Detoxification of Deoxynivalenol via Glycosylation Represents Novel Insights on Antagonistic Activities of Trichoderma when Confronted with Fusarium graminearum

Deoxynivalenol (DON) is a mycotoxin mainly produced by theFusarium graminearumcomplex, which are important phytopathogens that can infect crops and lead to a serious disease calledFusariumhead blight (FHB). As the most common B type trichothecene mycotoxin, DON has toxic effects on animals and humans, which poses a risk to food security. Thus, efforts have been devoted to control DON contamination in different ways. Management of DON production byTrichodermastrains as a biological control-based strategy has drawn great attention recently. In our study, eight selectedTrichodermastrains were evaluated for their antagonistic activities onF. graminearumby dual culture on potato dextrose agar (PDA) medium. As potential antagonists,Trichodermastrains showed prominent inhibitory effects on mycelial growth and mycotoxin production ofF. graminearum. In addition, the modified mycotoxin deoxynivalenol-3-glucoside (D3G), which was once regarded as a detoxification product of DON in plant defense, was detected whenTrichodermawere confronted withF. graminearum. The occurrence of D3G inF. graminearumandTrichodermainteraction was reported for the first time, and these findings provide evidence thatTrichodermastrains possess a self-protection mechanism as plants to detoxify DON into D3G when competing withF. graminearum.Keywords:mycotoxin;toxigenicFusarium;biological control;Trichoderma;modified mycotoxin