JAZ转录抑制因子在棉纤维细胞早期发育中的分子作用机制研究

JAZ (JASMONATE-ZIM DOMAIN) proteins act as a class of plant-specific transcriptional repressors and jasmonate (JA) co-receptors, and play important roles in JA signalling in Arabidopsis thaliana. Studies have shown that JAZs play a key role during Arabidopsis trichomes initiation. Cotton fiber cells are single-cell seed trichomes that differentiate from the outer integuments of the ovule. Transcription factors and plant hormones play important roles during cotton fiber initiation, but their mechanisms are still unclear. The project will elucidate two JAZ genes functioning in cotton fiber initiation and elongation by using in vitro ovule culture, overexpression, double RNAi technology. Yeast two-hybrid system will be employed to identify transcription factors and hormone-related factors that interact with JAZ proteins during cotton fiber initiation, and these interactions will be futher verified by pull-down and bimolecular fluorescence complementation. This study will clarify functions and regulatory mechanisms of JAZs in cotton fiber initiation, and improving fiber quality for molecular breeding.

JAZ(Jasmonate ZIM domain)蛋白家族是一类植物特有的转录抑制因子，在拟南芥中作为茉莉素(Jasmonate, JA)的共受体而在JA介导的信号通路中发挥重要作用。研究表明JAZs在拟南芥表皮毛起始过程中起重要的调控作用。棉纤维细胞是起源于外珠被的单细胞种子表皮毛，在其起始分化过程中转录因子和植物激素起重要的作用，但其作用机制还不清楚。本项目拟通过离体胚珠培养、过量表达、双RNAi等技术，研究2个棉花纤维起始表达的JAZ基因在棉纤维细胞起始发育和极性生长等方面的功能；采用酵母双杂交法筛选与JAZ蛋白相互作用的转录因子和激素信号相关因子，并通过pull-down和双分子荧光互补技术(BiFC)验证这些相互作用。本研究将阐明JAZs抑制因子在棉花纤维起始发育中的作用及其调控机制，同时还可为改良纤维品质的分子育种提供基因元件。