Role of aquaporins in plant water relations

点击翻译按钮获取中文摘要

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.