Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 29, 2000
Publication Date: N/A
Technical Abstract: Fumonisins are a family of toxic fungal metabolites produced by Fusarium verticillioides (synonyms F. moniliforme and Gibberella fujikuroi mating population A) and related species. The recent cloning of fumonisin biosynthetic genes and development of techniques for gene disruption allow critical analysis of the ecology of fumonisins and the potential for their biological control. A polyketide synthase gene, FUM5, required for fumonisin biosynthesis has been cloned from F. verticillioides. Disruption of FUM5 in an FB1, FB2 and FB3-producing strain and in an FB2-producing strain reduced fumonisin production by more than 99% in both strains. In a field test in 1999, silk-channel application of fumonisin-nonproducing strains decreased the production of fumonisins in the kernels but also caused ear rot. In contrast, application of strains by silk-spray, stalk-injection, or seed treatment increased their frequency in kernels but did not increase levels of ear rot or prevent the production of fumonisins. Thus, further development of fungal strains and application methods will be necessary for fumonisin-nonproducing strains to succeed as biological control agents for reducing fumonisins in maize.