拟南芥COP1 SUPPRESSOR 6调控光形态建成的的分子机理研究

C2H2型锌指蛋白是植物中最大的转录因子家族之一，在植物生长发育、逆境响应等生物学过程中发挥重要作用，然而C2H2型锌指蛋白是否参与调控植物光形态建成尚不清楚。本项目前期通过正向遗传筛选到CSU6（COP1 SUPPRESSOR 6），其编码一个C2H2型锌指蛋白。研究发现CSU6是光形态建成的正调控因子，光促进CSU6的蛋白积累，同时发现CSU6具有转录抑制活性，且与光信号负调控子PIF4/PIF5互作。本项目拟通过解析光信号调控CSU6蛋白稳定性的分子机制，CSU6与PIF4/PIF5互作的生理生化机制以及对下游靶基因的调控机制，构建CSU6调控光形态建成的分子信号通路，阐明CSU6发挥功能的分子机理。该项研究将揭示CSU6在光形态建成中的重要作用，完善对C2H2型锌指蛋白这一重要转录因子家族的生物学功能及作用机理的认识，并为光生物学研究服务于作物分子育种提供分子生物学信息和基因资源。

C2H2-type zinc finger proteins are one of the largest transcription factor families in plants. Recent studies have revealed that C2H2-type zinc finger proteins play vital roles in plant development and stress responses, but their involvement in photomorphogenesis, as well as regulatory mechanisms, remain largely unclear. In this study, we used forward genetic screen to identify COP1 SUPPRESSOR 6 (CSU6), which encodes a C2H2 zinc finger protein. We found that CSU6 is a positive regulator of photomorphogenesis, and CSU6 protein accumulation is induced by light. Further studies showed that CSU6 protein has transcriptional repression activity and interacts with PIF4 and PIF5, which are key negative regulators in light signaling. In this project, we propose to determine how CSU6 protein accumulation is regulated by light and reveal the physiological and biochemical mechanism underlying the interactions between CSU6 and PIF4/PIF5, we also propose to investigate the transcriptional regulation mechanism of CSU6 to downstream genes, thereby further elucidating the molecular mechanism of CSU6 in seedling photomorphogenesis. Our studies will reveal the essential role of CSU6 in light signaling, which can expand the knowledge of C2H2 zinc finger family in plants, and also provide molecular biological information and gene resources for integrating photobiology studies into crop molecular breeding.