Effect of different ecological conditions on secondary metabolite production and gene expression in two mycotoxigenic plant pathogen species: F. verticillioides and F. equiseti.

The genus Fusarium includes many species that are plant pathogens and many produce harmful secondary metabolites including fumonisins and trichothecenes. These mycotoxins can cause disease in animals and have been associated with cancers and birth defects in humans. Many factors influence the production of secondary metabolites in Fusarium species; however regulation of secondary metabolite gene expression is not well understood. We are interested in environmental factors that affect secondary metabolite gene expression and production of mycotoxins. Water activity has been shown to affect both fungal growth and mycotoxin production in a variety of fungi. Here we investigate the effect of water activity on toxin production and the expression of the FUM genes in the fumonisin producing maize pathogen F. verticillioides and the TRI genes in the trichothecene producing soil born pathogen F. equiseti using quantitative real-time PCR.