重力是地球上重要的环境因子之一，在植物的生长发育中起到了关键的调控作用，但是，植物对重力信号感知与转导的分子机制仍然是个谜。近年来，关于植物感知重力早期信号途径的研究取得了很多新进展，其中研究最为深入的是胞质pH和胞质钙离子信号途径。膜联蛋白作为细胞质钙离子的感应器，可能在响应重力早期信号中起到关键的作用，但是，其分子机制仍不清楚。本申请拟通过分析拟南芥根平衡细胞中胞质钙离子和胞质pH对膜联蛋白的表达与分布的影响，尤其是精细的亚细胞定位的调控，确定膜联蛋白在参与重力信号转导中时空定位的生理基础与分子基础，丰富对重力信号转导通路与功能的认识；寻找膜联蛋白及其结合蛋白质参与重力信号转导通路的新机制与新功能，揭示胞质pH信号与胞质钙离子信号在重力信号转导中的内在关系，加深对植物向重力性反应机制本质的认识。

Gravity is one of the most important environmental factors on earth, which play a key role in regulating plant growth and development, but the molecular mechanism of gravity sensing and signal transduction in plant still remains one of the most exciting mysteries. The progresses of studies on gravity sensing and signal transduction have been recently achieved, including the physiological outputs of a fast cytosolic alkalinization and a fast change in cytosolic calcium levels in the statocytes in response to gravistimulation. Annexins, which are considered as calcium sensors or effectors in cytosolic calcium -driven processes, could play an important role in gravity sensing and signal transduction. In the present proposal, we are planning to study the response of annexin to the cytosolic pH and cytosolic calcium in the statocytes of roots of Arabidopsis wild-type and related mutants and to identify the function of annexins as complex components in plant gravity signal transduction networks. The goal is to understand the molecular mechanism of the role of annexins in gravity signal transduction and to provide new knowledge to further uncover the mechanism of gravitropic response.