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Deb SK, Edger PP, Pires JC, McKain MR. Patterns, mechanisms, and consequences of homoeologous exchange in allopolyploid angiosperms: a genomic and epigenomic perspective. THE NEW PHYTOLOGIST 2023; 238:2284-2304. [PMID: 37010081 DOI: 10.1111/nph.18927] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 03/16/2023] [Indexed: 05/19/2023]
Abstract
Allopolyploids result from hybridization between different evolutionary lineages coupled with genome doubling. Homoeologous chromosomes (chromosomes with common shared ancestry) may undergo recombination immediately after allopolyploid formation and continue over successive generations. The outcome of this meiotic pairing behavior is dynamic and complex. Homoeologous exchanges (HEs) may lead to the formation of unbalanced gametes, reduced fertility, and selective disadvantage. By contrast, HEs could act as sources of novel evolutionary substrates, shifting the relative dosage of parental gene copies, generating novel phenotypic diversity, and helping the establishment of neo-allopolyploids. However, HE patterns vary among lineages, across generations, and even within individual genomes and chromosomes. The causes and consequences of this variation are not fully understood, though interest in this evolutionary phenomenon has increased in the last decade. Recent technological advances show promise in uncovering the mechanistic basis of HEs. Here, we describe recent observations of the common patterns among allopolyploid angiosperm lineages, underlying genomic and epigenomic features, and consequences of HEs. We identify critical research gaps and discuss future directions with far-reaching implications in understanding allopolyploid evolution and applying them to the development of important phenotypic traits of polyploid crops.
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Affiliation(s)
- Sontosh K Deb
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, 35487, USA
- Department of Forestry and Environmental Science, Shahjalal University of Science and Technology, Sylhet, 3114, Bangladesh
| | - Patrick P Edger
- Department of Horticulture, Michigan State University, East Lansing, MI, 48823, USA
- Genetics and Genome Sciences Program, Michigan State University, East Lansing, MI, 48823, USA
| | - J Chris Pires
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, 80523, USA
| | - Michael R McKain
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, 35487, USA
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2
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de Jong GW, Adams KL. Subgenome-dominant expression and alternative splicing in response to Sclerotinia infection in polyploid Brassica napus and progenitors. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:142-158. [PMID: 36710652 DOI: 10.1111/tpj.16127] [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: 03/14/2022] [Accepted: 01/11/2023] [Indexed: 06/18/2023]
Abstract
Polyploidy has played an extensive role in the evolution of flowering plants. Allopolyploids, with subgenomes containing duplicated gene pairs called homeologs, can show rapid transcriptome changes including novel alternative splicing (AS) patterns. The extent to which abiotic stress modulates AS of homeologs is a nascent topic in polyploidy research. We subjected both resynthesized and natural lines of polyploid Brassica napus, along with the progenitors Brassica rapa and Brassica oleracea, to infection with the fungal pathogen Sclerotinia sclerotiorum. RNA-sequencing analyses revealed widespread divergence between polyploid subgenomes in both gene expression and AS patterns. Resynthesized B. napus displayed significantly more A and C subgenome biased homeologs under pathogen infection than during uninfected growth. Differential AS (DAS) in response to infection was highest in natural B. napus (12 709 DAS events) and lower in resynthesized B. napus (8863 DAS events). Natural B. napus had more upregulated events and fewer downregulated events. There was a global expression bias towards the B. oleracea-derived (C) subgenome in both resynthesized and natural B. napus, enhanced by widespread non-parental downregulation of the B. rapa-derived (A) homeolog. In the resynthesized B. napus, this resulted in a disproportionate C subgenome contribution to the pathogen defense response, characterized by biases in both transcript expression levels and the proportion of induced genes. Our results elucidate the complex ways in which Sclerotinia infection affects expression and AS of homeologous genes in resynthesized and natural B. napus.
