1
|
Khouider S, Gehring M. Parental dialectic: Epigenetic conversations in endosperm. CURRENT OPINION IN PLANT BIOLOGY 2024; 81:102591. [PMID: 38944896 DOI: 10.1016/j.pbi.2024.102591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/21/2024] [Accepted: 06/07/2024] [Indexed: 07/02/2024]
Abstract
Endosperm is a major evolutionary innovation of flowering plants, and its proper development critically impacts seed growth and viability. Epigenetic regulators have a key function in parental control of endosperm development. Notably, epigenetic regulation of parental genome dosage is a major determinant of seed development success, and disruption of this balance can produce inviable seed, as observed in some interploidy and interspecific crosses. These postzygotic reproduction barriers are also a potent driver of speciation. The molecular machinery and regulatory architecture governing endosperm development is proposed to have evolved under parental conflict. In this review, we emphasize parental conflict as a dialectic conflict and discuss recent findings about the epigenetic molecular machinery that mediates parental conflict in the endosperm.
Collapse
Affiliation(s)
- Souraya Khouider
- Whitehead Institute for Biomedical Research, Cambridge MA 02142, USA
| | - Mary Gehring
- Whitehead Institute for Biomedical Research, Cambridge MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge MA 02139, USA.
| |
Collapse
|
2
|
Bente H, Köhler C. Molecular basis and evolutionary drivers of endosperm-based hybridization barriers. PLANT PHYSIOLOGY 2024; 195:155-169. [PMID: 38298124 PMCID: PMC11060687 DOI: 10.1093/plphys/kiae050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 01/05/2024] [Accepted: 01/06/2024] [Indexed: 02/02/2024]
Abstract
The endosperm, a transient seed tissue, plays a pivotal role in supporting embryo growth and germination. This unique feature sets flowering plants apart from gymnosperms, marking an evolutionary innovation in the world of seed-bearing plants. Nevertheless, the importance of the endosperm extends beyond its role in providing nutrients to the developing embryo by acting as a versatile protector, preventing hybridization events between distinct species and between individuals with different ploidy. This phenomenon centers on growth and differentiation of the endosperm and the speed at which both processes unfold. Emerging studies underscore the important role played by type I MADS-box transcription factors, including the paternally expressed gene PHERES1. These factors, along with downstream signaling pathways involving auxin and abscisic acid, are instrumental in regulating endosperm development and, consequently, the establishment of hybridization barriers. Moreover, mutations in various epigenetic regulators mitigate these barriers, unveiling a complex interplay of pathways involved in their formation. In this review, we discuss the molecular underpinnings of endosperm-based hybridization barriers and their evolutionary drivers.
Collapse
Affiliation(s)
- Heinrich Bente
- Department of Plant Reproductive Biology and Epigenetics, Max Planck Institute of Molecular Plant Physiology, Potsdam 14476, Germany
| | - Claudia Köhler
- Department of Plant Reproductive Biology and Epigenetics, Max Planck Institute of Molecular Plant Physiology, Potsdam 14476, Germany
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
| |
Collapse
|
3
|
Dong X, Luo H, Yao J, Guo Q, Yu S, Ruan Y, Li F, Jin W, Meng D. The conservation of allelic DNA methylation and its relationship with imprinting in maize. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:1376-1389. [PMID: 37935439 PMCID: PMC10901201 DOI: 10.1093/jxb/erad440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 11/02/2023] [Indexed: 11/09/2023]
Abstract
Genomic imprinting refers to allele-specific expression of genes depending on parental origin, and it is regulated by epigenetic modifications. Intraspecific allelic variation for imprinting has been detected; however, the intraspecific genome-wide allelic epigenetic variation in maize and its correlation with imprinting variants remain unclear. Here, three reciprocal hybrids were generated by crossing Zea mays inbred lines CAU5, B73, and Mo17 in order to examine the intraspecific conservation of the imprinted genes in the kernel. The majority of imprinted genes exhibited intraspecific conservation, and these genes also exhibited interspecific conservation (rice, sorghum, and Arabidopsis) and were enriched in some specific pathways. By comparing intraspecific allelic DNA methylation in the endosperm, we found that nearly 15% of DNA methylation existed as allelic variants. The intraspecific whole-genome correlation between DNA methylation and imprinted genes indicated that DNA methylation variants play an important role in imprinting variants. Disruption of two conserved imprinted genes using CRISPR/Cas9 editing resulted in a smaller kernel phenotype. Our results shed light on the intraspecific correlation of DNA methylation variants and variation for imprinting in maize, and show that imprinted genes play an important role in kernel development.
Collapse
Affiliation(s)
- Xiaomei Dong
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang 110866, Liaoning, China
| | - Haishan Luo
- College of Agronomy, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
| | - Jiabin Yao
- College of Agronomy, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
| | - Qingfeng Guo
- College of Agronomy, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
| | - Shuai Yu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang 110866, Liaoning, China
| | - Yanye Ruan
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang 110866, Liaoning, China
| | - Fenghai Li
- College of Agronomy, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
| | - Weiwei Jin
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center, Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
- Department of Agronomy, College of Agriculture & Resources and Environmental Sciences, Tianjin Agricultural University, Tianjin 300392, China
| | - Dexuan Meng
- College of Agronomy, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
| |
Collapse
|
4
|
Soliman HK, Coughlan JM. United by Conflict: Convergent Signatures of Parental Conflict in Angiosperms and Placental Mammals. J Hered 2024:esae009. [PMID: 38366852 DOI: 10.1093/jhered/esae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Indexed: 02/18/2024] Open
Abstract
Endosperm in angiosperms and placenta in eutherians are convergent innovations for efficient embryonic nutrient transfer. Despite advantages, this reproductive strategy incurs metabolic costs that maternal parents disproportionately shoulder, leading to potential inter-parental conflict over optimal offspring investment. Genomic imprinting-parent-of-origin-biased gene expression-is fundamental for endosperm and placenta development and has convergently evolved in angiosperms and mammals, in part, to resolve parental conflict. Here, we review the mechanisms of genomic imprinting in these taxa. Despite differences in the timing and spatial extent of imprinting, these taxa exhibit remarkable convergence in the molecular machinery and genes governing imprinting. We then assess the role of parental conflict in shaping evolution within angiosperms and eutherians using four criteria: (1) Do differences in the extent of sibling relatedness cause differences in the inferred strength of parental conflict? (2) Do reciprocal crosses between taxa with different inferred histories of parental conflict exhibit parent-of-origin growth effects? (3) Are these parent-of-origin growth effects caused by dosage-sensitive mechanisms and do these loci exhibit signals of positive selection? (4) Can normal development be restored by genomic perturbations that restore stoichiometric balance in the endosperm/placenta? Although we find evidence for all criteria in angiosperms and eutherians, suggesting that parental conflict may help shape their evolution, many questions remain. Additionally, myriad differences between the two taxa suggest that their respective biologies may shape how/when/where/to what extent parental conflict manifests. Lastly, we discuss outstanding questions, highlighting the power of comparative work in quantifying the role of parental conflict in evolution.
Collapse
Affiliation(s)
- Hagar K Soliman
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, 06511, United States
- Department of Biotechnology, Faculty of Science, Cairo University, Giza, 12613, Egypt
| | - Jenn M Coughlan
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, 06511, United States
| |
Collapse
|
5
|
Han B, Li Y, Wu D, Li DZ, Liu A, Xu W. Dynamics of imprinted genes and their epigenetic mechanisms in castor bean seed with persistent endosperm. THE NEW PHYTOLOGIST 2023; 240:1868-1882. [PMID: 37717216 DOI: 10.1111/nph.19265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 08/25/2023] [Indexed: 09/19/2023]
Abstract
Genomic imprinting refers to parent-of-origin-dependent gene expression and primarily occurs in the endosperm of flowering plants, but its functions and epigenetic mechanisms remain to be elucidated in eudicots. Castor bean, a eudicot with large and persistent endosperm, provides an excellent system for studying the imprinting. Here, we identified 131 imprinted genes in developing endosperms and endosperm at seed germination phase of castor bean, involving into the endosperm development, accumulation of storage compounds and specially seed germination. Our results showed that the transcriptional repression of maternal allele of DNA METHYLTRANSFERASE 1 (MET1) may be required for maternal genome demethylation in the endosperm. DNA methylation analysis showed that only a small fraction of imprinted genes was associated with allele-specific DNA methylation, and most of them were closely associated with constitutively unmethylated regions (UMRs), suggesting a limited role for DNA methylation in controlling genomic imprinting. Instead, histone modifications can be asymmetrically deposited in maternal and paternal genomes in a DNA methylation-independent manner to control expression of most imprinted genes. These results expanded our understanding of the occurrence and biological functions of imprinted genes and showed the evolutionary flexibility of the imprinting machinery and mechanisms in plants.
Collapse
Affiliation(s)
- Bing Han
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| | - Yelan Li
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| | - Di Wu
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| | - De-Zhu Li
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| | - Aizhong Liu
- Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming, 650224, China
| | - Wei Xu
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| |
Collapse
|
6
|
Dong X, Luo H, Bi W, Chen H, Yu S, Zhang X, Dai Y, Cheng X, Xing Y, Fan X, Zhu Y, Guo Y, Meng D. Transcriptome-wide identification and characterization of genes exhibit allele-specific imprinting in maize embryo and endosperm. BMC PLANT BIOLOGY 2023; 23:470. [PMID: 37803280 PMCID: PMC10557216 DOI: 10.1186/s12870-023-04473-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 09/18/2023] [Indexed: 10/08/2023]
Abstract
BACKGROUND Genomic imprinting refers to a subset of genes that are expressed from only one parental allele during seed development in plants. Studies on genomic imprinting have revealed that intraspecific variations in genomic imprinting expression exist in naturally genetic varieties. However, there have been few studies on the functional analysis of allele-specific imprinted genes. RESULTS Here, we generated three reciprocal crosses among the B73, Mo17 and CAU5 inbred lines. Based on the transcriptome-wide analysis of allele-specific expression using RNA sequencing technology, 305 allele-specific imprinting genes (ASIGs) were identified in embryos, and 655 ASIGs were identified in endosperms from three maize F1 hybrids. Of these ASIGs, most did not show consistent maternal or paternal bias between the same tissue from different hybrids or different tissues from one hybrid cross. By gene ontology (GO) analysis, five and eight categories of GO exhibited significantly higher functional enrichments for ASIGs identified in embryo and endosperm, respectively. These functional categories indicated that ASIGs are involved in intercellular nutrient transport, signaling pathways, and transcriptional regulation of kernel development. Finally, the mutation and overexpression of one ASIG (Zm305) affected the length and width of the kernel. CONCLUSION In this study, our data will be helpful in gaining further knowledge of genes exhibiting allele-specific imprinting patterns in seeds. The gain- and loss-of-function phenotypes of ASIGs associated with agronomically important seed traits provide compelling evidence for ASIGs as crucial targets to optimize seed traits in crop plants.
