Biophysical and Biochemical Studies on Ion Transport in Plants

植物中离子传输的生物物理和生化研究

• 批准号: 8716363
• 负责人: Roger Spanswick
• 金额: --
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-03-01 至 1991-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8716363&HistoricalAwards=false
• 关键词: Biophysical; Biochemical; Studies; Ion; Transport

The funded project continues testing a chemiosmotic hypothesis for the transport of ions across plant cell membranes. It is postulated that the H+ -translocating ATPases, which have been demonstrated to be located in the plasma membrane and the tonoplast, set up electrochemical potential gradients of H+ which provide the driving force for the transport of other ions and small organic molecules via proton cotransport systems. Tomato and corn roots are the experimental material. Fluorescent probes for pH gradients and membrane potentials are used in conjunction with radioactive tracers to investigate the occurence of cotransport systems for sodium, potassium and nitrate in isolated plasma membrane vesicles. An attempt will be made to identify the carrier protein for nitrate in the plasma membrane following induction of nitrate transport. Whole- cell voltage clamp recordings from protoplasts are being obtained with tight-seal patch pipets. This technique will be used to investigate the contribution of the electrogenic H+ -ATPase to the membrane potential and conductance of the tomato root cell plasma membrane. Control of the "cytoplasmic" pH and ATP level by perfusion of the patch pipet with different solutions will be used to compare the behavior of the electrogenic pump with the known kinetic properties of the H+ -ATPase. The significance of this work lies in elucidating the mechanism of ion transport in plants, a process of crucial metabolic importance. It is through ion transport that nutrients are absorbed, acidity is controlled and starting materials are provided for biosynthesis.***//

受资助的项目继续测试一种化学渗透剂， 离子跨细胞转运假说 膜。 据推测， ATP酶，已被证明位于 质膜和液泡膜，建立电化学 提供驱动力的H+的电位梯度 其他离子和小的有机分子通过 质子共转运系统 番茄和玉米的根是 实验材料 pH梯度荧光探针 和膜电位结合使用， 放射性示踪剂来调查 钠、钾和硝酸盐共转运系统 分离的质膜囊泡。 将尝试 来鉴定血浆中硝酸盐的载体蛋白 膜后诱导硝酸盐运输。 整个- 原生质体的细胞电压钳记录 用密封的贴片移液管获得。 这种技术将 用于研究生电 H ~+ -ATP酶对膜电位和电导的影响 番茄根细胞质膜。 控制 贴片灌注的“细胞质”pH和ATP水平 将使用带有不同溶液的移液管来比较 具有已知动力学的生电泵的行为 H+ -ATPase的特性。 这项工作的意义在于阐明 离子在植物中的运输机制，一个关键的过程， 代谢的重要性。 正是通过离子传输， 营养物质被吸收，酸度被控制， 为生物合成提供材料。*//