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

Abstract 

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.  

栽培花生是异源四倍体作物，种植地区主要是在亚洲，非洲和美国，用于供应食用油和蛋白。为了探索他四倍性的起源和影响，我们对四倍体的花生进行了测序，并且和相近的二倍体Arahis duranensis 和Arachis ipaensis的基因组进行比较。我们在四倍体的花生种注释了39888个A亚基因组的基因和41526个B亚基因组的基因。亚基因组发生了不对称的进化，B亚基因组发生了保存了祖先状态A亚基因组发生了更多的基因破坏，丢失，转换，转做原件的扩张和种子发育过程种基因表达的降低。大多数油脂代谢基因在种子发育早期改变表达，在干燥过程中停止表达，从基因组和转录组角度为花生油脂生物合成提供了图谱。这些基因组资源将促进复杂基因组结构的理解，挖掘农艺性状和经济相关的基因，加速花生遗传改良。