膜联蛋白AtANN2和光受体AtCRY2在光周期调控拟南芥水分胁迫耐受性过程中的作用

Annexins are calcium-binding proteins in plant cells, the physiological function and regulation mechanism of them remains to be elucidated. Our previous experiments have demonstrated that AtANN2 is involved in water stress resistance of Arabidopsis. Moreover, AtANN2 are found to be regulated by photoperiod. Based on these results, Arabidopsis will be used as material, the effect of photoperiod on AtANN2 and its possible mechanism are planned to be investigated by using methods of plant physiology, cell biology, molecular biology and electrophysiology. Four main items will be verified: (1)the effect of photoperiod on physiological function of AtANN2; (2) gene expression and protein localization of AtANN2 under different photoperiod; (3) the role of AtCRY2 in photoperiod-regulated AtANN2 function; (4) the regulatory effect of AtANN2 and AtCRY2 in water stress resistance-induced ions flux under different photoperiod. The results of this project are of good help for understanding the function and regulation of AtANN2-participated plant stress tolerance.

膜联蛋白是植物细胞中一类重要的钙结合蛋白，它们的生理功能和调控机制还有待于阐明。我们的前期实验发现拟南芥膜联蛋白AtANN2参与植物水分胁迫的耐受过程，这种生理功能的实现与光周期相关。在此基础上，本项目以拟南芥为材料，利用植物生理学、细胞生物学、分子生物学和电生理学手段，对AtANN2受到光周期调控的信号转导机制进行探究，主要包括四项内容：（1）光周期对AtANN2生理功能的调控；（2）光周期对AtANN2基因表达和定位的调控；（3）光受体AtCRY2在光周期调控AtANN2过程中的作用；（4）不同光周期培养条件下AtANN2和AtCRY2对水分胁迫介导的跨膜离子流动的影响。项目对于阐明AtANN2的生理功能和活性调控机制具有积极的理论意义。

植物膜联蛋白（Annexins）是一类重要的多功能钙结合蛋白，其抗旱生理功能和调控机制待阐明。本研究发现光周期调控AtANN2参与植物干旱胁迫的耐受过程。在短日照下为了应对甘露醇处理，地下部AtANN2的基因表达量升高，其编码蛋白迅速向质膜聚集，调控了质膜上Ca2+的流动。隐花色素不仅可以作为光受体感受光周期，而且可以通过调控离子通道影响钙离子流动，引起下游生理反应。AtCRY2负向调控了AtANN2在特定光周期下的抗性生理功能，超表达AtCRY2会抑制甘露醇诱导的AtANN2生理功能、亚细胞定位的变化和细胞膜表面钙离子流动。总之，本项目阐明了拟南芥中存在“光周期-AtCRY2-AtANN2-钙信号-抗旱生理功能”这一信号通路。