Collapse
Affiliation(s)
- Xiaomei Dong
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Haishan Luo
- College of Agronomy, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
| | - Wenjing Bi
- College of Agronomy, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
| | - Hanyu Chen
- College of Agronomy, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
| | - Shuai Yu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Xiaoyu Zhang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yuxin Dai
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Xipeng Cheng
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yupeng Xing
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Xiaoqin Fan
- Manas Agricultural Experimental Station of Xinjiang Academy of Agricultural Sciences, Changji, 832200, Xinjiang, China
| | - Yanbin Zhu
- National Key Laboratory of Maize Biological Breeding, Key Laboratory of Genetics and Breeding of Main Crops in Northeast Region, Ministry of Agriculture and Rural Affairs, Liaoning Dongya Seed Industry Co., Ltd, Shenyang, Liaoning, 110164, China
| | - Yanling Guo
- National Key Laboratory of Maize Biological Breeding, Key Laboratory of Genetics and Breeding of Main Crops in Northeast Region, Ministry of Agriculture and Rural Affairs, Liaoning Dongya Seed Industry Co., Ltd, Shenyang, Liaoning, 110164, China
| | - Dexuan Meng
- College of Agronomy, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China.
| |
Collapse
|
7
|
Liu B, Zhao M. How transposable elements are recognized and epigenetically silenced in plants? CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102428. [PMID: 37481986 DOI: 10.1016/j.pbi.2023.102428] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/25/2023]
Abstract
Plant genomes are littered with transposable elements (TEs). Because TEs are potentially highly mutagenic, host organisms have evolved a set of defense mechanisms to recognize and epigenetically silence them. Although the maintenance of TE silencing is well studied, our understanding of the initiation of TE silencing is limited, but it clearly involves small RNAs and DNA methylation. Once TEs are silent, the silent state can be maintained to subsequent generations. However, under some circumstances, such inheritance is unstable, leading to the escape of TEs to the silencing machinery, resulting in the transcriptional activation of TEs. Epigenetic control of TEs has been found to be closely linked to many other epigenetic phenomena, such as genomic imprinting, and is known to contribute to regulation of genes, especially those near TEs. Here we review and discuss the current models of TE silencing, its unstable inheritance after hybridization, and the effects of epigenetic regulation of TEs on genomic imprinting.
Collapse
Affiliation(s)
- Beibei Liu
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | - Meixia Zhao
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA.
| |
Collapse
|
8
|
Sharma U, Sikdar A, Igamberdiev AU, Debnath SC. Exploring Genetic and Epigenetic Changes in Lingonberry Using Molecular Markers: Implications for Clonal Propagation. Curr Issues Mol Biol 2023; 45:6296-6310. [PMID: 37623216 PMCID: PMC10453208 DOI: 10.3390/cimb45080397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/20/2023] [Accepted: 07/26/2023] [Indexed: 08/26/2023] Open
Abstract
Lingonberry (Vaccinium vitis-idaea L.) is an important and valuable horticultural crop due to its high antioxidant properties. Plant tissue culture is an advanced propagation system employed in horticultural crops. However, the progeny derived using this technique may not be true-to-type. In order to obtain the maximum return of any agricultural enterprise, uniformity of planting materials is necessary, which sometimes is not achieved due to genetic and epigenetic instabilities under in vitro culture. Therefore, we analyzed morphological traits and genetic and epigenetic variations under tissue-culture and greenhouse conditions in lingonberry using molecular markers. Leaf length and leaf width under greenhouse conditions and shoot number per explant, shoot height and shoot vigor under in vitro conditions were higher in hybrid H1 compared to the cultivar Erntedank. Clonal fidelity study using one expressed sequence tag (EST)-polymerase chain reaction (PCR), five EST-simple sequence repeat (SSR) and six genomic (G)-SSR markers revealed monomorphic bands in micropropagated shoots and plants in lingonberry hybrid H1 and cultivar Erntedank conforming genetic integrity. Epigenetic variation was studied by quantifying cytosine methylation using a methylation-sensitive amplification polymorphism (MSAP) technique. DNA methylation ranged from 32% in greenhouse-grown hybrid H1 to 44% in cultivar Erntedank under a tissue culture system. Although total methylation was higher in in vitro grown shoots, fully methylated bands were observed more in the greenhouse-grown plants. On the contrary, hemimethylated DNA bands were more prominent in tissue culture conditions as compared to the greenhouse-grown plants. The study conclude that lingonberry maintains its genetic integrity but undergoes variable epigenetic changes during in vitro and ex vitro conditions.
Collapse
Affiliation(s)
- Umanath Sharma
- Department of Biology, Memorial University of Newfoundland, 45 Arctic Avenue, St. John’s, NL A1C 5S7, Canada; (U.S.); (A.S.); (A.U.I.)
- St. John’s Research and Development Centre, Agriculture and Agri-Food Canada, 204 Brookfield Road, St. John’s, NL A1E 0B2, Canada
| | - Arindam Sikdar
- Department of Biology, Memorial University of Newfoundland, 45 Arctic Avenue, St. John’s, NL A1C 5S7, Canada; (U.S.); (A.S.); (A.U.I.)
- St. John’s Research and Development Centre, Agriculture and Agri-Food Canada, 204 Brookfield Road, St. John’s, NL A1E 0B2, Canada
| | - Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, 45 Arctic Avenue, St. John’s, NL A1C 5S7, Canada; (U.S.); (A.S.); (A.U.I.)
| | - Samir C. Debnath
- St. John’s Research and Development Centre, Agriculture and Agri-Food Canada, 204 Brookfield Road, St. John’s, NL A1E 0B2, Canada
| |
Collapse
|
9
|
Coughlan JM. The role of hybrid seed inviability in angiosperm speciation. AMERICAN JOURNAL OF BOTANY 2023; 110:1-14. [PMID: 36801827 DOI: 10.1002/ajb2.16135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 01/05/2023] [Accepted: 01/05/2023] [Indexed: 05/11/2023]
Abstract
Understanding which reproductive barriers contribute to speciation is essential to understanding the diversity of life on earth. Several contemporary examples of strong hybrid seed inviability (HSI) between recently diverged species suggest that HSI may play a fundamental role in plant speciation. Yet, a broader synthesis of HSI is needed to clarify its role in diversification. Here, I review the incidence and evolution of HSI. Hybrid seed inviability is common and evolves rapidly, suggesting that it may play an important role early in speciation. The developmental mechanisms that underlie HSI involve similar developmental trajectories in endosperm, even between evolutionarily deeply diverged incidents of HSI. In hybrid endosperm, HSI is often accompanied by whole-scale gene misexpression, including misexpression of imprinted genes which have a key role in endosperm development. I explore how an evolutionary perspective can clarify the repeated and rapid evolution of HSI. In particular, I evaluate the evidence for conflict between maternal and paternal interests in resource allocation to offspring (i.e., parental conflict). I highlight that parental conflict theory generates explicit predictions regarding the expected hybrid phenotypes and genes responsible for HSI. While much phenotypic evidence supports a role of parental conflict in the evolution of HSI, an understanding of the underlying molecular mechanisms of this barrier is essential to test parental conflict theory. Lastly, I explore what factors may influence the strength of parental conflict in natural plant populations as an explanation for why rates of HSI may differ between plant groups and the consequences of strong HSI in secondary contact.
Collapse
Affiliation(s)
- Jenn M Coughlan
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06511, USA
| |
Collapse
|
10
|
Li T, Yin L, Stoll CE, Lisch D, Zhao M. Conserved noncoding sequences and de novo Mutator insertion alleles are imprinted in maize. PLANT PHYSIOLOGY 2023; 191:299-316. [PMID: 36173333 PMCID: PMC9806621 DOI: 10.1093/plphys/kiac459] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 08/30/2022] [Indexed: 05/20/2023]
Abstract
Genomic imprinting is an epigenetic phenomenon in which differential allele expression occurs in a parent-of-origin-dependent manner. Imprinting in plants is tightly linked to transposable elements (TEs), and it has been hypothesized that genomic imprinting may be a consequence of demethylation of TEs. Here, we performed high-throughput sequencing of ribonucleic acids from four maize (Zea mays) endosperms that segregated newly silenced Mutator (Mu) transposons and identified 110 paternally expressed imprinted genes (PEGs) and 139 maternally expressed imprinted genes (MEGs). Additionally, two potentially novel paternally suppressed MEGs are associated with de novo Mu insertions. In addition, we find evidence for parent-of-origin effects on expression of 407 conserved noncoding sequences (CNSs) in maize endosperm. The imprinted CNSs are largely localized within genic regions and near genes, but the imprinting status of the CNSs are largely independent of their associated genes. Both imprinted CNSs and PEGs have been subject to relaxed selection. However, our data suggest that although MEGs were already subject to a higher mutation rate prior to their being imprinted, imprinting may be the cause of the relaxed selection of PEGs. In addition, although DNA methylation is lower in the maternal alleles of both the maternally and paternally expressed CNSs (mat and pat CNSs), the difference between the two alleles in H3K27me3 levels was only observed in pat CNSs. Together, our findings point to the importance of both transposons and CNSs in genomic imprinting in maize.
Collapse
Affiliation(s)
- Tong Li
- Department of Biology, Miami University, Oxford, Ohio 45056, USA
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, P.R. China
| | - Liangwei Yin
- Department of Biology, Miami University, Oxford, Ohio 45056, USA
| | - Claire E Stoll
- Department of Biology, Miami University, Oxford, Ohio 45056, USA
| | - Damon Lisch
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Meixia Zhao
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA
| |
Collapse
|
11
|
Conservation Study of Imprinted Genes in Maize Triparental Heterozygotic Kernels. Int J Mol Sci 2022; 23:ijms232315424. [PMID: 36499766 PMCID: PMC9735609 DOI: 10.3390/ijms232315424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/02/2022] [Accepted: 12/04/2022] [Indexed: 12/12/2022] Open
Abstract
Genomic imprinting is a classic epigenetic phenomenon related to the uniparental expression of genes. Imprinting variability exists in seeds and can contribute to observed parent-of-origin effects on seed development. Here, we conducted allelic expression of the embryo and endosperm from four crosses at 11 days after pollination (DAP). First, the F1 progeny of B73(♀) × Mo17(♂) and the inducer line CAU5 were used as parents to obtain reciprocal crosses of BM-C/C-BM. Additionally, the F1 progeny of Mo17(♀) × B73(♂) and CAU5 were used as parents to obtain reciprocal crosses of MB-C/C-MB. In total, 192 and 181 imprinted genes were identified in the BM-C/C-BM and MB-C/C-MB crosses, respectively. Then, by comparing the allelic expression of these imprinted genes in the reciprocal crosses of B73 and CAU5 (BC/CB), fifty-one Mo17-added non-conserved genes were identified as exhibiting imprinting variability. Fifty-one B73-added non-conserved genes were also identified by comparing the allelic expression of imprinted genes identified in BM-C/C-BM, MB-C/C-MB and MC/CM crosses. Specific Gene Ontology (GO) terms were not enriched in B73-added/Mo17-added non-conserved genes. Interestingly, the imprinting status of these genes was less conserved across other species. The cis-element distribution, tissue expression and subcellular location were similar between the B73-added/Mo17-added conserved and B73-added/Mo17-added non-conserved imprinted genes. Finally, genotypic and phenotypic analysis of one non-conserved gene showed that the mutation and overexpression of this gene may affect embryo and kernel size, which indicates that these non-conserved genes may also play an important role in kernel development. The findings of this study will be helpful for elucidating the imprinting mechanism of genes involved in maize kernel development.
Collapse
|
12
|
Vignati E, Lipska M, Dunwell JM, Caccamo M, Simkin AJ. Options for the generation of seedless cherry, the ultimate snacking product. PLANTA 2022; 256:90. [PMID: 36171415 PMCID: PMC9519733 DOI: 10.1007/s00425-022-04005-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/21/2022] [Indexed: 05/09/2023]
Abstract
This manuscript identifies cherry orthologues of genes implicated in the development of pericarpic fruit and pinpoints potential options and restrictions in the use of these targets for commercial exploitation of parthenocarpic cherry fruit. Cherry fruit contain a large stone and seed, making processing of the fruit laborious and consumption by the consumer challenging, inconvenient to eat 'on the move' and potentially dangerous for children. Availability of fruit lacking the stone and seed would be potentially transformative for the cherry industry, since such fruit would be easier to process and would increase consumer demand because of the potential reduction in costs. This review will explore the background of seedless fruit, in the context of the ambition to produce the first seedless cherry, carry out an in-depth analysis of the current literature around parthenocarpy in fruit, and discuss the available technology and potential for producing seedless cherry fruit as an 'ultimate snacking product' for the twenty-first century.
