Lipidomic-based approach to identify possible lipid compounds able to modify Fusariumverticillioides metabolism

Fusarium verticillioides is one of the most important fungal pathogen to cause ear and stalk rot in maize, even if frequently asymptomatic. The interest for this fungus increased significantly after the discovery of fumonisins, hypothesized to contribute to F. verticillioides colonization and confirmed harmful to human and animal health. The understanding of the mechanisms associated with pathogenicity and fumonisin biosynthesis in F. verticillioides could help to mitigate Fusarium diseases. Endogenous fungal oxylipins are known for their roles in carrying out pathogenic strategies to successfully colonize their host, reproduce, and synthesize toxins. A synthetic medium (CDY), amended (FB1‐conducive) or not (FB1‐non conducive) with lyophilized maize, inoculated with F. verticillioides has been used for studying the importance of the lipid by‐products such as oxylipins and their role in fumonisin B1 (FB1) formation. We analysed some molecular and physiological parameters: the expression of genes whose products are related to oxylipin synthesis (such as lipoxygenase, diol synthases and fatty acid oxidases) by relative Real Time PCR, the fatty acids and oxylipin profile using a lipidomic approach, i.e. combining LC‐TOF with a robust statistical analysis (i.e. PCA) and the FB1 biosynthesis by HPLC. The results obtained indicate that the presence of lyophilised maize induces the up‐regulation of all the genes analysed, the modification of lipid profile of F. verticillioides and the biosynthesis of FB1 without significantly affecting fungal growth. The crucial role of lipid compounds in F. verticillioides lifestyle emerges also in this study. Work supported by FIRB‐RBFR08JKHI MIUR project