Mechanisms of Biocontrol on Poplar Anthracnose and Growth Promotion by Trichoderma asperelloides Tas369 and Tri-Trichoderma Composite Strain

Evaluation of Microbial Consortia of Trichoderma harzianum and Bacillus amyloliquefaciens for the Management of Groundnut Stem Rot under Controlled Conditions

Scanning electron micrographs of Sclerotium rolfsii paired with effective Trichoderma and Bacillus isolates showed swollen hyphae with cell-wall damage, providing clear evidence of antagonistic interactions caused by volatile compounds produced by B. amyloliquefaciens and T. harzianum.

Agroecological functions of Trichoderma harzianum, an endophytic fungus of the avocado root: its role in plant growth, defense and multitrophic interactions.

The results support the use of T. harzianum as an effective bioinoculant to enhance plant growth and suppress pests, offering a sustainable alternative to synthetic agrochemicals.

Biocontrol efficacy of Trichoderma viride TVa199 against Fusarium wilt and growth promotion in cucumber through direct and indirect mechanisms.

Fusarium oxysporum f. sp. cucumerinum is a destructive soilborne pathogen that causes Fusarium wilt in cucumbers. This study evaluated the antagonistic activity of the endophytic fungus Trichoderma viride TVa199 against F. oxysporum f. sp. cucumerinum and the mechanisms underlying its suppression of fungal virulence. TVa199 exhibited strong activity against F. oxysporum f. sp. cucumerinum, achieving 96.03 % inhibition in a dual culture assay. The culture filtrate, ethyl acetate, and methanol extracts of T. viride effectively inhibited mycelial growth, spore germination, and germ tube elongation of F. oxysporum f. sp. cucumerinum. The ethyl acetate extract caused severe damage to the morphology and ultrastructure of the hyphae and conidia of the pathogen, as evidenced by SEM and TEM observations. GC-MS analysis identified various bioactive secondary metabolites. Molecular docking predicted strong interactions between representative metabolites and virulence-associated proteins, including Avr2, M36 metalloprotease, and feruloyl esterase C. In the greenhouse experiments, the incidence of Fusarium wilt was reduced by 89.9 %, with a control efficacy of 87.5 % following the application of T. viride culture filtrate at 80 %. It also enhanced host defense by increasing phenolic content and defense-related enzyme activities while reducing oxidative stress markers. These results demonstrate that T. viride TVa199 suppresses F. oxysporum f. sp. cucumerinum via a multi-target mechanism involving direct microbial antagonism, disruption of fungal cellular integrity, and metabolite-mediated interference with virulence-associated proteins. This study provides mechanistic evidence that fungal secondary metabolites contribute to the suppression of pathogen virulence. These findings expand the current understanding of microbial antagonism beyond conventional growth inhibition and support the development of sustainable biocontrol strategies against Fusarium wilt.

The Suppressive Impact of Mycorrhizal Fungi (Rhizophagus irregularis and Piriformospora indica) on Root-Knot Nematode (Meloidogyne incognita) in Lettuce

Integrative transcriptomic and metabolomic analysis of the antifungal mechanisms of Bacillus velezensis L33a against tomato Verticillium Wilt.

Verticillium dahliae is a destructive soil-borne fungus with a broad host range, and its persistence in soil complicates control. Current measures, mainly resistant cultivars and chemicals, are limited and environmentally risky, promoting biocontrol as a green alternative. Here, we investigated the biocontrol mechanisms of Bacillus velezensis L33a against V. dahliae JR2 in tomato. In vitro assays on PDA plates at 26°C for 9 d showed that L33a inhibited JR2 by 58.6%, caused hyphal malformation and disruption, and its volatile organic compounds suppressed pathogen growth. In pot experiments, tomato roots dipped in JR2 suspension (1 ×10⁶ CFU/mL) for 30 min at 7 d after transplanting and grown for 21 d achieved 60.9% control efficacy. Physiological assays indicated reduced peroxidase and catalase activities, while qPCR revealed that L33a alone upregulated JA signaling (SlJAZ1, SlMYC2, SlPI II) and antioxidant (SlCAT, SlAPX) genes, with further enhancement upon JR2 co-treatment. To track their interactions, we generated GFP-labeled JR2 and RFP-labeled L33a; dual fluorescence labeling showed that L33a endophytically colonized Arabidopsis thaliana roots and competed with JR2 for the same niche, correlating with reduced pathogen colonization. Integrated metabolomic and transcriptomic analysis further revealed that L33a treatment altered pathways related to ABC transporters, amino acid metabolism, cell wall integrity, and energy metabolism in JR2, with tyrosine metabolism significantly enriched at both levels. Collectively, these findings suggest that L33a is a promising biocontrol strain for green management of tomato Verticillium wilt.

Laboratory evaluation of enhanced biocontrol efficacy of Bacillus atrophaeus SF9 via fermentation optimization against Bauhinia blakeana leaf spot disease caused by Colletotrichum endophyticum