Collapse
Affiliation(s)
- Edoardo Vignati
- NIAB East Malling, Department of Genetics, Genomics and Breeding, New Road, West Malling, Kent, ME19 6BJ, UK
- School of Agriculture, Policy and Development, University of Reading, Whiteknights, Reading, Berkshire, RG6 6EU, UK
| | - Marzena Lipska
- NIAB East Malling, Department of Genetics, Genomics and Breeding, New Road, West Malling, Kent, ME19 6BJ, UK
| | - Jim M Dunwell
- School of Agriculture, Policy and Development, University of Reading, Whiteknights, Reading, Berkshire, RG6 6EU, UK
| | - Mario Caccamo
- NIAB, Cambridge Crop Research, Lawrence Weaver Road, Cambridge, CB3 0LE, UK
| | - Andrew J Simkin
- NIAB East Malling, Department of Genetics, Genomics and Breeding, New Road, West Malling, Kent, ME19 6BJ, UK.
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK.
| |
Collapse
|
13
|
Gent JI, Higgins KM, Swentowsky KW, Fu FF, Zeng Y, Kim DW, Dawe RK, Springer NM, Anderson SN. The maize gene maternal derepression of r1 encodes a DNA glycosylase that demethylates DNA and reduces siRNA expression in the endosperm. THE PLANT CELL 2022; 34:3685-3701. [PMID: 35775949 PMCID: PMC9516051 DOI: 10.1093/plcell/koac199] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 06/27/2022] [Indexed: 06/01/2023]
Abstract
Demethylation of transposons can activate the expression of nearby genes and cause imprinted gene expression in the endosperm; this demethylation is hypothesized to lead to expression of transposon small interfering RNAs (siRNAs) that reinforce silencing in the next generation through transfer either into egg or embryo. Here we describe maize (Zea mays) maternal derepression of r1 (mdr1), which encodes a DNA glycosylase with homology to Arabidopsis thaliana DEMETER and which is partially responsible for demethylation of thousands of regions in endosperm. Instead of promoting siRNA expression in endosperm, MDR1 activity inhibits it. Methylation of most repetitive DNA elements in endosperm is not significantly affected by MDR1, with an exception of Helitrons. While maternally-expressed imprinted genes preferentially overlap with MDR1 demethylated regions, the majority of genes that overlap demethylated regions are not imprinted. Double mutant megagametophytes lacking both MDR1 and its close homolog DNG102 result in early seed failure, and double mutant microgametophytes fail pre-fertilization. These data establish DNA demethylation by glycosylases as essential in maize endosperm and pollen and suggest that neither transposon repression nor genomic imprinting is its main function in endosperm.
Collapse
Affiliation(s)
| | - Kaitlin M Higgins
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011, USA
| | - Kyle W Swentowsky
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Fang-Fang Fu
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602, USA
- Co‐Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China
| | - Yibing Zeng
- Department of Genetics, University of Georgia, Athens, Georgia 30602, USA
| | - Dong won Kim
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602, USA
| | - R Kelly Dawe
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602, USA
- Department of Genetics, University of Georgia, Athens, Georgia 30602, USA
| | - Nathan M Springer
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, Minnesota 55108, USA
| | - Sarah N Anderson
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011, USA
| |
Collapse
|
14
|
Roy SW. How illuminates why in plant germline methylation. TRENDS IN PLANT SCIENCE 2022; 27:325-327. [PMID: 35074266 DOI: 10.1016/j.tplants.2022.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/22/2021] [Accepted: 01/07/2022] [Indexed: 06/14/2023]
Abstract
In modern biology, inquiry into proximal mechanistic and ultimate evolutionary causes are often segregated, pursued by different communities of specialists. Yet, the two are often mutually informative. As a case in point, a recent study by Long et al. on mechanisms of arabidopsis (Arabidopsisthaliana) male germline methylation promises insights into long-obscure ultimate causes.
Collapse
|
15
|
Matilla AJ. Exploring Breakthroughs in Three Traits Belonging to Seed Life. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11040490. [PMID: 35214823 PMCID: PMC8875957 DOI: 10.3390/plants11040490] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 02/02/2022] [Accepted: 02/09/2022] [Indexed: 05/06/2023]
Abstract
Based on prior knowledge and with the support of new methodology, solid progress in the understanding of seed life has taken place over the few last years. This update reflects recent advances in three key traits of seed life (i.e., preharvest sprouting, genomic imprinting, and stored-mRNA). The first breakthrough refers to cloning of the mitogen-activated protein kinase-kinase 3 (MKK3) gene in barley and wheat. MKK3, in cooperation with ABA signaling, controls seed dormancy. This advance has been determinant in producing improved varieties that are resistant to preharvest sprouting. The second advance concerns to uniparental gene expression (i.e., imprinting). Genomic imprinting primarily occurs in the endosperm. Although great advances have taken place in the last decade, there is still a long way to go to complete the puzzle regarding the role of genomic imprinting in seed development. This trait is probably one of the most important epigenetic facets of developing endosperm. An example of imprinting regulation is polycomb repressive complex 2 (PRC2). The mechanism of PRC2 recruitment to target endosperm with specific genes is, at present, robustly studied. Further progress in the knowledge of recruitment of PRC2 epigenetic machinery is considered in this review. The third breakthrough referred to in this update involves stored mRNA. The role of the population of this mRNA in germination is far from known. Its relations to seed aging, processing bodies (P bodies), and RNA binding proteins (RBPs), and how the stored mRNA is targeted to monosomes, are aspects considered here. Perhaps this third trait is the one that will require greater experimental dedication in the future. In order to make progress, herein are included some questions that are needed to be answered.
Collapse
Affiliation(s)
- Angel J Matilla
- Departamento de Biología Funcional (Área Fisiología Vegetal), Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| |
Collapse
|
16
|
Zhang Z, Yu S, Li J, Zhu Y, Jiang S, Xia H, Zhou Y, Sun D, Liu M, Li C, Zhu Y, Ruan Y, Dong X. Epigenetic modifications potentially controlling the allelic expression of imprinted genes in sunflower endosperm. BMC PLANT BIOLOGY 2021; 21:570. [PMID: 34863098 PMCID: PMC8642925 DOI: 10.1186/s12870-021-03344-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 10/26/2021] [Indexed: 06/02/2023]
Abstract
BACKGROUND Genomic imprinting is an epigenetic phenomenon mainly occurs in endosperm of flowering plants. Genome-wide identification of imprinted genes have been completed in several dicot Cruciferous plant and monocot crops. RESULTS Here, we analyzed global patterns of allelic gene expression in developing endosperm of sunflower which belongs to the composite family. Totally, 691 imprinted loci candidates were identified in 12 day-after-pollination sunflower endosperm including 79 maternally expressed genes (MEG) and 596 paternally expressed genes (PEG), 6 maternally expressed noncoding RNAs (MNC) and 10 paternally expressed noncoding RNAs (PNC). And a clear clustering of imprinted genes throughout the rapeseed genome was identified. Generally, imprinting in sunflower is conserved within a species, but intraspecific variation also was detected. Limited loci in sunflower are imprinted in other several different species. The DNA methylation pattern around imprinted genes were investigated in embryo and endosperm tissues. In CG context, the imprinted genes were significantly associated with differential methylated regions exhibiting hypomethylation in endosperm and hypermethylation in embryo, which indicated that the maternal demethylation in CG context potentially induce the genomic imprinting in endosperm. CONCLUSION Our study would be helpful for understanding of genomic imprinting in plants and provide potential basis for further research in imprinting in sunflower.
Collapse
Affiliation(s)
- Zhichao Zhang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Shuai Yu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Jing Li
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, China
| | - Yanbin Zhu
- State Key Laboratory of Maize Bio-Breeding, Shenyang, China
- State Key Laboratory of the Northeast Crop Genetics and Breeding, Shenyang, China
| | - Siqi Jiang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Haoran Xia
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yue Zhou
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Daqiu Sun
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Meiling Liu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Cong Li
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yanshu Zhu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yanye Ruan
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Xiaomei Dong
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China.
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China.
- State Key Laboratory of Maize Bio-Breeding, Shenyang, China.
| |
Collapse
|
17
|
Montgomery SA, Berger F. The evolution of imprinting in plants: beyond the seed. PLANT REPRODUCTION 2021; 34:373-383. [PMID: 33914165 PMCID: PMC8566399 DOI: 10.1007/s00497-021-00410-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/12/2021] [Indexed: 05/14/2023]
Abstract
Genomic imprinting results in the biased expression of alleles depending on if the allele was inherited from the mother or the father. Despite the prevalence of sexual reproduction across eukaryotes, imprinting is only found in placental mammals, flowering plants, and some insects, suggesting independent evolutionary origins. Numerous hypotheses have been proposed to explain the selective pressures that favour the innovation of imprinted gene expression and each differs in their experimental support and predictions. Due to the lack of investigation of imprinting in land plants, other than angiosperms with triploid endosperm, we do not know whether imprinting occurs in species lacking endosperm and with embryos developing on maternal plants. Here, we discuss the potential for uncovering additional examples of imprinting in land plants and how these observations may provide additional support for one or more existing imprinting hypotheses.
Collapse
Affiliation(s)
- Sean A Montgomery
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Dr. Bohr Gasse 3, 1030, Vienna, Austria
| | - Frédéric Berger
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Dr. Bohr Gasse 3, 1030, Vienna, Austria.
| |
Collapse
|
18
|
Picard CL, Povilus RA, Williams BP, Gehring M. Transcriptional and imprinting complexity in Arabidopsis seeds at single-nucleus resolution. NATURE PLANTS 2021; 7:730-738. [PMID: 34059805 PMCID: PMC8217372 DOI: 10.1038/s41477-021-00922-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 04/15/2021] [Indexed: 05/06/2023]
Abstract
Seeds are a key life cycle stage for many plants. Seeds are also the basis of agriculture and the primary source of calories consumed by humans1. Here, we employ single-nucleus RNA-sequencing to generate a transcriptional atlas of developing Arabidopsis thaliana seeds, with a focus on endosperm. Endosperm, the primary site of gene imprinting in flowering plants, mediates the relationship between the maternal parent and the embryo2. We identify transcriptionally uncharacterized nuclei types in the chalazal endosperm, which interfaces with maternal tissue for nutrient unloading3,4. We demonstrate that the extent of parental bias of maternally expressed imprinted genes varies with cell-cycle phase, and that imprinting of paternally expressed imprinted genes is strongest in chalazal endosperm. Thus, imprinting is spatially and temporally heterogeneous. Increased paternal expression in the chalazal region suggests that parental conflict, which is proposed to drive imprinting evolution, is fiercest at the boundary between filial and maternal tissues.
Collapse
Affiliation(s)
- Colette L Picard
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Computational and Systems Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Ben P Williams
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Mary Gehring
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| |
Collapse
|
19
|
İltaş Ö, Svitok M, Cornille A, Schmickl R, Lafon Placette C. Early evolution of reproductive isolation: A case of weak inbreeder/strong outbreeder leads to an intraspecific hybridization barrier in Arabidopsis lyrata. Evolution 2021; 75:1466-1476. [PMID: 33900634 DOI: 10.1111/evo.14240] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 02/08/2021] [Accepted: 04/10/2021] [Indexed: 12/18/2022]
Abstract
Reproductive strategies play a major role in plant speciation. Notably, transitions from outcrossing to selfing may lead to relaxed sexual selection and parental conflict. Shifts in mating systems can affect maternal and paternal interests, and thus parent-specific influence on endosperm development, leading to reproductive isolation: if selfing and outcrossing species hybridize, the resulting seeds may not be viable due to endosperm failure. Nevertheless, it remains unclear how the switch in mating systems can impact reproductive isolation between recently diverged lineages, that is, during the process of speciation. We investigated this question using Arabidopsis lyrata, which recently transitioned to selfing (10,000 years ago) in certain North American populations, where European populations remain outcrossing. We performed reciprocal crosses between selfers and outcrossers, and measured seed viability and endosperm development. We show that parental genomes in the hybrid seed negatively interact, as predicted by parental conflict. This leads to extensive hybrid seed lethality associated with endosperm cellularization disturbance. Our results suggest that this is primarily driven by divergent evolution of the paternal genome between selfers and outcrossers. In addition, we observed other hybrid seed defects, suggesting that sex-specific interests are not the only processes contributing to postzygotic reproductive isolation.
