Mycoparasitism-related genes expression of Trichoderma harzianum isolates to evaluate their efficacy as biological control agent

The selection of new isolates of Trichoderma harzianum with high suppressive activity against Fusarium oxysporum is a suitable strategy to avoid the increase of chemical pesticides. In this study, 31 isolates of Trichoderma sp. were analyzed by RAPD-PCR and five isolates of T. harzianum (T-30, T-31, T-32, T-57 and T-78) were selected. The expression of genes encoding for NAGases (exc1 and exc2), chitinases (chit42 and chit33), proteases (prb1) and β-glucanases (bgn13.1) activities and their respective in vitro enzymatic activities were measured. Dual plate confrontation assays of the isolates against F. oxysporum were also tested. Different profiles of gene expression between the different T. harzianum isolates were related to enzymatic activities values and dual plate confrontation. In this work, the T. harzianum isolates T-30 and T-78 showed the greatest mycoparasitic potential against F. oxysporum, which could lead to improved biocontrol of this phytopathogen.

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► Five different isolates of Trichoderma harzianum were selected from 31 isolates of Trichoderma thought RAPD-PCR, band profile analysis, and sequencing.
► Only four isolates showed overgrowth on the pathogen Fusarium oxysporum.
► The production of hydrolytic enzymes in T. harzianum was vastly different depending on the isolate.
► The mycoparasitism-related genes in T. harzianum are expressed or not depending on the isolate.
► T-78 and T-30 possess promising mycoparasitic activity against F. oxysporum and they could be used in agricultural situations to reduce infection.