Significantly, nonsyntenic genes that evolved after the last whole genome duplication of a maize progenitor from genes with synteny to sorghum (Sorghum bicolor) were highly overrepresented among differential, nonadditive, and allelic expression patterns compared with the fraction of these genes among all expressed genes. This observation underscores the role of nonsyntenic genes in shaping the transcriptomic landscape of maize hybrids during the early developmental manifestation of heterosis in root tissues of maize hybrids.
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Affiliation(s)
- Jutta A Baldauf
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113 Bonn, Germany
| | - Caroline Marcon
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113 Bonn, Germany
| | - Anja Paschold
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113 Bonn, Germany
| | - Frank Hochholdinger
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, 53113 Bonn, Germany
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Stelpflug SC, Sekhon RS, Vaillancourt B, Hirsch CN, Buell CR, de Leon N, Kaeppler SM. An Expanded Maize Gene Expression Atlas based on RNA Sequencing and its Use to Explore Root Development. THE PLANT GENOME 2016; 9. [PMID: 27898762 DOI: 10.3835/plantgenome2015.04.0025] [Citation(s) in RCA: 181] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Comprehensive and systematic transcriptome profiling provides valuable insight into biological and developmental processes that occur throughout the life cycle of a plant. We have enhanced our previously published microarray-based gene atlas of maize ( L.) inbred B73 to now include 79 distinct replicated samples that have been interrogated using RNA sequencing (RNA-seq). The current version of the atlas includes 50 original array-based gene atlas samples, a time-course of 12 stalk and leaf samples postflowering, and an additional set of 17 samples from the maize seedling and adult root system. The entire dataset contains 4.6 billion mapped reads, with an average of 20.5 million mapped reads per biological replicate, allowing for detection of genes with lower transcript abundance. As the new root samples represent key additions to the previously examined tissues, we highlight insights into the root transcriptome, which is represented by 28,894 (73.2%) annotated genes in maize. Additionally, we observed remarkable expression differences across both the longitudinal (four zones) and radial gradients (cortical parenchyma and stele) of the primary root supported by fourfold differential expression of 9353 and 4728 genes, respectively. Among the latter were 1110 genes that encode transcription factors, some of which are orthologs of previously characterized transcription factors known to regulate root development in (L.) Heynh., while most are novel, and represent attractive targets for reverse genetics approaches to determine their roles in this important organ. This comprehensive transcriptome dataset is a powerful tool toward understanding maize development, physiology, and phenotypic diversity.
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Wang T, Sui Z, Liu X, Li Y, Li H, Xing J, Song F, Zhang Y, Sun Q, Ni Z. Ectopic expression of a maize hybrid up-regulated gene, ErbB-3 binding Protein 1 (ZmEBP1), increases organ size by promoting cell proliferation in Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 243:23-34. [PMID: 26795148 DOI: 10.1016/j.plantsci.2015.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 11/02/2015] [Accepted: 11/04/2015] [Indexed: 05/21/2023]
Abstract
The alteration of gene expression in hybrids may be an important factor promoting phenotypic variation and plasticity. To provide insight into the underlying molecular basis of maize heterosis in terms of the kernel number per ear, we established DGE profiles for the immature ears of maize hybrid Zong3/87-1 and its parental lines at the floral organ differentiation stage. Among 4,337 identified differentially expressed genes, 4,021 (92%) exhibited nonadditive expression patterns in the hybrid. Notably, the maize homolog of Arabidopsis EBP1, designated ZmEBP1, displayed an overdominant expression pattern in the Zong3/87-1 hybrid. Moreover, the results of qRT-PCR revealed that the ZmEBP1 gene was upregulated in the immature ears of the reciprocal hybrids Zong3/87-1 and 87-1/Zong3 at different developmental stages. Additionally, ectopic expression of ZmEBP1 in Arabidopsis increased organ size, which was mainly attributed to an increase in cell numbers, rather than cell size. Considering all of these findings together, we speculate that upregulation of ZmEBP1 in maize hybrids may accelerate cell proliferation and promote ear development.
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Affiliation(s)
- Tianya Wang
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China; National Plant Gene Research Centre (Beijing), Beijing 100193, China
| | - Zhipeng Sui
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China; National Plant Gene Research Centre (Beijing), Beijing 100193, China
| | - Xinye Liu
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China; National Plant Gene Research Centre (Beijing), Beijing 100193, China
| | - Yangyang Li
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China; National Plant Gene Research Centre (Beijing), Beijing 100193, China
| | - Hongjian Li
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China; National Plant Gene Research Centre (Beijing), Beijing 100193, China
| | - Jiewen Xing
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China; National Plant Gene Research Centre (Beijing), Beijing 100193, China
| | - Fangwei Song
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China; National Plant Gene Research Centre (Beijing), Beijing 100193, China
| | - Yirong Zhang
- National Maize Improvement Centre of China, China Agricultural University, Beijing 100193, China
| | - Qixin Sun
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China; National Plant Gene Research Centre (Beijing), Beijing 100193, China
| | - Zhongfu Ni
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China; National Plant Gene Research Centre (Beijing), Beijing 100193, China.
