How do plants take up water in a drying climate?Listen to Emeritus Professor Ulrich Zimmermann’s talk which was given at the Distinguished visitor Seminar on the 22st February, 2011.
The traditional paradigm of how plants take up water from the soil and transport it to the leaves is that water is pulled exclusively by transpiration-induced negative pressure gradients through continuous water columns. Water under negative pressure is in a metastable state. Cavitation is therefore a frequent event and can be catastrophic to water transport during drought. I will show how plants use other forces (such as gel-supported and interfacial forces) in order to overcome drought-induced interruption of the water columns. Evidence for this comes from non-invasive and minimally invasive techniques, such as NMR imaging, xylem probe and cell turgor probe, applied to crop and (fruit) trees. NMR imaging and non-invasive probes have also provided evidence that moisture uptake from the atmosphere by mucilage-containing epistomatal plugs plays an important role in the water supply of leaves of crop (such as grapevine and tomato), but also of 60-m tall trees. The results challenge our current view about the mechanism of water transport in plants and have paved the way for the development of new tools for online monitoring the water supply of crop under field conditions.
Short Speaker Biography
Currently, Emeritus Professor Ulrich Zimmermann is Senior Professor at the Biocenter of the University of Würzburg and chair of the scientific advisory board of ZIM Plant Technology. He was Head of the Membrane Research Group at the Research Center Jülich, Germany (1969-1984), and from 1984 – 2009 led the Department of Biotechnology at the University of Würzburg, Germany. The main focus of his research includes water transport and salt tolerance of plants and development of irrigation systems, biophysics of membrane transport, electromanipulation of cells and organelles, and turgor-mediated processes in algae and higher plants. He has authored c. 500 publications and more than 120 patents. Some of his most important inventions, which are used worldwide, include the plant cell turgor probe, xylem pressure probe and the magnetic, non-invasive probe for measuring turgor in leafy plants.