Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 12, 2000
Publication Date: N/A
Technical Abstract: Fumonisins are a family of mycotoxins produced by the fungus Giberrella fujikuori mating population A (Fusarium verticillioides) which infects corn world-wide. Fumonisin contamination of corn presents a potential health risk to humans and animals consuming corn. Fumonisin B1, the predominant fumonisin produced by the fungus in corn, is associated with a wide variety of animal toxicoses (including equine leukoencephalomalicia, porcine pulmonary edema), is a potent liver toxin, and is a suspected carcinogen. Recognizing that the fumonisin problem in corn occurs primarily in the field rather than in storage, our research target is developing the tools to minimize or eliminate fumonisin production by this fungus in corn in the field. Our research is focused on understanding, at the molecular level, how the corn plant and pathogen interact during infection and toxin production. As a result of our field studies, we have discovered that fumonisins are not randomly distributed on corn ears but reside to a major extent in kernels that are visually abnormal. Our classical genetic analysis of strains of F. verticillioides (and F. proliferatum) with different toxin profiles show that fumonisin production is controlled by several closely linked loci. Using molecular techniques we have identified a fumonisin biosynthetic gene cluster and characterized a polyketide synthase gene that is required for fumonisin production. Results of field tests indicate that fumonisin non producing strains are competitive colonizers and promising candidates for biological control to minimize fumonisins.