Fatty acid metabolism in Fusarium verticillioides

Fatty acids (FA) are a metabolic energy source and are building blocks of membrane lipids; moreover, they play a role in the signaling among hosts and pathogens. The ascomycete Fusarium verticillioides is a pathogenic fungus of maize; it is a valuable organism for elucidating processes in eukaryotic cell such as fatty acid metabolism. Oxidized FA, i.e. the oxylipins, are important driver of the host-pathogen interaction. Previous studies assessed that their synthesis appear tightly coordinated within the subset of oxylipin-related genes and with the genes controlling the synthesis of FA. We suggest here that the calcium-regulated transcription factor Crz1 (orthologue in F. verticillioides Fvcrz1) is probably involved in the upstream regulation of several genes related to fatty acid and oxylipin synthesis. Through a transcriptomic and metabolomics approach, we analyzed gene expression and FA synthesis in F. verticillioides wild type and mutant strain crz1 under in vitro conditions. Notably, we evaluated the expression of genes related to the FA biosynthesis, transformation, and oxylipins synthesis. Transcriptomic approach was associated to a mass spectrometry analysis to quantify several lipids. Apparently and intriguingly, Crz1 did not affect - significantly - the expression of FA- and oxylipin-related genes but controlled the total amount of FA and oxylipin in F. verticillioides. In fact, FA and oxylipin amount is reduced significantly in crz1 compared to WT strain whilst gene expression resulted almost unscathed. Advances in understanding such processes in F. verticillioides will provide helpful insights to the study of lipid-mediated cross talk within fungus-plant interaction.