Dr Uwe Hacke, Canada Research Chair in Tree-Water Relations, Department of Renewable Resources, University of Alberta presented a seminar on Thursday, October 13 2011 at 12.30 p.m. in the Wyatt Lecture Room (236 Earth Sciences Building) University of Alberta, Edmonton, Alberta.

Plants lose large amounts of water vapor in exchange for the uptake of CO2 which is required for photosynthesis. To fulfill the leaves’ demand for water, the xylem of trees moves more fluid, over longer distances, than any other fluid transport system in organisms. However, before water molecules enter the xylem, they have to pass cell membranes in roots. This pathway is facilitated by membrane channels called aquaporins. In this talk, I will focus on how the hydraulic design of trees varies in response to environmental factors. Since trees are long-living organisms, they have to cope with different and changing environments. I will discuss the influence of shade and nitrogen fertilization on xylem structure and function, and will end with a case study on how aquaporin expression responds to changes in light level.