Evaluation of botanical extracts and molecular docking approaches for sustainable management of rice blast disease in Mushk Budji rice

Abstract

A study was carried out to explore and address the challenges posed by rice blast disease (Magnaporthe oryzae B. C. Couch.). Keeping in view the unique qualities and cultural importance of this variety, the research introduces an innovative approach by integrating plant extracts into disease management practices through in-depth analyses and field experiments. Three concentrations of ethanol-based extracts each of the twenty-one were evaluated in vitro against the control. The percentage of mycelial inhibition was recorded and based on their effectiveness; six efficient botanicals were further evaluated in the field. The field experiments were carried out on the susceptible Mushk Budji cultivar of rice for two successive years. The results demonstrated that certain botanicals, especially extracts of Syzygium aromaticum and Podophyllum hexandrum, significantly reduced disease incidence and severity, and improved grain and straw yields, performing on par with the chemical control, Tricyclazole. Additionally, molecular docking was conducted to identify active compounds responsible for antifungal effects. The ligands for docking studiesquercetin, podophyllotoxin, and eugenolwere chosen based on literature mining for their reported antifungal activity. These phytochemicals displayed strong binding affinities ( -5.5 to − -3.8 kcal/mol) to the ToxB-like effector protein of M. oryzae, suggesting interference with fungal pathogenicity mechanisms. Among these, quercetin and podophyllotoxin were the most promising ligands. The integration of wet-lab assays and in silico analysis strengthens the case for deploying bioactive botanicals in integrated disease management. Our findings advocate the use of eco-friendly, plant-based fungicides as a viable strategy for blast disease control, promoting organic farming and preservation of indigenous rice varieties. The findings highlight the importance of developing eco-friendly, plant-based alternatives to chemical fungicides, aligning with the goals of sustainable agriculture and organic farming. Future research should focus on developing stable formulations of these botanicals, evaluating their synergistic potential with biocontrol agents, and validating their effectiveness through multi-location field trials. Additionally, further investigation into the molecular mechanisms of action and the long-term ecological and economic impacts of botanical fungicides is warranted.