We concentrate our effort on a pathogen of maize called Ustilago maydis, the causal agent of corn smut disease.
Corn smut is one of the important model systems for the study of fungal-plant disease interactions.
U. maydis has a complex life cycle in which dimorphism plays a central role in pathogenesis. In corn smut, the yeast form cannot colonize the plant, but the filamentous phase is able to infect and ramify throughout the host tissue. We have identified a number of mutants which are affected in the ability of the fungus to grow in the filamentous phase. At least some of these mutations dramatically affect disease progression. We have now cloned several genes that control filamentous growth and will further characterize their role in morphological and disease development.