Integrating electrophysiology, behavioral response, and docking studies to decipher odorant-binding protein function in the brinjal shoot and fruit borer, Leucinodes orbonalis Guenee

Abstract

The brinjal shoot and fruit borer, Leucinodes orbonalis Guenée, inflicts significant yield losses in brinjal, often resulting in the extensive use of insecticides. Development of insecticide resistance and ecological concerns demand safer and species-specific alternatives. This study examines plant-derived volatile organic compounds (VOCs) as potential semiochemicals for its management. The present study employed electroantennography (EAG) to examine the summated neuronal response in the antennal of unmated male and female L. orbonalis moths to host plant VOCs. Both male and female antennae showed higher response when exposed to nonanal, α-terpineol, 2-ethyl-1-hexanol, linalool, methyl salicylate, and phenylacetaldehyde, with females showing greater sensitivity than males. The behavioral assays using a Y-tube olfactometer demonstrated significant attraction of moths towards 2-ethyl-1-hexanol, benzaldehyde, and phenylacetaldehyde. To further substantiate these findings, molecular docking studies were conducted using homology models of general odorant-binding proteins (GOBPs: GOBP1, GOBP2, and GOBP3) of L. orbonalis. Protein models were constructed through MODELLER, validated for structural accuracy, and docked with selected VOCs obtained from PubChem using AutoDock Vina. Among the three proteins, GOBP2 displayed the strongest and broadest ligand-binding affinities, followed by GOBP3 and GOBP1. Notably, high-affinity interactions with 2-ethyl-1-hexanol, benzaldehyde, and phenylacetaldehyde were characterized by π–π stacking, van der Waals forces, and hydrophobic bonding. The docking outcomes correspond closely with EAG and behavioral results, underscoring the potential of these VOCs as eco-friendly semiochemicals based management of L. orbonalis. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.