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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Toxicology & Mycotoxin Research » Research » Publications at this Location » Publication #322424

Title: Characterization of stuA mutants in the mycotoxigenic maize pathogen Fusarium verticillioides

item RATH, MANISHA - University Of Georgia
item Crenshaw, Nicole
item Gold, Scott

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/8/2015
Publication Date: 8/1/2015
Citation: Rath, M., Crenshaw, N.J., Gold, S.E. 2015. Characterization of stuA mutants in the mycotoxigenic maize pathogen Fusarium verticillioides. American Phytopathological Society Annual Meeting. Pasadena, CA. Aug. 1-5, 2015.

Interpretive Summary: A gene (stuA) encoding a major transcription factor involved in normal development in the mycotoxigenic fungus, Fusarium verticillioides, was deleted. Mutants show reduced mycotoxin production, show a slightly reduced growth rate and have much reduced sporulation. Preliminary experiments indicate a reduction in virulence toward corn plants. Future transcriptional studies are planned comparing the stuA mutants to the wild type fungus.

Technical Abstract: Fusarium verticillioides is a major pathogen of maize, causing root, stalk and ear rots and seedling blight. It also produces fumonisin mycotoxins. Ingestion of fumonisin-contaminated corn causes acute toxicity in livestock and is a potential carcinogen to humans. StuA, an APSES protein class transcription factor, is a global regulator with stuA homologs regulating sporulation, mycelial and several other developmental processes in different fungal species. In F. graminearum, StuA is associated with regulation of pathogenicity, spore development and secondary metabolism. We hypothesize that the stuA homolog in F. verticillioides directly or indirectly regulates the production of fumonisin. Characterizing stuA mutants will help determine genes regulated by stuA and consequently should provide insight into fumonisin production and pathogenicity of F. verticillioides. stuA deletion mutants are being characterized phenotypically and preliminary data indicates mutants have slightly slower vegetative growth and reduced sporulation. More importantly, maize kernels inoculated with stuA mutants had reduced fumonisin accumulation compared to the wild-type F. verticillioides, as determined by a standard cracked corn assay. Further phenotypic and biochemical characterization of the mutants is underway. We plan to report construction, phenotypic characterization and initial global gene expression analysis of stuA mutants.