Guard cell wall epitope patterns and stomatal function

用水效率是农作物产量的一个重要决定因素，特别是在容易发生干旱的国家。水分通过气孔从植物中流失，气孔是叶子表皮表面的微观孔隙，两侧是两个专门的保护细胞。保卫细胞扩张打开气孔，气体通过气孔进入和离开植物，因此水分也会流失。保卫细胞必须高度灵活而又强壮，以允许气孔的打开和关闭。这些结构特性被认为是由于特殊的保护细胞壁，已知富含赋予强度和柔韧性的多糖。在这个项目中，我的目标是使用分子和成像技术来鉴定拟南芥保护细胞壁的结构和力学特性以及负责这些表型的基因。这将允许产生缺乏这些已确定基因的突变系，然后可以对整个植物的生理特性进行测试，例如气体交换。先前关于保护细胞壁机制的工作都是在拟南芥中进行的，因此该项目的下一阶段是整理这些数据并研究作物物种的保护细胞壁。免疫标记技术将有助于确定拟南芥和草保护细胞是否具有相似的结构特性，功能分析将表明草保护细胞壁是否显示与拟南芥保护细胞壁基因同源的基因。可以创建突变系来研究选定的基因对保护细胞和随后的整个植物生理性状的影响。总的来说，这个项目旨在将我们目前对保护细胞壁的知识转移到作物物种中。先前的研究表明，对拟南芥保护细胞壁基因的操纵可以改变保护细胞的运动，这可能也适用于禾草。在未来，这可能有潜力在预测的二氧化碳升高和水可用性减少的气候条件下改善植物生长。

Water use efficiency is an important determinant of crop yield, particularly in drought prone countries. Water is lost from plants through the stomata, microscopic pores in the epidermal surface of the leaf, which are flanked by two specialised guard cells. The guard cells expand to open the stomatal pore through which gases enter and leave the plant, and consequently water is also lost. The guard cells must be highly flexible yet strong to allow for stomatal opening and closure. These structural properties are thought to be due to the specialised guard cell wall, which is known to be enriched in polysaccharides which confer strength and flexibility. In this project I am aiming to use molecular and imaging techniques to identify the structural and mechanical properties of the Arabidopsis guard cell walls and the genes responsible for these phenotypes. This will allow for the creation of mutant lines which are deficient in these identified genes, which can then be tested for whole plant physiological traits such as gas exchange. Previous work on guard cell wall mechanics has all been carried out in Arabidopsis, so the next stage of the project is to collate this data and investigate guard cell walls in a crop species. Immunolabelling techniques will help to determine whether Arabidopsis and grass guard cells show similar structural properties and functional analysis will show whether grass guard cell walls display genes homologous to Arabidopsis guard cell wall genes. Mutant lines can be created to investigate the effects of selected genes upon the guard cells and subsequent whole plant physiological traits.Overall this project aims to transfer our current knowledge of guard cell walls into a crop species. Previous work has shown that the manipulation of guard cell wall genes in Arabidopsis can alter the movement of the guard cells, and this may also be true of grasses. In the future this may have the potential to improve plant growth under the predicted climatic conditions of elevated CO2 and reduced water availability.