Sequencing of cultivated peanut, Arachis hypogaea, yields insights into genome evolution and oil improvement

First author: Xiaoping Chen; Affiliations: Crops Research Institute, Guangdong Academy of Agricultural Sciences (广东农科院作物所): Guangzhou, China

Corresponding author: Xuanqiang Liang

Cultivated peanut (Arachis hypogaea L.) is an allotetraploid crop, planted in Asia, Africa and America for edible oil and protein. To explore the origins and consequences of tetraploidy, we sequenced the allotetraploid A. hypogaea genome and compared it to the related diploid Arachis duranensis and Arachis ipaensis genomes. We annotated 39,888 A-subgenome genes and 41,526 B-subgenome genes in the allotetraploid subgenomes. The subgenomes have evolved asymmetrically, with the B subgenome resembling the ancestral state and the A subgenome undergoing more gene disruption, loss, conversion, transposable element proliferation and reduced gene expression in seed development despite lacking genome-wide expression dominance. Most oil metabolism genes alter their expression early in seed development, and cease expression during desiccation, presenting a map for peanut lipid biosynthesis from genomic and transcriptomic perspectives. The availability of these genomic resources will facilitate better understanding of the complex genome architecture, agronomically and economically important genes, and genetic improvement of peanut.

栽培种花生是异源四倍体作物，种植地区主要是在亚洲、非洲和美洲，用于供应油和蛋白。为了研究花生四倍体的起源以及对于花生的影响，作者对四倍体花生的基因组进行了测序，并于其二倍体近缘种蔓花生和Arachis ipaensis进行了比较基因组学的研究。作者在四倍体花生基因组上注释到了39,888个A亚基因组基因，41,526个B亚基因组基因。四倍体花生的两套亚基因组演化不对称，B套亚基因组保留了更多的祖先状态，而A套亚基因组则经历了更多的基因打断、丢失、转换、转座子扩增以及种子发育过程中基因表达的降低。大多数油代谢相关基因的表达在种子发育早期就发生改变，并且在种子干燥过程中停止表达，从基因组及转录组的水平绘制了一幅花生脂类物质生物合成的图谱。本文所报道的四倍体花生基因组将有助于促进对于复杂基因组结构的理解，并且有利于深入挖掘花生种农艺和经济性状相关的基因，加速花生的遗传改良。

通讯：梁炫强 (http://www.crigdaas.com/Personnel/Detail/1071.html)

研究方向：主要从事花生种质资源的引进，鉴定和创新，新品种的培育，抗黄曲霉机制的研究。

doi: https://doi.org/10.1016/j.molp.2019.03.005

Journal: Molecular Plant

Published online: March 18, 2019