Unveiling plant-derived inhibitors for nucleocapsid protein of pigeonpea sterility mosaic virus: Molecular docking, simulation and In vitro investigations

Pigeonpea sterility mosaic virus (PPSMV) causes significant agricultural losses, particularly in pigeonpea crops. This study evaluated the antiviral potential of curcumin, a phytophenol derived from Curcuma longa, against PPSMV. Computational molecular docking and dynamics simulations revealed that curcumin is a high-affinity inhibitor of −7.3 kcal/mol that binds to the nucleocapsid protein of PPSMV through strong hydrophobic and hydrogen bond interactions. Glasshouse trials demonstrated the effectiveness of curcumin, with pre-inoculation treatments at 300 ppm achieving the lowest disease incidence (6.67 %) and significantly promoting plant growth. Real-time PCR revealed a significant reduction of 7.47 × 10⁴ in the level of viral cDNA in treated plants at 21 days post inoculation (dpi). The regression analysis revealed an R2 value of 0.907, suggesting that the virus titer had a significant effect on the percent disease incidence. These findings highlight the potential of curcumin as an eco-friendly alternative to synthetic pesticides for managing PPSMV, offering insights into its molecular interactions and antiviral mechanisms.