The transcription factor SNT2 is involved in fungal respiration and reactive oxidative stress in Fusarium oxysporum and Neurospora crassa

The Fusarium oxysporum f. sp. melonis (FOM) Snt2 transcription factor is related to pathogenesis. In FOM and Neurospora crassa Δsnt2 strains, hydrogen peroxide-induced SOD activity was impaired. The expression of fe,mn sod genes in the Δsnt2 mutants, was up-regulated following hydrogen peroxide induction, indicative of a mitochondrial function defect. Furthermore, cytochrome-dependent oxidation in FOM and N. crassa was affected, leading to reduced oxygen consumption in the mutants, linking snt2 to regulation of fungal aerobic respiration. This was accompanied by increased expression of an alternative oxidase gene, suggesting the presence of a compensatory mechanism or the potential presence of a direct link between snt2 and regulation of alternative oxidation.

► The Snt2 transcription factor is involved in fungal oxygen consumption.
► Constant level of superoxide dismutase activity is independent of hydrogen peroxide stimulus.
► Up-regulation of fe,mn sod expression in the Δsnt2 mutants takes place following hydrogen peroxide induction.
► Up-regulation of the alternative oxidase gene exists in Δsnt2 mutants.