Open AccessAccumulation of deoxynivalenol and its 15‐acetylated form is significantly modulated by oxidative stress in liquid cultures of Fusarium graminearum
Author(s) -
Ponts Nadia,
PinsonGadais Laetitia,
VerdalBonnin MarieNoëlle,
Barreau Christian,
RichardForget Florence
Publication year - 2006
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2006.00200.x
Subject(s) - trichothecene , oxidative stress , fusarium , paraquat , toxin , mycotoxin , conidium , microbiology and biotechnology , inoculation , virulence , oxidative phosphorylation , germination , fungus , chemistry , pathogen , biology , food science , biochemistry , botany , horticulture , gene
Liquid cultures of Fusarium graminearum were supplemented with H 2 O 2 or other oxidative compounds. The accumulation kinetics of the resulting trichothecenes were monitored. At non‐lethal concentrations, the H 2 O 2 treatments modulated toxin accumulation, dependent on the method of supplementation. When H 2 O 2 was added at the same time as the inoculation, higher levels of toxins accumulated 30 days later. Conversely, adding H 2 O 2 2 or 7 days after inoculation had little effect. When H 2 O 2 was added daily over the course of the culture, the accumulation of trichothecenes was rapidly and strongly enhanced. The fungus may adapt to oxidative stress when the first exposure to H 2 O 2 occurs at the beginning of the culture course. The highest toxin levels were measured when the H 2 O 2 was added daily. The importance of the first hours of culture was confirmed: pre‐treating conidia with H 2 O 2 does not affect their germination kinetics but leads to a reduction in the yield of trichothecenes 40 days later. The H 2 O 2 regulation of this trichothecene accumulation may be specific, as paraquat, another pro‐oxidant compound, inhibits their production. Since H 2 O 2 is a major component of the oxidative burst occurring in pathogen/host interactions, these data support the theory that trichothecenes may act as virulence factors.