Shape Shifting Stomata: The Role of Geometry in Plant Cell Function

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拉到植物的顶部，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。进化导致了两种主要类型的气孔：一种是由两个细胞组成的简单形式（在大多数植物中发现），另一种是由四个细胞组成的更复杂的形式。这些更复杂的气孔存在于玉米、水稻、小麦和大麦等植物中，这些植物是世界上最重要的粮食作物。这些植物如此成功的原因之一被认为是因为它们的气孔功能比其他植物更好，导致水分流失更少。然而，四细胞气孔究竟如何比两细胞气孔“更好”还不清楚。我们的假设是，气孔的结构（细胞的特殊形状和/或气孔中细胞壁的机械性能）使它们成为控制水分散失的更有效的系统。这个项目将研究和测试这个想法。要解决草气孔如何能更好地发挥作用的问题，将涉及理解气孔的机械特性，以确定结构的哪些元素对气孔功能最重要。生物学家和计算科学家将合作创建一个四细胞气孔模型，使用模型草系统，短柄草，其中气孔生物学最近取得了重大进展，为该项目提供了重要的工具和资源。通过创建一个计算机模型，我们将能够快速探索气孔如何工作的想法。然后，我们将通过实验测试这些想法，在实验室中创建新型气孔并评估其性能。在项目期间，我们将应用新的软件工具来生成这些模型。这将使我们能够额外测试细胞的特定形状可以对细胞的行为产生重要影响的想法。这将推进我们对生物学的基本理解，并为气孔如何工作提供新的见解：叶片上不同气孔之间形状的微小变化实际上对气孔控制水分流失的效果有很大影响吗？作为这项工作的结果，我们将确定是什么使四细胞气孔比两细胞气孔更好，回答了植物生物学中一个长期存在的问题，并提供了可能用于作物育种者的信息，以提高作物在干旱下的生存能力-这是英国和世界农业的一个重大挑战。

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 up to the top of 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. Evolution has led to two main types of stomata: a simple form composed of just two cells (found in the majority of plants) and a more complex form composed of four cells. These more complex stomata are found in plants such as maize, rice, wheat and barley- the most important crops for feeding the world. One of the reasons why these plants are so successful is thought to be because their stomata function better than those found in other plants, leading to less water loss. However, exactly how the four-celled stomata are "better" than the two-celled type is unclear. Our hypothesis is that it is the structure of the stomata (both the special shape of the cells and/or the mechanical properties of the cell walls in the stomata) that make them a more efficient system for controlling water loss. This project will investigate and test this idea. To resolve the question of how grass stomata can perform better will involve understanding the mechanical properties of stomata to identify which elements of the structure are most important for stomatal function. Biologists and computational scientists will work together to create a model of the four-celled stomata, using a model grass system, brachypodium, in which significant advances in stomatal biology have recently been made, providing important tools and resources for this project.By creating a computer model we will be able to rapidly explore ideas on how the stomata work. We will then test these ideas experimentally, creating new types of stomata in the laboratory and evaluating their performance. During the project we will apply new software tools to generate these models. This will allow us to additionally test the idea that the specific shape of a cell can have a major outcome on what a cell does. This will both advance our fundamental understanding of biology and provide a new insight into how stomata work: do apparently minor changes in shape between different stomata on a leaf actually have a large influence on how well the stomata control water loss? As a result of this work we will determine what makes four-cell stomata better than two-cell stomata, answering a long-held question in plant biology and providing information that will be of potential use to crop breeders looking to improve how well crops survive under drought- a major challenge in UK and world agriculture.