水稻PSRK2参与赤霉素信号途径调控株高发育的分子机制

Plant height is an important agronomic trait in rice. It directly affects the shaping of rice plant type, and is the decisive factor of yield and quality. Therefore, the isolation and identification of plant height genes are of great significance in the breeding of ideal rice plant type. The applicant previously cloned and reported a rice receptor-like kinase gene PSRK2 (Plant Stature Related receptor-like Kinase 2), which is able to mediate the gibberellin signaling pathway to involve in the regulation of plant height development, but the molecular mechanism has not been confirmed. Based on the previous studies, this project will do：（1）Lost-of-function mutants and over-expression genetic lines of PSRK2 were obtained to verify the biological function of PSRK2 during rice plant height development；（2）Analyze the correlation between PSRK2 and gibberellin signaling pathway regulators, and clarify the regulatory relationship of PSRK2 in gibberellin signaling pathway；（3）Identify the interaction receptor-like kinase and phosphorylation substrate of PSRK2, and analyze the molecular mechanism of PSRK2 involving in the gibberellin signaling pathway to regulate plant height development. This study will provide a new research direction for the regulatory network of rice plant height development, and provide theoretical guidance for rice plant type improvement and molecular design breeding.

株高是水稻重要的农艺性状，直接影响水稻株型的塑造，是产量和品质的决定性因素。分离鉴定株高控制基因，在水稻理想株型育种中有着重大的意义。申请人前期克隆并报道了一个新的水稻类受体蛋白激酶基因PSRK2（Plant Stature Related receptor-like Kinase 2），该基因能够参与赤霉素信号途径调控水稻株高，但分子机制尚未证实。本项目拟开展以下工作: （1）获得PSRK2功能缺失突变体及过量表达遗传株系，验证PSRK2在水稻株高发育过程中的生物学功能；（2）分析PSRK2与赤霉素信号途径调控因子的相关性，阐明PSRK2在赤霉素信号途径中的功能定位及调控关系；（3）鉴定PSRK2的互作类受体蛋白激酶及磷酸化底物，解析PSRK2参与赤霉素信号途径调控水稻株高发育的分子机制。本项目将为水稻株高发育的调控网络研究提供新的方向，为水稻株型改良及分子设计育种提供理论指导。

株高是水稻重要的农艺性状，是产量和品质的决定性因素，在水稻理想株型育种中有着重大的意义。本研究前期克隆到一个新的水稻类受体蛋白激酶基因PSRK2，该基因能够调控水稻株高的发育，但分子机制尚未证实。通过本项目的开展已基本阐明了PSRK2调控水稻茎节及穗的伸长的生物学功能，揭示了PSRK2通过与小G蛋白家族成员RAD6、RAD7和RAD8互作共同参与调控水稻节间的伸长，且PSRK2激酶磷酸化RAD8的过程是依赖GA信号分子。与此同时，通过组学联合分析，克隆到一个能够与GA受体GID1直接互作的类受体蛋白激酶SRK1，通过参与GA信号传导途径来调控株高发育的发育。本项目为水稻株高的分子调控机制研究提供了新的思路。同时本项目的开展，也获得了大量水稻优势株型的稳定遗传材料，为品种选育和改良提供了材料基础。