A protein scaffold essential for K+ transport and stomatal control

对于钾离子运输和气孔控制至关重要的蛋白质支架

• 批准号: BB/H009817/1
• 负责人: Michael Blatt
• 金额: $ 56.25万
• 依托单位: University of Glasgow
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FH009817%2F1
• 关键词: protein; scaffold; essential; K+; transport

This proposal builds on the discovery in this laboratory of an unusual SNARE protein complex that is essential for K+ channel regulation in Arabidopsis, and of our recent finding of its impact on K+ uptake by the roots and plant growth. Because the SNARE, SYP121, is already known to have roles in pathogen defence and cell volume responses meidated by the plant hormone abscisic acid (ABA), these findings offer the first substantive evidence that physically links the protein complex to actions in abiotic stress, mineral nutrition, water use efficiency (defined as the amount of dry matter produced per unit of water transpired through stomata) and cell expansion in the plant. 'Closing the circle' of K+ channel control, its contributions to K+ assimilation, water flux and cell volume control in the growing plant is expected to yield substantive insights in future efforts towards 'hardening' and development of water-effcient crops. In general, eukaryotic cells engage SNARE proteins as part of a well-defined mechanism for traffic of membrane vesicles, proteins and soluble cargo between compartments within the cell. Work from this laboratory first identified genes encoding two plasma membrane SNAREs from tobacco and Arabidopsis, and demonstrated their association with the ABA signalling cascade leading stomata to close and reduce water loss from the plant. Much is known about these cellular signals as well as the mechanisms they engage in regulating transmembrane ion flux. By contrast, we have little knowledge of the mechanisms coordinating ion transport with cellular volume and membrane surface in guard cells. Indeed, how plant cells regulate transport of osmotically-active solutes (especially of K+) in parallel with cell volume, whether reversible as in guard cells or during irreversible expansive growth, remains a matter of considerable debate. Knowing how transport is coordinated with changes in cell surface area will be of great fundament importance to understanding cell volume control in plants generally, and is likely to have practical relevance in our ability to manipulate the growth and homeostasis of plants, for example in altering stomatal controls to improve water use efficiency of crops. Our working hypothesis is that SNARE-K+ channel interaction serves as a molecular governor, analogous to the mechanical invention of James Watt, to coordinate channel-mediated uptake of the osmotically-active K+ ion with cell expansion We want to explore the molecular mechanics of the interaction, its implications for such a governor model in cell volume control and, equally, we want to examine its potential for applications in agriculture. Our immediate goals are (1) to explore the dynamics of the protein partners and their interactions, (2) to analyse their impact on ion transport and its coordination with membrane traffic, and (3) to assess their importance for stomatal function and water use by plants under stress.

该提案基于本实验室发现的一种不寻常的 SNARE 蛋白复合物，该蛋白复合物对于拟南芥 K+ 通道调节至关重要，以及我们最近发现的其对根部吸收 K+ 和植物生长的影响。由于 SNARE SYP121 已知在植物激素脱落酸 (ABA) 介导的病原体防御和细胞体积反应中发挥作用，因此这些发现提供了第一个实质性证据，证明该蛋白质复合物与非生物胁迫、矿物质营养、水分利用效率（定义为通过气孔蒸腾每单位水产生的干物质的量）和植物细胞扩张的作用有物理联系。 K+通道控制的“闭合循环”，其对生长植物中K+同化、水通量和细胞体积控制的贡献预计将为未来“硬化”和开发节水作物的努力产生实质性的见解。一般来说，真核细胞将 SNARE 蛋白作为细胞内区室之间膜囊泡、蛋白质和可溶性货物运输的明确机制的一部分。该实验室的工作首先鉴定了编码来自烟草和拟南芥的两个质膜 SNARE 的基因，并证明了它们与导致气孔关闭和减少植物水分流失的 ABA 信号级联的关联。人们对这些细胞信号以及它们参与调节跨膜离子流的机制了解很多。相比之下，我们对保卫细胞中离子转运与细胞体积和膜表面的协调机制知之甚少。事实上，植物细胞如何与细胞体积平行地调节渗透活性溶质（尤其是 K+）的运输，无论是在保卫细胞中是可逆的还是在不可逆的扩张生长过程中，仍然是一个相当有争议的问题。了解运输如何与细胞表面积的变化相协调对于理解植物细胞体积控制具有重要的基础意义，并且可能对我们操纵植物生长和稳态的能力具有实际意义，例如改变气孔控制以提高作物的水分利用效率。我们的工作假设是 SNARE-K+ 通道相互作用充当分子调控器，类似于 James Watt 的机械发明，以协调通道介导的渗透活性 K+ 离子的吸收与细胞扩张。我们想要探索相互作用的分子机制，其对细胞体积控制中这种调控器模型的影响，同样，我们想要研究其在农业中应用的潜力。我们的近期目标是（1）探索蛋白质伙伴的动态及其相互作用，（2）分析它们对离子运输的影响及其与膜运输的协调，以及（3）评估它们对胁迫下植物的气孔功能和水利用的重要性。

项目成果

Plant Physiology Launches Associate Features Editors.

植物生理学推出副专题编辑。

• DOI: 10.1104/pp.18.00113
• 发表时间: 2018
• 期刊: Plant physiology
• 影响因子: 7.4
• 作者: Blatt MR

The conceptual approach to quantitative modeling of guard cells

• DOI: 10.4161/psb.22747
• 发表时间: 2013-01-01
• 期刊: PLANT SIGNALING & BEHAVIOR
• 影响因子: 2.9
• 作者: Blatt, Michael R.;Hills, Adrian;Lew, Vigilio L.
• 通讯作者: Lew, Vigilio L.

Exploring emergent properties in cellular homeostasis using OnGuard to model K+ and other ion transport in guard cells.

• DOI: 10.1016/j.jplph.2013.09.014
• 发表时间: 2014-05-15
• 期刊: JOURNAL OF PLANT PHYSIOLOGY
• 影响因子: 4.3
• 作者: Blatt, Michael R.;Wang, Yizhou;Leonhardt, Nathalie;Hills, Adrian
• 通讯作者: Hills, Adrian

New Faces behind the Scenes.

幕后新面孔。

• DOI: 10.1104/pp.18.00140
• 发表时间: 2018
• 期刊: Plant physiology
• 影响因子: 7.4
• 作者: Blatt MR