ARS | Publication request: Disease Control Via Understanding Molecular Determinants of Sexual Reproduction

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract
Publication Acceptance Date: July 31, 2002
Publication Date: July 31, 2002
Citation: Turgeon, G., Brown, D.W., Yun, S., Plattner, R.D., Lee, T., Dyer, R.B., Desjardins, A.E. 2002. Disease control via understanding molecular determinants of sexual reproduction. American Phytopathological Society Annual Meeting.

Technical Abstract: Gibberella zeae (anamorph Fusarium graminearum), a self fertile (homothallic) ascomycete, causes wheat head blight and corn ear rot, destructive diseases that impose a serious economic toll on North American farmers. Damage includes both yield loss due to kernel rot and reduced quality resulting from mycotoxin contamination. Among pathogenic Fusarium species associated with wheat and corn, G. zeae is the only one that undergoes massive sexual reproduction during the disease cycle. We have recently demonstrated experimentally that sexual spores are a primary inoculum source leading to scab in the field. The experimental proof was made possible by the cloning of the G. zeae MAT (mating type) locus, the master regulator of sexual development. Cloning allowed construction of G. zeae MAT-deletion strains that fail to form sexual spores. A preliminary field study conducted in Illinois subsequently demonstrated that MAT deletion strains cause less disease than wild type; these data support the hypothesis that sexual spore load is directly related to disease severity and suggest that interference with sexual development will reduce disease in the field. Each gene or gene product in sexual reproductive pathway is a potential target for disease control.