Identification and expression analysis of putative chemoreception genes from Cyrtorhinus lividipennis (Hemiptera: Miridae) antennal transcriptome

Gui-Yao Wang,Zeng-Rong Zhu,Quais Md Khairul,Jing-Lei Zhu,Naved Ahmad Ansari,Su Liu,Wen-Wu Zhou

doi:10.1038/s41598-018-31294-9

Abstract

Cyrtorhinus lividipennis Reuter (Hemiptera: Miridae) is an important egg predator of planthoppers which are destructive rice pests. The chemosensory genes in the mirid antennae play important roles in mating and prey-seeking behaviors. To gain a better understanding of the olfaction of C. lividipennis, we sequenced the antennal transcriptomes of the predator to identify the key olfaction genes. We identified 18 odorant binding proteins (OBPs), 12 chemosensory proteins (CSPs), 1 Niemann-Pick C2 protein (NPC2), 15 odorant receptors (ORs), 6 ionotropic receptors (IRs), 3 gustatory receptors (GRs) and 3 sensory neuron membrane proteins (SNMPs). Quantitative real-time PCR results showed that the relative transcript levels of three ClivORs (ClivOR6, 7 and 14) in the female antennae were 3 to 6 folds higher than that in the male antennae, indicating these genes were more related to oviposition site selection. The relative transcript levels of ClivCSP8 and ClivOR11 were 2.6 and 2.7 times higher in the male antennae than that of the female, respectively, indicating that these genes might be involved in mate searching. Moreover, the responses of dsorco treated predators to volatiles emitted from infested rice were significantly reduced, indicating these volatiles might serve as crucial cues in the host searching of C. lividipennis.

Highlights

Natural enemies of herbivorous insects often depend on volatile chemical cues to locate their concealed prey in the complex environment[1]
Results of the quantitative real-time PCR (qRT-PCR) assays indicated that three ClivOBPs (15, 17, 18), four ClivCSPs (6, 9, 11, 12), twelve ClivORs (1, 2, 4, 6–10, 12, 13, 14 and orco), ClivIRs (1–6), three ClivGRs (1–3) and two ClivSNMPs (ClivSNMP2-1 and 2-2) were more highly expressed in the female antennae than in the male
Two ClivOBPs (14, 16), two ClivCSPs (7, 8), ClivOR11 and ClivSNMP1 were highly expressed in the male antennae

Summary

Introduction

Natural enemies of herbivorous insects often depend on volatile chemical cues to locate their concealed prey in the complex environment[1]. Some studies have reported the role of rice volatiles in regulating the behavior of natural enemies[6]. C. lividipennis were found to be attracted by volatiles emitted from herbivore-infested plants, suggesting that olfaction played an essential role in their prey search[6,7]. The key olfactory proteins involved in the perception of odorants in insects are odorant-binding proteins (OBPs), chemosensory proteins (CSPs), Niemann-Pick C2 protein (NPC2), odorant /ionotropic receptors (ORs and IRs), gustatory receptors (GRs) and sensory neuron membrane proteins (SNMPs)[5,15,16,17,18,19]. CSPs were reported to act as carriers for visual pigments in insects[33]

Methods

Results

Conclusion