叶绿体状态转换协调细胞核基因组稳定性的机制探究

质体可以通过逆向信号对环境变化做出应答，目前已发现的质体逆向信号主要通过调节细胞核基因表达而发挥作用，而关于质体逆向信号在细胞核基因组状态中的调控作用还知之甚少。我们前期通过系统筛查发现状态转换重要蛋白STN7缺失的植株中，DNA损伤修复基因上调，细胞倍性增加，同时，DNA链的损伤也增多，提示状态转换有可能在细胞核基因组稳定性中发挥作用。有趣的是，我们还发现，诱导状态转换异常的stn7突变体中，光合活性不变，而生物量却明显降低。本项目拟在此基础上，进一步深入探究状态转换引发细胞核基因组稳定性的信号通路，包括筛查细胞核基因组稳定性调控的关键调控因子，鉴定下游靶基因及其功能，探究质体向细胞核传递的信号途径，以及其在植物生长发育和环境适应中的作用。本研究将通过对状态转换调控细胞核基因组稳定性的作用机制探究，为理解叶绿体与细胞核信号交流机制提供新思路。

Plastids respond to environmental changes through retrograde signaling. Previous studies on plastid retrograde signaling have mainly focused on regulating nuclear gene expression, but little is known about the regulatory role in the status of nuclear genome. We systematically screened, previously, and found that the deficiency of the important protein STN7 in state transitions, leading to the increases the expression of DNA damage repair genes and the cell ploidy, the DNA damage has increased, too. We predicted that state transitions may play a role in the stability of the nucleus genome. Interestingly, we also found that the photosynthetic activity did not change, while the biomass was significantly reduced in the mutation of stn7. Basis on this, this project is further to explore the regulation signaling from the state transitions to the nucleus genome stability, we will find out the key regulatory factors in nuclear genome stability, identify the downstream target genes and their function, explore the signals from plastid to the nucleus, and their role in plant growth and development and environmental adaptation. The coordination mechanism study of state transitions on the nuclear genome stability will provide a new idea to understand the mechanism of signal communication between chloroplast and nucleus.