随着全球气温变暖，高温胁迫成为限制植物光合作用和作物产量的主要环境压力。其中，叶绿体的光合作用被认为是对热最敏感的细胞功能之一。SUMO化修饰是将一种被称为类泛素（SUMO）的多肽分子连接到底物蛋白上的翻译后修饰方式，蛋白的SUMO化修饰与植物的热应答过程有密切联系。近期，蛋白组学研究发现叶绿体中可能存在潜在的SUMO化修饰底物，但其作用和调控机制未明。本研究前期通过生物信息学及生物化学方法筛选叶绿体中潜在的SUMO化修饰底物，发现了一个与光合作用相关的SUMO化底物蛋白，命名为SPP1，且SPP1的SUMO化修饰可能与热胁迫响应有关，在此基础上本项目拟通过生理学，遗传学，生物化学等手段分析SUMO化修饰参与光合作用调控的分子机制，阐明热胁迫下光合蛋白SUMO化修饰的生理学意义。本研究对于探明SUMO化修饰是否参与调控光合作用有创新性意义，同时也为遗传改良农作物在高温胁迫下的光合能力提供理

With global warming, high temperature stress has become a major environmental pressure limiting plant photosynthesis and crop yield. Among the biological processes, chloroplast photosynthesis is considered to be the most sensitive process to heat stress. SUMOylation is a post-translational modification that attaching a polypeptide molecule called a small ubiquitin-related modifier (SUMO) to the substrate proteins. The protein SUMOylation is closely related to the heat stress responses in plants. Recently, proteomic studies have found that there may be some potential SUMO targets in chloroplasts, but its role and the regulatory mechanism are unknown. In this study, through screening the potential SUMO substrates in chloroplasts, a SUMO substrate protein related to photosynthesis named as SPP1 was found and its SUMOylation may be related to the responses to heat stress. On this basis, we intend to explore the physiological importance of the SUMOylation involved in the regulation of the photosynthetic protein under heat stress by analyzing the molecular mechanism behind it via biological, genetic and biochemical methods. This study is of innovative significance to find out whether SUMOylation is involved in regulating photosynthesis, and could provide theoretical basis and gene resources for genetically improving the photosynthetic capacity of crops under high temperature stress.