低温胁迫下SlbZIP13蛋白调节Rubisco及PSI循环电子传递的机理研究

光合作用是作物产量和品质的基础和保证。低温胁迫是我国北方设施蔬菜栽培中的主要障碍因素之一，严重影响番茄等冷敏感作物光合作用的碳同化及电子传递的进程。碱性亮氨酸拉链（bZIP）转录因子家族成员广泛参与了植物对非生物胁迫的响应，然而它们在低温胁迫下对光合作用的调控机制还鲜为人知。我们在前期研究发现了番茄中一个既受低温诱导又同时定位于叶绿体和细胞核的bZIP蛋白SlbZIP13，该蛋白能够在低温胁迫下维持Rubisco的含量、活性以及PSI的效率。但其具体的作用机理仍不清楚。本项目拟在获得SlbZIP13过表达、突变体及只在细胞核中表达的叶绿体信号肽敲除株系的基础上，解析低温胁迫下SlbZIP13维持番茄Rubsico含量和活性及光系统I效率的作用机制，为指导喜温蔬菜抗逆栽培和育种提供理论依据。

Photosynthesis is the basis and guarantee for the yield and quality of crops. Chilling stress severely limits the carbon assimilation and electron transfer process of plants, especially cold-sensitive crops such as tomato, thus becoming one of the major limiting factors in greenhouse production in northern of China. In plants, basic leucine zipper (bZIP) transcription factors widely functioned in the abiotic stress response. However, their roles on photosynthesis are not clear, and no bZIPs have been found to localize in the chloroplast until now. In our previous study, we found a bZIP protein SlbZIP13 in tomato, which is not only induced by chilling stress but also located in the chloroplast and nucleus. And it positively maintained the Rubisco content and activity and photosystem I efficiency under chilling stress. Nevertheless, its specific mechanism is still unclear. On the basis of obtaining SlbZIP13 overexpression, mutants, and chloroplast signal peptide deletion lines, this project intends to clarify the specific mechanism of SlbZIP13 maintaining the Rubsico content, activity and photosystem I efficiency under chilling stress. This may provide an effective strategy for enhancing resistance to chilling stress in chilling-sensitive crops in agricultural production.