设施番茄生产中常出现低夜温导致的光合抑制，从而产生过剩光能破坏光合机构。环式电子流（CEF）可保护光合机构免受光破坏，而这一过程受质子梯度调节蛋白复合体（PGR5/PGRL1）的介导，但其介导机制尚不清楚。本项目拟在超表达和敲除所获得的转基因植株基础上，经6℃低夜温胁迫后，采用qRT-PCR等技术，明确SlPGR5和SlPGRL1基因和蛋白时空表达；分析CEF和活性氧积累与分布，明确SlPGR5和SlPGRL1在CEF运转和活性氧积累中作用；采用GFS-3000和DUAL-PAM-100同步测量及叶绿素荧光成像系统分析光系统活性，明确SlPGR5/PGRL1介导CEF的光保护作用；分析热耗散、D1蛋白周转及类囊体膜差异蛋白的变化，明确SlPGR5/PGRL1介导CEF的光保护途径。最终明确SlPGR5/PGRL1介导番茄响应低夜温的CEF光保护机制，为调控低夜温下番茄的光合作用提供新途径。

The protected tomato (Solanum lycopersicum L.)in winter and spring seasons cultivation easily suffer from low night temperature(LNT),which result in photoinhibition, produce excess light energy, then destroy photosynthetic apparatus. Cyclic electron flow (CEF) can protect the photosynthetic apparatus suffering photodamaging,Which is mediated the proton gradient regulatory proteins composite (PGR5/PGRL1),nevertheless,the mechanism of action is still dimness. We obtain transgenic plants through the CRISPR/Cas9 knock out and overexpression techniques, which are subjected to 6℃ LNT treatment. On this basis,first,we realize the characteristic of the gene and protein expression of SlPGR5 and SlPGRL1 in space and time. Second, we analysis CEF rate and accumulation and distribution of ROS in a bid to clear SlPGR5 and SlPGRL1 role in CEF and accumulation of ROS.Then, to investigate the photoprotection effect of the SlPGR5/PGRL1 mediated CEF by analysis of photosystem activity using GFS-3000 and DUAL-PAM-100 synchronous measurement system and green fluorescence imaging system. Finally,in order to clarify photoprotection approach of SlPGR5/PGRL1 mediated CEF by analyzing the change of the heat dissipation,D1 protein turnover and differential protein in thylakoid membrane.We clear ultimately the photoprotection mechanism of CEF in tomato mediated by SlPGR5/PGRL1 in response to LNT, which will provide a new proposal for the regulation photosynthesis in tomato under LNT.