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Affiliation(s)
- Grant W de Jong
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
| | - Keith L Adams
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
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3
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Wang B, Lv R, Zhang Z, Yang C, Xun H, Liu B, Gong L. Homoeologous exchange enables rapid evolution of tolerance to salinity and hyper-osmotic stresses in a synthetic allotetraploid wheat. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:7488-7502. [PMID: 36055762 DOI: 10.1093/jxb/erac355] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
The link between polyploidy and enhanced adaptation to environmental stresses could be a result of polyploidy itself harbouring higher tolerance to adverse conditions, or polyploidy possessing higher evolvability than diploids under stress conditions. Natural polyploids are inherently unsuitable to disentangle these two possibilities. Using selfed progenies of a synthetic allotetraploid wheat AT3 (AADD) along with its diploid parents, Triticum urartu TMU38 (AA) and Aegilops tauschii TQ27 (DD), we addressed the foregoing issue under abiotic salinity and hyper-osmotic (drought-like) stress. Under short duration of both stresses, euploid plants of AT3 showed intermediate tolerance of diploid parents; under life-long duration of both stresses, tolerant individuals to either stress emerged from selfed progenies of AT3, but not from comparable-sized diploid parent populations. Tolerance to both stresses were conditioned by the same two homoeologous exchanges (HEs; 2DS/2AS and 3DL/3AL), and at least one HE needed to be at the homozygous state. Transcriptomic analyses revealed that hyper-up-regulation of within-HE stress responsive genes of the A sub-genome origin is likely responsible for the dual-stress tolerant phenotypes. Our results suggest that HE-mediated inter-sub-genome rearrangements can be an important mechanism leading to adaptive evolution in allopolyploids as well as a promising target for genetic manipulation in crop improvement.
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Affiliation(s)
- Bin Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Ruili Lv
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Zhibin Zhang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Chunwu Yang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Hongwei Xun
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Bao Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Lei Gong
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
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Zhang Z, Xun H, Lv R, Gou X, Ma X, Li J, Zhao J, Li N, Gong L, Liu B. Effects of homoeologous exchange on gene expression and alternative splicing in a newly formed allotetraploid wheat. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:1267-1282. [PMID: 35763523 DOI: 10.1111/tpj.15886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 06/18/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Homoeologous exchange (HE) is a major mechanism generating post-polyploidization genetic variation with important evolutionary consequences. However, the direct impacts of HE on gene expression and transcript diversity in allopolyploids without the intertwined evolutionary processes remain to be fully understood. Here, we analyzed high-throughput RNA-seq data of young leaves from plant groups of a synthetic allotetraploid wheat (AADD), which contained variable numbers of HEs. We aimed to investigate if and to which extent HE directly impacts gene expression and alternative splicing (AS). We found that HE impacts expression of genes located within HE regions primarily via a cis-acting dosage effect, which led to significant changes in the total expression level of homoeologous gene pairs, especially for homoeologs whose original expression was biased. In parallel, HE also influences expression of a large number of genes residing in non-HE regions by trans-regulation leading to convergent expression of homoeologs. Intriguingly, when taking the original relative homoeolog expression states into account, homoeolog pairs under trans-effect are more prone to manifesting a convergent response to the HEs whereas those under cis-regulation tended to show further exacerbated subgenome-biased expression. Moreover, HE-induced quantitative, largely individual-specific, changes of AS events were detected. Similar to homoeologous expression, homoeo-AS events under trans-effect were more responsive to HE. HE therefore exerts multifaceted immediate effects on gene expression and, to a less extent, on individualized transcript diversity in nascent allopolyploidy.
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Affiliation(s)
- Zhibin Zhang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Hongwei Xun
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Ruili Lv
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Xiaowan Gou
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
- School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Xintong Ma
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Juzuo Li
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Jing Zhao
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Ning Li
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Lei Gong
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Bao Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
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Zhang M, Li N, Yang W, Liu B. Genome-wide differences in gene expression and alternative splicing in developing embryo and endosperm, and between F1 hybrids and their parental pure lines in sorghum. PLANT MOLECULAR BIOLOGY 2022; 108:1-14. [PMID: 34846608 DOI: 10.1007/s11103-021-01196-y] [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: 06/03/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
Developing embryo and endosperm of sorghum show substantial and multifaceted differences in gene expression and alternative splicing, which are potentially relevant to heterosis. Differential regulation of gene expression and alternative splicing (AS) are major molecular mechanisms dictating plant growth and development, as well as underpinning heterosis in F1 hybrids. Here, using deep RNA-sequencing we analyzed differences in genome-wide gene expression and AS between developing embryo and endosperm, and between F1 hybrids and their pure-line parents in sorghum. We uncover dramatic differences in both gene expression and AS between embryo and endosperm with respect to gene features and functions, which are consistent with the fundamentally different biological roles of the two tissues. Accordingly, F1 hybrids showed substantial and multifaceted differences in gene expression and AS compared with their pure-line parents, again with clear tissue specificities including extents of difference, genes involved and functional enrichments. Our results provide useful transcriptome resources as well as novel insights for further elucidation of seed yield heterosis in sorghum and related crops.
