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Genome-Wide Identification and Characterization of the RCI2 Gene Family in Allotetraploid Brassica napus Compared with Its Diploid Progenitors. Int J Mol Sci 2022; 23:ijms23020614. [PMID: 35054810 PMCID: PMC8775908 DOI: 10.3390/ijms23020614] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 12/30/2021] [Accepted: 01/05/2022] [Indexed: 12/14/2022] Open
Abstract
Brassica napus and its diploid progenitors (B. rapa and B. oleracea) are suitable for studying the problems associated with polyploidization. As an important anti-stress protein, RCI2 proteins widely exist in various tissues of plants, and are crucial to plant growth, development, and stress response. In this study, the RCI2 gene family was comprehensively identified and analyzed, and 9, 9, and 24 RCI2 genes were identified in B. rapa, B. oleracea, and B. napus, respectively. Phylogenetic analysis showed that all of the identified RCI2 genes were divided into two groups, and further divided into three subgroups. Ka/Ks analysis showed that most of the identified RCI2 genes underwent a purifying selection after the duplication events. Moreover, gene structure analysis showed that the structure of RCI2 genes is largely conserved during polyploidization. The promoters of the RCI2 genes in B. napus contained more cis-acting elements, which were mainly involved in plant development and growth, plant hormone response, and stress responses. Thus, B. napus might have potential advantages in some biological aspects. In addition, the changes of RCI2 genes during polyploidization were also discussed from the aspects of gene number, gene structure, gene relative location, and gene expression, which can provide reference for future polyploidization analysis.
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Sun Y, Wu Y, Wang Y, Wang S, Wang X, Li G, Zhang X, Liang Z, Li J, Gong L, Wendel JF, Wang D, Liu B. Homoploid F1 hybrids and segmental allotetraploids of japonica and indica rice subspecies show similar and enhanced tolerance to nitrogen deficiency than parental lines. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5612-5624. [PMID: 33909897 DOI: 10.1093/jxb/erab184] [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: 12/31/2020] [Accepted: 04/24/2021] [Indexed: 06/12/2023]
Abstract
It remains unclear whether the merger of two divergent genomes by hybridization at the homoploid level or coupled with whole-genome duplication (WGD; allopolyploidy) can result in plants having better tolerance to stress conditions. In this study, we compared phenotypic performance and gene expression in the two diploid subspecies of rice (Oryza sativa subsp. japonica and indica), their reciprocal F1 hybrids, and in segmental allotetraploids under normal and nitrogen (N)-deficient conditions. We found that F1 hybrids and tetraploids showed higher and similar levels of tolerance to N deficiency than either parent. In parallel, total expression levels of 18 relevant functional genes were less perturbed by N deficiency in the F1 hybrids and tetraploids than in the parents. This was consistent with stable intrinsic partitioning of allelic/homoeologous expression defined by parental legacy in the homoploid F1 hybrids/tetraploids between the two conditions. The results suggest that genetic additivity at both the homoploid and allopolyploidy level might lead to similar beneficial phenotypic responses to nitrogen stress compared with the parents. The lack of synergistic responses to N limitation concomitant with WGD, relative to that exhibited by F1 hybrids, adds new empirical evidence in support of the emerging hypothesis that hybridization by itself can play a significant role in plant adaptive evolution in times of stress.
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Affiliation(s)
- Yue Sun
- Key Laboratory of Vegetation Ecology of Ministry of Education (MOE), Institute of Grassland Science, Northeast Normal University, Changchun 130024, China
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Ying Wu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Yangzhi Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Shengnan Wang
- Key Laboratory of Vegetation Ecology of Ministry of Education (MOE), Institute of Grassland Science, Northeast Normal University, Changchun 130024, China
| | - Xiaofei Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Guo Li
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China
| | - Xue Zhang
- Key Laboratory of Vegetation Ecology of Ministry of Education (MOE), Institute of Grassland Science, Northeast Normal University, Changchun 130024, China
| | - Zidong Liang
- Key Laboratory of Vegetation Ecology of Ministry of Education (MOE), Institute of Grassland Science, Northeast Normal University, Changchun 130024, China
| | - Jiahao 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
| | - Jonathan F Wendel
- Department of Ecology, Evolution & Organismal Biology, lowa State University, Ames, IA 50011, USA
| | - Deli Wang
- Key Laboratory of Vegetation Ecology of Ministry of Education (MOE), Institute of Grassland Science, 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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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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