This Americas Program award will support Prof. Joseph Chappell of the University of Kentucky in a research collaboration with Prof. Edmundo Lozoya of the Centro de Investigacion y de Estudios Avanzados del IPN (CINVESTAV), Irapuato, and Prof. Victor M. Loyola of the Scientific Research Center in Yucatan. The researchers intend to study the isoprenoid biosynthetic pathway and its regulation. Isoprenoids are ubiquitous in nature, essential for life, and mediate a number of interactions between organisms and their environment. In addition, plants are a rich source for pharmaceutically important isoprenoids. Recent results suggest that compartmentation of the biosynthetic machinery plays an important role in regulating what type of isoprenoids are actually made. Through novel experiments the researchers intend to test the hypothesis that discrete metabolic units are dedicated to specific metabolic products. Results from these studies will help to elucidate the mechanisms regulating isoprenoid metabolism in plants, and will have important ramifications for future manipulations of this pathway using genetic engineering technology.