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Affiliation(s)
- Meishan Zhang
- Department of Agronomy, Jilin Agricultural University, Changchun, 130118, People's Republic of China
| | - Ning Li
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China
| | - Weiguang Yang
- Department of Agronomy, Jilin Agricultural University, Changchun, 130118, People's Republic of China.
| | - Bao Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China.
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Gao P, Quilichini TD, Zhai C, Qin L, Nilsen KT, Li Q, Sharpe AG, Kochian LV, Zou J, Reddy AS, Wei Y, Pozniak C, Patterson N, Gillmor CS, Datla R, Xiang D. Alternative splicing dynamics and evolutionary divergence during embryogenesis in wheat species. PLANT BIOTECHNOLOGY JOURNAL 2021; 19:1624-1643. [PMID: 33706417 PMCID: PMC8384600 DOI: 10.1111/pbi.13579] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 02/25/2021] [Accepted: 03/08/2021] [Indexed: 05/07/2023]
Abstract
Among polyploid species with complex genomic architecture, variations in the regulation of alternative splicing (AS) provide opportunities for transcriptional and proteomic plasticity and the potential for generating trait diversities. However, the evolution of AS and its influence on grain development in diploid grass and valuable polyploid wheat crops are poorly understood. To address this knowledge gap, we developed a pipeline for the analysis of alternatively spliced transcript isoforms, which takes the high sequence similarity among polyploid wheat subgenomes into account. Through analysis of synteny and detection of collinearity of homoeologous subgenomes, conserved and specific AS events across five wheat and grass species were identified. A global analysis of the regulation of AS in diploid grass and polyploid wheat grains revealed diversity in AS events not only between the endosperm, pericarp and embryo overdevelopment, but also between subgenomes. Analysis of AS in homoeologous triads of polyploid wheats revealed evolutionary divergence between gene-level and transcript-level regulation of embryogenesis. Evolutionary age analysis indicated that the generation of novel transcript isoforms has occurred in young genes at a more rapid rate than in ancient genes. These findings, together with the development of comprehensive AS resources for wheat and grass species, advance understanding of the evolution of regulatory features of AS during embryogenesis and grain development in wheat.
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Affiliation(s)
- Peng Gao
- Global Institute for Food SecurityUniversity of SaskatchewanSaskatoonSKCanada
| | - Teagen D. Quilichini
- Aquatic and Crop Resource DevelopmentNational Research Council CanadaSaskatoonSKCanada
| | - Chun Zhai
- Agriculture and Agri‐Food CanadaSaskatoon Research and Development CentreSaskatoonSKCanada
| | - Li Qin
- College of Art & ScienceUniversity of SaskatchewanSaskatoonSKCanada
| | - Kirby T. Nilsen
- Agriculture and Agri‐Food CanadaBrandon Research and Development CentreBrandonMBCanada
| | - Qiang Li
- National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanChina
| | - Andrew G. Sharpe
- Global Institute for Food SecurityUniversity of SaskatchewanSaskatoonSKCanada
| | - Leon V. Kochian
- Global Institute for Food SecurityUniversity of SaskatchewanSaskatoonSKCanada
| | - Jitao Zou
- Aquatic and Crop Resource DevelopmentNational Research Council CanadaSaskatoonSKCanada
| | - Anireddy S.N. Reddy
- Department of Biology and Program in Cell and Molecular BiologyColorado State UniversityFort CollinsCOUSA
| | - Yangdou Wei
- College of Art & ScienceUniversity of SaskatchewanSaskatoonSKCanada
| | - Curtis Pozniak
- Crop Development CentreUniversity of SaskatchewanSaskatoonSKCanada
| | - Nii Patterson
- Aquatic and Crop Resource DevelopmentNational Research Council CanadaSaskatoonSKCanada
| | - C. Stewart Gillmor
- Laboratorio Nacional de Genómica para la Biodiversidad (Langebio)Unidad de Genómica AvanzadaCentro de Investigación y Estudios Avanzados del IPN (CINVESTAV‐IPN)IrapuatoGuanajuatoMexico
| | - Raju Datla
- Global Institute for Food SecurityUniversity of SaskatchewanSaskatoonSKCanada
| | - Daoquan Xiang
- Aquatic and Crop Resource DevelopmentNational Research Council CanadaSaskatoonSKCanada
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Cenci A, Sardos J, Hueber Y, Martin G, Breton C, Roux N, Swennen R, Carpentier SC, Rouard M. Unravelling the complex story of intergenomic recombination in ABB allotriploid bananas. ANNALS OF BOTANY 2021; 127:7-20. [PMID: 32104882 PMCID: PMC7750727 DOI: 10.1093/aob/mcaa032] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/25/2020] [Indexed: 05/24/2023]
Abstract
