Metabolomic and Docking Insights into Trichoderma viride-Mediated Suppression of Ralstonia solanacearum

Bacterial wilt, caused by Ralstonia solanacearum, is one of the most destructive vascular diseases of tomato (Solanum lycopersicum L.), resulting in severe yield losses and posing major challenges to sustainable crop production. The present study comprehensively provides a novel mechanistic evaluation of the biocontrol potential of Trichoderma viride against R. solanacearum through an integrated framework combining in vitro, in vivo, and in silico approaches. Crude metabolite extracts of T. viride were characterized using GC-HRMS and FTIR to determine their chemical composition and functional groups, while their antagonistic efficacy was assessed through agar well diffusion assays and greenhouse trials. In vitro results revealed notable, concentration-dependent inhibition of R. solanacearum, with maximum inhibition zones of 32.0 ± 1.15 mm at 200 mg/mL, while in vivo treatment significantly reduced disease incidence, delaying symptom expression by three days and lowering the percent disease index (PDI) by 63.3% relative to the untreated control. GC-HRMS profiling identified several bioactive metabolites, notably Methanone (4-nitrophenyl) (4-benzoyl-3-isoxazoyl), an isoxazole derivative exhibiting the strongest molecular docking affinities with key virulence regulators PhcA, PhcR, PehA and RipD (binding energies up to -9.5 kcal mol^-1). This study provides computational evidence supporting putative molecular interactions between specific T. viride metabolites and key virulence associated proteins of R. solanacearum. The favourable binding affinities observed suggest the potential of these metabolites to interact with pathways involved in pathogenicity, however, these findings remain preliminary and require experimental validation. Overall, the results demonstrate promising biocontrol efficacy of T. viride and underscore its novelty as a multi-target, eco-friendly alternative to chemical bactericides for sustainable management of bacterial wilt and other soil-borne diseases.