Collapse
Affiliation(s)
- Ömer İltaş
- Department of Botany, Faculty of Science, Charles University, Prague, CZ-128 01, Czech Republic
| | - Marek Svitok
- Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, Zvolen, SK-960 01, Slovakia.,Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, České Budějovice, CZ-370 05, Czech Republic
| | - Amandine Cornille
- Université Paris-Saclay, INRAE, CNRS, AgroParisTech, GQE-Le Moulon, Gif-sur-Yvette, 91190, France
| | - Roswitha Schmickl
- Department of Botany, Faculty of Science, Charles University, Prague, CZ-128 01, Czech Republic.,Institute of Botany, The Czech Academy of Sciences, Průhonice, CZ-252 43, Czech Republic
| | - Clément Lafon Placette
- Department of Botany, Faculty of Science, Charles University, Prague, CZ-128 01, Czech Republic
| |
Collapse
|
20
|
Köhler C, Dziasek K, Del Toro-De León G. Postzygotic reproductive isolation established in the endosperm: mechanisms, drivers and relevance. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200118. [PMID: 33866810 DOI: 10.1098/rstb.2020.0118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The endosperm is a developmental innovation of angiosperms that supports embryo growth and germination. Aside from this essential reproductive function, the endosperm fuels angiosperm evolution by rapidly establishing reproductive barriers between incipient species. Specifically, the endosperm prevents hybridization of newly formed polyploids with their non-polyploid progenitors, a phenomenon termed the triploid block. Furthermore, recently diverged diploid species are frequently reproductively isolated by endosperm-based hybridization barriers. Current genetic approaches have revealed a prominent role for epigenetic processes establishing these barriers. In particular, imprinted genes, which are expressed in a parent-of-origin-specific manner, underpin the interploidy barrier in the model species Arabidopsis. We will discuss the mechanisms establishing hybridization barriers in the endosperm, the driving forces for these barriers and their impact for angiosperm evolution. This article is part of the theme issue 'How does epigenetics influence the course of evolution?'
Collapse
Affiliation(s)
- Claudia Köhler
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - Katarzyna Dziasek
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - Gerardo Del Toro-De León
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
| |
Collapse
|
21
|
Widespread imprinting of transposable elements and variable genes in the maize endosperm. PLoS Genet 2021; 17:e1009491. [PMID: 33830994 PMCID: PMC8057601 DOI: 10.1371/journal.pgen.1009491] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 04/20/2021] [Accepted: 03/15/2021] [Indexed: 11/19/2022] Open
Abstract
Fertilization and seed development is a critical time in the plant life cycle, and coordinated development of the embryo and endosperm are required to produce a viable seed. In the endosperm, some genes show imprinted expression where transcripts are derived primarily from one parental genome. Imprinted gene expression has been observed across many flowering plant species, though only a small proportion of genes are imprinted. Understanding how imprinted expression arises has been complicated by the reliance on single nucleotide polymorphisms between alleles to enable testing for imprinting. Here, we develop a method to use whole genome assemblies of multiple genotypes to assess for imprinting of both shared and variable portions of the genome using data from reciprocal crosses. This reveals widespread maternal expression of genes and transposable elements with presence-absence variation within maize and across species. Most maternally expressed features are expressed primarily in the endosperm, suggesting that maternal de-repression in the central cell facilitates expression. Furthermore, maternally expressed TEs are enriched for maternal expression of the nearest gene, and read alignments over maternal TE-gene pairs indicate that these are fused rather than independent transcripts.
Collapse
|
22
|
Xu X, E Z, Zhang D, Yun Q, Zhou Y, Niu B, Chen C. OsYUC11-mediated auxin biosynthesis is essential for endosperm development of rice. PLANT PHYSIOLOGY 2021; 185:934-950. [PMID: 33793908 PMCID: PMC8133553 DOI: 10.1093/plphys/kiaa057] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 11/18/2020] [Indexed: 05/06/2023]
Abstract
Auxin is a phytohormone essential for plant development. However, our understanding of auxin-regulated endosperm development remains limited. Here, we described rice YUCCA (YUC) flavin-containing monooxygenase encoding gene OsYUC11 as a key contributor to auxin biosynthesis in rice (Oryza sativa) endosperm. Grain filling or storage product accumulation was halted by mutation of OsYUC11, but the deficiencies could be recovered by the exogenous application of auxin. A rice transcription factor (TF) yeast library was screened, and 41 TFs that potentially bind to the OsYUC11 promoter were identified, of which OsNF-YB1, a member of the nuclear factor Y family, is predominantly expressed in the endosperm. Both osyuc11 and osnf-yb1 mutants exhibited reduced seed size and increased chalkiness, accompanied by a reduction in indole-3-acetic acid biosynthesis. OsNF-YB1 can bind the OsYUC11 promoter to induce gene expression in vivo. We also found that OsYUC11 was a dynamically imprinted gene that predominantly expressed the paternal allele in the endosperm up to 10 d after fertilization (DAF) but then became a non-imprinted gene at 15 DAF. A functional maternal allele of OsYUC11 was able to recover the paternal defects of this gene. Overall, the findings indicate that OsYUC11-mediated auxin biosynthesis is essential for endosperm development in rice.
Collapse
Affiliation(s)
- Xinyu Xu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou 225009, China
| | - Zhiguo E
- Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Dongping Zhang
- Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou 225009, China
| | - Qianbin Yun
- Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou 225009, China
| | - Yong Zhou
- Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou 225009, China
| | - Baixiao Niu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou 225009, China
| | - Chen Chen
- Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Author for communication:
| |
Collapse
|
23
|
Anderson SN, Zhou P, Higgins K, Brandvain Y, Springer NM. Widespread imprinting of transposable elements and variable genes in the maize endosperm. PLoS Genet 2021. [PMID: 33830994 DOI: 10.1371/journal.pgen.100949] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023] Open
Abstract
Fertilization and seed development is a critical time in the plant life cycle, and coordinated development of the embryo and endosperm are required to produce a viable seed. In the endosperm, some genes show imprinted expression where transcripts are derived primarily from one parental genome. Imprinted gene expression has been observed across many flowering plant species, though only a small proportion of genes are imprinted. Understanding how imprinted expression arises has been complicated by the reliance on single nucleotide polymorphisms between alleles to enable testing for imprinting. Here, we develop a method to use whole genome assemblies of multiple genotypes to assess for imprinting of both shared and variable portions of the genome using data from reciprocal crosses. This reveals widespread maternal expression of genes and transposable elements with presence-absence variation within maize and across species. Most maternally expressed features are expressed primarily in the endosperm, suggesting that maternal de-repression in the central cell facilitates expression. Furthermore, maternally expressed TEs are enriched for maternal expression of the nearest gene, and read alignments over maternal TE-gene pairs indicate that these are fused rather than independent transcripts.
Collapse
Affiliation(s)
- Sarah N Anderson
- Department of Genetics, Development, and Cell Biology; Iowa State University; Ames, Iowa, United States of America
| | - Peng Zhou
- Department of Plant and Microbial Biology; University of Minnesota; St. Paul, Minnesota, United States of America
| | - Kaitlin Higgins
- Department of Genetics, Development, and Cell Biology; Iowa State University; Ames, Iowa, United States of America
| | - Yaniv Brandvain
- Department of Plant and Microbial Biology; University of Minnesota; St. Paul, Minnesota, United States of America
| | - Nathan M Springer
- Department of Plant and Microbial Biology; University of Minnesota; St. Paul, Minnesota, United States of America
| |
Collapse
|
24
|
Rong H, Yang W, Zhu H, Jiang B, Jiang J, Wang Y. Genomic imprinted genes in reciprocal hybrid endosperm of Brassica napus. BMC PLANT BIOLOGY 2021; 21:140. [PMID: 33726676 PMCID: PMC7968328 DOI: 10.1186/s12870-021-02908-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 02/28/2021] [Indexed: 05/06/2023]
Abstract
BACKGROUND Genomic imprinting results in the expression of parent-of-origin-specific alleles in the offspring. Brassica napus is an oil crop with research values in polyploidization. Identification of imprinted genes in B. napus will enrich the knowledge of genomic imprinting in dicotyledon plants. RESULTS In this study, we performed reciprocal crosses between B. napus L. cultivars Yangyou 6 (Y6) and Zhongshuang 11 (ZS11) to collect endosperm at 20 and 25 days after pollination (DAP) for RNA-seq. In total, we identified 297 imprinted genes, including 283 maternal expressed genes (MEGs) and 14 paternal expressed genes (PEGs) according to the SNPs between Y6 and ZS11. Only 36 genes (35 MEGs and 1 PEG) were continuously imprinted in 20 and 25 DAP endosperm. We found 15, 2, 5, 3, 10, and 25 imprinted genes in this study were also imprinted in Arabidopsis, rice, castor bean, maize, B. rapa, and other B. napus lines, respectively. Only 26 imprinted genes were specifically expressed in endosperm, while other genes were also expressed in root, stem, leaf and flower bud of B. napus. A total of 109 imprinted genes were clustered on rapeseed chromosomes. We found the LTR/Copia transposable elements (TEs) were most enriched in both upstream and downstream of the imprinted genes, and the TEs enriched around imprinted genes were more than non-imprinted genes. Moreover, the expression of 5 AGLs and 6 pectin-related genes in hybrid endosperm were significantly changed comparing with that in parent endosperm. CONCLUSION This research provided a comprehensive identification of imprinted genes in B. napus, and enriched the gene imprinting in dicotyledon plants, which would be useful in further researches on how gene imprinting regulates seed development.
Collapse
Affiliation(s)
- Hao Rong
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Wenjing Yang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Haotian Zhu
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Bo Jiang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Jinjin Jiang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Youping Wang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou, 225009 China
| |
Collapse
|
25
|
Liu Y, Jing X, Zhang H, Xiong J, Qiao Y. Identification of Imprinted Genes Based on Homology: An Example of Fragaria vesca. Genes (Basel) 2021; 12:genes12030380. [PMID: 33800118 PMCID: PMC7999015 DOI: 10.3390/genes12030380] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/28/2021] [Accepted: 03/04/2021] [Indexed: 01/04/2023] Open
Abstract
Genomic imprinting has drawn increasing attention in plant biology in recent years. At present, hundreds of imprinted genes have been identified in various plants, and some of them have been reported to be evolutionarily conserved in plant species. In this research, 17 candidate genes in Fragaria vesca were obtained based on the homologous imprinted genes in Arabidopsis thaliana and other species. We further constructed reciprocal crosses of diploid strawberry (F. vesca) using the varieties 10-41 and 18-86 as the parents to investigate the conservation of these imprinted genes. Potentially informative single nucleotide polymorphisms (SNPs) were used as molecular markers of two parents obtained from candidate imprinted genes which have been cloned and sequenced. Meanwhile, we analyzed the SNP site variation ratios and parent-of-origin expression patterns of candidate imprinted genes at 10 days after pollination (DAP) endosperm and embryo for the hybrids of reciprocal cross, respectively. A total of five maternally expressed genes (MEGs), i.e., FvARI8, FvKHDP-2, FvDRIP2, FvBRO1, and FvLTP3, were identified in the endosperm, which did not show imprinting in the embryo. Finally, tissues expression analysis indicated that the five imprinted genes excluding FvDRIP2 mainly expressed in the endosperm. This is the first report on imprinted genes of Fragaria, and we provide a simple and rapid method based on homologous conservation to screen imprinted genes. The present study will provide a basis for further study of function and mechanism of genomic imprinting in F. vesca.
