基于蛋白质组学方法的唐古特白刺盐胁迫应答分子机制研究

Soil salinity is one of main abiotic stresses to severely influence the plants' growth, development and distribution, so it plays an important roles in theoretics and practices to study and decipher the mechanism of salt tolerance/resistance in plants. Nitraria tangotorum Bobr is a peculiarly ecological and economical desert shrub in China with the great characteristic of salinity tolerance, which has been acting as one of ideal materials to study the mechanism of plants response to salinity conditions. In this project, the profiles of proteins'expression (including phosphorylated protein) in roots and leaves of tissue culture seedlings of N. tangotorum were investigated under the treatments of different NaCl concentrations with proteomics method. Firstly, differentially expressed proteins were screened from salt stress by fluorescent two-dimensional difference gel electrophoresis (2D-DIGE), and then identified using MALDI-TOF/MS coupled with proteins/peptides databases, eventually proteins closely responsive to salt stress and their related metabalism pathways were mined; furthermore, the functions of proteins were evaluated by using western, RT-PCR, overexpression & RNAi knockout and physiological determination; finally, the mechanism of salinity tolerance in N. tangotroum was deciphered by combining with the previous data of proteomics and digital gene expression profiles. These studies would not only benefit to understand the genetic bases of plants adaptation to salinity conditions, but also benefit to cultivate new species and genetic improvement in halophytes.

盐渍化危害是严重影响植物生长、发育及分布的主要非生物胁迫因子之一。研究和掌握植物的耐/抗盐机理，具有重要的理论和实践意义。唐古特白刺为我国特有种，是极耐盐碱的生态经济灌木，也是研究植物耐盐机理的理想材料之一。本项目拟以唐古特白刺组培植株为研究材料，通过运用比较蛋白质组学技术，研究其在不同盐胁迫处理下根、叶蛋白质（包括磷酸化蛋白）的表达变化规律；筛选出响应盐胁迫的应答蛋白或信号转导分子，确定其蛋白身份及其参与的主要代谢途径；利用Western、RT-PCR、过量表达与RNAi敲除及生理生化测定等手段进行蛋白功能验证，并结合已有转录组及差异表达谱研究数据，揭示唐古特白刺耐/抗盐分子响应机制，这将对进一步阐明植物耐盐性状的遗传基础、耐盐植物新品种培育及遗传改良具有重要意义。

唐古特白刺是一种优良的耐盐抗逆植物，能抗干旱、极耐盐碱，在土壤含盐量高达4%的重盐碱地，仍能正常生长发育，具有重要的生态、经济价值。研究植物在盐胁迫下所产生复杂的生物化学和生理学上的响应，可以探索阐明引起这些响应的分子机制。本项目以唐古特白刺愈伤细胞和再生植株为材料，通过分别对其进行不同浓度盐胁迫处理，调查了其表型、生物量变化，测定了包括光合作用、抗氧化性酶系、胁迫密切相关的物质含量、渗透相关的离子含量等一系列生理生化指标的改变，以及在蛋白质水平上的差异蛋白质组表达谱分析，获得响应盐胁迫的功能蛋白群，并对关键蛋白进行分子生物学验证；同时结合生物信息学分析，获得了白刺耐受高盐胁迫的分子应答途径和网络，初步解析了唐古特白刺耐受高盐胁迫的生理生化与分子机理。同时克隆了耐盐重要基因CIPK9，并分析其在转基因拟南芥中的耐盐性分析。取得了预期的研究结果。.已发表论文8篇(其中SCI收录论文2篇），申请发明专利3项（授权3项），培养研究生2名。