麻疯树胚乳油脂积累调控因子的鉴定和功能研究

Jatropha curcas, a small perennial tree, is an ideal woody oil plant for biodiesel production and multiple purposes. However, its utilization is much limited by the lack of high-yeild cultivars.Oil contents of endosperm from different wild lines vary significantly. We study the mechamism of endosperm oil accumulation in the lines with high or low oil content using high-throughput omics methods. First, to find the differentially expressed genes and miRNAs involved in oil accumulation,we estabolish the differential expression profiles of mRNAs, miRNAs and proteins through high-throughput sequencing and bioinformatics in these endosperms with different oil contents. Second, the key regulators are constructed into overexpression or gene-silencing vectors which are used to transform J. curcas. The gene expression and oil accumulation in transgenic plants are analyzed using molecular biology and biochemistry methods. Finally, the role of key regulators involved in the oil accumulation will be understood by integration of these genes/proteins profiles and other proofs from transgenic plants. It is hopeful to find the molecular regulation mechanism involved in oil accumulation, and to provide new theory and technologies to cultivate biodiesel tree with high oil production.

麻疯树(Jatropha curcas L.)为多年生小乔木，是一种具有较高综合利用价值的木本油料树种，也是世界公认的制备生物柴油的理想材料。然而，缺乏优质品种是其推广利用的瓶颈。野生麻疯树不同株系的胚乳含油量差异极大。本研究以麻疯树高含油量株系和低含油量株系种子的胚乳为材料，首先用高通量组学研究方法建立二者的mRNAs、miRNAs和蛋白质的差异表达谱，结合生物信息学方法筛选出与油脂积累调控相关的特异表达基因/蛋白和miRNAs；然后构建这些关键调控因子的过表达载体或沉默载体，转化麻疯树获得转基因植株，用分子生物学和生物化学方法分析转基因植株的油脂积累和基因表达规律；最后，综合分析以上结果，解析麻疯树调控基因/蛋白和miRNAs在油脂积累调控网络中的作用，阐明麻疯树胚乳油脂积累的分子调控机制，为获得含油量高且稳定的麻疯树转基因新品种探索理论和方法依据。

麻疯树(Jatropha curcas L.)为多年生小乔木，是一种具有较高综合利用价值的木本油料树种，也是世界公认的制备生物柴油的理想材料。然而，缺乏优质品种是其推广利用的瓶颈。本项目研究麻疯树发育种子的胚乳中mRNAs、miRNAs和LncRNAs差异表达谱，采用严格的筛选条件，鉴定了93个高可信度miRNA和603个LncRNA，找到调控种子基因表达、初生/次生代谢、生长发育、信号转导和胁迫响应相关的miRNA和LncRNA。 其中5个保守miRNA（MIR156f, MIR403, MIR827, MIR1446a, MIR1446b）和3个新miRNA（nMIR008, nMIR011, nMIR013）调控油脂代谢相关基因的表达。这些miRNA和LncRNA可能用于基因工程调控种子油脂的积累。发明的快速鉴定miRNA靶基因的方法，可以鉴定疯树的靶基因切割特征。Wri1和FAD2等转基因研究结果对调控作物种子的油脂积累和油脂品质的控制具有参考价值。总之，本项目研究结果，深入探讨了麻疯树胚乳油脂积累的分子调控机制，为培育含油量高的麻疯树转基因新品种提供了科学依据。