COMPUTATIONAL DOCKING ANALYSIS OF WRKY33 TRANSCRIPTION FACTOR IN PEPPER (CAPSICUM ANNUUM) TO IDENTIFY SMALL MOLECULES INVOLVED IN FUNGAL DEFENCE REGULATION

The WRKY33 transcription factor is a key regulator of plant immune responses, yet its molecular interactions in Capsicum annuum remain poorly understood. This study employed a computational docking approach to investigate potential small molecules that may modulate the activity of WRKY33 in pepper, with the aim of identifying compounds involved in fungal defense regulation. The full-length WRKY33 protein sequence of Capsicum annuum was obtained from public databases and subjected to structural modeling using homology- and AI-based prediction tools. A curated panel of defense-related small molecules—including plant hormones, signaling compounds, and antifungal phytochemicals—was selected for molecular docking analysis using AutoDock Vina. Binding affinities and interaction profiles were evaluated to determine the strength and specificity of ligand–protein interactions. Several molecules, particularly salicylic acid, jasmonic acid, quercetin, and hydrogen peroxide, demonstrated notable binding affinity to the WRKY33 DNA-binding domain, suggesting their potential roles in modulating transcriptional activity during pathogen attack. Key interacting residues were identified, offering insights into the biochemical mechanisms underlying WRKY33-mediated defense responses. Overall, this study provides the first computational evidence of small molecules that may influence WRKY33 function in Capsicum annuum, contributing to a deeper understanding of fungal defense pathways and supporting future research in crop protection and molecular breeding.