细胞感应水分变化是生命的基本生理过程，寻找水分胁迫或干旱信号接收和传递的感应或受体分子，一直是人们追求的目标。从胞内钙离子上升、感应水分胁迫的原初反应出发，利用膜蛋白CDS文库，我们筛选出对渗透变化快速反应的多个细胞株，进而克隆了AtCSC1（Calcium permeable Stress-gated cation Channel 1）,经研究现已发现CSCs可介导水分变化门控的第二信使离子内流,但其感应、通道特征、生理功能和调控途径仍不清楚。本课题以此为切入点，深入解析CSCs作为水分感应通道分子的特性和结构元件，分析该蛋白的通道选择性、渗透门控特性等，鉴定出接受水分变化刺激的结构域和导致钙离子信使信号传递的结构域，探索分离出该蛋白的相互作用或调节分子，重组调控途径，结合反向遗传学和转基因的方法在体内研究CSCs突变体的表型及生理功能，理解作CSCs为水分变化原初信号接收分子的特性.

Water is the origin of life. Cytosolic calcium elevation is one of the earliest responses of plant cells to water changes，However, none of the primary messengers or receptors has been found to respond directly to this signal. In an attempt to identify this kind of molecule, we used heterologous expression of Arabidopsis CDS genes in Chinese Hamster Ovary (CHO) cells and screened membrane proteins for osmosensitive conductance. These screens led to the identification of Arabidopsis CSC1 (Calcium permeable Stress-gated cation Channel 1) that cause the intracellular Ca2+ concentration promptly rising by water changes. Based on these results, we try to determine the receptor-channel electrophysiological characterization of CSCs, including ion selectivity, rectification and water-change gating of the property, to identify their functional domains for osmotic sensing and the Ca2+-messenger conductance, In order to further investigation the regulation of CSCs, we will isolate the interacting factors of this protein and reconstitute the partners in vitro. Morever, by employing anti-genetic and trangentic approaches to analyze the phenotype of cscs mutants and the physiological function of CSCs, especially the rapid reponsiveness to water changes.