Screening secretomes to limit deoxynivalenol production in Fusarium graminearum: a fast in vitro assay

Biological control against mycotoxins accumulation is challenging due to the complex interactions on cereal spikes during the Fusarium head blight disease. Identification of novel active compounds able to limit deoxynivalenol (DON) accumulation in cereals is a potentially effective strategy to limit mycotoxin accumulation in food products. Moreover, the control of deoxynivalenol synthesis reduces the incidence of the disease, because DON is a pathogenicity factor in wheat infection. Here, we developed a fast microtiter assay to identify molecules able to reduce DON synthesis by Fusarium graminearum in vitro. The assay based on the fluorescent detection of the Tri5-GFP gene fusion protein, showed a good correlation with DON content measured with LC-MS/MS method (r>0.7; p-value <0.0001). Using the secretomes of five streptomycetes strains with interesting biological properties against the pathogen, we identified two extracts from two different strains able to reduce DON synthesis effectively up to 99%. Further studies are warranted to characterise the effective molecule(s) from the secretomes of both Streptomyces spp. Our assay can screen multiple extracts and molecules with a potential role in deoxynivalenol synthesis inhibition in six days.