Chemosensory Proteins Mediated Repellency of Terpinolene to <i>Bemisia tabaci</i>

Terpinolene, a monoterpene volatile, has been demonstrated to exhibit repellent activity against <i>Bemisia tabaci</i> adults. However, molecular basis of <i>B. tabaci</i> 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 <i>BtabCSP</i> genes in <i>B. tabaci</i> 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 <i>BtabCSP1</i> or <i>BtabCSP12</i> genes weakened the repellency effect of terpinolene to <i>B. tabaci</i>. Our results not only revealed molecular mechanism of CSPs-mediated repellency of terpinolene against <i>B. tabaci</i>, but also provided a theoretical basis for terpinolene-based repellent for pest management.