Chemosensory Proteins Mediated Repellency of Terpinolene to Bemisia tabaci

Terpinolene, a monoterpene volatile, has been demonstrated to exhibit repellent activity against Bemisia tabaci adults. However, molecular basis of B. tabaci identifying and responding to terpinolene was unclear. Chemosensory proteins (CSPs) family is one of the most important member in insect olfaction system which plays a crucial role in hosts selection. Here, we cloned 13 BtabCSP genes in B. tabaci MED and detected transcriptional response to terpinolene. Based on proteins structure prediction, molecular docking, protein expression and fluorescence competition binding assay, BtabCSP1and BtabCSP12 exhibited strong binding affinity to terpinolene. Moreover, RNA interference (RNAi) combined with Y-tube assays showed that silencing BtabCSP1 or BtabCSP12 genes weakened the repellency effect of terpinolene to B. tabaci. Our results not only revealed molecular mechanism of CSPs-mediated repellency of terpinolene against B. tabaci, but also provided a theoretical basis for terpinolene-based repellent for pest management.