茉莉酸与生长素互作调控根干细胞维持的分子机理

作为茉莉酸途径的核心转录因子，MYC2与中介体亚基MED25相互作用调控茉莉酸响应基因的表达。我们前期的研究表明，在茉莉酸信号转导过程中，MYC2直接结合干细胞转录因子PLT1和PLT2的启动子并抑制其表达，进而影响根干细胞的功能和根的生长，因此MYC2是茉莉酸和生长素途径互作调控干细胞功能和根发育的重要节点。为了阐明茉莉酸通过MYC2抑制PLT1和PLT2表达的分子机理，我们从MYC2-MED25的互作入手，通过高通量的蛋白组技术鉴定MYC2-MED25 功能复合物(MYC2-MED25 Functional Complex, MMFC)。本申请将综合采用分子遗传学、细胞生物学和生物化学等多学科交叉的手段，系统研究MMFC1，MMFC2在干细胞维持中的功能及作用机理，为深入认识茉莉酸和生长素互作调控根生长的分子机理提供创新性的知识积累。

As a master regulator of jasmonic acid (JA)-mediated gene expression, the bHLH-type transcription factor MYC2 regulates JA-responsive gene transcription through interacting with the MED25 subunit of the Arabidopsis mediator complex. Our recent studies reveal that, underlying JA-mediated inhibition of root growth, MYC2 directly represses the transcriptional expression of the stem cell transcription factors PLT1 and PLT2, which were considered as molecular components of the auxin pathway in regulating stem cell maintenance and root growth. Therefore, MYC2-mediated repression of PLT expression integrates the JA action into the auxin pathway in regulating root meristem activity and stem cell maintenance. We propose to identify a MYC2-MED25 functional complex (MMFC) using high-throughput proteomic approach and elucidate its action mechanisms. We will perform in-depth analysis on the function of MMFC1 and MMFC2 in regulating JA-mediated regulation of root stem cell maintenance. This study promises to shed new light on the molecular mechanisms of JA-auxin interaction in regulating root growth.