GUN1介导质体逆向信号调控拟南芥低温响应的机制研究

低温是限制植物生长和植被分布的重要环境因子之一。因此，研究植物如何应对低温胁迫具有重要的理论意义和实际价值。质体逆向信号是由质体发出的调节细胞核基因表达的信号，在叶绿体发生、光合作用基因表达调控等过程中均具有重要作用，并参与植物的多种抗逆过程。然而，对质体逆向信号在植物低温胁迫响应中的作用还缺乏系统研究。最近，我们对质体逆向信号的中心调控子GUN1的研究发现，gun1突变体在低温下叶绿体发生与类囊体发育严重受阻，表现为花叶甚至白化的表型，而高比率的红光/远红光可部分抑制该表型。在本项目中，我们将利用遗传学、生物化学、转录组和蛋白组学等手段：1）鉴定参与该过程的调控因子，阐明GUN1参与植物应对低温胁迫的机制；2）解析质体逆向信号和光信号互作在植物低温响应中的作用。这些研究将解析质体逆向信号参与调控植物低温胁迫响应的新功能，为进一步认识植物应对低温胁迫的机制和分子育种提供线索和理论依据。

Low temperature is one of the key environmental factors that limits plant growth and geographical distribution. Study on the mechanism of plants in response to cold stress has important theoretical and practical values. Plastid retrograde signals are emitted by plastids to regulate nuclear gene expression. They play important roles in chloroplast biogenesis and the regulation of the expression of photosynthesis-associated nuclear genes (PhANGs), participate in many stress response pathways of plants. However, the role of plastid retrograde signaling in plant cold stress remains largely unknow. Recently, our work on GENOMES UNCOUPLED1 (GUN1), the central integrator of multiple plastid retrograde signaling pathways, demonstrated that gun1 mutants show a severe variegation to albino phenotype under low temperature, while high ratio of red/far-red light can largely suppress this phenotype. In this project, we will use genetic, biochemical, transcriptomic and proteomic approaches to: 1) identify downstream regulatory factors in this pathway to understand how GUN1-related retrograde signals participate in cold adaptation of Arabidopsis; 2) explore the role of plastid retrograde signaling and light signaling crosstalk in plant growth under low temperature. This study will dissect a new role of plastid retrograde signaling in plant cold response, and help to further understand the molecular mechanism of cold adaptation, with this to provide hints and supports for molecular breeding.