The Regulation of Leaf Cell Expansion by Light and Ion Flux

叶片生长对光的响应对于植物最大化其光合能力，同时保存有效的营养和水分是重要的。红光和蓝光通过不同的机制刺激叶片的光形态发育，并通过生长细胞中的光合作用增强叶片的生长。生长对光的响应与质子外排和其他离子穿过质膜的通量有关。本研究的目的是问：1。在表皮和叶肉细胞中，光如何调节质膜质子泵？2. 叶片细胞中光诱导的离子通量是否部分由离子通道携带，如果是这样，光是否调节通道的活性？3. 生长对光反应有缺陷的突变体对光的电反应会改变吗？这些问题将通过电生理（微电极和膜片钳）技术来解决，利用拟南芥突变体对光的生长反应发生改变。叶片生长对光的响应对于植物最大限度地发挥光合作用的能力，同时保存有效的养分和水分是很重要的。叶片生长受到红光和蓝光的刺激，并通过生长细胞中的光合作用得到加强。生长对光的反应与穿过细胞膜的离子通量有关。这个项目将使用电技术来研究离子在响应光的情况下穿过叶细胞膜的机制。本研究结果将阐明生长叶片细胞光响应的初始事件。

Leaf growth responses to light are important for a plant to maximize its photosynthetic capacity while conserving available nutrients and water. Leaf growth is stimulated photo- morphogenically by red and blue light acting by separate mechanisms, and is enhanced by photosynthesis occurring in the growing cells. The growth response to light is associated with proton efflux, and other ion fluxes across the plasma membrane. The objectives of this study are to ask: 1. How is the plasma membrane proton pump regulated by light in epidermal and mesophyll cells? 2. Are light-induced ion fluxes in leaf cells carried in part by ion channels, and if so, does light regulate channel activity? 3. Will mutants defective in growth responses to light exhibit altered electrical responses to light? These questions will be approached by electrophysiological (microelectrode and patch clamp) techniques taking advantage of mutants of Arabidopsis showing altered growth responses to light. %%% Leaf growth responses to light are important for a plant to maximize its ability to carry out photosynthesis while conserving available nutrients and water. Leaf growth is stimulated by red and blue light and is enhanced by photosynthesis occurring in the growing cells. The growth response to light is associated with ion fluxes across the cell membrane. This project will use electrical techniques to study the mechanisms by which ions move across the membranes of leaf cells in response to light. The results of this research will clarify the initial events occurring in light responses of growing leaf cells.