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Fan C, Lyu M, Zeng B, He Q, Wang X, Lu MZ, Liu B, Liu J, Esteban E, Pasha A, Provart NJ, Wang H, Zhang J. Profiling of the gene expression and alternative splicing landscapes of Eucalyptus grandis. PLANT, CELL & ENVIRONMENT 2024; 47:1363-1378. [PMID: 38221855 DOI: 10.1111/pce.14814] [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: 10/21/2023] [Revised: 12/05/2023] [Accepted: 01/01/2024] [Indexed: 01/16/2024]
Abstract
Eucalyptus is a widely planted hardwood tree species due to its fast growth, superior wood properties and adaptability. However, the post-transcriptional regulatory mechanisms controlling tissue development and stress responses in Eucalyptus remain poorly understood. In this study, we performed a comprehensive analysis of the gene expression profile and the alternative splicing (AS) landscape of E. grandis using strand-specific RNA-Seq, which encompassed 201 libraries including different organs, developmental stages, and environmental stresses. We identified 10 416 genes (33.49%) that underwent AS, and numerous differentially expressed and/or differential AS genes involved in critical biological processes, such as primary-to-secondary growth transition of stems, adventitious root formation, aging and responses to phosphorus- or boron-deficiency. Co-expression analysis of AS events and gene expression patterns highlighted the potential upstream regulatory role of AS events in multiple processes. Additionally, we highlighted the lignin biosynthetic pathway to showcase the potential regulatory functions of AS events in the KNAT3 and IRL3 genes within this pathway. Our high-quality expression atlas and AS landscape serve as valuable resources for unravelling the genetic control of woody plant development, long-term adaptation, and understanding transcriptional diversity in Eucalyptus. Researchers can conveniently access these resources through the interactive ePlant browser (https://bar.utoronto.ca/eplant_eucalyptus).
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Affiliation(s)
- Chunjie Fan
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of State Forestry and Grassland Administration on Tropical Forestry, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
- State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, Zhejiang, China
| | - Mingjie Lyu
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
- Institute of Crop Germplasm and Biotechnology, Tianjin Academy of Agricultural Sciences, Tianjin, China
| | - Bingshan Zeng
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of State Forestry and Grassland Administration on Tropical Forestry, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
| | - Qiang He
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaoping Wang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of State Forestry and Grassland Administration on Tropical Forestry, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
| | - Meng-Zhu Lu
- State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, Zhejiang, China
| | - Bobin Liu
- Jiansu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, School of Wetlands, Yancheng Teachers University, Yancheng, China
| | - Jun Liu
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Eddi Esteban
- Department of Cell and Systems Biology, Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
| | - Asher Pasha
- Department of Cell and Systems Biology, Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
| | - Nicholas J Provart
- Department of Cell and Systems Biology, Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
| | - Huan Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jin Zhang
- State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, Zhejiang, China
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Timofeyenko K, Kanavalau D, Alexiou P, Kalyna M, Růžička K. Catsnap: a user-friendly algorithm for determining the conservation of protein variants reveals extensive parallelisms in the evolution of alternative splicing. THE NEW PHYTOLOGIST 2023; 238:1722-1732. [PMID: 36751910 PMCID: PMC10952736 DOI: 10.1111/nph.18799] [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: 12/09/2022] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
Understanding the evolutionary conservation of complex eukaryotic transcriptomes significantly illuminates the physiological relevance of alternative splicing (AS). Examining the evolutionary depth of a given AS event with ordinary homology searches is generally challenging and time-consuming. Here, we present Catsnap, an algorithmic pipeline for assessing the conservation of putative protein isoforms generated by AS. It employs a machine learning approach following a database search with the provided pair of protein sequences. We used the Catsnap algorithm for analyzing the conservation of emerging experimentally characterized alternative proteins from plants and animals. Indeed, most of them are conserved among other species. Catsnap can detect the conserved functional protein isoforms regardless of the AS type by which they are generated. Notably, we found that while the primary amino acid sequence is maintained, the type of AS determining the inclusion or exclusion of protein regions varies throughout plant phylogenetic lineages in these proteins. We also document that this phenomenon is less seen among animals. In sum, our algorithm highlights the presence of unexpectedly frequent hotspots where protein isoforms recurrently arise to carry physiologically relevant functions. The user web interface is available at https://catsnap.cesnet.cz/.
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Affiliation(s)
- Ksenia Timofeyenko
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental BotanyCzech Academy of Sciences165 02Prague 6Czech Republic
- Functional Genomics and Proteomics of Plants and National Centre for Biomolecular ResearchMasaryk University625 00BrnoCzech Republic
| | | | - Panagiotis Alexiou
- Central European Institute of TechnologyMasaryk University625 00BrnoCzech Republic
| | - Maria Kalyna
- Department of Applied Genetics and Cell Biology, Institute of Molecular Plant BiologyUniversity of Natural Resources and Life Sciences (BOKU)1190ViennaAustria
| | - Kamil Růžička
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental BotanyCzech Academy of Sciences165 02Prague 6Czech Republic
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Hussain SS, Abbas M, Abbas S, Wei M, El-Sappah AH, Sun Y, Li Y, Ragauskas AJ, Li Q. Alternative splicing: transcriptional regulatory network in agroforestry. FRONTIERS IN PLANT SCIENCE 2023; 14:1158965. [PMID: 37123829 PMCID: PMC10132464 DOI: 10.3389/fpls.2023.1158965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 03/13/2023] [Indexed: 05/03/2023]
Abstract
Alternative splicing (AS) in plants plays a key role in regulating the expression of numerous transcripts from a single gene in a regulatory pathway. Variable concentrations of growth regulatory hormones and external stimuli trigger alternative splicing to switch among different growth stages and adapt to environmental stresses. In the AS phenomenon, a spliceosome causes differential transcriptional modifications in messenger RNA (mRNAs), resulting in partial or complete retention of one or more introns as compared to fully spliced mRNA. Differentially expressed proteins translated from intron-retaining messenger RNA (mRNAir) perform vital functions in the feedback mechanism. At the post-transcriptional level, AS causes the remodeling of transcription factors (TFs) by the addition or deletion of binding domains to activate and/or repress transcription. In this study, we have summarized the specific role of AS in the regulation of gene expression through repression and activation of the transcriptional regulatory network under external stimuli and switch among developmental stages.