Collapse
|
26
|
Harman-Ware AE, Macaya-Sanz D, Abeyratne CR, Doeppke C, Haiby K, Tuskan GA, Stanton B, DiFazio SP, Davis MF. Accurate determination of genotypic variance of cell wall characteristics of a Populus trichocarpa pedigree using high-throughput pyrolysis-molecular beam mass spectrometry. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:59. [PMID: 33676543 PMCID: PMC7937246 DOI: 10.1186/s13068-021-01908-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Pyrolysis-molecular beam mass spectrometry (py-MBMS) analysis of a pedigree of Populus trichocarpa was performed to study the phenotypic plasticity and heritability of lignin content and lignin monomer composition. Instrumental and microspatial environmental variability were observed in the spectral features and corrected to reveal underlying genetic variance of biomass composition. RESULTS Lignin-derived ions (including m/z 124, 154, 168, 194, 210 and others) were highly impacted by microspatial environmental variation which demonstrates phenotypic plasticity of lignin composition in Populus trichocarpa biomass. Broad-sense heritability of lignin composition after correcting for microspatial and instrumental variation was determined to be H2 = 0.56 based on py-MBMS ions known to derive from lignin. Heritability of lignin monomeric syringyl/guaiacyl ratio (S/G) was H2 = 0.81. Broad-sense heritability was also high (up to H2 = 0.79) for ions derived from other components of the biomass including phenolics (e.g., salicylates) and C5 sugars (e.g., xylose). Lignin and phenolic ion abundances were primarily driven by maternal effects, and paternal effects were either similar or stronger for the most heritable carbohydrate-derived ions. CONCLUSIONS We have shown that many biopolymer-derived ions from py-MBMS show substantial phenotypic plasticity in response to microenvironmental variation in plantations. Nevertheless, broad-sense heritability for biomass composition can be quite high after correcting for spatial environmental variation. This work outlines the importance in accounting for instrumental and microspatial environmental variation in biomass composition data for applications in heritability measurements and genomic selection for breeding poplar for renewable fuels and materials.
Collapse
Affiliation(s)
- Anne E Harman-Ware
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
| | - David Macaya-Sanz
- Department of Biology, West Virginia University, Morgantown, WV, 26506, USA
| | | | - Crissa Doeppke
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | | | - Gerald A Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | | | - Stephen P DiFazio
- Department of Biology, West Virginia University, Morgantown, WV, 26506, USA
| | - Mark F Davis
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| |
Collapse
|
27
|
Bhadouriya SL, Mehrotra S, Basantani MK, Loake GJ, Mehrotra R. Role of Chromatin Architecture in Plant Stress Responses: An Update. FRONTIERS IN PLANT SCIENCE 2021; 11:603380. [PMID: 33510748 PMCID: PMC7835326 DOI: 10.3389/fpls.2020.603380] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/07/2020] [Indexed: 05/08/2023]
Abstract
Sessile plants possess an assembly of signaling pathways that perceive and transmit environmental signals, ultimately resulting in transcriptional reprogramming. Histone is a key feature of chromatin structure. Numerous histone-modifying proteins act under different environmental stress conditions to help modulate gene expression. DNA methylation and histone modification are crucial for genome reprogramming for tissue-specific gene expression and global gene silencing. Different classes of chromatin remodelers including SWI/SNF, ISWI, INO80, and CHD are reported to act upon chromatin in different organisms, under diverse stresses, to convert chromatin from a transcriptionally inactive to a transcriptionally active state. The architecture of chromatin at a given promoter is crucial for determining the transcriptional readout. Further, the connection between somatic memory and chromatin modifications may suggest a mechanistic basis for a stress memory. Studies have suggested that there is a functional connection between changes in nuclear organization and stress conditions. In this review, we discuss the role of chromatin architecture in different stress responses and the current evidence on somatic, intergenerational, and transgenerational stress memory.
Collapse
Affiliation(s)
- Sneha Lata Bhadouriya
- Department of Biological Sciences, Birla Institute of Technology and Sciences, Sancoale, India
| | - Sandhya Mehrotra
- Department of Biological Sciences, Birla Institute of Technology and Sciences, Sancoale, India
| | - Mahesh K. Basantani
- Institute of Bioscience and Technology, Shri Ramswaroop Memorial University, Lucknow, India
| | - Gary J. Loake
- School of Biological Sciences, Institute of Molecular Plant Sciences, University of Edinburg, Edinburg, United Kingdom
| | - Rajesh Mehrotra
- Department of Biological Sciences, Birla Institute of Technology and Sciences, Sancoale, India
| |
Collapse
|
28
|
Cheng X, Pan M, E Z, Zhou Y, Niu B, Chen C. The maternally expressed polycomb group gene OsEMF2a is essential for endosperm cellularization and imprinting in rice. PLANT COMMUNICATIONS 2021; 2:100092. [PMID: 33511344 DOI: 10.1016/j.xplc.2020.10009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 06/17/2020] [Accepted: 06/22/2020] [Indexed: 05/22/2023]
Abstract
Cellularization is a key event in endosperm development. Polycomb group (PcG) genes, such as Fertilization-Independent Seed 2 (FIS2), are vital for the syncytium-to-cellularization transition in Arabidopsis plants. In this study, we found that OsEMF2a, a rice homolog of the Arabidopsis PcG gene Embryonic Flower2 (EMF2), plays a role similar to that of FIS2 in regard to seed development, although there is limited sequence similarity between the genes. Delayed cellularization was observed in osemf2a, associated with an unusual activation of type I MADS-box genes. The cell cycle was persistently activated in osemf2a caryopses, which was likely caused by cytokinin overproduction. However, the overaccumulation of auxin was not found to be associated with the delayed cellularization. As OsEMF2a is a maternally expressed gene in the endosperm, a paternally inherited functional allele was unable to recover the maternal defects of OsEMF2a. Many imprinted rice genes were deregulated in the defective hybrid seeds of osemf2a (♀)/9311 (♂) (m9). The paternal expression bias of some paternally expressed genes was disrupted in m9 due to either the activation of maternal alleles or the repression of paternal alleles. These findings suggest that OsEMF2a-PRC2-mediated H3K27me3 is necessary for endosperm cellularization and genomic imprinting in rice.
Collapse
Affiliation(s)
- Xiaojun Cheng
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Meiyao Pan
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Zhiguo E
- Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Yong Zhou
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Baixiao Niu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Chen Chen
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| |
Collapse
|
29
|
Cheng X, Pan M, E Z, Zhou Y, Niu B, Chen C. The maternally expressed polycomb group gene OsEMF2a is essential for endosperm cellularization and imprinting in rice. PLANT COMMUNICATIONS 2021; 2:100092. [PMID: 33511344 PMCID: PMC7816080 DOI: 10.1016/j.xplc.2020.100092] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 06/17/2020] [Accepted: 06/22/2020] [Indexed: 05/18/2023]
Abstract
Cellularization is a key event in endosperm development. Polycomb group (PcG) genes, such as Fertilization-Independent Seed 2 (FIS2), are vital for the syncytium-to-cellularization transition in Arabidopsis plants. In this study, we found that OsEMF2a, a rice homolog of the Arabidopsis PcG gene Embryonic Flower2 (EMF2), plays a role similar to that of FIS2 in regard to seed development, although there is limited sequence similarity between the genes. Delayed cellularization was observed in osemf2a, associated with an unusual activation of type I MADS-box genes. The cell cycle was persistently activated in osemf2a caryopses, which was likely caused by cytokinin overproduction. However, the overaccumulation of auxin was not found to be associated with the delayed cellularization. As OsEMF2a is a maternally expressed gene in the endosperm, a paternally inherited functional allele was unable to recover the maternal defects of OsEMF2a. Many imprinted rice genes were deregulated in the defective hybrid seeds of osemf2a (♀)/9311 (♂) (m9). The paternal expression bias of some paternally expressed genes was disrupted in m9 due to either the activation of maternal alleles or the repression of paternal alleles. These findings suggest that OsEMF2a-PRC2-mediated H3K27me3 is necessary for endosperm cellularization and genomic imprinting in rice.
Collapse
Affiliation(s)
- Xiaojun Cheng
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Meiyao Pan
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Zhiguo E
- Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Yong Zhou
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Baixiao Niu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Chen Chen
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
- Corresponding author
| |
Collapse
|
30
|
Marshall H, van Zweden JS, Van Geystelen A, Benaets K, Wäckers F, Mallon EB, Wenseleers T. Parent of origin gene expression in the bumblebee, Bombus terrestris, supports Haig's kinship theory for the evolution of genomic imprinting. Evol Lett 2020; 4:479-490. [PMID: 33312684 PMCID: PMC7719552 DOI: 10.1002/evl3.197] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 07/02/2020] [Accepted: 09/17/2020] [Indexed: 12/11/2022] Open
Abstract
Genomic imprinting is the differential expression alleles in diploid individuals, with the expression being dependent on the sex of the parent from which it was inherited. Haig's kinship theory hypothesizes that genomic imprinting is due to an evolutionary conflict of interest between alleles from the mother and father. In social insects, it has been suggested that genomic imprinting should be widespread. One recent study identified parent-of-origin expression in honey bees and found evidence supporting the kinship theory. However, little is known about genomic imprinting in insects and multiple theoretical predictions must be tested to avoid single-study confirmation bias. We, therefore, tested for parent-of-origin expression in a primitively eusocial bee. We found equal numbers of maternally and paternally biased expressed genes. The most highly biased genes were maternally expressed, offering support for the kinship theory. We also found low conservation of potentially imprinted genes with the honey bee, suggesting rapid evolution of genomic imprinting in Hymenoptera.
Collapse
Affiliation(s)
- Hollie Marshall
- Department of Genetics and Genome BiologyThe University of Leicester, Leicester LE1 7RHUnited Kingdom
| | - Jelle S. van Zweden
- Laboratory of Socioecology and Social EvolutionDepartment of Biology, KU Leuven, 3000LeuvenBelgium
| | - Anneleen Van Geystelen
- Laboratory of Socioecology and Social EvolutionDepartment of Biology, KU Leuven, 3000LeuvenBelgium
| | - Kristof Benaets
- Laboratory of Socioecology and Social EvolutionDepartment of Biology, KU Leuven, 3000LeuvenBelgium
| | - Felix Wäckers
- Biobest Belgium N.V., 2260 WesterloBelgium
- The Lancaster Environmental CentreUniversity of Lancaster, Lancaster LA1 4YWUnited Kingdom
| | - Eamonn B. Mallon
- Department of Genetics and Genome BiologyThe University of Leicester, Leicester LE1 7RHUnited Kingdom
| | - Tom Wenseleers
- Laboratory of Socioecology and Social EvolutionDepartment of Biology, KU Leuven, 3000LeuvenBelgium
| |
Collapse
|
31
|
Abstract
RNA-directed DNA methylation (RdDM) is a biological process in which non-coding RNA molecules direct the addition of DNA methylation to specific DNA sequences. The RdDM pathway is unique to plants, although other mechanisms of RNA-directed chromatin modification have also been described in fungi and animals. To date, the RdDM pathway is best characterized within angiosperms (flowering plants), and particularly within the model plant Arabidopsis thaliana. However, conserved RdDM pathway components and associated small RNAs (sRNAs) have also been found in other groups of plants, such as gymnosperms and ferns. The RdDM pathway closely resembles other sRNA pathways, particularly the highly conserved RNAi pathway found in fungi, plants, and animals. Both the RdDM and RNAi pathways produce sRNAs and involve conserved Argonaute, Dicer and RNA-dependent RNA polymerase proteins. RdDM has been implicated in a number of regulatory processes in plants. The DNA methylation added by RdDM is generally associated with transcriptional repression of the genetic sequences targeted by the pathway. Since DNA methylation patterns in plants are heritable, these changes can often be stably transmitted to progeny. As a result, one prominent role of RdDM is the stable, transgenerational suppression of transposable element (TE) activity. RdDM has also been linked to pathogen defense, abiotic stress responses, and the regulation of several key developmental transitions. Although the RdDM pathway has a number of important functions, RdDM-defective mutants in Arabidopsis thaliana are viable and can reproduce, which has enabled detailed genetic studies of the pathway. However, RdDM mutants can have a range of defects in different plant species, including lethality, altered reproductive phenotypes, TE upregulation and genome instability, and increased pathogen sensitivity. Overall, RdDM is an important pathway in plants that regulates a number of processes by establishing and reinforcing specific DNA methylation patterns, which can lead to transgenerational epigenetic effects on gene expression and phenotype.
