Role of aquaporins in plant water relations

自从水通道蛋白（水通道蛋白）被发现以来，人们开始认识到它们在植物水分关系中的关键作用。目前，研究影响、调节和协调植物水通道蛋白功能的因素和过程是一个重要的课题。该项目的主要目的是发展有关水通道蛋白在植物水流调节中的作用的知识。拟议的项目包括一系列的研究，旨在贡献知识的水通道蛋白介导的运输在植物水关系中的作用。在一项研究中，我们将调查细胞水的关系，在不同的叶组织检查的假设，水细胞的运输特性不同，反映其功能的差异，这些差异反映了单个水通道蛋白的表达水平。另一项研究将使用过表达主要水通道蛋白的遗传转化杂交杨树进行，以研究水通道蛋白在植物根和叶水分运输过程的协调和整合中的功能。我们还将使用过表达水孔蛋白的基因转化真菌来检验真菌水孔蛋白有助于菌根植物根和叶水分运输的假设。同时，还将在接种了Laccaria bicolor菌根真菌的白杨（Populus tremuloides）中研究菌根对根和叶水分运输的影响，以探讨茉莉酸信号通路通过改变水孔蛋白表达参与菌根侵染的根水力响应的假说。内生真菌对植物水分关系的影响也将与最近发现的根内生真菌Piriformospora indica定殖拟南芥进行。这种真菌由于其促进植物生长和保护压力的特性而引起了广泛的兴趣。我们将研究真菌通过改变水通道蛋白的功能来触发植物中这些反应的假设。拟议的研究将填补我们的知识的植物水分关系，这是至关重要的方法和实践的发展，旨在提高生长和产量的重要空白。

Since the discovery of water channel proteins (aquaporins), recognition of their pivotal role in plant water relations has begun to emerge. Major effort is now required to learn about the factors and processes which affect, regulate and coordinate the functions of aquaporins in plants. The principal objective of the proposed project is to develop knowledge concerning the role of aquaporins in water flow regulation in plants. The proposed project consists of the series of studies aimed at contributing knowledge concerning the role of the aquaporin-mediated transport in plant water relations. In one study, we will investigate cell water relations in different leaf tissues to examine the hypothesis that the water cell transport properties differ in leaf tissues reflecting their functional differences and that these differences are reflected by the expression levels of individual aquaporins. Another study will be carried out using genetically-transformed hybrid poplars, which overexpress a major aquaporin, to study the function of aquaporins in the coordination and integration of root and leaf water transport processes in plants. We will also use genetically-transformed fungi which overexpress aquaporins to examine the hypothesis that the fungal aquaporins contribute to root and leaf water transport of mycorrhizal plants. Effects of mycorrhizal associations on root and leaf water transport will be also carried out in aspen (Populus tremuloides) inoculated with Laccaria bicolor mycorrhizal fungus to study the hypothesis that jasmonic acid-signalling pathway is involved in the root hydraulic responses to mycorrhizal colonization through changes in aquaporin expression. The effects of endophytic fungi on plant water relations will be also conducted with Arabidopsis thaliana colonized by a recently discovered root endophyte Piriformospora indica. This fungus has generated extensive interest due to its plant growth-promoting and stress-protecting properties. We will examine the hypothesis that the fungus triggers triggers these responses in plants by altering the function of aquaporins. The proposed studies will fill important gaps in our knowledge of plant water relations which is crucial to the development of methods and practices aimed at growth and yield improvement.