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Affiliation(s)
- Syed Sarfaraz Hussain
- State Key Laboratory of Tree Genetics and Breeding, Engineering Technology Research Center of Black Locust of National Forestry and Grassland Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
| | - Manzar Abbas
- Faculty of Agriculture, Forestry and Food Engineering, Yibin University, Yibin, Sichuan, China
| | - Sammar Abbas
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Mingke Wei
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
| | - Ahmed H. El-Sappah
- Faculty of Agriculture, Forestry and Food Engineering, Yibin University, Yibin, Sichuan, China
- Genetics Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| | - Yuhan Sun
- State Key Laboratory of Tree Genetics and Breeding, Engineering Technology Research Center of Black Locust of National Forestry and Grassland Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Yun Li
- State Key Laboratory of Tree Genetics and Breeding, Engineering Technology Research Center of Black Locust of National Forestry and Grassland Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- *Correspondence: Yun Li, ; Arthur J. Ragauskas, ; Quanzi Li,
| | - Arthur J. Ragauskas
- Department of Forestry, Wildlife, and Fisheries, Center for Renewable Carbon, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
- Joint Institute for Biological Science, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Department of Chemical and Biomolecular Engineering, The University of Tennessee-Knoxville, Knoxville, TN, United States
- *Correspondence: Yun Li, ; Arthur J. Ragauskas, ; Quanzi Li,
| | - Quanzi Li
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
- *Correspondence: Yun Li, ; Arthur J. Ragauskas, ; Quanzi Li,
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Rawoof A, Ahmad I, Islam K, Momo J, Kumar A, Jaiswal V, Ramchiary N. Integrated omics analysis identified genes and their splice variants involved in fruit development and metabolites production in Capsicum species. Funct Integr Genomics 2022; 22:1189-1209. [PMID: 36173582 DOI: 10.1007/s10142-022-00902-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/10/2022] [Accepted: 09/19/2022] [Indexed: 11/27/2022]
Abstract
To date, several transcriptomic studies during fruit development have been reported; however, no comprehensive integrated study on expression diversity, alternative splicing, and metabolomic profiling was reported in Capsicum. This study analyzed RNA-seq data and untargeted metabolomic profiling from early green (EG), mature green (MG), and breaker (Br) fruit stages from two Capsicum species, i.e., C. annuum (Cann) and C. frutescens (Cfrut) from Northeast India. A total of 117,416 and 96,802 alternatively spliced events (AltSpli-events) were identified from Cann and Cfrut, respectively. Among AltSpli-events, intron retention (IR; 32.2% Cann and 25.75% Cfrut) followed by alternative acceptor (AA; 15.4% Cann and 18.9% Cfrut) were the most abundant in Capsicum. Around 7600 genes expressed in at least one fruit stage of Cann and Cfrut were AltSpli. The study identified spliced variants of genes including transcription factors (TFs) potentially involved in fruit development/ripening (Aux/IAA 16-like, ETR, SGR1, ARF, CaGLK2, ETR, CaAGL1, MADS-RIN, FUL1, SEPALLATA1), carotenoid (PDS, CA1, CCD4, NCED3, xanthoxin dehydrogenase, CaERF82, CabHLH100, CaMYB3R-1, SGR1, CaWRKY28, CaWRKY48, CaWRKY54), and capsaicinoids or flavonoid biosynthesis (CaMYB48, CaWRKY51), which were significantly differentially spliced (DS) between consecutive Capsicum fruit stages. Also, this study observed that differentially expressed isoforms (DEiso) from 38 genes with differentially spliced events (DSE) were significantly enriched in various metabolic pathways such as starch and sucrose metabolism, amino acid metabolism, cysteine cutin suberin and wax biosynthesis, and carotenoid biosynthesis. Furthermore, the metabolomic profiling revealed that metabolites from aforementioned pathways such as carbohydrates (mainly sugars such as D-fructose, D-galactose, maltose, and sucrose), organic acids (carboxylic acids), and peptide groups significantly altered during fruit development. Taken together, our findings could help in alternative splicing-based targeted studies of candidate genes involved in fruit development and ripening in Capsicum crop.
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Affiliation(s)
- Abdul Rawoof
- Translational and Evolutionary Genomics Lab, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ilyas Ahmad
- Translational and Evolutionary Genomics Lab, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Khushbu Islam
- Translational and Evolutionary Genomics Lab, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - John Momo
- Translational and Evolutionary Genomics Lab, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ajay Kumar
- Department of Plant Science, School of Biological Sciences, Central University of Kerala, Kasaragod, 671316, Kerala, India
| | - Vandana Jaiswal
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Nirala Ramchiary
- Translational and Evolutionary Genomics Lab, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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Xylem Transcriptome Analysis in Contrasting Wood Phenotypes of Eucalyptus urophylla × tereticornis Hybrids. FORESTS 2022. [DOI: 10.3390/f13071102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
An investigation of the effects of two important post-transcriptional regulatory mechanisms, gene transcription and alternative splicing (AS), on the wood formation of Eucalyptusurophylla × tereticornis, an economic tree species widely planted in southern China, was carried out. We performed RNA-seq on E. urophylla × tereticornis hybrids with highly contrasting wood basic density (BD), cellulose content (CC), hemicellulose content (HC), and lignin content (LC). Signals of strong differentially expressed genes (DEGs) and differentially spliced genes (DSGs) were detected in all four groups of wood properties, suggesting that gene transcription and selective splicing may have important regulatory roles in wood properties. We found that there was little overlap between DEGs and DSGs in groups of the same trait. Furthermore, the key DEGs and DSGs that were detected simultaneously in the four groups tended to be enriched in different Gene Ontology terms, Kyoto Encyclopedia of Genes and Genomes pathways, and transcription factors. These results implied that regulation of gene transcription and AS is controlled by independent regulatory systems in wood formation. Lastly, we detected transcript levels of known wood biosynthetic genes and found that 79 genes encoding mainly enzymes or proteins such as UGT, LAC, CAD, and CESA may be involved in the positive or negative regulation of wood properties. This study reveals potential molecular mechanisms that may regulate wood formation and will contribute to the genetic improvement of Eucalyptus.
