Genome Triplication Drove the Diversification of Brassica Plants
Genome Triplication Drove the Diversification of Brassica Plants
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DOI：
10.1007/978-3-662-47901-8_10
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发表时间：
2015-01-01
期刊：
影响因子：
--
通讯作者：
Wang, Xiaowu
中科院分区：
文献类型：
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作者：
Cheng, Feng;Wu, Jian;Wang, Xiaowu
芸苔属植物多样性显著。首先，它有许多相近但不同的品种，如油菜、甘蓝、黑油菜、甘蓝型油菜、芥菜等，其中许多都是重要的作物。其次，每一种芸苔属植物都有丰富的形态型，它们都有独特而令人印象深刻的特征，如B. rapa（白菜和萝卜）或B. oleracea（白菜和甘蓝）的抽头叶和扩大的根，B. oleracea（西兰花、花椰菜）的花序扩大。所有这些芸苔属植物都是从一个共同的六倍体祖先进化而来的，该祖先经历了全基因组三倍复制（WGT）事件。研究表明，WGT促进了芸苔属植物在物种形成和形态繁荣方面的多样化。WGT之后，三倍二倍体祖先通过重倍化过程和杂交进行了广泛的块重组和染色体减少，促进了芸苔属物种的形成。偏倚基因保留和亚基因组显性效应进一步促进了多拷贝基因的功能进化，最终导致油菜丰富形态型的扩展。综上所述，WGT事件通过启动基因组和基因水平的进化，在推动芸苔属植物多样化中发挥了重要作用。
Brassica species are significant in diversity. First, it has many close but different species, such as Brassica rapa, Brassica oleracea, Brassica nigra, Brassica napus, Brassica juncea, etc, many of which are important crops. Second, for each Brassica species, it is rich in morphotypes, they have distinctive and impressive traits, such as the heading leaves and enlarged roots in B. rapa (Chinese cabbage and turnip) or B. oleracea (cabbage and kohlrabi), and the enlarged inflorescences in B. oleracea, i.e. broccoli, cauliflower. All these Brassicas are evolved from a common hexaploidy ancestor that experienced a whole genome triplication (WGT) event. Studies show that WGT drove the diversification of Brassica plants in both the speciation and booming of morphotypes. Following WGT, the extensive block reshuffling and chromosome reduction of the triplicated diploid ancestor through rediploidization process as well as hybridization promoted the Brassica speciation. The biased gene retention and subgenome dominance effect further promoted function evolution of multi-copy genes, and finally lead to the expansion of rich morphotypes in Brassicas. Conclusively, the WGT event plays important role in driving the diversification of Brassicas by initiating the genome and gene-level evolution.