Antagonistic potential of Trichoderma as a biocontrol agent against Sclerotinia asari

In the present study, the inhibitory potential of 14 Trichoderma strains (isolated from Asarum rhizosphere) was investigated against Sclerotinia asari using the plate dilution method. The activity of antioxidant enzymes viz; catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and malondialdehyde (MDA) in S. asari treated with the two Trichoderma strains was also evaluated. Untargeted metabolomic analysis by using LC/MS analysis was carried out to determine differential metabolites in T. hamatum (A26) and T. koningiopsis (B30) groups. Moreover, transcriptome analysis of S. asari during the inhibition of S. asari by B30, and A26 compared with the control (CK) was performed. Results indicated that inhibition rates of T. koningiopsis B30, and T. hamatum A26 were highest compared to other strains. Similarly, non-volatile metabolites extracted from the B30 strain showed a 100% inhibition of S. asari. The activity of CAT, SOD, and POD decreased after treatment with A26 and B30 strains while increasing MDA content of S. asari. Antifungal activity of differential metabolites like abamectin, eplerenone, behenic acid, lauric acid, josamycin, erythromycin, and minocycline exhibited the highest inhibition of S. asari. Transcriptome analysis showed that differentially expressed genes were involved in many metabolic pathways which subsequently contributed toward antifungal activity of Trichoderma. These findings suggested that both Trichoderma strains (B30 and A26) could be effectively used as biocontrol agents against Sclerotinia disease of Asarum.