Molecular characterization and its binding properties of general odorant binding protein 2 in Dioryctria abietella

Dioryctria abietella is a major pest of conifer cones that can initiate specific behaviours (locating hosts, finding mates and selecting oviposition sites) through sensitive olfactory systems. General odorant-binding proteins are involved in the first step in odorant perception in insects, but their specific functional roles in D . abietella chemoreception have not been fully elucidated. In this study, quantitative real-time polymerase chain reaction (PCR) examinations showed that DabiGOBP2 is predominantly expressed in the antennae of female adults. Western blot experiments further confirmed that these proteins show biased expression in the tissues. Binding property analysis demonstrated that DabiGOBP2 exhibited ligand specificity to terpenes, especially myrcene ( K i = 8.19 ± 0.05). Electroantennogram (EAG) and Y-tube assays showed that three plant volatiles elicited high EAG responses, but only dodecanal showed a strong attraction to females. However, myrcene and isobutyl benzoate were significantly repellent to males at high doses in the behaviour test. In conclusion, exploring the functions of DabiGOBP2 can help in better understanding the mechanism of the olfactory system of D . abietella and developing novel strategies to control this pest.