Agronomy, Vol. 15, Pages 1539: Antenna-Specific TabsOBP45 and TabsOBP46 Mediate Plant Volatile Recognition in Tuta absoluta (Lepidoptera: Gelechiidae)

Agronomy doi: 10.3390/agronomy15071539

Authors:
Qingyu Liu
Liuyang Wang
Panjing Liu
Lingrui Li
Jun Ning
Tao Zhang

The tomato leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae), is a destructive pest of Solanaceae crops worldwide. Its olfactory system plays an important role in locating mating partners and recognizing host plants. Understanding its olfactory recognition mechanism, particularly the function of odorant-binding proteins (OBPs), may reveal potential targets for pest management. In this study, we characterized two antenna-specific OBPs, TabsOBP45 and TabsOBP46, which were identified from the T. absoluta genome. Sequence analysis revealed that both TabsOBPs belong to the classic OBP subfamily, which is characterized by the presence of six conserved cysteine residues and an N-terminal signal peptide. Both TabsOBPs showed predominant antennal expression in quantitative real-time PCR (qRT-PCR) assays, suggesting their key roles in olfactory perception. Fluorescence competitive binding assays with a total of 63 tested volatiles revealed that 13 compounds exhibited strong binding affinities (Ki < 22 µM) to TabsOBP45, with the highest binding affinity to β-ionone, β-caryophyllene, terpinolene, and cinnamaldehyde. Nine compounds showed strong binding affinities to TabsOBP46, with the strongest binding to 4-anisaldehyde, 4-methoxybenzaldehyde, cinnamaldehyde, and β-ionone. Molecular docking analysis revealed the key residues involved in β-ionone binding: TabsOBP45 interacted with ILE8, ALA9, PHE12, TRP37, ILE92, PHE94, THR115, and PHE118, while TabsOBP46 interacted with ILE8, PHE12, PHE36, TRP37, ILE92, LEU94, PHE118, and VAL134. These results provide new insights into the olfactory mechanism of T. absoluta and potential molecular targets for the development of olfactory-based pest control strategies.

Source link

Qingyu Liu www.mdpi.com