Polyploid Evolution of the Brassicaceae during the Cenozoic Era
Polyploid Evolution of the Brassicaceae during the Cenozoic Era
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DOI：
10.1105/tpc.114.126391
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发表时间：
2014-07-01
期刊：
影响因子：
11.6
通讯作者：
Parkin, Isobel A. P.
中科院分区：
文献类型：
--
作者：
Kagale, Sateesh;Robinson, Stephen J.;Parkin, Isobel A. P.
十字花科（Cruciferae）因其丰富的物种多样性、遗传多样性和生理多样性以及巨大的经济潜力，已成为多倍体和进化研究的典范。利用广泛的转录组焦磷酸测序的不同类群，我们建立了一个解决的十字花科植物物种的一个子集。我们阐明了频率，年龄，和系统发育的位置，多倍性和谱系分离事件，标志着进化历史的菊科。除了众所周知的古代a（4700万年前[Mya]）和β（124 Mya）古多倍体事件外，有几个物种还经历了更近的（类似于7至12 Mya）一轮基因组倍增。我们确定了8个全基因组重复，对应于至少5个独立的新/中多倍性事件。虽然紫云英科在地球新生代（60 Mya）开始时从其他真双子叶植物进化而来，但主要的多样化只发生在新近纪（0至23 Mya）。值得注意的是，广泛的物种分歧，主要的多倍性，和谱系分离的事件在菊科进化过程中聚集在时间周围的时代过渡的特点是长期不稳定的气候条件。同步化的菊科物种多样性表明，多倍体事件可能赋予了更高的适应性和耐受性急剧变化的全球环境，从而促进物种辐射。
The Brassicaceae (Cruciferae) family, owing to its remarkable species, genetic, and physiological diversity as well as its significant economic potential, has become a model for polyploidy and evolutionary studies. Utilizing extensive transcriptome pyrosequencing of diverse taxa, we established a resolved phylogeny of a subset of crucifer species. We elucidated the frequency, age, and phylogenetic position of polyploidy and lineage separation events that have marked the evolutionary history of the Brassicaceae. Besides the well-known ancient a (47 million years ago [Mya]) and beta (124 Mya) paleopolyploidy events, several species were shown to have undergone a further more recent (similar to 7 to 12 Mya) round of genome multiplication. We identified eight whole-genome duplications corresponding to at least five independent neo/mesopolyploidy events. Although the Brassicaceae family evolved from other eudicots at the beginning of the Cenozoic era of the Earth (60 Mya), major diversification occurred only during the Neogene period (0 to 23 Mya). Remarkably, the widespread species divergence, major polyploidy, and lineage separation events during Brassicaceae evolution are clustered in time around epoch transitions characterized by prolonged unstable climatic conditions. The synchronized diversification of Brassicaceae species suggests that polyploid events may have conferred higher adaptability and increased tolerance toward the drastically changing global environment, thus facilitating species radiation.