Evaluation of the olfactory compensation role of transient receptor potential channels in oviposition site location of Diaphorina citri

Insect Transient Receptor Potential (TRP) channels play a central role in multisensory signal integration, and their functional diversity can compensate for the limitations of Olfactory Receptors (ORs) in regulating complex behaviors such as oviposition. In this study, Diaphorina citri was used as the research object to explore the regulation of its TRP family on complex oviposition behavior and olfactory compensation. By combining chemical analysis, transcriptomics, evolutionary analysis, and molecular docking simulations, the volatile odor compounds in the host plant Murraya exotica were identified, and the interaction between key lactone ligands and D. citri TRP channels was analyzed. Volatile components in M. exotica tissues of different leaf ages were analyzed using gas chromatography-mass spectrometry (GC-MS). Significant differences were found in the composition of volatile odors among tender buds, young leaves, and old leaves. Among them, seselin was only detected in tender buds and young leaves. Compound correlation analysis showed that the enrichment of isoauraptene was similar to that of seselin, suggesting that it might be another bioactive ligand for TRP recognition. Based on transcriptome data, 12 TRP channels were identified in D. citri, belonging to 7 subfamilies: TRPC, TRPV, TRPA, TRPN, TRPP, TRPML, and TRPM. The phylogenetic tree showed that the evolutionary relationships between D. citri TRPs and homologous genes in related species were conserved. Expression level analysis indicated that DcPkd2, a member of the TRPP subfamily, exhibited significantly higher expression than that of other genes in the antennae. Structural analysis revealed that DcPkd2 belonged to the Mplasa_alph_rch superfamily, and its structure might be involved in olfactory regulation. In the TRPA family, DcTRPA1, DcPain, and DcWtrw all displayed highly conserved structures. Molecular docking results showed that DcPkd2 could form stable binding conformations with both seselin and isoauraptene. D. citri may specifically recognize the volatile compounds seselin and isoauraptene from M. exotica tender buds or leaves through the TRP family member DcPkd2, encoding lactone compounds to compensate for OR functions, and jointly regulating the oviposition positioning of female adults on tender buds. This study established, for the first time, a TRP channel-plant volatile interaction model in D. citri, providing a new target for pest control strategies based on olfactory interference and a new perspective for understanding the olfactory compensation mechanism in oviposition positioning of Hemipteran insects.