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Submitted to: ARS Workshop on Fusarium Toxins Proceedings
Publication Type: Abstract Only Publication Acceptance Date: 9/26/1995 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Recent advances in the area of mycotoxin biosynthesis research have created opportunities for the application of direct molecular approaches to the isolation of mycotoxin pathway genes. The clustering of mycotoxin pathway genes has been observed for both trichothecene and aflatoxin pathways suggesting that gene clustering is a general feature of mycotoxin pathway gene organization. This is because gene clusters facilitate efforts to isolate pathway genes by presenting larger targets for molecular gene isolation strategies. It has also been observed that the branch point steps in both polyketide and non-ribosomal peptide pathways employ enzymes that contain highly conserved sequences useful for the design of molecular probes. Exploiting these aspects of mycotoxin pathways will greatly speed-up efforts to characterize pathway genes. We are presently employing these approaches to identify genes for the polyketide mycotoxins, fumonisin and zearalenone, and for the non-ribosomal peptide mycotoxin, beauvericin. Isolation of genes encoding branch-point step enzymes will permit us to create genetically defined mycotoxin-deficient mutants by gene disruption for studies of mycotoxin involvement in plant disease. These mutants will also be useful determining the contribution of specific mycotoxins to animal toxicity within the complex mixtures of mycotoxins produced by some Fusarium species. |
