This award supports Dr. Malcolm Potts of Virginia Polytechnic Institute and State University for a research visit to work with Dr. Siegfried Scherer of the Institute of Plant Biochemistry and Physiology of the University of Konstanz, Germany. They are collaborating in an effort to elucidate the molecular mechanisms for desiccation tolerance in cyanobacteria. The specific goals of their current work are to characterize the recently isolated 'wsp' gene, to understand how transcription of 'wsp' is regulated by water stress, and to obtain milligram amounts of the water stress protein (Wsp) produced by the 'wsp' gene for future structural analysis. Dr. Scherer has excellent facilities for the growth of cyanobacteria in culture and for protein purification and characterization. He has made substantial contributions to the understanding of photosynthesis, respiration and electron transport in cyanobacteria. Dr. Potts has focused more on the physiology, biochemistry and genetics of water stress tolerance. Recently, Dr. Potts has developed the necessary techniques to understand aspects of the molecular biology of Nostoc commune. Water availability limits the distribution and the activities of all living cells. It is of particular importance to the future of managed agriculture. Despite the considerable biochemical restraints imposed by a cell-water deficit, certain cells have the capacity to retain both structural and functional integrity after exposure to repeated cycles of acute water stress. Cells of the desiccation-tolerant photosynthetic procaryote Nostoc commune, a cyanobacterium, accumulate massive amounts of a soluble protein when they are exposed to repeated cycles of drying and rewetting. This water stress protein (Wsp) has been isolated, purified, and partially characterized at the biochemical level. Recently, the gene responsible for encoding this protein has been isolated. This is the subject of the proposed collaborative research.
