光温敏雄性不育系的选育是两系杂交水稻育种技术体系研发和应用的核心，但目前生产上应用的主推品种的育性转换临界点受环境温度变化影响较大。因此，选育性转换稳定的不育系一直是两系杂交育种的重点研究方向之一。申请人前期筛选获得了短光不育、长光可育的光敏不育系csa，并证明CSA可以调控糖从叶片(源)运输到花药(库)中。为了深入研究CSA如何感受光照变化调控育性转换的分子网络，本项目拟以CSA基因及其同源基因CSA2为研究入手点，开展CSA感应光周期信号的分子机制、CSA调节糖的源库分配和花粉发育的分子网络、长日光敏雄性不育基因CSA2的作用机制、以及CSA和CSA2在不同光照条件下协同调控光敏不育的分子机制等内容的研究，以期提供植物发育和光互作的新知识，揭示CSA和CSA2感受光照长度，调节导糖的源库分配的分子作用网络，为未来培育育种转换稳定可控的水稻光敏核不育株系提供理论基础和遗传材料。

The identification of photoperiod/thermo-sensitive male sterile line is the core of two-line hybrid breeding research and application. However, the transition point of major cultivars in breeding is largely affected by environmental temperatures. As a result, the identification of male sterile lines with stable transition condition is one of the important research areas. We have identified a reverse photoperiod-sensitive male sterile line named as csa, with normal fertility in long day conditions and male sterility in short day conditions, and have proved that CSA regulates sugar partition from source (leaf) to sink (anther).To find out the molecular network of CSA in regulating male fertility under different light conditions, this project will focus on CSA and its homolog CSA2, and address on how CSA senses photoperiod changes as well the regulatory network of CSA in controlling sugar partition and pollen development. In addition, the molecular mechanism of CSA2 controlling pollen development under long day conditions will be also investigated. The project aims to: 1, provide new knowledge on how plants interact with light controlling the male fertility; 2, uncover the molecular network of CSA and CSA2 in regulating sugar partition, 3; provide new knowledge and genetic resources for creating rice photoperiod-sensitive male sterile line for breeding.