Unveiling the Substrate-Dependent Dynamics of Mycotoxin Production in Fusarium verticillioides Using an OSMAC-Metabolomics Approach

Abstract Fusarium verticillioides is a prevalent plant pathogenic fungus known to produce harmful mycotoxins, including fumonisins and emerging toxins. This study aimed to investigate the influence of substrate on the temporal patterns of mycotoxin biosynthesis by F. verticillioides, employing a combined OSMAC (One Strain-Many Compounds) strategy and metabolomics approach. The fungus was cultured under various media conditions, and samples were collected over time. LC-MS/MS analyses and a dereplicative workflow were used to profile the secondary metabolite production, focusing on mycotoxins. The results demonstrated that modifying the culture conditions led to significant variations in fungal growth and the nature and relative concentrations of mycotoxins produced. Corn meal agar (CMA) medium was favorable for fumonisins A1 and B1, while malt extract agar (MEA) favored fumonisins A2 and B2. The study also identified the production of other mycotoxins related compounds as fusarins, bikaverin derivatives and fumonisins analogs, under different growth conditions. This study highlights the potential of combining OSMAC and metabolomics to unravel the substrate-dependent and time-dependent variations in mycotoxin biosynthesis by F. verticillioides. The insights gained provide a better understanding of the ecophysiology of this fungus and the occurrence of its mycotoxins, which can inform targeted mitigation strategies to ensure food and feed safety.