Collapse
|
32
|
Botet R, Keurentjes JJB. The Role of Transcriptional Regulation in Hybrid Vigor. FRONTIERS IN PLANT SCIENCE 2020; 11:410. [PMID: 32351526 PMCID: PMC7174566 DOI: 10.3389/fpls.2020.00410] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/23/2020] [Indexed: 05/19/2023]
Abstract
The genetic basis of hybrid vigor in plants remains largely unsolved but strong evidence suggests that variation in transcriptional regulation can explain many aspects of this phenomenon. Natural variation in transcriptional regulation is highly abundant in virtually all species and thus a potential source of heterotic variability. Allele Specific Expression (ASE), which is tightly linked to parent of origin effects and modulated by complex interactions in cis and in trans, is generally considered to play a key role in explaining the differences between hybrids and parental lines. Here we discuss the recent developments in elucidating the role of transcriptional variation in a number of aspects of hybrid vigor, thereby bridging old paradigms and hypotheses with contemporary research in various species.
Collapse
Affiliation(s)
- Ramon Botet
- Laboratory of Genetics, Wageningen University & Research, Wageningen, Netherlands
| | | |
Collapse
|
33
|
Hitchcock TJ, Paracchini S, Gardner A. Genomic Imprinting As a Window into Human Language Evolution. Bioessays 2020; 41:e1800212. [PMID: 31132171 DOI: 10.1002/bies.201800212] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 03/22/2019] [Indexed: 01/20/2023]
Abstract
Humans spend large portions of their time and energy talking to one another, yet it remains unclear whether this activity is primarily selfish or altruistic. Here, it is shown how parent-of-origin specific gene expression-or "genomic imprinting"-may provide an answer to this question. First, it is shown why, regarding language, only altruistic or selfish scenarios are expected. Second, it is pointed out that an individual's maternal-origin and paternal-origin genes may have different evolutionary interests regarding investment into language, and that this intragenomic conflict may drive genomic imprinting which-as the direction of imprint depends upon whether investment into language is relatively selfish or altruistic-may be used to discriminate between these two possibilities. Third, predictions concerning the impact of various mutations and epimutations at imprinted loci on language pathologies are derived. In doing so, a framework is developed that highlights avenues for using intragenomic conflicts to investigate the evolutionary drivers of language.
Collapse
Affiliation(s)
- Thomas J Hitchcock
- School of Biology, University of St Andrews, Dyers Brae, St Andrews, KY16 9TH, UK
| | - Silvia Paracchini
- School of Medicine, University of St Andrews, North Haugh, St Andrews, KY16 9TF, UK
| | - Andy Gardner
- School of Biology, University of St Andrews, Dyers Brae, St Andrews, KY16 9TH, UK
| |
Collapse
|
34
|
Abstract
In this review, Batista and Köhler revisit the current models explaining imprinting regulation in plants, and discuss novel regulatory mechanisms that could function independently of parental DNA methylation asymmetries in the establishment of imprinting. Genomic imprinting is an epigenetic phenomenon leading to parentally biased gene expression. Throughout the years, extensive efforts have been made to characterize the epigenetic marks underlying imprinting in animals and plants. As a result, DNA methylation asymmetries between parental genomes emerged as the primary factor controlling the imprinting status of many genes. Nevertheless, the data accumulated so far suggest that this process cannot solely explain the imprinting of all genes. In this review, we revisit the current models explaining imprinting regulation in plants, and discuss novel regulatory mechanisms that could function independently of parental DNA methylation asymmetries in the establishment of imprinting.
Collapse
Affiliation(s)
- Rita A Batista
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Centre for Plant Biology, Uppsala SE-750 07, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Centre for Plant Biology, Uppsala SE-750 07, Sweden
| |
Collapse
|
35
|
Abstract
Genomic imprinting is a phenomenon that occurs in flowering plants and mammals, whereby a gene is expressed in a parent-of-origin-specific manner. Although imprinting has now been examined genome-wide in a number of species using RNA-seq, the analyses used to assess imprinting vary between studies, making consistent comparisons between species difficult. Here we present a simple, easy-to-use bioinformatic pipeline for imprinting analyses suitable for any tissue, including plant endosperm. All relevant scripts can be downloaded. As an illustrative example, we reanalyze published data from A. thaliana and Z. mays endosperm using the pipeline and then demonstrate how to use the results to assess the conservation of imprinting between these species. We also introduce the Plant Imprinting Database, a repository for published imprinting datasets in plants that can be used to view, compare, and download data.
Collapse
Affiliation(s)
- Colette L Picard
- Computational and Systems Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA, USA
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Mary Gehring
- Computational and Systems Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| |
Collapse
|
36
|
Bjerkan KN, Hornslien KS, Johannessen IM, Krabberød AK, van Ekelenburg YS, Kalantarian M, Shirzadi R, Comai L, Brysting AK, Bramsiepe J, Grini PE. Genetic variation and temperature affects hybrid barriers during interspecific hybridization. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:122-140. [PMID: 31487093 DOI: 10.1111/tpj.14523] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 07/31/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
Genomic imprinting regulates parent-specific transcript dosage during seed development and is mainly confined to the endosperm. Elucidation of the function of many imprinted genes has been hampered by the lack of corresponding mutant phenotypes, and the role of imprinting is mainly associated with genome dosage regulation or allocation of resources. Disruption of imprinted genes has also been suggested to mediate endosperm-based post-zygotic hybrid barriers depending on genetic variation and gene dosage. Here, we have analyzed the conservation of a clade from the MADS-box type I class transcription factors in the closely related species Arabidopsis arenosa, A. lyrata, and A. thaliana, and show that AGL36-like genes are imprinted and maternally expressed in seeds of Arabidopsis species and in hybrid seeds between outbreeding species. In hybridizations between outbreeding and inbreeding species the paternally silenced allele of the AGL36-like gene is reactivated in the hybrid, demonstrating that also maternally expressed imprinted genes are perturbed during hybridization and that such effects on imprinted genes are specific to the species combination. Furthermore, we also demonstrate a quantitative effect of genetic diversity and temperature on the strength of the post-zygotic hybridization barrier. Markedly, a small decrease in temperature during seed development increases the survival of hybrid F1 seeds, suggesting that abiotic and genetic parameters play important roles in post-zygotic species barriers, pointing at evolutionary scenarios favoring such effects. OPEN RESEARCH BADGES: This article has earned an Open Data Badge for making publicly available the digitally-shareable data necessary to reproduce the reported results. The data is available at https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA562212. All sequences generated in this study have been deposited in the National Center for Biotechnology Information Sequence Read Archive (https://www.ncbi.nlm.nih.gov/sra/) with project number PRJNA562212.
Collapse
Affiliation(s)
- Katrine N Bjerkan
- EVOGENE, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
- CEES, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
| | - Karina S Hornslien
- EVOGENE, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
| | - Ida M Johannessen
- EVOGENE, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
| | - Anders K Krabberød
- EVOGENE, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
| | | | - Maryam Kalantarian
- EVOGENE, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
| | - Reza Shirzadi
- EVOGENE, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
| | - Luca Comai
- Plant Biology and Genome Center, University of California, Davis, Davis, CA, 95616, USA
| | - Anne K Brysting
- EVOGENE, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
- CEES, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
| | - Jonathan Bramsiepe
- EVOGENE, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
- CEES, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
| | - Paul E Grini
- EVOGENE, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
| |
Collapse
|
37
|
Flores-Vergara MA, Oneal E, Costa M, Villarino G, Roberts C, De Luis Balaguer MA, Coimbra S, Willis J, Franks RG. Developmental Analysis of Mimulus Seed Transcriptomes Reveals Functional Gene Expression Clusters and Four Imprinted, Endosperm-Expressed Genes. FRONTIERS IN PLANT SCIENCE 2020; 11:132. [PMID: 32161609 PMCID: PMC7052496 DOI: 10.3389/fpls.2020.00132] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 01/28/2020] [Indexed: 05/15/2023]
Abstract
The double fertilization of the female gametophyte initiates embryogenesis and endosperm development in seeds via the activation of genes involved in cell differentiation, organ patterning, and growth. A subset of genes expressed in endosperm exhibit imprinted expression, and the correct balance of gene expression between parental alleles is critical for proper endosperm and seed development. We use a transcriptional time series analysis to identify genes that are associated with key shifts in seed development, including genes associated with secondary cell wall synthesis, mitotic cell cycle, chromatin organization, auxin synthesis, fatty acid metabolism, and seed maturation. We relate these genes to morphological changes in Mimulus seeds. We also identify four endosperm-expressed transcripts that display imprinted (paternal) expression bias. The imprinted status of these four genes is conserved in other flowering plants, suggesting that they are functionally important in endosperm development. Our study explores gene regulatory dynamics in a species with ab initio cellular endosperm development, broadening the taxonomic focus of the literature on gene expression in seeds. Moreover, it is the first to validate genes with imprinted endosperm expression in Mimulus guttatus, and will inform future studies on the genetic causes of seed failure in this model system.
Collapse
Affiliation(s)
- Miguel A. Flores-Vergara
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
| | - Elen Oneal
- Department of Biology, Duke University, Durham, NC, United States
- *Correspondence: Elen Oneal,
| | - Mario Costa
- GreenUPorto, Sustainable Agrifood Production Research Centre, Biology Department, Faculty of Sciences, University of Porto, Porto, Portugal
| | - Gonzalo Villarino
- Biology Department, San Diego State University, San Diego, CA, United States
| | - Caitlyn Roberts
- Department of Biology, Berea College, Berea, KY, United States
| | | | - Sílvia Coimbra
- GreenUPorto, Sustainable Agrifood Production Research Centre, Biology Department, Faculty of Sciences, University of Porto, Porto, Portugal
| | - John Willis
- Department of Biology, Duke University, Durham, NC, United States
| | - Robert G. Franks
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
| |
Collapse
|
38
|
Cruz MV, Mori GM, Oh DH, Dassanayake M, Zucchi MI, Oliveira RS, Souza APD. Molecular responses to freshwater limitation in the mangrove tree Avicennia germinans (Acanthaceae). Mol Ecol 2019; 29:344-362. [PMID: 31834961 DOI: 10.1111/mec.15330] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 11/27/2019] [Accepted: 11/28/2019] [Indexed: 12/31/2022]
Abstract
Environmental variation along the geographical space can shape populations by natural selection. In the context of global warming and changing precipitation regimes, it is crucial to understand the role of environmental heterogeneity in tropical trees adaptation, given their disproportional contribution to water and carbon biogeochemical cycles. Here, we investigated how heterogeneity in freshwater availability along tropical wetlands has influenced molecular variations of the black mangrove (Avicennia germinans). A total of 57 trees were sampled at seven sites differing markedly in precipitation regime and riverine freshwater inputs. Using 2,297 genome-wide single nucleotide polymorphic markers, we found signatures of natural selection by the association between variations in allele frequencies and environmental variables, including the precipitation of the warmest quarter and the annual precipitation. Additionally, we found candidate loci for selection based on statistical deviations from neutral expectations of interpopulation differentiation. Most candidate loci within transcribed sequences were functionally associated with central aspects of drought tolerance or plant response to drought. Moreover, our results suggest the occurrence of the rapid evolution of a population, probably in response to sudden and persistent limitations in plant access to soil water, following a road construction in 1974. Observations supporting rapid evolution included the reduction in tree size and changes in allele frequencies and in transcript expression associated with increased drought tolerance through the accumulation of osmoprotectants and antioxidants, biosynthesis of cuticles, protection against protein degradation, stomatal closure, photorespiration and photosynthesis. We describe a major role of spatial heterogeneity in freshwater availability in the specialization of this typically tropical tree.