BACKGROUND AND AIMS Bananas (Musa spp.) are a major staple food for hundreds of millions of people in developing countries. The cultivated varieties are seedless and parthenocarpic clones of which the ancestral origin remains to be clarified. The most important cultivars are triploids with an AAA, AAB or ABB genome constitution, with A and B genomes provided by M. acuminata and M. balbisiana, respectively. Previous studies suggested that inter-genome recombinations were relatively common in banana cultivars and that triploids were more likely to have passed through an intermediate hybrid. In this study, we investigated the chromosome structure within the ABB group, composed of starchy cooking bananas that play an important role in food security. METHODS Using SNP markers called from RADSeq data, we studied the chromosome structure of 36 ABB genotypes spanning defined taxonomic subgroups. To complement our understanding, we searched for similar events within nine AB hybrid genotypes. KEY RESULTS Recurrent homologous exchanges (HEs), i.e. chromatin exchanges between A and B subgenomes, were unravelled with at least nine founding events (HE patterns) at the origin of ABB bananas prior to clonal diversification. Two independent founding events were found for Pisang Awak genotypes. Two HE patterns, corresponding to genotypes Pelipita and Klue Teparod, show an over-representation of B genome contribution. Three HE patterns mainly found in Indian accessions shared some recombined regions and two additional patterns did not correspond to any known subgroups. CONCLUSIONS The discovery of the nine founding events allowed an investigation of the possible routes that led to the creation of the different subgroups, which resulted in new hypotheses. Based on our observations, we suggest different routes that gave rise to the current diversity in the ABB cultivars, routes involving primary AB hybrids, routes leading to shared HEs and routes leading to a B excess ratio. Genetic fluxes took place between M. acuminata and M. balbisiana, particularly in India, where these unbalanced AB hybrids and ABB allotriploids originated, and where cultivated M. balbisiana are abundant. The result of this study clarifies the classification of ABB cultivars, possibly leading to the revision of the classification of this subgroup.
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Affiliation(s)
- Alberto Cenci
- Alliance Bioversity International - CIAT, Montpellier, France
| | - Julie Sardos
- Alliance Bioversity International - CIAT, Montpellier, France
| | - Yann Hueber
- Alliance Bioversity International - CIAT, Montpellier, France
| | - Guillaume Martin
- AGAP, Université de Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
- CIRAD, UMR AGAP, Montpellier, France
| | | | - Nicolas Roux
- Alliance Bioversity International - CIAT, Montpellier, France
| | - Rony Swennen
- Alliance Bioversity International - CIAT, Leuven, Belgium
- Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, KU Leuven, Leuven, Belgium
- International Institute of Tropical Agriculture, c/o The Nelson Mandela African Institution of Science and Technology (NM-AIST), Arusha, Tanzania
| | | | - Mathieu Rouard
- Alliance Bioversity International - CIAT, Montpellier, France
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Wu Y, Lin F, Zhou Y, Wang J, Sun S, Wang B, Zhang Z, Li G, Lin X, Wang X, Sun Y, Dong Q, Xu C, Gong L, Wendel JF, Zhang Z, Liu B. Genomic mosaicism due to homoeologous exchange generates extensive phenotypic diversity in nascent allopolyploids. Natl Sci Rev 2020; 8:nwaa277. [PMID: 34691642 PMCID: PMC8288387 DOI: 10.1093/nsr/nwaa277] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/01/2020] [Indexed: 01/03/2023] Open
Abstract
Allopolyploidy is an important process in plant speciation, yet newly formed allopolyploid species typically suffer from extreme genetic bottlenecks. One escape from this impasse might be homoeologous meiotic pairing, during which homoeologous exchanges (HEs) generate phenotypically variable progeny. However, the immediate genome-wide patterns and resulting phenotypic diversity generated by HEs remain largely unknown. Here, we analyzed the genome composition of 202 phenotyped euploid segmental allopolyploid individuals from the fourth selfed generation following chromosomal doubling of reciprocal F1 hybrids of crosses between rice subspecies, using whole-genome sequencing. We describe rampant occurrence of HEs that, by overcoming incompatibility or conferring superiority of hetero-cytonuclear interactions, generate extensive and individualized genomic mosaicism across the analyzed tetraploids. We show that the resulting homoeolog copy number alteration in tetraploids affects known-function genes and their complex genetic interactions, in the process creating extraordinary phenotypic diversity at the population level following a single initial hybridization. Our results illuminate the immediate genomic landscapes possible in a tetraploid genomic environment, and underscore HE as an important mechanism that fuels rapid phenotypic diversification accompanying the initial stages of allopolyploid evolution.