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Yan X, Bai D, Song H, Lin K, Pang E. Alternative splicing during fruit development among fleshy fruits. BMC Genomics 2021; 22:762. [PMID: 34702184 PMCID: PMC8547070 DOI: 10.1186/s12864-021-08111-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 10/20/2021] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Alternative splicing (AS) is an important mechanism of posttranscriptional modification and dynamically regulates multiple physiological processes in plants, including fruit ripening. However, little is known about alternative splicing during fruit development in fleshy fruits. RESULTS We studied the alternative splicing at the immature and ripe stages during fruit development in cucumber, melon, papaya and peach. We found that 14.96-17.48% of multiexon genes exhibited alternative splicing. Intron retention was not always the most frequent event, indicating that the alternative splicing pattern during different developmental process differs. Alternative splicing was significantly more prevalent at the ripe stage than at the immature stage in cucumber and melon, while the opposite trend was shown in papaya and peach, implying that developmental stages adopt different alternative splicing strategies for their specific functions. Some genes involved in fruit ripening underwent stage-specific alternative splicing, indicating that alternative splicing regulates fruits ripening. Conserved alternative splicing events did not appear to be stage-specific. Clustering fruit developmental stages across the four species based on alternative splicing profiles resulted in species-specific clustering, suggesting that diversification of alternative splicing contributes to lineage-specific evolution in fleshy fruits. CONCLUSIONS We obtained high quality transcriptomes and alternative splicing events during fruit development across the four species. Dynamics and nonconserved alternative splicing were discovered. The candidate stage-specific AS genes involved in fruit ripening will provide valuable insight into the roles of alternative splicing during the developmental processes of fleshy fruits.
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Affiliation(s)
- Xiaomin Yan
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, No 19 Xinjiekouwai Street, Beijing, 100875, China
| | - Dan Bai
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, No 19 Xinjiekouwai Street, Beijing, 100875, China
| | - Hongtao Song
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, No 19 Xinjiekouwai Street, Beijing, 100875, China
| | - Kui Lin
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, No 19 Xinjiekouwai Street, Beijing, 100875, China
| | - Erli Pang
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, No 19 Xinjiekouwai Street, Beijing, 100875, China.
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Wang R, Reng M, Tian S, Liu C, Cheng H, Liu Y, Zhang H, Saqib M, Wei H, Wei Z. Transcriptome-wide identification and characterization of microRNAs in diverse phases of wood formation in Populus trichocarpa. G3 (BETHESDA, MD.) 2021; 11:jkab195. [PMID: 34849817 PMCID: PMC8633455 DOI: 10.1093/g3journal/jkab195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 05/29/2021] [Indexed: 01/15/2023]
Abstract
We applied miRNA expression profiling method to Populus trichocarpa stems of the three developmental stages, primary stem (PS), transitional stem (TS), and secondary stem (SS), to investigate miRNA species and their regulation on lignocellulosic synthesis and related processes. We obtained 892, 872, and 882 known miRNAs and 1727, 1723, and 1597 novel miRNAs, from PS, TS, and SS, respectively. Comparisons of these miRNA species among different developmental stages led to the identification of 114, 306, and 152 differentially expressed miRNAs (DE-miRNAs), which had 921, 2639, and 2042 candidate target genes (CTGs) in the three respective stages of the same order. Correlation analysis revealed 47, 439, and 71 DE-miRNA-CTG pairs of high negative correlation in PS, TS, and SS, respectively. Through biological process analysis, we finally identified 34, 6, and 76 miRNA-CTG pairs from PS, TS, and SS, respectively, and the miRNA target genes in these pairs regulate or participate lignocellulosic biosynthesis-related biological processes: cell division and differentiation, cell wall modification, secondary cell wall biosynthesis, lignification, and programmed cell death processes. This is the first report on an integrated analysis of genome-wide mRNA and miRNA profilings during multiple phases of poplar stem development. Our analysis results imply that individual miRNAs modulate secondary growth and lignocellulosic biosynthesis through regulating transcription factors and lignocellulosic biosynthetic pathway genes, resulting in more dynamic promotion, suppression, or regulatory circuits. This study advanced our understanding of many individual miRNAs and their essential, diversified roles in the dynamic regulation of secondary growth in woody tree species.
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Affiliation(s)
- Ruiqi Wang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin 150040, China
| | - Mengxuan Reng
- Research Center of Saline and Alkali Land of State Forestry and Grassland Administration, Chinese Academy of Forestry, Beijing 100091, China
| | - Shuanghui Tian
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin 150040, China
| | - Cong Liu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin 150040, China
| | - He Cheng
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin 150040, China
| | - Yingying Liu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang Harbin 150040, China
| | - Huaxin Zhang
- Research Center of Saline and Alkali Land of State Forestry and Grassland Administration, Chinese Academy of Forestry, Beijing 100091, China
| | - Muhammad Saqib
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad 38000, Pakistan
| | - Hairong Wei
- College of Forest Resource and Environmental Science, Michigan Technological University, Houghton MI49931, USA
| | - Zhigang Wei
- Research Center of Saline and Alkali Land of State Forestry and Grassland Administration, Chinese Academy of Forestry, Beijing 100091, China
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Li H, Chen G, Pang H, Wang Q, Dai X. Investigation Into Different Wood Formation Mechanisms Between Angiosperm and Gymnosperm Tree Species at the Transcriptional and Post-transcriptional Level. FRONTIERS IN PLANT SCIENCE 2021; 12:698602. [PMID: 34276747 PMCID: PMC8283789 DOI: 10.3389/fpls.2021.698602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/01/2021] [Indexed: 05/19/2023]
Abstract
Enormous distinctions of the stem structure and cell types between gymnosperms and angiosperms tree species are expected to cause quite different wood physical and mechanical attributes, however, the molecular mechanisms underlying the differing wood morphology are still unclear. In this study, we compared the transcriptomes obtained by RNA-Seq between Populus alba × P. glandulosa clone 84K, and Larix kaempferi (Lamb.) Carr trees. Available genome resource served as reference for P. alba × P. glandulosa and the Iso-Seq results of a three-tissues mixture (xylem, phloem, and leaf) were used as the reference for L. kaempferi to compare the xylem-specifically expressed genes and their alternative splicing model. Through screening, we obtained 13,907 xylem-specifically expressed genes (5,954 up-regulated, 7,953 down-regulated) in the xylem of P. alba × P. glandulosa, and 2,596 xylem-specifically expressed genes (1,648 up-regulated, 948 down-regulated) in the xylem of L. kaempferi. From the GO and KEGG analyses, some genes associated with two wood formation-related pathways, namely those for phenylpropanoid biosynthesis, and starch and sucrose metabolism, were successfully screened. Then the distributions and gene expression models between P. alba × P. glandulosa and L. kaempferi in those pathways were compared, which suggested differential wood formation processes between the angiosperm and gymnosperm trees. Furthermore, a Weight Gene Co-expression Network Analysis (WGCNA) for total xylem-specifically expressed genes in two species was conducted, from which wood formation-related modules were selected to build a co-expression network for the two tree species. The genes within this co-expression network showed different co-expression relationships between the angiosperm and gymnosperm woody species. Comparing the alternative splicing events for wood formation-related genes suggests a different post-transcriptional regulation process exists between the angiosperm and gymnosperm trees. Our research thus provides the foundation for the in-depth investigation of different wood formation mechanisms of angiosperm and gymnosperm species.
