Unraveling the antifungal mechanisms of Clonostachys rosea: Morpho-molecular characterization and its bioactive compounds against Macrophomina phaseolina in-vitro and in-silico

Clonostachys rosea is recognized for its potential as a biocontrol agent against soil-borne pathogens, yet its antifungal mechanisms remain underexplored. In the present study, five strains of Clonostachys rosea were isolated from rhizhosphere soil samples from various agroecosystem. They were characterized morphologically using taxonomical keys, Scanning Electron Microscopy (SEM) and molecularly using Internal Transcribed Spacer (ITS) primers. The antagonistic activity of C. rosea against Macrophomina phaseolina (Mp) was evaluated through a dual culture assay. Additionally, bioactive compounds were identified using GC-MS analysis and their anti- fungal potential was analyzed using molecular docking simulations to predict interactions with M. phaseolina. In silico docking studies identified key bioactive compounds viz ., (5S, 8R, 9S, 10S, 13S, 14S, 17S)-17-hydroxy-10,13dimethyl-1, 2, 4, 5, 6, 7, 8, 9, 11, 12, 14, 15, 16, 17 tetradecahydrocyclopenta[a]phenanthren-3-one and 2-oxochromene-6-carbaldehyde with high binding affinity to fungal targets with low binding energy, suggesting their role in the observed antifungal activity.