Zwiazek, Janusz (University of Alberta)

Purpose

Aquaporins are proteins which form channels in cell membranes to facilitate the passage of water and other small molecules. Since aquaporins regulate water transport, they are also the key to understanding plant water relations. Additionally, recent findings point to the functional importance of aquaporins in the transport of gases and other molecules participating in gas exchange and signalling processes. Regulation of aquaporin-mediated transport processes involves complex processes that are affected by internal and environmental factors. The proposed research consists of studies that will be carried out under controlled-environment conditions to examine the functions of aquaporins and the significance of these proteins in plant responses to environmental factors. The research will use a combination of the whole plant physiology, cell physiology, and molecular biology approach to address the study questions. The long-term goals of my research are to: 1) Expand the knowledge concerning the functional significance of plant and fungal aquaporins; and 2) Train the graduate students and postdoctoral fellows to provide them with the current knowledge and familiarity of the state-of-the art aquaporin research to become future leaders in this important area of science. The specific objectives of the studies are to: 1) Understand the salt tolerance features of aquaporins in salt-resistant, halophytic, plants by examining their structural and functional properties; 2) Explain the role of hydraulic signals in regulation of root aquaporin expression by the ectomycorrhizal fungus Laccaria bicolor; 3) Determine the role of aquaporin-mediated carbon dioxide transport in the development of root ectomycorrhizal structures; 4) Examine water and gas transport properties of different aquaporin isoforms in relation to their distribution in root and leaf tissues; and 5) Determine the importance of AQP-mediated oxygen transport in flooding tolerance of plants. The proposed project is a direct continuation of my research aimed at understanding the functions of aquaporins, which is the key to understanding how water and gases are transported, used, and conserved by plants. This knowledge has a significant impact on many research areas and has important practical applications, especially in the fields of agriculture, horticulture, and forestry.