Cell-free culture filtrate of Trichoderma longibrachiatum AD-1 as alternative approach to control Fusarium solani and induce defense response Phaseolus vulgaris L. plants

The present study was conducted to evaluate the antifungal activities of cell-free culture filtrate of Trichoderma isolated from rhizospheric soil of common bean (Phaseolus vulgaris L.) plants against growth and spore germination of Fusarium solani. The results noted that the cell-free culture filtrate of Trichoderma at different concentrations of isolated Trichoderma longibrachiatum AD-1 significantly inhibited mycelial growth of F. solani with growth reduction ranging from 28.8 to 97.3% and inhibited spore germination up to 96%. Compared to control, soil treated with cell-free culture filtrate of T. longibrachiatum AD-1 exhibited a significant reduction in the frequency of root rot disease and boosted the percentage of surviving plants and vegetative growth. To get insight into the biocontrol mechanism, we employed Real-Time Quantitative Reverse Transcription PCR (RT-qPCR), which revealed that the cell-free culture filtrate of Trichoderma in common bean (Phaseolus vulgaris L.) showed significant upregulation of defense-related genes PR1, PR2, PR3, and PR4. This study revealed that the cell-free culture filtrate of Trichoderma could be promising to develop an alternative natural agent to control root rot diseases caused by Fusarium spp.