TabsPBP2, a Pheromone-Binding Protein Highly Expressed in Male Antennae of Tuta absoluta, Binds Sex Pheromones and Tomato Volatiles

The tomato leafminer (Tuta absoluta), a globally invasive pest, poses a major economic threat to tomato production. Although chemical control remains the primary management method, sustainable alternatives are urgently needed. Sex pheromone communication is critical for moth courtship and mating, with pheromone-binding proteins (PBPs) playing a key role in this process. In this study, we identified a PBP gene, TabsPBP2, from the T. absoluta transcriptome. Real-time quantitative PCR (RT-qPCR) revealed that TabsPBP2 is highly expressed in the antennae, with a strong male-biased expression pattern. Ligand-binding assays demonstrated that TabsPBP2 has the highest affinity for the sex pheromones (3E, 8Z, 11Z)-tetradecatrienyl acetate (TDTA) and (3E, 8Z)-tetradecadienyl acetate (TDDA). It also demonstrated a moderate-to-strong binding affinity to several tomato volatiles, including 2-carene, myrcene, α-pinene, cis-3-hexen-l-ol, methyl salicylate, sabinene, and α-terpinene. Molecular docking suggested that hydrophobic interactions predominantly stabilize the TabsPBP2–ligand complexes, with PHE118, PHE12, LEU90, LEU68, and ALA73 identified as key interacting residues. Electroantennogram (EAG) and Y-tube olfactometer assays confirmed that TDTA and TDDA act as strong attractants for male T. absoluta. This study enhances our understanding of the pheromone recognition in T. absoluta and provides a foundation for developing novel, pheromone-based pest control strategies.