9422459 Dure The P.I. will examine the roles of several plant proteins in allowing plant cells to become desiccation tolerant/drought resistant. These proteins accumulate to high levels in plant seeds and in water-stressed tissues of mature plants. Genes for these proteins have been isolated and a continuous supply of these proteins in pure form is insured by their synthesis in and purification from transformed bacteria. In particular, the possibility will be tested that these proteins promote cell survival in the water depleted state by electrostatically coating cell constituents (enzymes, membranes, etc.), thus mimicking the solvation role of water in the hydrated state. Such a "solvation" may be necessary for cell constituents to be preserved in their biologically functional structure in the reduced water environment. The efficacy of these pure proteins, singly and in combination, in maintaining enzyme activity, membrane organization and organelle integrity during a round of dehydration-rehydration will be experimentally determined. %%% Plant seeds are subjected to severe dessication. Other types of plant cells are also able to withstand severe and prolonged dessication. In the early stages of drying out, seeds and other plant tissues produce proteins that allow plant cells to tolerate the extraordinary loss of cell water. The P.I. has named these LEA proteins, for late embryogenesis abundant. The objective of this project is to understand what these proteins do that allow plant cells to survive the loss of up to 90% of their water. The function of these proteins has ramifications in the agricultural engineering of greater drought resistance in crop plants and in the food and dairy industry which seeks to improve the texture and nutritional qualities of preserved or dried products.