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Affiliation(s)
- Ying Wu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
- Department of Crop & Soil Sciences, Washington State University, Pullman, WA 99164, USA
| | - Fan Lin
- Brightseed Inc., San Francisco, CA 94107, USA
| | - Yao Zhou
- Department of Crop & Soil Sciences, Washington State University, Pullman, WA 99164, USA
| | - Jie Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
| | - Shuai Sun
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
| | - Bin Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
| | - Zhibin Zhang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
| | - Guo Li
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
| | - Xiuyun Lin
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
| | - Xutong Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
| | - Yue Sun
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
| | - Qianli Dong
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
| | - Chunming Xu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
| | - Lei Gong
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
- Department of Ecology, Evolution & Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Jonathan F Wendel
- Department of Ecology, Evolution & Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Zhiwu Zhang
- Department of Crop & Soil Sciences, Washington State University, Pullman, WA 99164, USA
| | - Bao Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China
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Scarrow M, Wang Y, Sun G. Molecular regulatory mechanisms underlying the adaptability of polyploid plants. Biol Rev Camb Philos Soc 2020; 96:394-407. [PMID: 33098261 DOI: 10.1111/brv.12661] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 12/11/2022]
Abstract
Polyploidization influences the genetic composition and gene expression of an organism. This multi-level genetic change allows the formation of new regulatory pathways leading to increased adaptability. Although both forms of polyploidization provide advantages, autopolyploids were long thought to have little impact on plant divergence compared to allopolyploids due to their formation through genome duplication only, rather than in combination with hybridization. Recent advances have begun to clarify the molecular regulatory mechanisms such as microRNAs, alternative splicing, RNA-binding proteins, histone modifications, chromatin remodelling, DNA methylation, and N6 -methyladenosine (m6A) RNA methylation underlying the evolutionary success of polyploids. Such research is expanding our understanding of the evolutionary adaptability of polyploids and the regulatory pathways that allow adaptive plasticity in a variety of plant species. Herein we review the roles of individual molecular regulatory mechanisms and their potential synergistic pathways underlying plant evolution and adaptation. Notably, increasing interest in m6A methylation has provided a new component in potential mechanistic coordination that is still predominantly unexplored. Future research should attempt to identify and functionally characterize the evolutionary impact of both individual and synergistic pathways in polyploid plant species.
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Affiliation(s)
- Margaret Scarrow
- Department of Biology, Saint Mary's University, Halifax, Nova Scotia, B3H 3C3, Canada
| | - Yiling Wang
- College of Life Science, Shanxi Normal University, Linfen, Shanxi, 041000, China
| | - Genlou Sun
- Department of Biology, Saint Mary's University, Halifax, Nova Scotia, B3H 3C3, Canada
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10
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Mason AS, Wendel JF. Homoeologous Exchanges, Segmental Allopolyploidy, and Polyploid Genome Evolution. Front Genet 2020; 11:1014. [PMID: 33005183 PMCID: PMC7485112 DOI: 10.3389/fgene.2020.01014] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/10/2020] [Indexed: 01/08/2023] Open
Abstract
Polyploidy is a major force in plant evolution and speciation. In newly formed allopolyploids, pairing between related chromosomes from different subgenomes (homoeologous chromosomes) during meiosis is common. The initial stages of allopolyploid formation are characterized by a spectrum of saltational genomic and regulatory alterations that are responsible for evolutionary novelty. Here we highlight the possible effects and roles of recombination between homoeologous chromosomes during the early stages of allopolyploid stabilization. Homoeologous exchanges (HEs) have been reported in young allopolyploids from across the angiosperms. Although all lineages undergo karyotype change via chromosome rearrangements over time, the early generations after allopolyploid formation are predicted to show an accelerated rate of genomic change. HEs can also cause changes in allele dosage, genome-wide methylation patterns, and downstream phenotypes, and can hence be responsible for speciation and genome stabilization events. Additionally, we propose that fixation of duplication - deletion events resulting from HEs could lead to the production of genomes which appear to be a mix of autopolyploid and allopolyploid segments, sometimes termed "segmental allopolyploids." We discuss the implications of these findings for our understanding of the relationship between genome instability in novel polyploids and genome evolution.
