蓖麻油酸含量的分子遗传机制研究

蓖麻油因其稳定性强、粘度高等理化性质，在航空、汽车、化工、医药等领域有着重要和不可替代的价值。蓖麻油酸是蓖麻油的主要脂肪酸组分，约占其70%-90%，其含量的高低直接决定了蓖麻油的品质，是蓖麻重要农业性状之一。但是目前人们并不清楚控制蓖麻油酸含量的分子遗传机制。在前期工作中，我们发现非洲野生蓖麻的蓖麻油酸含量普遍且显著高于国内栽培品种。通过群体遗传学和比较基因组学分析，推测蓖麻油酸合成关键酶12-羟化酶（FAH12）基因的启动子区的遗传变异可能是导致蓖麻油酸含量差异的主要原因之一。本项目拟在基础上通过比较野生和栽培蓖麻种子发育和油脂累积过程中的转录组和DNA甲基化的差异，研究遗传变异如何影响FAH12及其它油脂合成关键基因的表达调控；并克隆FAH12优势基因型，结合功能实验研究其对蓖麻油酸含量的控制。研究结果将为蓖麻分子育种提供理论基础和靶标，具有重要的科学意义和应用价值。

Castor oil has important and irreplaceable value in aviation, automobile, chemical industry, medicine and other fields because of its strong stability and high viscosity. Ricinoleic acid is the main component of castor oil, accounting for about 70% - 90%. Its content directly determines the quality of castor oil, which is one of the important agricultural traits of castor oil. However, presently, it is nuclear about the molecular genetic mechanisms underlying the control of ricinoleic acid content. In this work, we first found that the content of ricinoleic acid in the wild ricinus varieties from Africa was significantly higher than that in the domestic cultivated varieties. Furthermore, through the analyses of population genetics and comparative genomics, we speculated that the genetic variation in the regulatory region of the gene FAH12 encoding the key enzyme in ricinoleic acid synthesis might be the one of the reasons for the difference of ricinoleic acid content. On the basis of these findings, we plan to study the influence of genetic and epigenetic variations within the regulatory region on the expression regulation of FAH12 and other key genes of oil synthesis via data integration of the transcriptome and DNA methylation during seed development and oil accumulation of wild and cultivated castors. We also plan to clone the dominant genotype of FAH12 gene and study its control on the content of ricinoleic acid. The results will provide theoretical basis and target for molecular breeding of castor, and have important theoretical and practical significance.