15 NSFBIO SAUR regulation of stomatal aperture

15 NSFBIO SAUR 气孔孔径调节

• 批准号: BB/P011586/1
• 负责人: Michael Blatt
• 金额: $ 59.76万
• 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: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FP011586%2F1
• 关键词: 15; NSFBIO; SAUR; regulation; stomatal

Guard cells control photosynthesis and transpiration by regulating opening and closing of stomatal pores. We know much about how guard cells shrink in response to the drought stress hormone ABA, leading to stomatal closure. In contrast, we have sparse knowledge of the biochemical events by which guard cells swell to cause stomatal opening in response to light and diurnal rhythms. We have found that Arabidopsis SAUR (Small Auxin Up RNA) proteins can promote stomatal opening. This proposal will be to unravel under what conditions and by what mechanisms they do so.SAUR genes are a large class in all land plants. Several Arabidopsis SAUR proteins localize to the plasma membrane and promote cell expansion. These proteins are normally short-lived, but can be stabilized in the plasma membrane. We know that closely related SAUR proteins promote growth by inhibiting membrane-associated protein phosphatases that otherwise dephosphorylate plasma membrane H+-ATPases at a key regulatory site and increase H+-ATPase proton pumping. The same SAURs also promote stomatal opening when expressed in guard cells and a subset of these are preferentially expressed in guard cells under conditions in which stomata are open, but are repressed by drought or ABA. By contrast, ABA activates other SAUR genes in guard cells which may have opposing effects on stomatal function. Thus, what we do not know is whether these opposing actions are unique, whether they overlap, or whether SAUR-mediated signalling affects other transport and homeostatic processes in guard cells. Multiple transporters in both the plasma membrane and the tonoplast influence guard cell shrinking and swelling, and their activities often depend either directly or indirectly on the activation status of the others. Thus, to understand stomatal dynamics, it is essential to gain a global, systems view of guard cell transport and homeostasis. A major component of this project will exploit computational models that simulate these couplings using parameters based on experimental measurements. Starting points for current modelling will draw on past predictions that changes in H+-ATPase activity will have significant effects on stomatal aperture. For example, increased H+-ATPase activity in the model leads to slower stomatal closing at dusk and also to changed cytoplasmic concentrations of several other ions. Such knowledge will aid in experimental design and will also form a basis for subsequent validation.The collaborating researchers have complementary expertise in guard cell physiology (Blatt), computational modeling (Blatt), biochemistry (Gray), genetics (Reed, Nagpal), and auxin response (Gray, Nagpal, Reed). The collaboration will pool resources and expertise developed in the three labs to make possible the multipronged approach.

保卫细胞通过调节气孔的打开和关闭来控制光合作用和蒸腾作用。我们非常了解保卫细胞如何响应干旱应激激素 ABA 而收缩，从而导致气孔关闭。相比之下，我们对保卫细胞响应光和昼夜节律而膨胀导致气孔打开的生化事件知之甚少。我们发现拟南芥SAUR（小生长素上RNA）蛋白可以促进气孔开放。该提案将阐明它们在什么条件下以及通过什么机制这样做。SAUR 基因是所有陆地植物中的一大类。几种拟南芥 SAUR 蛋白定位于质膜并促进细胞扩张。这些蛋白质通常寿命较短，但可以在质膜中稳定。我们知道，密切相关的 SAUR 蛋白通过抑制膜相关蛋白磷酸酶来促进生长，否则膜相关蛋白磷酸酶会在关键调节位点使质膜 H+-ATP 酶去磷酸化，并增加 H+-ATP 酶质子泵送。当在保卫细胞中表达时，相同的 SAUR 也促进气孔开放，其中一部分在气孔开放的条件下优先在保卫细胞中表达，但受到干旱或 ABA 抑制。相比之下，ABA 激活保卫细胞中的其他 SAUR 基因，这可能对气孔功能产生相反的影响。因此，我们不知道这些相反的作用是否独特，它们是否重叠，或者 SAUR 介导的信号传导是否影响保卫细胞中的其他运输和稳态过程。质膜和液泡膜中的多种转运蛋白影响保卫细胞的收缩和肿胀，它们的活性通常直接或间接取决于其他转运蛋白的激活状态。因此，为了了解气孔动力学，必须获得保卫细胞运输和稳态的全局系统视图。该项目的一个主要组成部分将利用计算模型，使用基于实验测量的参数来模拟这些耦合。当前建模的起点将借鉴过去的预测，即 H+-ATP 酶活性的变化将对气孔孔径​​产生重大影响。例如，模型中 H+-ATP 酶活性的增加会导致黄昏时气孔关闭速度变慢，并且还会导致其他几种离子的细胞质浓度发生变化。这些知识将有助于实验设计，也将构成后续验证的基础。合作研究人员在保卫细胞生理学 (Blatt)、计算模型 (Blatt)、生物化学 (Gray)、遗传学 (Reed、Nagpal) 和生长素反应（Gray、Nagpal、Reed）。此次合作将汇集三个实验室开发的资源和专业知识，使多管齐下的方法成为可能。

项目成果

Plant Physiology Launches Associate Features Editors.

植物生理学推出副专题编辑。

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

What can mechanistic models tell us about guard cells, photosynthesis, and water use efficiency?

关于保卫细胞、光合作用和水分利用效率，机械模型能告诉我们什么？

• DOI: http://dx.10.1016/j.tplants.2021.08.010
• 发表时间: 2022
• 期刊: Trends in plant science
• 影响因子: 20.5
• 作者: Blatt MR

Liposome-based measurement of light-driven chloride transport kinetics of halorhodopsin.

基于脂质体的光驱动氯化物转运动力学的盐视紫红质测量。

• DOI: http://dx.10.1016/j.bbamem.2021.183637
• 发表时间: 2021
• 期刊: Biochimica et biophysica acta. Biomembranes
• 作者: Feroz H

Light-Driven Chloride Transport Kinetics of Halorhodopsin.

盐视紫红质的光驱动氯离子转运动力学。

• DOI: http://dx.10.1016/j.bpj.2018.06.009
• 发表时间: 2018
• 期刊: Biophysical journal
• 影响因子: 3.4
• 作者: Feroz H

New Faces behind the Scenes.

幕后新面孔。

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