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Affiliation(s)
- Hui Li
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
- Guangzhou Institute of Forestry and Landscape Architecture, Guangzhou, China
| | - Guanghui Chen
- Shandong Peanut Research Institute, Shandong Academy of Agricultural Sciences, Qingdao, China
| | - Hongying Pang
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
| | - Qiao Wang
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Xinren Dai
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
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Matallana-Ramirez LP, Whetten RW, Sanchez GM, Payn KG. Breeding for Climate Change Resilience: A Case Study of Loblolly Pine ( Pinus taeda L.) in North America. FRONTIERS IN PLANT SCIENCE 2021; 12:606908. [PMID: 33995428 PMCID: PMC8119900 DOI: 10.3389/fpls.2021.606908] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 04/08/2021] [Indexed: 05/25/2023]
Abstract
Earth's atmosphere is warming and the effects of climate change are becoming evident. A key observation is that both the average levels and the variability of temperature and precipitation are changing. Information and data from new technologies are developing in parallel to provide multidisciplinary opportunities to address and overcome the consequences of these changes in forest ecosystems. Changes in temperature and water availability impose multidimensional environmental constraints that trigger changes from the molecular to the forest stand level. These can represent a threat for the normal development of the tree from early seedling recruitment to adulthood both through direct mortality, and by increasing susceptibility to pathogens, insect attack, and fire damage. This review summarizes the strengths and shortcomings of previous work in the areas of genetic variation related to cold and drought stress in forest species with particular emphasis on loblolly pine (Pinus taeda L.), the most-planted tree species in North America. We describe and discuss the implementation of management and breeding strategies to increase resilience and adaptation, and discuss how new technologies in the areas of engineering and genomics are shaping the future of phenotype-genotype studies. Lessons learned from the study of species important in intensively-managed forest ecosystems may also prove to be of value in helping less-intensively managed forest ecosystems adapt to climate change, thereby increasing the sustainability and resilience of forestlands for the future.
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Affiliation(s)
- Lilian P. Matallana-Ramirez
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, Raleigh, NC, United States
| | - Ross W. Whetten
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, Raleigh, NC, United States
| | - Georgina M. Sanchez
- Center for Geospatial Analytics, North Carolina State University, Raleigh, Raleigh, NC, United States
| | - Kitt G. Payn
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, Raleigh, NC, United States
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Wang R, Yin P, Ruixia Y, Liu X, Luo L, Xu J. Genome-wide profiling of alternative splicing genes in hybrid poplar (P.alba×P.glandulosa cv.84K) leaves. PLoS One 2020; 15:e0241914. [PMID: 33206683 PMCID: PMC7673502 DOI: 10.1371/journal.pone.0241914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 10/22/2020] [Indexed: 12/23/2022] Open
Abstract
Alternative splicing (AS) is a post-transcriptional process common in plants and essential for regulation of environmental fitness of plants. In the present study, we focus on the AS events in poplar leaves to understand their effects on plant growth and development. The hybrid poplar (P.alba×P.glandulosa cv.84K) leaves were collected for RNA extraction. The extracted RNA was sequenced using on an Illumina HiSeq™ 2000 platform. Using the Populus trichocarpa genome as the reference, a total of 3810 AS genes were identified (9225 AS events), which accounted for 13.51% of all the expressed genes. Intron retention was the most common AS event, accounting for 43.86% of all the AS events, followed by alternative 3′ splice sites (23.75%), alternative 5′ splice sites (23.71%), and exon skipping (8.68%). Chromosomes 10 had the most condensed AS events (33.67 events/Mb) and chromosome 19 had the least (12.42 events/Mb). Association analysis showed that AS in the poplar leaves was positively correlated with intron length, exon number, exon length, and gene expression level, and was negatively correlated with GC content. AS genes in the poplar leaves were associated mainly with inositol phosphate metabolism and phosphatidylinositol signaling system pathways that would be significant on wooden plant production.
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Affiliation(s)
- Ruixue Wang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
| | - Peng Yin
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
| | - Yang Ruixia
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
| | - Xiao Liu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
| | - Lie Luo
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
| | - Jichen Xu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
- * E-mail:
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11
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Chen MX, Zhang KL, Zhang M, Das D, Fang YM, Dai L, Zhang J, Zhu FY. Alternative splicing and its regulatory role in woody plants. TREE PHYSIOLOGY 2020; 40:1475-1486. [PMID: 32589747 DOI: 10.1093/treephys/tpaa076] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 06/05/2020] [Accepted: 06/16/2020] [Indexed: 05/22/2023]
Abstract
Alternative splicing (AS) is an important post-transcriptional process to enhance proteome diversity in eukaryotic organisms. In plants, numerous reports have primarily focused on AS analysis in model plant species or herbaceous plants, leading to a notable lack of research on AS in woody plants. More importantly, emerging evidence indicates that many important traits, including wood formation and stress resistance, in woody plants are controlled by AS. In this review article, we summarize the current progress of all kinds of AS studies in different tree species at various stages of development and in response to various stresses, revealing the significant role played by AS in woody plants, as well as the similar properties and differential regulation within their herbaceous counterparts. Furthermore, we propose several potential strategies to facilitate the functional characterization of splicing factors in woody plants and evaluate a general pipeline for the systematic characterization of splicing isoforms in a complex AS regulatory network. The utilization of genetic studies and high-throughput omics integration approaches to analyze AS genes and splicing factors is likely to further advance our understanding of AS modulation in woody plants.
