9802638 Gold This Americas Program award will support a cooperative research project between Dr. Scott E. Gold, University of Georgia, and Drs. Jose Ruiz Herrera and Alfredo Martinez Espinoza, Centro de Investigacion y de Estudios Avanzados, (CINVESTAV), Irapuato, Mexico. The objective of the project is to elucidate underlying mechanisms controlling dimorphism in the fungus Ustilago maydis, the causal agent of corn smut disease. These fungi grow in two morphologies, as a budding yeast form or as long tubular cells or filaments. The yeast cells do not attack the plants, but the filaments can. This fungus dimorphism is known to be affected by genetic programming and by environmental conditions. The two groups of researchers have independently discovered mutations in genes that control the ability of the fungus to alternate between the two forms, and both have observed similar phenotypic results. Their overall goal for this collaboration is to determine the interaction between the two morphogenic triggers. To accomplish this, they have designed an experimental program to investigate the relationship between the two signal response pathways and, specifically, to determine how the environment regulates dimorphism. The topic of morphogenic switching has fundamental and applied significance, both within plant pathology and across biology. Results of the proposed research could provide guidance for effective strategies for the control of fungal diseases in plants. ***
