Transcriptional and Post-Translational Regulation of Plant Vacuolar Na+/H+ Antiports

植物液泡 Na /H 反向端口的转录和翻译后调控

• 批准号: 0110622
• 负责人: Eduardo Blumwald
• 金额: $ 36万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-15 至 2005-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0110622&HistoricalAwards=false
• 关键词: Transcriptional; Post; Translational; Regulation; Plant

Environmental stress due to salinity is one of the most serious factors limiting the productivity of agricultural crops, which are predominantly sensitive to the presence of high concentrations of salts in the soil. A comparison of ion distribution in cells and tissues of various plant species indicates that a primary characteristic of salt tolerant plants is their ability to exclude sodium out of the cell and to take up sodium and to sequester it in the cell vacuoles. Dr. Blumwald's work has identified a family of vacuolar Na+/H+ antiports that play a paramount role in the ability of plants to grow in high NaCl concentrations. These antiports actively move ions into the vacuole, removing the potentially harmful ions from the cytosol. These ions, in turn, act as an osmoticum within the vacuole, which then maintain water flow into the cell, thus allowing plants to grow in soils containing high salinity. The cloning of plant Na+/H+ antiports and the generation of transgenic Arabidopsis thaliana plants with enhanced salt tolerance provides a unique opportunity to study the role of these transporters in salt tolerance and ion homeostasis in vivo. Dr. Blumwald's proposed research aims to identify and characterize proteins regulating the vacuolar Na+/H+ antiport activity, providing insights on the role of Ca2+-dependent transduction processes in the regulation of intracellular ion balance. The second objective will serve to identify mechanisms regulating the transcription of the antiports in salt tolerant plants that could be used to design crops with enhanced salt tolerance. The third objective, will use knockout mutants and RNA interference to determine the physiological role of the vacuolar antiports in K+ nutrition.

盐度造成的环境压力是限制农作物生产力的最严重因素之一，农作物主要对土壤中高浓度盐的存在敏感。不同植物物种细胞和组织中离子分布的比较表明，耐盐植物的主要特征是它们能够将钠排除在细胞外、吸收钠并将其隔离在细胞液泡中。 Blumwald 博士的工作已经确定了一个液泡 Na+/H+ 反向端口家族，它们在植物在高 NaCl 浓度下生长的能力中发挥着至关重要的作用。这些反向端口主动将离子移入液泡，从细胞质中去除潜在有害的离子。这些离子反过来又充当液泡内的渗透剂，维持水流进入细胞，从而使植物能够在高盐度的土壤中生长。植物Na+/H+反向转运蛋白的克隆和耐盐性增强的转基因拟南芥植物的产生为研究这些转运蛋白在体内耐盐性和离子稳态中的作用提供了独特的机会。 Blumwald 博士提出的研究旨在识别和表征调节液泡 Na+/H+ 反向转运活性的蛋白质，从而深入了解 Ca2+ 依赖性转导过程在细胞内离子平衡调节中的作用。第二个目标将用于确定耐盐植物中反向端口转录的调节机制，这些机制可用于设计具有增强耐盐性的作物。第三个目标，将使用敲除突变体和 RNA 干扰来确定液泡反向端口在 K+ 营养中的生理作用。