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Affiliation(s)
- Mo-Xian Chen
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
- Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha, 410128, China
| | - Kai-Lu Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Min Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Debatosh Das
- Department of Biology, Hong Kong Baptist University, and State Key Laboratory of Agrobiotechnology, the Chinese University of Hong Kong, Shatin 999077, Hong Kong
| | - Yan-Ming Fang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Lei Dai
- Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Jianhua Zhang
- Department of Biology, Hong Kong Baptist University, and State Key Laboratory of Agrobiotechnology, the Chinese University of Hong Kong, Shatin 999077, Hong Kong
| | - Fu-Yuan Zhu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
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12
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Zhang J, Tuskan GA, Tschaplinski TJ, Muchero W, Chen JG. Transcriptional and Post-transcriptional Regulation of Lignin Biosynthesis Pathway Genes in Populus. FRONTIERS IN PLANT SCIENCE 2020; 11:652. [PMID: 32528504 PMCID: PMC7262965 DOI: 10.3389/fpls.2020.00652] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/28/2020] [Indexed: 05/04/2023]
Abstract
Lignin is a heterogeneous polymer of aromatic subunits derived from phenylalanine. It is polymerized in intimate proximity to the polysaccharide components in plant cell walls and provides additional rigidity and compressive strength for plants. Understanding the regulatory mechanisms of lignin biosynthesis is important for genetic modification of the plant cell wall for agricultural and industrial applications. Over the past 10 years the transcriptional regulatory model of lignin biosynthesis has been established in plants. However, the role of post-transcriptional regulation is still largely unknown. Increasing evidence suggests that lignin biosynthesis pathway genes are also regulated by alternative splicing, microRNA, and long non-coding RNA. In this review, we briefly summarize recent progress on the transcriptional regulation, then we focus on reviewing progress on the post-transcriptional regulation of lignin biosynthesis pathway genes in the woody model plant Populus.
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Affiliation(s)
- Jin Zhang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- *Correspondence: Jin Zhang,
| | - Gerald A. Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Timothy J. Tschaplinski
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Wellington Muchero
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Jin-Gui Chen
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Jin-Gui Chen,
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13
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Hybrid Sequencing of Full-Length cDNA Transcripts of the Medicinal Plant Scutellaria baicalensis. Int J Mol Sci 2019; 20:ijms20184426. [PMID: 31505762 PMCID: PMC6770217 DOI: 10.3390/ijms20184426] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/28/2019] [Accepted: 09/04/2019] [Indexed: 11/17/2022] Open
Abstract
Scutellaria baicalensis is a well-known medicinal plant that produces biologically active flavonoids, such as baicalin, baicalein, and wogonin. Pharmacological studies have shown that these compounds have anti-inflammatory, anti-bacterial, and anti-cancer activities. Therefore, it is of great significance to investigate the genetic information of S. baicalensis, particularly the genes related to the biosynthetic pathways of these compounds. Here, we constructed the full-length transcriptome of S. baicalensis using a hybrid sequencing strategy and acquired 338,136 full-length sequences, accounting for 93.3% of the total reads. After the removal of redundancy and correction with Illumina short reads, 75,785 nonredundant transcripts were generated, among which approximately 98% were annotated with significant hits in the protein databases, and 11,135 sequences were classified as lncRNAs. Differentially expressed gene (DEG) analysis showed that most of the genes related to flavonoid biosynthesis were highly expressed in the roots, consistent with previous reports that the flavonoids were mainly synthesized and accumulated in the roots of S. baicalensis. By constructing unique transcription models, a total of 44,071 alternative splicing (AS) events were identified, with intron retention (IR) accounting for the highest proportion (44.5%). A total of 94 AS events were present in five key genes related to flavonoid biosynthesis, suggesting that AS may play important roles in the regulation of flavonoid biosynthesis in S. baicalensis. This study provided a large number of highly accurate full-length transcripts, which represents a valuable genetic resource for further research of the molecular biology of S. baicalensis, such as the development, breeding, and biosynthesis of active ingredients.
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14
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Song QA, Catlin NS, Brad Barbazuk W, Li S. Computational analysis of alternative splicing in plant genomes. Gene 2019; 685:186-195. [PMID: 30321657 DOI: 10.1016/j.gene.2018.10.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 09/16/2018] [Accepted: 10/11/2018] [Indexed: 12/11/2022]
Abstract
Computational analyses play crucial roles in characterizing splicing isoforms in plant genomes. In this review, we provide a survey of computational tools used in recently published, genome-scale splicing analyses in plants. We summarize the commonly used software and pipelines for read mapping, isoform reconstruction, isoform quantification, and differential expression analysis. We also discuss methods for analyzing long reads and the strategies to combine long and short reads in identifying splicing isoforms. We review several tools for characterizing local splicing events, splicing graphs, coding potential, and visualizing splicing isoforms. We further discuss the procedures for identifying conserved splicing isoforms across plant species. Finally, we discuss the outlook of integrating other genomic data with splicing analyses to identify regulatory mechanisms of AS on genome-wide scale.
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Affiliation(s)
- Qi A Song
- Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States of America
| | - Nathan S Catlin
- Department of Biology, University of Florida, Gainesville, FL 32611, United States of America
| | - W Brad Barbazuk
- Department of Biology, University of Florida, Gainesville, FL 32611, United States of America; Genetics Institute, University of Florida, Gainesville, FL 32611, United States of America
| | - Song Li
- School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States of America.
