Interfungal antagonism between Trichoderma and Fusarium proliferatum - metabolomic and DNA-based analyses.

This study evaluated the antagonistic capacity of eight Trichoderma isolates against two Fusarium proliferatum isolates that differed in their toxigenic potential. Using co-cultures on solid and liquid media, significant variability in antifungal efficacy was observed among Trichoderma species. T. atroviride and T. viridescens isolates demonstrated the highest antagonistic activity, with markedly stronger inhibition of the less toxigenic F. proliferatum isolate. Quantitative PCR analysis confirmed a reduction in Fusarium biomass, which closely correlated with decreased levels of fumonisins (FB1, FB2, FB3) and beauvericin, as determined by UHPLC-HRMS. Notably, the most effective Trichoderma isolates (AN153, AN215, AN523) consistently suppressed both fungal growth and mycotoxin biosynthesis. Although fumonisin levels were reduced in co-cultures, independent assays in FB1-supplemented liquid media indicated that Trichoderma did not directly degrade mycotoxin. The presence of selected secondary metabolites, including 6-pentyl-2H-pyrone and phenolic acids, was confirmed in co-culture extracts. These findings highlight the isolate-specific nature of Trichoderma-Fusarium interactions and emphasise the potential of selected Trichoderma isolates as biocontrol agents capable of simultaneously limiting pathogen growth and mycotoxin accumulation. Further mechanistic studies are warranted to identify the molecular basis of these antagonistic effects.