Musa balbisiana genome reveals subgenome evolution and functional divergence
Musa balbisiana genome reveals subgenome evolution and functional divergence
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芭比蕉基因组揭示亚基因组进化和功能分化
DOI：
10.1038/s41477-019-0452-6
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发表时间：
2019-08-01
期刊：
影响因子：
18
通讯作者：
Jin, Zhiqiang
中科院分区：
文献类型：
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作者：
Wang, Zhuo;Miao, Hongxia;Jin, Zhiqiang
香蕉（Musa ssp.）是由尖叶野蕉和野蕉杂交而成的二倍体、三倍体和四倍体杂种。我们提出了一个高质量的草图基因组组装的M。balbisiana的染色体长度为430 Mb（87%），组装成11条染色体。我们发现M. acuminata（A基因组）和M. Balbisiana（B-基因组）发生在谱系特异性全基因组复制之后，并且与A-基因组相比，B-基因组可能对分馏过程更敏感。在异源多倍体中，A亚基因组和B亚基因组之间经常发生同源互换。基因组内的祖先的变异导致亚基因组的功能分歧。异源三倍体的亚基因组之间存在全局同源基因表达优势。与乙烯生物合成和淀粉代谢相关的基因家族在异源三倍体的B亚基因组中表现出在途径水平上的显著扩展和广泛的同源表达优势。1-氨基环丙烷-1-羧酸氧化酶（ACO）同源基因对的独立起源和B亚基因组中ACO基因的串联重复驱动的扩增有助于异源三倍体香蕉果实采后快速和主要的乙烯产生。这项研究的结果为理解水果生物学提供了更大的背景，并有助于开发培育最佳香蕉品种的工具。
Banana cultivars (Musa ssp.) are diploid, triploid and tetraploid hybrids derived from Musa acuminata and Musa balbisiana. We presented a high-quality draft genome assembly of M. balbisiana with 430 Mb (87%) assembled into 11 chromosomes. We identified that the recent divergence of M. acuminata (A-genome) and M. balbisiana (B-genome) occurred after lineage-specific whole-genome duplication, and that the B-genome may be more sensitive to the fractionation process compared to the A-genome. Homoeologous exchanges occurred frequently between A-and B-subgenomes in allopolyploids. Genomic variation within progenitors resulted in functional divergence of subgenomes. Global homoeologue expression dominance occurred between subgenomes of the allotriploid. Gene families related to ethylene biosynthesis and starch metabolism exhibited significant expansion at the pathway level and wide homoeologue expression dominance in the B-subgenome of the allotriploid. The independent origin of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) homoeologue gene pairs and tandem duplication-driven expansion of ACO genes in the B-subgenome contributed to rapid and major ethylene production post-harvest in allotriploid banana fruits. The findings of this study provide greater context for understanding fruit biology, and aid the development of tools for breeding optimal banana cultivars.