Circadian Evening Complex Represses Jasmonate-lnduced Leaf Senescence in Arabidopsis  

作　　者：Yuanyuan Zhang Yan Wang Hua Wei Na Li Wenwen Tian Kang Chong Lei Wang 

机构地区：[1]Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences,Beijing 100093, China [2]University of Chinese Academy of Sciences, Beijing 100049, China [3]National Center for Plant Gene Research, Beijing 100093, China

出　　处：《Molecular Plant》2018年第2期326-337,共12页分子植物（英文版）

摘　　要：Plants initiate leaf senescence to reallocate energy and nutrients from aging to developing tissues for optimizing growth fitness and reproduction at the end of the growing season or under stress. Jasmonate （JA）, a lipid-derived phytohormone, is known as an important endogenous signal in inducing leaf senescence. However, whether and how the circadian clock gates JA signaling to induce leaf senescence in plants remains elusive. In this study, we show that Evening Complex （EC）, a core component of the circadian oscillator, negatively regulates leaf senescence in Arabidopsis thaliana. Transcriptomic profiling analysis reveals that EC is closely involved in JA signaling and response, consistent with accelerated leaf senescence unanimously displayed by EC mutants upon JA induction. We found that EC directly binds the promoter of MYC2, which encodes a key activator of JA-induced leaf senescence, and represses its expression. Ge- netic analysis further demonstrated that the accelerated JA-induced leaf senescence in EC mutants is abrogated by myc2 myc3 myc4 triple mutation. Collectively, these results reveal a critical molecular mechanism illustrating how the core component of the circadian clock gates JA signaling to regulate leaf senescence.Plants initiate leaf senescence to reallocate energy and nutrients from aging to developing tissues for optimizing growth fitness and reproduction at the end of the growing season or under stress. Jasmonate （JA）, a lipid-derived phytohormone, is known as an important endogenous signal in inducing leaf senescence. However, whether and how the circadian clock gates JA signaling to induce leaf senescence in plants remains elusive. In this study, we show that Evening Complex （EC）, a core component of the circadian oscillator, negatively regulates leaf senescence in Arabidopsis thaliana. Transcriptomic profiling analysis reveals that EC is closely involved in JA signaling and response, consistent with accelerated leaf senescence unanimously displayed by EC mutants upon JA induction. We found that EC directly binds the promoter of MYC2, which encodes a key activator of JA-induced leaf senescence, and represses its expression. Ge- netic analysis further demonstrated that the accelerated JA-induced leaf senescence in EC mutants is abrogated by myc2 myc3 myc4 triple mutation. Collectively, these results reveal a critical molecular mechanism illustrating how the core component of the circadian clock gates JA signaling to regulate leaf senescence.

关 键 词：circadian clock Evening Complex JA signal leaf senescence MYC2 

分 类 号：Q4[生物学—生理学] X173[环境科学与工程—环境科学]