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15
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Myburg AA, Hussey SG, Wang JP, Street NR, Mizrachi E. Systems and Synthetic Biology of Forest Trees: A Bioengineering Paradigm for Woody Biomass Feedstocks. FRONTIERS IN PLANT SCIENCE 2019; 10:775. [PMID: 31281326 PMCID: PMC6597874 DOI: 10.3389/fpls.2019.00775] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 05/28/2019] [Indexed: 05/07/2023]
Abstract
Fast-growing forest plantations are sustainable feedstocks of plant biomass that can serve as alternatives to fossil carbon resources for materials, chemicals, and energy. Their ability to efficiently harvest light energy and carbon from the atmosphere and sequester this into metabolic precursors for lignocellulosic biopolymers and a wide range of plant specialized metabolites make them excellent biochemical production platforms and living biorefineries. Their large sizes have facilitated multi-omics analyses and systems modeling of key biological processes such as lignin biosynthesis in trees. High-throughput 'omics' approaches have also been applied in segregating tree populations where genetic variation creates abundant genetic perturbations of system components allowing construction of systems genetics models linking genes and pathways to complex trait variation. With this information in hand, it is now possible to start using synthetic biology and genome editing techniques in a bioengineering approach based on a deeper understanding and rational design of biological parts, devices, and integrated systems. However, the complexity of the biology and interacting components will require investment in big data informatics, machine learning, and intuitive visualization to fully explore multi-dimensional patterns and identify emergent properties of biological systems. Predictive systems models could be tested rapidly through high-throughput synthetic biology approaches and multigene editing. Such a bioengineering paradigm, together with accelerated genomic breeding, will be crucial for the development of a new generation of woody biorefinery crops.
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Affiliation(s)
- Alexander A. Myburg
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Hatfield, South Africa
- *Correspondence: Alexander A. Myburg, ;
| | - Steven G. Hussey
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Hatfield, South Africa
| | - Jack P. Wang
- Forest Biotechnology Group, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, United States
| | - Nathaniel R. Street
- Umeå Plant Science Center, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Eshchar Mizrachi
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Hatfield, South Africa
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16
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Clark S, Yu F, Gu L, Min XJ. Expanding Alternative Splicing Identification by Integrating Multiple Sources of Transcription Data in Tomato. FRONTIERS IN PLANT SCIENCE 2019; 10:689. [PMID: 31191588 PMCID: PMC6546887 DOI: 10.3389/fpls.2019.00689] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 05/08/2019] [Indexed: 05/17/2023]
Abstract
Tomato (Solanum lycopersicum) is an important vegetable and fruit crop. Its genome was completely sequenced and there are also a large amount of available expressed sequence tags (ESTs) and short reads generated by RNA sequencing (RNA-seq) technologies. Mapping transcripts including mRNA sequences, ESTs, and RNA-seq reads to the genome allows identifying pre-mRNA alternative splicing (AS), a post-transcriptional process generating two or more RNA isoforms from one pre-mRNA transcript. We comprehensively analyzed the AS landscape in tomato by integrating genome mapping information of all available mRNA and ESTs with mapping information of RNA-seq reads which were collected from 27 published projects. A total of 369,911 AS events were identified from 34,419 genomic loci involving 161,913 transcripts. Within the basic AS events, intron retention is the prevalent type (18.9%), followed by alternative acceptor site (12.9%) and alternative donor site (7.3%), with exon skipping as the least type (6.0%). Complex AS types having two or more basic event accounted for 54.9% of total AS events. Within 35,768 annotated protein-coding gene models, 23,233 gene models were found having pre-mRNAs generating AS isoform transcripts. Thus the estimated AS rate was 65.0% in tomato. The list of identified AS genes with their corresponding transcript isoforms serves as a catalog for further detailed examination of gene functions in tomato biology. The post-transcriptional information is also expected to be useful in improving the predicted gene models in tomato. The sequence and annotation information can be accessed at plant alternative splicing database (http://proteomics.ysu.edu/altsplice).
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Affiliation(s)
- Sarah Clark
- Department of Biological Sciences, Youngstown State University, Youngstown, OH, United States
| | - Feng Yu
- Department of Computer Science and Information Systems, Youngstown State University, Youngstown, OH, United States
| | - Lianfeng Gu
- Basic Forestry and Proteomics Center, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiang Jia Min
- Department of Biological Sciences, Youngstown State University, Youngstown, OH, United States
- *Correspondence: Xiang Jia Min,
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17
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Filichkin SA, Hamilton M, Dharmawardhana PD, Singh SK, Sullivan C, Ben-Hur A, Reddy ASN, Jaiswal P. Abiotic Stresses Modulate Landscape of Poplar Transcriptome via Alternative Splicing, Differential Intron Retention, and Isoform Ratio Switching. FRONTIERS IN PLANT SCIENCE 2018; 9:5. [PMID: 29483921 PMCID: PMC5816337 DOI: 10.3389/fpls.2018.00005] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/03/2018] [Indexed: 05/19/2023]
Abstract
Abiotic stresses affect plant physiology, development, growth, and alter pre-mRNA splicing. Western poplar is a model woody tree and a potential bioenergy feedstock. To investigate the extent of stress-regulated alternative splicing (AS), we conducted an in-depth survey of leaf, root, and stem xylem transcriptomes under drought, salt, or temperature stress. Analysis of approximately one billion of genome-aligned RNA-Seq reads from tissue- or stress-specific libraries revealed over fifteen millions of novel splice junctions. Transcript models supported by both RNA-Seq and single molecule isoform sequencing (Iso-Seq) data revealed a broad array of novel stress- and/or tissue-specific isoforms. Analysis of Iso-Seq data also resulted in the discovery of 15,087 novel transcribed regions of which 164 show AS. Our findings demonstrate that abiotic stresses profoundly perturb transcript isoform profiles and trigger widespread intron retention (IR) events. Stress treatments often increased or decreased retention of specific introns - a phenomenon described here as differential intron retention (DIR). Many differentially retained introns were regulated in a stress- and/or tissue-specific manner. A subset of transcripts harboring super stress-responsive DIR events showed persisting fluctuations in the degree of IR across all treatments and tissue types. To investigate coordinated dynamics of intron-containing transcripts in the study we quantified absolute copy number of isoforms of two conserved transcription factors (TFs) using Droplet Digital PCR. This case study suggests that stress treatments can be associated with coordinated switches in relative ratios between fully spliced and intron-retaining isoforms and may play a role in adjusting transcriptome to abiotic stresses.
