Systemic identification and analyses of genes potentially involved in chemosensory in the devastating tea pest Basilepta melanopus.

Basilepta melanopus is a serious insect pest of tea plantations in southern China. This tea pest poses a great threat to the tea industry in China. No effective and environmentally friendly methods have been established to control this pest at present. Olfactory genes play key roles in insect behaviour, and can potentially be used as targets for developing environmentally-friendly approaches for pest control. In this study, we produced a transcriptome derived from dissected antennae from B. melanopus using high-throughput sequencing. We identified gene families that are potentially involved in odorant reception and detection, including unigenes encoding 63 odorant receptors (ORs), 16 gustatory receptors (GRs), 18 ionotropic receptors (IRs), four sensory neuron membrane proteins (SNMPs), 46 odorant binding proteins (OBPs), and 19 chemosensory proteins (CSPs). Analyses of tissue expression profiles revealed that all 63 OR transcripts, 14 antennal IRs, one SNMP and six OBPs were predominately expressed in antennae. Real-time quantitative PCR assays were also adapted to examine sex-biased expression of selected antenna-predominant genes. Our results provide valuable information for further functional studies of olfactory genes in B. melanopus and potential novel targets for developing new pest control measures.