Collapse
Affiliation(s)
- Mariana Vargas Cruz
- Department of Plant Biology, Institute of Biology, University of Campinas (Unicamp), Campinas, Brazil
| | | | - Dong-Ha Oh
- Department of Biological Sciences, Louisiana State University (LSU), Louisiana, LA, USA
| | - Maheshi Dassanayake
- Department of Biological Sciences, Louisiana State University (LSU), Louisiana, LA, USA
| | | | - Rafael Silva Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas (Unicamp), Campinas, Brazil
| | - Anete Pereira de Souza
- Department of Plant Biology, Institute of Biology, University of Campinas (Unicamp), Campinas, Brazil
| |
Collapse
|
39
|
Batista RA, Moreno-Romero J, Qiu Y, van Boven J, Santos-González J, Figueiredo DD, Köhler C. The MADS-box transcription factor PHERES1 controls imprinting in the endosperm by binding to domesticated transposons. eLife 2019; 8:50541. [PMID: 31789592 PMCID: PMC6914339 DOI: 10.7554/elife.50541] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 11/30/2019] [Indexed: 12/31/2022] Open
Abstract
MADS-box transcription factors (TFs) are ubiquitous in eukaryotic organisms and play major roles during plant development. Nevertheless, their function in seed development remains largely unknown. Here, we show that the imprinted Arabidopsis thaliana MADS-box TF PHERES1 (PHE1) is a master regulator of paternally expressed imprinted genes, as well as of non-imprinted key regulators of endosperm development. PHE1 binding sites show distinct epigenetic modifications on maternal and paternal alleles, correlating with parental-specific transcriptional activity. Importantly, we show that the CArG-box-like DNA-binding motifs that are bound by PHE1 have been distributed by RC/Helitron transposable elements. Our data provide an example of the molecular domestication of these elements which, by distributing PHE1 binding sites throughout the genome, have facilitated the recruitment of crucial endosperm regulators into a single transcriptional network.
Collapse
Affiliation(s)
- Rita A Batista
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Jordi Moreno-Romero
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Yichun Qiu
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Joram van Boven
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Juan Santos-González
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Duarte D Figueiredo
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| |
Collapse
|
40
|
Tuteja R, McKeown PC, Ryan P, Morgan CC, Donoghue MTA, Downing T, O'Connell MJ, Spillane C. Paternally Expressed Imprinted Genes under Positive Darwinian Selection in Arabidopsis thaliana. Mol Biol Evol 2019; 36:1239-1253. [PMID: 30913563 PMCID: PMC6526901 DOI: 10.1093/molbev/msz063] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Genomic imprinting is an epigenetic phenomenon where autosomal genes display uniparental expression depending on whether they are maternally or paternally inherited. Genomic imprinting can arise from parental conflicts over resource allocation to the offspring, which could drive imprinted loci to evolve by positive selection. We investigate whether positive selection is associated with genomic imprinting in the inbreeding species Arabidopsis thaliana. Our analysis of 140 genes regulated by genomic imprinting in the A. thaliana seed endosperm demonstrates they are evolving more rapidly than expected. To investigate whether positive selection drives this evolutionary acceleration, we identified orthologs of each imprinted gene across 34 plant species and elucidated their evolutionary trajectories. Increased positive selection was sought by comparing its incidence among imprinted genes with nonimprinted controls. Strikingly, we find a statistically significant enrichment of imprinted paternally expressed genes (iPEGs) evolving under positive selection, 50.6% of the total, but no such enrichment for positive selection among imprinted maternally expressed genes (iMEGs). This suggests that maternally- and paternally expressed imprinted genes are subject to different selective pressures. Almost all positively selected amino acids were fixed across 80 sequenced A. thaliana accessions, suggestive of selective sweeps in the A. thaliana lineage. The imprinted genes under positive selection are involved in processes important for seed development including auxin biosynthesis and epigenetic regulation. Our findings support a genomic imprinting model for plants where positive selection can affect paternally expressed genes due to continued conflict with maternal sporophyte tissues, even when parental conflict is reduced in predominantly inbreeding species.
Collapse
Affiliation(s)
- Reetu Tuteja
- Genetics & Biotechnology Lab, Plant & AgriBiosciences Research Centre (PABC), School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland.,Center for Genomics and Systems Biology, New York University, New York, NY
| | - Peter C McKeown
- Genetics & Biotechnology Lab, Plant & AgriBiosciences Research Centre (PABC), School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland
| | - Pat Ryan
- Genetics & Biotechnology Lab, Plant & AgriBiosciences Research Centre (PABC), School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland
| | - Claire C Morgan
- School of Biotechnology, Faculty of Biological Sciences, Dublin City University, Dublin, Ireland.,Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, United Kingdom
| | - Mark T A Donoghue
- Genetics & Biotechnology Lab, Plant & AgriBiosciences Research Centre (PABC), School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland.,Memorial Sloan Kettering Cancer Center, New York, NY
| | - Tim Downing
- School of Biotechnology, Faculty of Biological Sciences, Dublin City University, Dublin, Ireland
| | - Mary J O'Connell
- Computational and Molecular Evolutionary Biology Research Group, School of Biology, Faculty of Biological Sciences, The University of Leeds, Leeds, United Kingdom.,Computational and Molecular Evolutionary Biology Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Charles Spillane
- Genetics & Biotechnology Lab, Plant & AgriBiosciences Research Centre (PABC), School of Natural Sciences, Ryan Institute, National University of Ireland Galway, Galway, Ireland
| |
Collapse
|
41
|
Hornslien KS, Miller JR, Grini PE. Regulation of Parent-of-Origin Allelic Expression in the Endosperm. PLANT PHYSIOLOGY 2019; 180:1498-1519. [PMID: 31064812 PMCID: PMC6752901 DOI: 10.1104/pp.19.00320] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 04/29/2019] [Indexed: 05/22/2023]
Abstract
Genomic imprinting is an epigenetic phenomenon established in the gametes prior to fertilization that causes differential expression of parental alleles, mainly in the endosperm of flowering plants. The overlap between previously identified panels of imprinted genes is limited. To investigate imprinting, we used high-resolution sequencing data acquired with sequence-capture technology. We present a bioinformatics pipeline to assay parent-of-origin allele-specific expression and report more than 300 loci with parental expression bias in Arabidopsis (Arabidopsis thaliana). In most cases, the level of expression from maternal and paternal alleles was not binary, instead supporting a differential dosage hypothesis for the evolution of imprinting in plants. To address imprinting regulation, we systematically employed mutations in regulative epigenetic pathways suggested to be major players in the process. We established the mechanistic mode of imprinting for more than 50 loci regulated by DNA methylation and Polycomb-dependent histone methylation. However, the imprinting patterns of most genes were not affected by these mechanisms. To this end, we also demonstrated that the RNA-directed DNA methylation pathway alone does not substantially influence imprinting patterns, suggesting that more complex epigenetic pathways regulate most of the identified imprinted genes.
Collapse
Affiliation(s)
- Karina S Hornslien
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, 0316 Oslo, Norway
| | - Jason R Miller
- College of Natural Sciences and Mathematics, Shepherd University, Shepherdstown, West Virginia 25443-5000
- J. Craig Venter Institute, Rockville, Maryland 20850
| | - Paul E Grini
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, 0316 Oslo, Norway
| |
Collapse
|
42
|
Liu J, Li J, Liu HF, Fan SH, Singh S, Zhou XR, Hu ZY, Wang HZ, Hua W. Genome-wide screening and analysis of imprinted genes in rapeseed (Brassica napus L.) endosperm. DNA Res 2019; 25:629-640. [PMID: 30272113 PMCID: PMC6289790 DOI: 10.1093/dnares/dsy030] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/09/2018] [Indexed: 12/28/2022] Open
Abstract
Species-specific genomic imprinting is an epigenetic phenomenon leading to parent-of-origin-specific differential expression of maternally and paternally inherited alleles. To date, no studies of imprinting have been reported in rapeseed, a tetraploid species. Here, we analysed global patterns of allelic gene expression in developing rapeseed endosperms from reciprocal crosses between inbred lines YN171 and 93275. A total of 183 imprinted genes, consisting of 167 maternal expressed genes (MEGs) and 16 paternal expressed genes (PEGs), were identified from 14,394 genes found to harbour diagnostic SNPs between the parental lines. Some imprinted genes were validated in different endosperm stages and other parental combinations by RT-PCR analysis. A clear clustering of imprinted genes throughout the rapeseed genome was identified, which was different from most other plants. Methylation analysis of 104 out of the 183 imprinted genes showed that 11 genes (7 MEGs and 4 PEGs) harboured differentially methylated regions (DMRs). Unexpectedly, only 1 MEG out of these 11 genes had a DMR that exhibited high CG methylation rate in paternal allele and had big difference between parent alleles. These results extend our understanding of gene imprinting in plants and provide potential avenues for further research in imprinted genes.
Collapse
Affiliation(s)
- Jing Liu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Jun Li
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Hong-Fang Liu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Shi-Hang Fan
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Surinder Singh
- Agriculture and Food Commonwealth Scientific and Industrial Research Organization, Canberra, ACT, Australia
| | - Xue-Rong Zhou
- Agriculture and Food Commonwealth Scientific and Industrial Research Organization, Canberra, ACT, Australia
| | - Zhi-Yong Hu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Han-Zhong Wang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Wei Hua
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| |
Collapse
|
43
|
Del Toro-De León G, Köhler C. Endosperm-specific transcriptome analysis by applying the INTACT system. PLANT REPRODUCTION 2019; 32:55-61. [PMID: 30588542 DOI: 10.1007/s00497-018-00356-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 12/14/2018] [Indexed: 05/06/2023]
Abstract
KEY MESSAGE We report the adaptation of the INTACT method for RNA-sequencing in the endosperm and demonstrate its feasibility for allele-specific expression analysis. Tissue-specific transcriptome analyses provide important insights into the developmental programs of defined cell types. The isolation of nuclei tagged in specific cell types (INTACT) is a versatile method that allows to isolate highly pure nuclei from defined tissue types that can be used for several downstream applications. Here, we describe the adaptation of INTACT from endosperm nuclei for high-throughput RNA-sequencing. By analyzing the ratio of parental reads and tissue-specific gene expression in the endosperm, we could assess the contamination level of our samples. Based on this analysis, we estimate that in most of the samples the contamination level is lower than in previously published datasets. We further show that the nuclear transcriptome and total transcriptome of the endosperm are well correlated. Together, our data show that INTACT of the endosperm is a reliable methodology for endosperm-specific transcriptome analysis that overcomes the limitation of time-consuming manual endosperm dissection that is connected with high levels of maternal tissue contamination. INTACT does not rely on expensive equipment and can be set up in every standard molecular biology laboratory, making it the method of choice for future molecular studies of the endosperm.
