植物启动叶片衰老过程促进营养和能量由源到库转移，提高植物对干旱等胁迫的耐逆性和存活率。生物钟在时间维度动态地调控着植物生长发育的多个方面，但对生物钟调控叶片衰老的研究还甚少。前期研究我们发现生物钟转录抑制复合体Evening Complex的相关突变体加速了茉莉酸诱导的叶片衰老过程，而超表达植株则减缓了此过程。本项目将深入研究Evening Complex调控茉莉酸诱导叶片衰老的分子机制。研究内容包括定性和定量分析Evening Complex相关材料对茉莉酸诱导叶片衰老的生理表型；发掘和定位Evening Complex调控茉莉酸信号途径的关键节点；利用分子生物学和遗传学手段确定MYC2为Evening Complex的靶基因，进而建立“Evening Complex—MYC2—SAG29—叶片衰老”模型等。本项目将精细解析生物钟调控茉莉酸诱导植物叶片衰老的机理，为分子设计育种提供借鉴。

By initiating leaf senescence to cope with environmental stresses or to utilize the limited nutrients and energy for growth and reproduction, plants are able to relocate energy and nutrients from aging leaves to developing tissues or storage organs. Circadian clock regulates many biological processes of plants, however, whether it can regulate leaf senescence still await further exploring. The evening complex, comprised of ELF4 (EARLY FLOWERING 4), ELF3 (EARLY FLOWERING 3) and LUX (LUX ARRHYTHMO) proteins, play a crucial repressive role in core oscillator of circadian clock. But whether it involved in the regulation of jasmonate-induced leaf senescence and the potential underlying molecular mechanism still remain elusive. During our preliminary study, we found the mutants of evening complex components showed accelerated JA-induced leaf senescence, while ovexpression ELF3 reduced the JA-induced leaf senescence. In this project, we will aiming to decipher the underlying molecular mechanism of evening complex regulating JA-induced leaf senescence. We will systematically investigate JA-induced leaf senescence in evening complex component mutants and transgenic lines by utilizing the established physiological experiments. Moreover, we want to investigate which component of JA signaling pathway is the direct target of evening complex. In addition, we will try to establish the signaling module of ‘Evening complex-MYC2-SAG29-leaf senescence’ which mediates the cross talk between circadian clock and plant leaf senescence. Our research in this project will elucidate the related underlying molecular mechanisms of the clock and plant leaf senescence and lay the broad foundation for cross talk between circadian clock and JA signaling, which will be beneficial for future crop breeding.