坛紫菜高盐胁迫应答中维持K+/Na+平衡的机制研究

紫菜具有很强的耐受高盐胁迫能力，前期研究中发现K+/Na+平衡在其中发挥着重要作用，但对其调控机理尚不清楚。本研究拟以坛紫菜为研究对象，通过测定高盐胁迫及抑制剂处理后藻体细胞内K+和Na+的含量变化，确定高盐胁迫下参与维持K+/Na+平衡的离子转运体和通道；采用非损伤微测技术测定藻体K+、Na+和H+的实时流速和流向变化，采用膜片钳等技术测定质膜离子通道及转运蛋白的活性，从动态离子转运和蛋白活性的角度揭示相关离子转运体和通道在坛紫菜维持K+/Na+平衡中的调控作用；并采用实时荧光定量和靶向定量蛋白组学技术分别对相应质膜离子转运体基因和蛋白在高盐胁迫下的表达水平进行定量分析，进一步分析相应基因和蛋白对坛紫菜维持K+/Na+平衡的分子调控机制，从而阐明K+/Na+平衡调控在坛紫菜应答高盐胁迫中的作用机制，完善人们对植物耐盐机理的认识，为耐盐植物的培育提供理论依据。

Pyropia has strong ability to tolerate severe hypersaline stresses. Our previous studies have shown that K+/Na+ homeostasis plays important role in the response of Pyropia to salinity stresses, however, the underlying mechanism is not clear. Pyropia haitanensis will be utilized in this study. Firstly, we will detect the change of ion (K+ and Na+) content to determine the plasma membrane ion transporter and channel regulating K+/Na+ homeostasis under hypersaline treatment. Furthermore, we will employ non-invasive micro-test technique to detect the real-time dynamic alterations of K+, Na+ and H+ fluxes and directions under salinity and inhibitors stresses, determine the activity of plasma membrane ions channel and transporters by Patch-Clamp and other technologies. This is aimed to uncover the functions of the plasma membrane ion transporter and channel in the process of P. haitanensis keeps K+/Na+ homeostasis under salinity stresses from the level of dynamic ion transport and protein activity. Finally, we will use qRT-PCR and targeted quantitative proteomics to analyze the expression of the corresponding genes and proteins that regulate plasma membrane ion transporter and channel under hypersaline stresses, respectively, to investigate the mechanisms behind P. haitanensis coping with K+/Na+ homeostasis under salinity stresses at the molecular level. The current project will elucidate the function of maintaining K+/Na+ homeostasis in the process of P. haitanensis response to hypersaline stresses, which will improve our understanding of the mechanistic study of salt tolerance in plant, and further provide theory evidence for the breeding of salt-tolerant plants.