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Tai H, Lu X, Opitz N, Marcon C, Paschold A, Lithio A, Nettleton D, Hochholdinger F. Transcriptomic and anatomical complexity of primary, seminal, and crown roots highlight root type-specific functional diversity in maize (Zea mays L.). JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:1123-35. [PMID: 26628518 PMCID: PMC4753849 DOI: 10.1093/jxb/erv513] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Maize develops a complex root system composed of embryonic and post-embryonic roots. Spatio-temporal differences in the formation of these root types imply specific functions during maize development. A comparative transcriptomic study of embryonic primary and seminal, and post-embryonic crown roots of the maize inbred line B73 by RNA sequencing along with anatomical studies were conducted early in development. Seminal roots displayed unique anatomical features, whereas the organization of primary and crown roots was similar. For instance, seminal roots displayed fewer cortical cell files and their stele contained more meta-xylem vessels. Global expression profiling revealed diverse patterns of gene activity across all root types and highlighted the unique transcriptome of seminal roots. While functions in cell remodeling and cell wall formation were prominent in primary and crown roots, stress-related genes and transcriptional regulators were over-represented in seminal roots, suggesting functional specialization of the different root types. Dynamic expression of lignin biosynthesis genes and histochemical staining suggested diversification of cell wall lignification among the three root types. Our findings highlight a cost-efficient anatomical structure and a unique expression profile of seminal roots of the maize inbred line B73 different from primary and crown roots.
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Affiliation(s)
- Huanhuan Tai
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
| | - Xin Lu
- Experimental Medicine and Therapy Research, University of Regensburg, D-93053 Regensburg, Germany
| | - Nina Opitz
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
| | - Caroline Marcon
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
| | - Anja Paschold
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
| | - Andrew Lithio
- Department of Statistics, Iowa State University, Ames, IA 50011-1210, USA
| | - Dan Nettleton
- Department of Statistics, Iowa State University, Ames, IA 50011-1210, USA
| | - Frank Hochholdinger
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
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Opitz N, Marcon C, Paschold A, Malik WA, Lithio A, Brandt R, Piepho HP, Nettleton D, Hochholdinger F. Extensive tissue-specific transcriptomic plasticity in maize primary roots upon water deficit. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:1095-107. [PMID: 26463995 PMCID: PMC4753846 DOI: 10.1093/jxb/erv453] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Water deficit is the most important environmental constraint severely limiting global crop growth and productivity. This study investigated early transcriptome changes in maize (Zea mays L.) primary root tissues in response to moderate water deficit conditions by RNA-Sequencing. Differential gene expression analyses revealed a high degree of plasticity of the water deficit response. The activity status of genes (active/inactive) was determined by a Bayesian hierarchical model. In total, 70% of expressed genes were constitutively active in all tissues. In contrast, <3% (50 genes) of water deficit-responsive genes (1915) were consistently regulated in all tissues, while >75% (1501 genes) were specifically regulated in a single root tissue. Water deficit-responsive genes were most numerous in the cortex of the mature root zone and in the elongation zone. The most prominent functional categories among differentially expressed genes in all tissues were 'transcriptional regulation' and 'hormone metabolism', indicating global reprogramming of cellular metabolism as an adaptation to water deficit. Additionally, the most significant transcriptomic changes in the root tip were associated with cell wall reorganization, leading to continued root growth despite water deficit conditions. This study provides insight into tissue-specific water deficit responses and will be a resource for future genetic analyses and breeding strategies to develop more drought-tolerant maize cultivars.
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Affiliation(s)
- Nina Opitz
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
| | - Caroline Marcon
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
| | - Anja Paschold
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
| | - Waqas Ahmed Malik
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, D-70599 Stuttgart, Germany
| | - Andrew Lithio
- Department of Statistics, Iowa State University, Ames, IA 50011-1210, USA
| | - Ronny Brandt
- Leibniz Institute of Plant Genetics and Crop Plant Research, D-06466 Gatersleben, Germany
| | - Hans-Peter Piepho
- Institute for Crop Science, Biostatistics Unit, University of Hohenheim, D-70599 Stuttgart, Germany
| | - Dan Nettleton
- Department of Statistics, Iowa State University, Ames, IA 50011-1210, USA
| | - Frank Hochholdinger
- Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany
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Choo-Wosoba H, Levy SM, Datta S. Marginal regression models for clustered count data based on zero-inflated Conway-Maxwell-Poisson distribution with applications. Biometrics 2015; 72:606-18. [PMID: 26575079 DOI: 10.1111/biom.12436] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Revised: 09/01/2015] [Accepted: 09/01/2015] [Indexed: 10/22/2022]
Abstract
Community water fluoridation is an important public health measure to prevent dental caries, but it continues to be somewhat controversial. The Iowa Fluoride Study (IFS) is a longitudinal study on a cohort of Iowa children that began in 1991. The main purposes of this study (http://www.dentistry.uiowa.edu/preventive-fluoride-study) were to quantify fluoride exposures from both dietary and nondietary sources and to associate longitudinal fluoride exposures with dental fluorosis (spots on teeth) and dental caries (cavities). We analyze a subset of the IFS data by a marginal regression model with a zero-inflated version of the Conway-Maxwell-Poisson distribution for count data exhibiting excessive zeros and a wide range of dispersion patterns. In general, we introduce two estimation methods for fitting a ZICMP marginal regression model. Finite sample behaviors of the estimators and the resulting confidence intervals are studied using extensive simulation studies. We apply our methodologies to the dental caries data. Our novel modeling incorporating zero inflation, clustering, and overdispersion sheds some new light on the effect of community water fluoridation and other factors. We also include a second application of our methodology to a genomic (next-generation sequencing) dataset that exhibits underdispersion.
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Affiliation(s)
- Hyoyoung Choo-Wosoba
- Department of Bioinformatics and Biostatistics, University of Louisville, Louisville, Kentucky 40202, U.S.A
| | - Steven M Levy
- Department of Preventive and Community Dentistry Department of Epidemiology, University of Iowa, Iowa City, Iowa 52242, U.S.A
| | - Somnath Datta
- Department of Biostatistics, University of Florida, Gainesville, Florida 32610, U.S.A
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