蛋白激酶CdCIPK15A调控狗牙根株型的分子机制

株型形成与调控的分子机理是植物生长发育研究领域的重要科学问题。暖季型草坪草狗牙根同时拥有直立茎和匍匐茎，是研究株型调控尤其是茎生长角度调控的独特材料。项目申请人前期研究发现匍匐茎优势表达的狗牙根类钙调磷酸酶亚基B蛋白（CBL）互作蛋白激酶CdCIPK15A不仅和CdCBL1存在互作，和茎生长角度调控关键蛋白CdLA1也存在互作；抑制CdCIPK15A与CdLA1的表达对狗牙根的株型有着相反的影响。本项目拟通过分析CdCIPK15A和CdLA1、CdCBL1竞争互作的机制和意义、挖掘被CdCIPK15A磷酸化的下游效应蛋白并分析其功能、探寻调控CdCIPK15A表达的上游转录因子并分析其调控机理三个方面研究来初步阐明CdCIPK15A调控狗牙根茎生长角度株型特征的分子机制。项目研究结果不仅有助于我们理解植物株型形成与调控的分子机理，也将为理想株型草坪草和其他观赏植物分子育种提供重要理论依据。

Molecular mechanism of plant architecture formation and regulation is an important scientific question in plant growth and development research area. As a warm-season turfgrass species, bermudagrass (Cynodon dactylon L.) have both shoots and stolons, making it a unique material for studying plant architecture regulation, especially stem growth angle control. In our previous study, we found that CdCIPK15A, a calcineurin B-1 like protein (CBL)-interacting protein kinase family member that was preferentially expressed in bermudagrass stolons, not only interact with CdCBL1, but also interact with CdLA1, an important protein regulating stem growth angle. Notably, bermudagrass plants with down-regulated expression of CdCIPK15A and CdLA1 have opposite plant architectural changes. In this study, we attempt to elucidate the molecular mechanism how CdCIPK15A regulate stem growth angle in bermudagrass through following three parts of research: characterize the mechanism and biological significance of the competitive protein interaction between CdCIPK15A and CdCBL1/CdLA1, identify the downstream effect protein that is phosphorylated by CdCIPK15A and analyze its function, identify the upstream transcription factor regulating CdCIPK15A expression and explore its regulation mechanism. Results of this study could provide not only new insight into molecular mechanism underlying plant architecture formation and regulation but also important theoretical foundations for breeding turfgrasses and other ornamental plants with ideal architectural characteristics.