玉米响应钾胁迫的差异质膜蛋白及其功能分析

As an important food crops, maize needs more potassium (K) for plant growth, which shows sensitive to K deficiency. In plants, K absorb from external environments into plant cell is accomplished through K transporters and channels located at the plasma membrane of root cells. And these plasma membrane proteins that participating in K absorption and transportation become the research focus in plants K-efficient. To investigate the different K-efficiency between the K-efficient and K-inefficient maize, seedlings were grown under short-term K-free (0 mM K+) condition, and Maize seedling grown under high K (2.5 mM K+) as control. The plasma membrane were purified from K-efficient and K-inefficient maize, respectively. Then the plasma membrane proteins that response to K starvation were identified by iTRAQ (isobaric tags for relative and absolute quantitation) combined with mass spectrum. Furthermore, subcellular localization and gene function of the candidate protein as well as physiological and biochemical analysis were conducted to investigate the different mechanism for K absorption and utilization between the two maize, which can provide genetic improvement or gene resource of K nutritive characteristics on maize and other crops.

玉米为钾需求量大且缺钾敏感的粮食作物。植物主要通过根系质膜中的钾转运子和钾通道蛋白从外界吸收钾，这些与钾吸收转运相关的根系质膜蛋白成为揭示玉米钾高效利用机理的研究热点。本项目以已筛选获得的玉米钾高效（耐低钾）和钾低效（对缺钾敏感）品种为材料，利用营养液培养试验，设置苗期短期钾饥饿处理并以正常钾（2.5 mM K+）培养为对照，分离并纯化根系质膜蛋白，通过iTARQ（同位素标记相对和绝对定量）技术进行蛋白定量和质谱鉴定获得响应钾胁迫的差异蛋白，比较分析不同钾效率的玉米根系质膜中对钾吸收转运的转运子和通道蛋白差异，完成候选蛋白的亚细胞定位、对应基因的功能验证以及生理生化指标的验证等，克隆玉米钾吸收利用的功能基因，研究钾营养高效的分子机理，为玉米或其他作物钾营养性状的遗传改良和育种提供基因资源。