低温逆境严重影响植物的生长发育和作物产量，研究植物对低温的响应机制对提高植物耐冷性具有重要理论意义。光是植物必需的环境因子，在其生长发育过程中发挥关键作用。前期研究发现，光信号通路的关键转录因子PIF3 (phytochrome interacting factor3) 参与负调控植物的抗冻性。然而，植物如何整合光和温度信号来调节PIF介导的低温应答机制仍不清楚。本项目拟研究PIF家族蛋白在低温信号中的作用，以及光温信号协同调控PIF蛋白稳定性的分子机制，以期探究光信号关键组分在植物低温应答中的作用。该研究将有助于阐明光温信号在调控植物生长和逆境应答中的相互关系，为作物抗寒性育种提供基因资源和理论依据。

Cold stress is a major environmental factor that adversely affects plant growth and development, and crop productivity. Light is a major environmental factor that controls plant growth and development. Our previous study uncovers an important role of PIF3 (phytochrome interacting factor3) in Arabidopsis freezing tolerance by negatively regulating the expression of genes in the CBF pathway. However, how light and temperature signals coordinately integrate to regulate PIF-mediated cold responses is poorly understood. In this proposal, we will investigate the exact role of PIF family proteins in cold signaling, and reveal the mechanism by which low temperature and light signaling coordinately mediates the modification and stability of PIFs. Furthermore, the regulatory function of the key light components in plant cold response will be explored in details. This study will allow us to dissect a novel molecular mechanism by which light and temperature balance plant growth and stress response, and provide new information for molecular breeding and crop improvement.