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Affiliation(s)
- Sergei A. Filichkin
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States
| | - Michael Hamilton
- Department of Computer Science, Colorado State University, Fort Collins, CO, United States
| | | | - Sunil K. Singh
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States
| | - Christopher Sullivan
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, United States
| | - Asa Ben-Hur
- Department of Computer Science, Colorado State University, Fort Collins, CO, United States
| | - Anireddy S. N. Reddy
- Department of Biology and Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Pankaj Jaiswal
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States
- *Correspondence: Pankaj Jaiswal,
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Zhang QL, Zhu QH, Xie ZQ, Xu B, Wang XQ, Chen JY. Genome-wide gene expression analysis of amphioxus (Branchiostoma belcheri) following lipopolysaccharide challenge using strand-specific RNA-seq. RNA Biol 2017; 14:1799-1809. [PMID: 28837390 PMCID: PMC5731807 DOI: 10.1080/15476286.2017.1367890] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Amphioxus is the closest living proxy for exploring the evolutionary origin of the immune system in vertebrates. To understand the immune responses of amphioxus to lipopolysaccharide (LPS), 5 ribosomal RNA (rRNA)-depleted libraries of amphioxus were constructed, including one control (0 h) library and 4 treatment libraries at 6, 12, 24, and 48 h post-injection (hpi) with LPS. The transcriptome of Branchiostoma belcheri was analyzed using strand-specific RNA sequencing technology (RNA-seq). A total of 6161, 6665, 7969, and 6447 differentially expressed genes (DEGs) were detected at 6, 12, 24, and 48 hpi, respectively, compared with expression levels at 0 h. We identified amphioxus genes active during the acute-phase response to LPS at different time points after stimulation. Moreover, to better visualize the resolution phase of the immune process during immune response, we identified 6057 and 5235 DEGs at 48 hpi by comparing with 6 and 24 hpi, respectively. Through real-time quantitative PCR (qRT-PCR) analysis of 12 selected DEGs, we demonstrated the accuracy of the RNA-seq data in this study. Functional enrichment analysis of DEGs demonstrated that most terms were related to defense and immune responses, disease and infection, cell apoptosis, and metabolism and catalysis. Subsequently, we identified 1330, 485, 670, 911, and 1624 time-specific genes (TSGs) at 0, 6, 12, 24, and 48 hpi. Time-specific terms at each of 5 time points were primarily involved in development, immune signaling, signal transduction, DNA repair and stability, and metabolism and catalysis, respectively. As this is the first study to report the transcriptome of an organism with primitive immunity following LPS challenge at multiple time points, it provides gene expression information for further research into the evolution of immunity in vertebrates.
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Affiliation(s)
- Qi-Lin Zhang
- a LPS , Nanjing Institute of Geology and Paleontology, Chinese Academy of Science , Nanjing , China ; State Key Laboratory of Pharmaceutical Biotechnology , School of Life Science, Nanjing University , Nanjing , China
| | | | - Zheng-Qing Xie
- a LPS , Nanjing Institute of Geology and Paleontology, Chinese Academy of Science , Nanjing , China ; State Key Laboratory of Pharmaceutical Biotechnology , School of Life Science, Nanjing University , Nanjing , China
| | - Bin Xu
- a LPS , Nanjing Institute of Geology and Paleontology, Chinese Academy of Science , Nanjing , China ; State Key Laboratory of Pharmaceutical Biotechnology , School of Life Science, Nanjing University , Nanjing , China
| | - Xiu-Qiang Wang
- a LPS , Nanjing Institute of Geology and Paleontology, Chinese Academy of Science , Nanjing , China ; State Key Laboratory of Pharmaceutical Biotechnology , School of Life Science, Nanjing University , Nanjing , China
| | - Jun-Yuan Chen
- a LPS , Nanjing Institute of Geology and Paleontology, Chinese Academy of Science , Nanjing , China ; State Key Laboratory of Pharmaceutical Biotechnology , School of Life Science, Nanjing University , Nanjing , China
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19
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Evolutionarily Conserved Alternative Splicing Across Monocots. Genetics 2017; 207:465-480. [PMID: 28839042 DOI: 10.1534/genetics.117.300189] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 08/11/2017] [Indexed: 12/22/2022] Open
Abstract
One difficulty when identifying alternative splicing (AS) events in plants is distinguishing functional AS from splicing noise. One way to add confidence to the validity of a splice isoform is to observe that it is conserved across evolutionarily related species. We use a high throughput method to identify junction-based conserved AS events from RNA-Seq data across nine plant species, including five grass monocots (maize, sorghum, rice, Brachpodium, and foxtail millet), plus two nongrass monocots (banana and African oil palm), the eudicot Arabidopsis, and the basal angiosperm Amborella In total, 9804 AS events were found to be conserved between two or more species studied. In grasses containing large regions of conserved synteny, the frequency of conserved AS events is twice that observed for genes outside of conserved synteny blocks. In plant-specific RS and RS2Z subfamilies of the serine/arginine (SR) splice-factor proteins, we observe both conservation and divergence of AS events after the whole genome duplication in maize. In addition, plant-specific RS and RS2Z splice-factor subfamilies are highly connected with R2R3-MYB in STRING functional protein association networks built using genes exhibiting conserved AS. Furthermore, we discovered that functional protein association networks constructed around genes harboring conserved AS events are enriched for phosphatases, kinases, and ubiquitylation genes, which suggests that AS may participate in regulating signaling pathways. These data lay the foundation for identifying and studying conserved AS events in the monocots, particularly across grass species, and this conserved AS resource identifies an additional layer between genotype to phenotype that may impact future crop improvement efforts.