Collapse
Affiliation(s)
- Gerardo Del Toro-De León
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden.
| |
Collapse
|
44
|
Li J, Wang M, Li Y, Zhang Q, Lindsey K, Daniell H, Jin S, Zhang X. Multi-omics analyses reveal epigenomics basis for cotton somatic embryogenesis through successive regeneration acclimation process. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:435-450. [PMID: 29999579 PMCID: PMC6335067 DOI: 10.1111/pbi.12988] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/04/2018] [Accepted: 07/10/2018] [Indexed: 05/20/2023]
Abstract
Plant regeneration via somatic embryogenesis is time-consuming and highly genotype-dependent. The plant somatic embryogenesis process provokes many epigenetics changes including DNA methylation and histone modification. Recently, an elite cotton Jin668, with an extremely high regeneration ability, was developed from its maternal inbred Y668 cultivar using a Successive Regeneration Acclimation (SRA) strategy. To reveal the underlying mechanism of SRA, we carried out a genome-wide single-base resolution methylation analysis for nonembryogenic calluses (NECs), ECs, somatic embryos (SEs) during the somatic embryogenesis procedure and the leaves of regenerated offspring plants. Jin668 (R4) regenerated plants were CHH hypomethylated compared with the R0 regenerated plants of SRA process. The increase in CHH methylation from NEC to EC was demonstrated to be associated with the RNA-dependent DNA methylation (RdDM) and the H3K9me2-dependent pathway. Intriguingly, the hypomethylated CHH differentially methylated regions (DMRs) of promoter activated some hormone-related and WUSCHEL-related homeobox genes during the somatic embryogenesis process. Inhibiting DNA methylation using zebularine treatment in NEC increased the number of embryos. Our multi-omics data provide new insights into the dynamics of DNA methylation during the plant tissue culture and regenerated offspring plants. This study also reveals that induced hypomethylation (SRA) may facilitate the higher plant regeneration ability and optimize maternal genetic cultivar.
Collapse
Affiliation(s)
- Jianying Li
- National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanHubeiChina
| | - Maojun Wang
- National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanHubeiChina
| | - Yajun Li
- National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanHubeiChina
| | - Qinghua Zhang
- National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanHubeiChina
| | | | - Henry Daniell
- Department of BiochemistrySchool of Dental MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Shuangxia Jin
- National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanHubeiChina
| | - Xianlong Zhang
- National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanHubeiChina
| |
Collapse
|
45
|
Baroux C, Grossniklaus U. Seeds-An evolutionary innovation underlying reproductive success in flowering plants. Curr Top Dev Biol 2018; 131:605-642. [PMID: 30612632 DOI: 10.1016/bs.ctdb.2018.11.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
"Seeds nourish, seeds unite, seeds endure, seeds defend, seeds travel," explains the science writer Thor Hanson in his book The Triumph of Seeds (2015). The seed is an ultimate product of land plant evolution. The nursing and protective organization of the seed enable a unique parental care of the progeny that has fueled seed plant radiation. Seeds promote dispersal and optimize offspring production and thus reproductive fitness through biological adaptations that integrate environmental and developmental cues. The composite structure of seeds, uniting tissues that originate from three distinct organisms, enables the partitioning of tasks during development, maturation, and storage, while a sophisticated interplay between the compartments allows the fine-tuning of embryonic growth, as well as seed maturation, dormancy, and germination. In this review, we will highlight peculiarities in the development and evolution of the different seed compartments and focus on the molecular mechanisms underlying the interactions between them.
Collapse
Affiliation(s)
- Célia Baroux
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland.
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| |
Collapse
|
46
|
Yoshida T, Kawanabe T, Bo Y, Fujimoto R, Kawabe A. Genome-Wide Analysis of Parent-of-Origin Allelic Expression in Endosperms of Brassicaceae Species, Brassica rapa. PLANT & CELL PHYSIOLOGY 2018; 59:2590-2601. [PMID: 30165552 DOI: 10.1093/pcp/pcy178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 08/24/2018] [Indexed: 05/06/2023]
Abstract
Uniparental gene expression, observed in both animals and plants, is termed genomic imprinting. Genomic imprinting is a well-known epigenetic phenomenon regulated through epigenetic modifications such as DNA methylation and histone modifications. Recent genome-wide studies of endosperm transcription have revealed the rapid change of imprinted genes between species, suggesting the flexibility of this phenomenon. Although the functional significance and evolutionary trends of imprinted genes are still obscure, it can be clarified by inter-species comparisons. In this study, we analyzed the pattern of genomic imprinting in Brassica rapa, a species related to Arabidopsis thaliana. Compared with the ancient karyotype of A. thaliana and B. rapa, B. rapa has a triplicated genome. Many imprinted genes, beyond the estimated number previously reported in other species, were observed. Several imprinted genes have been conserved among species in Brassicaceae. We also observed rapid molecular evolution of imprinted genes compared to non-imprinted genes in B. rapa. Especially, imprinted gene overlapping between species showed more rapid molecular evolution and preferential expression in endosperms. It may imply that a small number of imprinted genes have retained functional roles among diverged species and have been the target of natural selection.
Collapse
Affiliation(s)
| | - Takahiro Kawanabe
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Yina Bo
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
| | - Ryo Fujimoto
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Akira Kawabe
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
| |
Collapse
|
47
|
|
48
|
Roth M, Florez-Rueda AM, Paris M, Städler T. Wild tomato endosperm transcriptomes reveal common roles of genomic imprinting in both nuclear and cellular endosperm. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 95:1084-1101. [PMID: 29953688 DOI: 10.1111/tpj.14012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 06/01/2018] [Accepted: 06/20/2018] [Indexed: 05/06/2023]
Abstract
Genomic imprinting is a conspicuous feature of the endosperm, a triploid tissue nurturing the embryo and synchronizing angiosperm seed development. An unknown subset of imprinted genes (IGs) is critical for successful seed development and should have highly conserved functions. Recent genome-wide studies have found limited conservation of IGs among distantly related species, but there is a paucity of data from closely related lineages. Moreover, most studies focused on model plants with nuclear endosperm development, and comparisons with properties of IGs in cellular-type endosperm development are lacking. Using laser-assisted microdissection, we characterized parent-specific expression in the cellular endosperm of three wild tomato lineages (Solanum section Lycopersicon). We identified 1025 candidate IGs and 167 with putative homologs previously identified as imprinted in distantly related taxa with nuclear-type endosperm. Forty-two maternally expressed genes (MEGs) and 17 paternally expressed genes (PEGs) exhibited conserved imprinting status across all three lineages, but differences in power to assess imprinted expression imply that the actual degree of conservation might be higher than that directly estimated (20.7% for PEGs and 10.4% for MEGs). Regardless, the level of shared imprinting status was higher for PEGs than for MEGs, indicating dissimilar evolutionary trajectories. Expression-level data suggest distinct epigenetic modulation of MEGs and PEGs, and gene ontology analyses revealed MEGs and PEGs to be enriched for different functions. Importantly, our data provide evidence that MEGs and PEGs interact in modulating both gene expression and the endosperm cell cycle, and uncovered conserved cellular functions of IGs uniting taxa with cellular- and nuclear-type endosperm.
Collapse
Affiliation(s)
- Morgane Roth
- Plant Ecological Genetics, Institute of Integrative Biology & Zurich-Basel Plant Science Center, ETH Zurich, 8092, Zurich, Switzerland
| | - Ana M Florez-Rueda
- Plant Ecological Genetics, Institute of Integrative Biology & Zurich-Basel Plant Science Center, ETH Zurich, 8092, Zurich, Switzerland
| | - Margot Paris
- Plant Ecological Genetics, Institute of Integrative Biology & Zurich-Basel Plant Science Center, ETH Zurich, 8092, Zurich, Switzerland
| | - Thomas Städler
- Plant Ecological Genetics, Institute of Integrative Biology & Zurich-Basel Plant Science Center, ETH Zurich, 8092, Zurich, Switzerland
| |
Collapse
|
49
|
Chen C, Li T, Zhu S, Liu Z, Shi Z, Zheng X, Chen R, Huang J, Shen Y, Luo S, Wang L, Liu QQ, E Z. Characterization of Imprinted Genes in Rice Reveals Conservation of Regulation and Imprinting with Other Plant Species. PLANT PHYSIOLOGY 2018; 177:1754-1771. [PMID: 29914891 PMCID: PMC6084669 DOI: 10.1104/pp.17.01621] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 06/07/2018] [Indexed: 05/08/2023]
Abstract
Genomic imprinting is an epigenetic phenomenon by which certain genes display differential expression in a parent-of-origin-dependent manner. Hundreds of imprinted genes have been identified from several plant species. Here, we identified, with a high level of confidence, 208 imprinted gene candidates from rice (Oryza sativa). Imprinted genes of rice showed limited association with the transposable elements, which contrasts with findings from Arabidopsis (Arabidopsis thaliana). Generally, imprinting in rice is conserved within a species, but intraspecific variation also was detected. The imprinted rice genes do not show signatures of selection, which suggests that domestication has had a limited evolutionary consequence on genomic imprinting. Although conservation of imprinting in plants is limited, we show that some loci are imprinted in several different species. Moreover, our results suggest that different types of epigenetic regulation can be established either before or after fertilization. Imprinted 24-nucleotide small RNAs and their neighboring genes tend to express alleles from different parents. This association was not observed between 21-nucleotide small RNAs and their neighboring genes. Together, our findings suggest that the regulation of imprinting can be diverse, and genomic imprinting has evolutionary and biological significance.
Collapse
Affiliation(s)
- Chen Chen
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, China, 225009
| | - Tingting Li
- China National Rice Research Institute, Hangzhou, China, 311401
| | - Shan Zhu
- Rice Research Institute, Jiangxi Academy of Agricultural Sciences, Nanchang, China, 330200
| | - Zehou Liu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China, 610041
| | - Zhenyuan Shi
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, China, 225009
| | - Xiaoming Zheng
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, National Key Facilities for Crop Gene Resources and Genetic Improvement, Beijing, China, 100081
| | - Rui Chen
- Tianjin Institute of Agricultural Quality Standard and Testing Technology, Tianjin Academy of Agricultural Sciences, Tianjin, China, 300381
| | - Jianfeng Huang
- Shanghai Biotechnology Corporation, Shanghai, China, 201203
| | - Yi Shen
- Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, China, 210014
| | - Shiyou Luo
- Rice Research Institute, Jiangxi Academy of Agricultural Sciences, Nanchang, China, 330200
| | - Lei Wang
- China National Rice Research Institute, Hangzhou, China, 311401
| | - Qiao-Quan Liu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, China, 225009
| | - Zhiguo E
- China National Rice Research Institute, Hangzhou, China, 311401
| |
Collapse
|
50
|
Dong X, Chen J, Li T, Li E, Zhang X, Zhang M, Song W, Zhao H, Lai J. Parent-of-origin-dependent nucleosome organization correlates with genomic imprinting in maize. Genome Res 2018; 28:1020-1028. [PMID: 29903724 PMCID: PMC6028132 DOI: 10.1101/gr.230201.117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 05/31/2018] [Indexed: 12/23/2022]
Abstract
Genomic imprinting refers to allele-specific expression of genes depending on their parental origin. Nucleosomes, the fundamental units of chromatin, play a critical role in gene transcriptional regulation. However, it remains unknown whether differential nucleosome organization is related to the allele-specific expression of imprinted genes. Here, we generated a genome-wide map of allele-specific nucleosome occupancy in maize endosperm and presented an integrated analysis of its relationship with parent-of-origin-dependent gene expression and DNA methylation. We found that ∼2.3% of nucleosomes showed significant parental bias in maize endosperm. The parent-of-origin-dependent nucleosomes mostly exist as single isolated nucleosomes. Parent-of-origin-dependent nucleosomes were significantly associated with the allele-specific expression of imprinted genes, with nucleosomes positioned preferentially in the promoter of nonexpressed alleles of imprinted genes. Furthermore, we found that most of the paternal specifically positioned nucleosomes (pat-nucleosomes) were associated with parent-of-origin-dependent differential methylated regions, suggesting a functional link between the maternal demethylation and the occurrence of pat-nucleosome. Maternal specifically positioned nucleosomes (mat-nucleosomes) were independent of allele-specific DNA methylation but seem to be associated with allele-specific histone modification. Our study provides the first genome-wide map of allele-specific nucleosome occupancy in plants and suggests a mechanistic connection between chromatin organization and genomic imprinting.
Collapse
Affiliation(s)
- Xiaomei Dong
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Jian Chen
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Tong Li
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - En Li
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Xiangbo Zhang
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Mei Zhang
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China.,Department of Biology, Stanford University, Stanford, California 94305, USA
| | - Weibin Song
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Haiming Zhao
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Jinsheng Lai
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China.,Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| |
Collapse
|