9604264 Buchanan The overall goal of this project is to enhance our understanding of seed germination with particular reference to cereals. In both wheat and barley, a ubiquitous regulatory protein, thioredoxin, appears to play an important role in triggering mobilization of carbon and nitrogen during early stages of germination. Current evidence indicates that thioredoxin exerts its effect in three ways: (1) by reducing major storage proteins thereby increasing their susceptibility to proteases; (2) by activating a protease, thiocalsin, that is specific for the storage proteins themselves reduced by thioredoxin; and (3) by reducing and thereby inactivating disulfide proteins that inhibit individual enzymes which affect carbohydrate breakdown. The goals of the present study are to complete our projects on (1) the protein found in our earlier NSF-supported research to inhibit pullulanase, an enzyme responsible for breaking down starch during germination, and (2) protein redox changes occurring during development of wheat.
