Computational identification of inhibitors from Aegle marmelos leaf extract targeting ergosterol biosynthesis ERG4/ERG24 enzyme and serine proteases for combatting mancozeb-resistant Fusarium

Fusarium species are major phytopathogens responsible for economically significant diseases such as vascular wilt, root rot, and necrosis in diverse crops. The increasing incidence of mancozeb-resistant strains has complicated disease management, underscoring the need for sustainable alternative or complementary strategies. In this study, phytochemicals from Aegle marmelos were evaluated against Fusarium spp. using an integrated computational approach combining molecular docking and molecular dynamics (MD) simulations. The ergosterol biosynthesis ERG4/ERG24 family enzyme (ERG) and serine protease (SEP) were selected for the first time as molecular targets to assess antifungal potential. Lupeol, not previously investigated in this context, was subjected to a 100 ns MD simulation to evaluate the stability and dynamic behaviour of the protein–ligand complexes. The simulation results revealed a good stability in the formation of complexes with lupeol, a finding that was further validated through Principal Component Analysis (PCA) and MMPBSA calculations. The ΔG binding values calculated by MMPBSA for the lupeol-ERG and lupeol-SEP interactions were found to be − 33.06 ± 3.10 and − 19.60 ± 3.43 kcal/mol, respectively. Complementary in vitro assays revealed that the combined application of A. marmelos leaf extract and mancozeb produced the highest inhibition of mycelial growth of Fusarium sp. strain AA1, accompanied by pronounced morphological deformities, including distorted and collapsed conidia. Collectively, this multi-level validation establishes a novel framework for developing plant-based antifungal strategies to combat mancozeb-resistant Fusarium. Moreover, the synergistic use of plant extract with reduced fungicide dosage offers a sustainable approach that may lower chemical inputs while advancing the development of eco-friendly antifungal strategies for agricultural applications.