ARS | Publication request: Trehalose-related Gene Deletions in Fusarium verticillioides

Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: June 19, 2012
Publication Date: June 19, 2012
Citation: Boudreau, B.A., Larson, T.M., Brown, D.W., Busman, M., Roberts, E.S., Nall, D., Mcquade, L. 2012. Trehalose-related Gene Deletions in Fusarium verticillioides. American Society for Microbiology.

Technical Abstract: Fusarium verticillioides is a widespread corn pathogen that causes root, stalk and ear rot and produces fumonisins, toxic secondary metabolites associated with disease in livestock and humans. Our goal is to assess the feasibility of exploiting trehalose metabolism as a target for F. verticillioides control. Trehalose is a disaccharide of glucose that plays a major role in environmental stress responses in fungi. We have hypothesized that disrupting trehalose metabolism may be a viable approach to reduce F. verticillioides pathogenicity. Because trehalose is present in only trace levels in all but a few plants, this type of approach should have little or no toxicity to corn. To test our hypothesis, we have used the split marker recombination strategy to generate eight mutant strains of F. verticillioides in which either one or two putative trehalose-related genes have been deleted. Preliminary characterization of the functional consequences of the deletions suggests that at least some of the mutants display measurable growth defects. Among these, the TPS1 mutant strain, which lacks the putative trehalose-phosphate synthase gene (TPS1), does not produce trehalose under any condition tested, but accumulates significantly higher levels of glycogen than wild type F. verticillioides. Surprisingly, fumonisin production in the TPS1 mutant is reduced to levels near the detection limit, suggesting a possible link between the biosynthetic pathways for trehalose and fumonisins. In conclusion, the data presented here demonstrate that blocking trehalose production in F. verticillioides impairs not only its growth but also its ability to produce toxin, suggesting that trehalose metabolic pathways may indeed be a viable target for the control of Fusarium corn rot.