Characterization of a Double Deletion Mutant of Fusarium verticillioides Lacking Two Putative Trehalose‐6‐Phosphate Phosphatase Genes

Abstract

Fusarium verticillioides is a fungal pathogen that commonly infects the stalk, ear, and kernels of corn and can produce fumonisins, a family of mycotoxins linked to disease in livestock and humans. Our goal is to characterize the role of the disaccharide trehalose in growth and stress response in F. verticillioides. Trehalose synthesis in fungi occurs via two steps, the first catalyzed by trehalose‐6‐phosphate synthase (TPS), and the second by trehalose‐6‐phosphate phosphatase (TPP). Previously, we found that trehalose synthesis is completely abolished in a strain lacking TPS, encoded by the TPS1 gene. We report here that mutant strains lacking either one (ΔTPS2) or both (ΔTPS2/ΔTPS3) of the putative TPP genes in F. verticillioides retain the ability to produce trehalose, albeit at reduced levels. The effects of osmotic and thermal stress on these mutants are being investigated.