GhCIPK23调控棉花响应缺钾胁迫的作用机制研究

钾对棉花发育至关重要，但人们对棉花响应缺钾胁迫的机制了解很少。课题组利用双向电泳发现，缺钾处理显著增加了一个棉花蛋白的丰度，该蛋白为类钙调磷酸酶B蛋白互作蛋白激酶23（GhCIPK23）。在拟南芥突变体cipk23中过表达GhCIPK23可回补其缺钾敏感表型。GhCIPK23沉默棉株对缺钾敏感。本项目拟分析缺钾胁迫下GhCIPK23基因的表达特点，通过研究GhCIPK23基因过表达和抑制表达转基因棉花与对照缺钾胁迫下表型、纤维产量和品质、K+含量及根吸收K+的差异，确定GhCIPK23在棉花响应缺钾胁迫中的作用；筛选鉴定GhCIPK23互作蛋白并研究其在调控缺钾响应中的功能；分析缺钾胁迫下GhCIPK23对K+通道GhAKT1和K+转运体GhHAK5等的调控作用，阐明GhCIPK23的作用机制。本项目将揭示GhCIPK23调控棉花应答缺钾胁迫反应的新机制，为培育耐缺钾棉花新品种奠定基础。

Potassium (K+) is essential for cotton development. However, knowledge about the mechanisms of cotton responses to potassium deficiency is limited. Previously, we found that the abundance of a protein in cotton roots clearly increased by potassium deprivation using two-dimensional electrophoresis technology. The protein was calcineurin B-like-interacting protein kinase23 (GhCIPK23). The sensitivity of Arabidopsis mutant cipk23 to potassium shortage could be restored by overexpressing GhCIPK23 gene in the mutant plants. Silencing GhCIPK23 in cotton led to increased sensitivity of the silenced plants to K+ deficiency. In this project, we will examine the expression patterns of GhCIPK23 gene, analyze the differences in phenotypes, fibre yield and quality, K+ contents and K+ absorption properties among the transgenic cotton plants overexpressing GhCIPK23, silencing GhCIPK23 and wild type plants under potassium deficiency. The functions of cotton GhCIPK23 in response to potassium starvation will be determined. Furthermore, the proteins that interact with GhCIPK23 will be screened and identified, and the functions of the proteins in modulating plant responding to K+ limitation will be studied. Additionally, the functions of GhCIPK23 will be investigated in regulating the activities of the K+ channel protein GhAKT1, K+ transporter GhHAK5, and so on under K-limited conditions. Thus, the functional mechanisms of GhCIPK23 in cotton will be elucidated. New molecular mechanisms of GhCIPK23 acting in cotton response to potassium deprivation will be unravelled. This will lay a foundation for breeding new cotton varieties tolerating to potassium deficiency in the future.