Publication

Abstract : Vicilins (7S globulins) are plant storage proteins increasingly recognized for their defensive functions. This study reports the isolation and characterization of a chitin-binding vicilin from Sesbania bispinosa seeds. LC-MS/MS analysis confirmed the protein's identity as vicilin and revealed peptide sequences that differed from previously reported vicilin homologs, suggesting sequence divergence within the identified regions. The vicilin, designated SBV, exhibited strong chitin-binding affinity, which underlies its dual antifungal and insecticidal activities. SBV demonstrated potent antifungal action against Fusarium oxysporum, with an MIC50 of 9.7 μM. Its fungicidal mechanism involves chitin-mediated association with the fungal cell surface, followed by membrane permeabilization and subsequent accumulation of reactive oxygen species (ROS). In addition, SBV imposed marked developmental toxicity on Drosophila melanogaster, achieving 50% larval mortality at 0.026% (w/v). This insecticidal effect is attributed to disruption of the chitin-rich peritrophic matrix, impairing midgut integrity and development. Overall, these findings establish SBV as a chitin-binding vicilin with robust, concentration-dependent antifungal and insecticidal properties. Its dual action, driven by chitin affinity, highlights its potential as a promising biopesticide candidate for sustainable crop protection.