A new model of stomatal function

气孔功能的新模型

• 批准号: BB/Y001257/1
• 负责人: Andrew James Fleming
• 金额: $ 77.53万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FY001257%2F1
• 关键词: new; model; stomatal; function

Plants need to draw water up from the soil to the shoots. They do this by losing water vapour via small, controllable pores on the leaf surface, termed stomata. Open stomata allow plants to pull water throughout the plant and, at the same time, they allow carbon dioxide into the leaf where it is used for photosynthesis, the process by which all our food is made. However, if stomata were always open this would lead to catastrophic water loss, wilting, and eventual death of the plant. Therefore, plants continually adjust their stomata, making sure that they are open enough to allow the plant to grow when conditions are good, but closed when there is the danger of losing too much water. Due to their critical role in plants, how stomata work has been a topic of extensive research for over 150 years. Most of this work has focussed on the two cells (guard cells) between which the stomatal pore is formed, leading to the widely accepted paradigm that these cells swell and deflate via the gain or loss of water, and that this change of guard cell size and shape is the primary mechanism by which stomatal pores open and close. Our recent research, using 3-dimensional imaging, has revealed that cells neighbouring the guard cells also undergo very large changes in size and shape in response to triggers known to close stomata. In addition, our imaging experiments have shown that the guard cells themselves undergo a much more complicated change in shape than has generally been described. Taken together, our new results suggest that the classical text-book descriptions do not fully capture the mechanism by which changes of cell size and shape lead to stomatal opening and closing. In particular, our new findings suggest that a combination of guard cell and neighbouring epidermal cell responses is required for a full and efficient mechanism for stomatal pore opening and closure. As well as providing a new insight into a classical and fundamental aspect of plant biology, these data may open new paths to optimising or improving stomatal performance, leading to new approaches to reducing crop water requirements and improving drought tolerance, major challenges for agriculture in a changing global environment.To test our ideas, we will use a combination of advanced imaging and computational modelling techniques, combined with an array of genetic resources. For example, we will expand our present investigations where we have looked at two known triggers of stomatal closure to see whether the guard cell/neighbouring cell response that we have observed reflects a general aspect of stomatal function. We will then use a variety of approaches to alter either neighbouring cell viability or responsiveness to stomatal opening/closure triggers, testing the idea that neighbouring cell function is required for full stomatal function. These same approaches will also be used to alter the guard cell shape response that we have observed, testing the idea that this specific shape change is intimately connected with the mechanism of stomatal pore opening and closure. Throughout the project we will create computational models of the stomatal systems that we are investigating. These models, which will be informed by our experimental results, will provide a strong theoretical underpinning to the project, helping us both to interpret our experiments, and allowing us to design further experiments to test our ideas on the mechanism by which both guard cells and their neighbouring cells work together in the opening and closure of stomata.The improved understanding of stomatal mechanics gained through this research could, in the future, aid the production of more resilient crops that are better suited to growth under climate change.

植物需要从土壤中吸取水分使其长出新芽。它们通过叶子表面的小而可控的气孔（称为气孔）来失去水蒸气。开放的气孔允许植物将水吸入整个植物，同时，它们允许二氧化碳进入叶子，用于光合作用，这是我们所有食物的制造过程。然而，如果气孔总是打开，这将导致灾难性的水分流失，枯萎，并最终死亡的植物。因此，植物不断地调整它们的气孔，确保它们在条件良好时足够开放以允许植物生长，但在有失去太多水分的危险时关闭。由于它们在植物中的关键作用，气孔如何工作一直是150多年来广泛研究的主题。大部分的工作都集中在两个细胞（保卫细胞）之间的气孔形成，导致广泛接受的范例，这些细胞膨胀和收缩通过获得或损失的水，这种变化的保卫细胞的大小和形状是气孔打开和关闭的主要机制。我们最近的研究，使用三维成像，已经揭示了邻近保卫细胞的细胞也会在大小和形状上发生非常大的变化，以响应已知的关闭气孔的触发器。此外，我们的成像实验表明，保卫细胞本身经历了比通常描述的更复杂的形状变化。综上所述，我们的新结果表明，经典的教科书描述没有完全捕捉细胞大小和形状的变化导致气孔打开和关闭的机制。特别是，我们的新发现表明，保卫细胞和相邻的表皮细胞反应的组合是需要一个完整的和有效的机制气孔开闭。除了为植物生物学的经典和基础方面提供新的见解外，这些数据还可能为优化或改善气孔性能开辟新的途径，从而导致减少作物需水量和提高耐旱性的新方法，这是农业在不断变化的全球环境中面临的主要挑战。为了测试我们的想法，我们将结合使用先进的成像和计算建模技术，再加上一系列的遗传资源。例如，我们将扩大我们目前的调查，我们已经在两个已知的触发气孔关闭，看看是否保卫细胞/相邻细胞的反应，我们观察到的反映气孔功能的一般方面。然后，我们将使用各种方法来改变相邻细胞的活力或响应气孔打开/关闭触发器，测试的想法，相邻细胞的功能是必需的完整的气孔功能。这些相同的方法也将被用来改变保卫细胞形状的反应，我们已经观察到，测试的想法，这种特定的形状变化是密切相关的气孔开闭的机制。在整个项目中，我们将创建我们正在研究的气孔系统的计算模型。这些模型将由我们的实验结果提供信息，将为该项目提供强有力的理论支持，帮助我们解释我们的实验，并允许我们设计进一步的实验来测试我们关于保卫细胞及其相邻细胞在气孔打开和关闭中共同工作的机制的想法。通过这项研究获得的对气孔力学的更好理解可以，在未来，帮助生产更适应气候变化的更有弹性的作物。