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20
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Iñiguez LP, Ramírez M, Barbazuk WB, Hernández G. Identification and analysis of alternative splicing events in Phaseolus vulgaris and Glycine max. BMC Genomics 2017; 18:650. [PMID: 28830361 PMCID: PMC5568362 DOI: 10.1186/s12864-017-4054-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 08/11/2017] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND The vast diversification of proteins in eukaryotic cells has been related with multiple transcript isoforms from a single gene that result in alternative splicing (AS) of primary transcripts. Analysis of RNA sequencing data from expressed sequence tags and next generation RNA sequencing has been crucial for AS identification and genome-wide AS studies. For the identification of AS events from the related legume species Phaseolus vulgaris and Glycine max, 157 and 88 publicly available RNA-seq libraries, respectively, were analyzed. RESULTS We identified 85,570 AS events from P. vulgaris in 72% of expressed genes and 134,316 AS events in 70% of expressed genes from G. max. These were categorized in seven AS event types with intron retention being the most abundant followed by alternative acceptor and alternative donor, representing ~75% of all AS events in both plants. Conservation of AS events in homologous genes between the two species was analyzed where an overrepresentation of AS affecting 5'UTR regions was observed for certain types of AS events. The conservation of AS events was experimentally validated for 8 selected genes, through RT-PCR analysis. The different types of AS events also varied by relative position in the genes. The results were consistent in both species. CONCLUSIONS The identification and analysis of AS events are first steps to understand their biological relevance. The results presented here from two related legume species reveal high conservation, over ~15-20 MY of divergence, and may point to the biological relevance of AS.
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Affiliation(s)
- Luis P. Iñiguez
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos Mexico
| | - Mario Ramírez
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos Mexico
| | | | - Georgina Hernández
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos Mexico
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21
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Zinkgraf M, Gerttula S, Groover A. Transcript profiling of a novel plant meristem, the monocot cambium. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2017; 59:436-449. [PMID: 28304126 DOI: 10.1111/jipb.12538] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 03/15/2017] [Indexed: 06/06/2023]
Abstract
While monocots lack the ability to produce a vascular cambium or woody growth, some monocot lineages evolved a novel lateral meristem, the monocot cambium, which supports secondary radial growth of stems. In contrast to the vascular cambium found in woody angiosperm and gymnosperm species, the monocot cambium produces secondary vascular bundles, which have an amphivasal organization of tracheids encircling a central strand of phloem. Currently there is no information concerning the molecular genetic basis of the development or evolution of the monocot cambium. Here we report high-quality transcriptomes for monocot cambium and early derivative tissues in two monocot genera, Yucca and Cordyline. Monocot cambium transcript profiles were compared to those of vascular cambia and secondary xylem tissues of two forest tree species, Populus trichocarpa and Eucalyptus grandis. Monocot cambium transcript levels showed that there are extensive overlaps between the regulation of monocot cambia and vascular cambia. Candidate regulatory genes that vary between the monocot and vascular cambia were also identified, and included members of the KANADI and CLE families involved in polarity and cell-cell signaling, respectively. We suggest that the monocot cambium may have evolved in part through reactivation of genetic mechanisms involved in vascular cambium regulation.
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Affiliation(s)
- Matthew Zinkgraf
- US Forest Service, Pacific Southwest Research Station, Davis, California, USA
- Department of Computer Science, University of California, Davis, USA
| | - Suzanne Gerttula
- US Forest Service, Pacific Southwest Research Station, Davis, California, USA
| | - Andrew Groover
- US Forest Service, Pacific Southwest Research Station, Davis, California, USA
- Department of Plant Biology, University of California, Davis, USA
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22
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Srinivasan A, Jiménez-Gómez JM, Fornara F, Soppe WJJ, Brambilla V. Alternative splicing enhances transcriptome complexity in desiccating seeds. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2016; 58:947-958. [PMID: 27121908 DOI: 10.1111/jipb.12482] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/20/2016] [Indexed: 05/22/2023]
Abstract
Before being dispersed in the environment, mature seeds need to be dehydrated. The survival of seeds after dispersal depends on their low hydration in combination with high desiccation tolerance. These characteristics are established during seed maturation. Some key seed maturation genes have been reported to be regulated by alternative splicing (AS). However, so far AS was described only for single genes and a comprehensive analysis of AS during seed maturation has been lacking. We investigated gene expression and AS during Arabidopsis thaliana seed development at a global level, before and after desiccation. Bioinformatics tools were developed to identify differentially spliced regions within genes. Our data suggest the importance and shows the peculiar features of AS during seed desiccation. We identified AS in 34% of genes that are expressed at both timepoints before and after desiccation. Most of these AS transcript variants had not been found before in other tissues. Among the AS genes some seed master regulators could be found. Interestingly, 6% of all expressed transcripts were not transcriptionally regulated during desiccation, but only modified by AS. We propose that AS should be more routinely taken into account in the analysis of transcriptomic data to prevent overlooking potentially important regulators.
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Affiliation(s)
- Arunkumar Srinivasan
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Open Analytics, Antwerp, Belgium
| | - José M Jiménez-Gómez
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, Versailles, France
| | - Fabio Fornara
- University of Milan, Department of Biosciences, Milano 20133, Italy
| | - Wim J J Soppe
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Vittoria Brambilla
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- University of Milan, Department of Biosciences, Milano 20133, Italy
- University of Milan, Department of Agricultural and Environmental Sciences, via Celoria 2, 20133 Milano, Italy
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Zhang C, Yang H, Yang H. Evolutionary Character of Alternative Splicing in Plants. Bioinform Biol Insights 2016; 9:47-52. [PMID: 26819552 PMCID: PMC4721685 DOI: 10.4137/bbi.s33716] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/19/2015] [Accepted: 10/24/2015] [Indexed: 12/21/2022] Open
Abstract
Alternative splicing (AS) is one of the most important ways to enhance the functional diversity of genes. Huge amounts of data have been produced by microarray, expressed sequence tag, and RNA-seq, and plenty of methods have been developed specifically for this task. The most frequently asked questions in previous research were as follows. What is the content rate of AS genes among the whole gene set? How many AS types are presented in the genome, and which type is dominant? How about the conservation ability of AS among different species? Which kinds of isoforms from some genes have the environmental response to help individual adaptation? Based on this background, we collected analysis results from 17 species to try to map out the landscape of AS studies in plants. We have noted the shortages of previous results, and we appeal to all scientists working in the AS field to make a standard protocol so that analyses between different projects are comparable.
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Affiliation(s)
- Chengjun Zhang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, People's Republic of China
| | - Hong Yang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, People's Republic of China
| | - Huizhao Yang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, People's Republic of China
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