Is theFgap1mediated response to oxidative stress chemotype dependent inFusarium graminearum?

Abstract

This study aims to compare the role of the transcription factor Fgap1 in oxidative stress response for two Fusarium graminearum strains belonging to the two chemotypes DON/ADON and NIV/FX. While the response to H2O2 was shown to be chemotype dependent, an opposite result was observed for diamide: whatever the chemotype, the global level of TCTB (i.e. trichothecene B) production was strongly increased by the treatment with diamide. Fgap1 was shown to be involved in this regulation for both chemotypes. Our data show that the response to diamide is mediated by Fgap1 whatever the chemotype of the F. graminearum strains. However, the NIV/FX chemotype has developed higher antioxidant capacities in response to oxidative stress. But when this capacity is overwhelmed by an increment in the H2O2 level, the NIV/FX strains also responds by an increase in toxin accumulation.

Bioprospecting Phenols as Inhibitors of Trichothecene-Producing Fusarium: Sustainable Approaches to the Management of Wheat Pathogens

“…Nonetheless, the hypothesis that antioxidant properties of cereal metabolites can play a critical role in their anti-mycotoxigenic activity is consistent with the postulated activating effect of oxidative stress on the biosynthesis of mycotoxins [63]. Montibus et al [212] emphasized the modulation of fungal secondary metabolism by oxidative stress and the enhancement of mycotoxin production, including DON, after exposure to reactive oxygen species. Thus, due to their ability to quench oxygen free radicals, antioxidant metabolites may reduce or suppress upstream signals such as oxidative stress that modulate toxin biosynthesis.…”

Cooperative interactions between seed-borne bacterial and air-borne fungal pathogens on rice

“…The vegetative growth of mutant strains carrying deletions of FgAP , FgSKN7 , FgATF1 , or FgELP1 has been associated with oxidative stress 28 – 31 . Here, the growth of these mutant strains was not suppressed on toxoflavin-supplemented media (Supplementary Fig.…”

Genetic Regulation of Mycotoxin Biosynthesis

“…But an opposite result was observed when treated with diamide. Whatever the chemotype is, the expression of TC biosynthesis was always strongly up-regulated during oxidative stress [ 130 ]. Fgap1 (Yap1 orthologue in F. graminearum ) was shown to be involved in this regulation for both chemotypes.…”

“…Fgap1 (Yap1 orthologue in F. graminearum ) was shown to be involved in this regulation for both chemotypes. The NIV/FX chemotype has higher antioxidant capacities than DON/ADON chemotype in response to oxidative stress [ 130 ].…”