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Affiliation(s)
- Annaliese S. Mason
- Plant Breeding Department, Justus Liebig University Giessen, Giessen, Germany
| | - Jonathan F. Wendel
- Ecology, Evolution, and Organismal Biology Department, Iowa State University, Ames, IA, United States
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Okada M, Michikawa A, Yoshida K, Nagaki K, Ikeda TM, Takumi S. Phenotypic effects of the U-genome variation in nascent synthetic hexaploids derived from interspecific crosses between durum wheat and its diploid relative Aegilops umbellulata. PLoS One 2020; 15:e0231129. [PMID: 32240263 PMCID: PMC7117738 DOI: 10.1371/journal.pone.0231129] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 03/17/2020] [Indexed: 12/12/2022] Open
Abstract
Aegilops umbellulata is a wild diploid wheat species with the UU genome that is an important genetic resource for wheat breeding. To exploit new synthetic allohexaploid lines available as bridges for wheat breeding, a total of 26 synthetic hexaploid lines were generated through crossing between the durum wheat cultivar Langdon and 26 accessions of Ae. umbellulata. In nascent synthetic hexaploids with the AABBUU genome, the presence of the set of seven U-genome chromosomes was confirmed with U-genome chromosome-specific markers developed based on RNA-seq-derived data from Ae. umbellulata. The AABBUU synthetic hexaploids showed large variations in flowering- and morphology-related traits, and these large variations transmitted well from the parental Ae. umbellulata accessions. However, the variation ranges in most traits examined were reduced under the AABBUU hexaploid background compared with under the diploid parents. The AABBUU and AABBDD synthetic hexaploids were clearly discriminated by several morphological traits, and an increase of plant height and in the number of spikes and a decrease of spike length were commonly observed in the AABBUU synthetics. Thus, interspecific differences in several morphological traits between Ae. umbellulata and A. tauschii largely affected the basic plant architecture of the synthetic hexaploids. In conclusion, the AABBUU synthetic hexaploid lines produced in the present study are useful resources for the introgression of desirable genes from Ae. umbellulata to common wheat.
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Affiliation(s)
- Moeko Okada
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Asami Michikawa
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Kentaro Yoshida
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Kiyotaka Nagaki
- Institute of Plant Science and Resources, Okayama University, Okayama, Japan
| | - Tatsuya M. Ikeda
- Western Region Agricultural Research Center, National Agriculture and Food Research Organization, Fukuyama, Hiroshima, Japan
| | - Shigeo Takumi
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- * E-mail:
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Wu M, Ge Y, Xu C, Wang J. Metabolome and Transcriptome Analysis of Hexaploid Solidago canadensis Roots Reveals its Invasive Capacity Related to Polyploidy. Genes (Basel) 2020; 11:genes11020187. [PMID: 32050732 PMCID: PMC7074301 DOI: 10.3390/genes11020187] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 02/08/2020] [Accepted: 02/08/2020] [Indexed: 12/29/2022] Open
Abstract
Polyploid plants are more often invasive species than their diploid counterparts. As the invasiveness of a species is often linked to its production of allelopathic compounds, we hypothesize that differences in invasive ability between cytotypes may be due to their different ability to synthesize allelopathic metabolites. We test this using two cytotypes of Solidago canadensis as the model and use integrated metabolome and transcriptome data to resolve the question. Metabolome analysis identified 122 metabolites about flavonoids, phenylpropanoids and terpenoids, of which 57 were differentially accumulated between the two cytotypes. Transcriptome analysis showed that many differentially expressed genes (DEGs) were enriched in ‘biosynthesis of secondary metabolites’, ‘plant hormone signal transduction’, and ‘MAPK signaling’, covering most steps of plant allelopathic metabolite synthesis. Importantly, the differentially accumulated flavonoids, phenylpropanoids and terpenoids were closely correlated with related DEGs. Furthermore, 30 miRNAs were found to be negatively associated with putative targets, and they were thought to be involved in target gene expression regulation. These miRNAs probably play a vital role in the regulation of metabolite synthesis in hexaploid S. canadensis. The two cytotypes of S. canadensis differ in the allelopathic metabolite synthesis and this difference is associated with regulation of expression of a range of genes. These results suggest that changes in gene expression may underlying the increased invasive potential of the polyploidy.
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