description
- 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.