Odorant-Binding Protein 1 Plays a Crucial Role in the Olfactory Response of to -Curcumene.

The cultivated tomato suffered a severe attack by the whitefly (Gennadius), causing damage to leaves by feeding as well as transmitting the tomato yellow leaf curl virus (TYLCV), while the wild tomato is considerably less appealing to this insect species. It is reported that shows innate avoidance to -curcumene, which is produced naturally by . However, the mechanisms involved in the avoidance behavior of in response to this chiral compound are still unclear yet. In this study, the functional and binding characterization of odorant-binding protein 1 of (BtOBP1) were examined and against -curcumene. The obtained results showed that BtOBP1 exhibits specific binding activity to -curcumene, which acts as repellents to . By using a fluorescence-based binding assay, the difference of binding-affinity for -curcumene between wild type BtOBP1 and the mutant BtOBP1 to -curcumene was performed, which resulted in a single amino acid mutation (ASN108 > SER); moreover, BtOBP1-N108 displays significantly decreased binding affinities to -curcumene. Most interestingly, a knock-down experiment with the BtOBP1 showed that the whitefly responses to -curcumene are impaired. This study illustrated that BtOBP1 is a crucial protein involved in the perception and discrimination of -curcumene. Our findings may provide an excellent chance of finding a suitable antagonist of eco-friendly features that can block the perception of chemosensory signals in insects, preventing behaviors like food-finding.