Deorphanization of an odorant receptor revealed new bioactive components for green mirid bug Apolygus lucorum (Hemiptera: Miridae)

Abstract

BACKGROUND The Apolygus lucorum is one of the most destructive insect pests in China with a wide range of host plants. Interaction of A. lucorum with surrounding environment heavily relies on chemical communication. Deorphanization of receptors involved in odors detection elevates our understanding of the olfactory system of this pest and may help to develop a chemical ecology‐based control strategy. RESULTS AlucOR80, an odorant receptor (OR) in A. lucorum was newly cloned. Gene expression analysis showed that this receptor was mainly expressed in the antennae and head of both sexes but with a male bias. The Xenopus oocytes heterologous expression system coupled with the two‐electrode voltage‐clamp (TEVC) recording revealed that AlucOR80 was tuned to 21 selected compounds. Furthermore, electroantennogram (EAG) tests confirmed that all 21 ligands of AlucOR80 were electrophysiologically active in antennae of both sexes. Behavioral trials in a three‐cage olfactometer indicated that 16 compounds were behaviorally active, amongst which, 12 components were attractants and four components were repellents for adults of both sexes. Butyl butyrate and Dimethyl disulfide (DMDS) were the strongest attractive and repellant compounds, respectively. Importantly, we found the repellency of 1, 8‐Cineole, S‐(−)‐cis‐Verbenol and (1S)–(1)‐beta‐Pinene against adults of A. lucorum. CONCLUSION Although AlucOR80 is a general OR, may play important role in the olfactory perception of A. lucorum. Screening of AlucOR80 ligands by behavioral assay provided valuable insights by which olfactory‐based management approaches could be developed by utilizing the behaviorally active components as attractants or repellents. © 2019 Society of Chemical Industry

Broadly Tuned Odorant Receptor AlinOR59 Involved in Chemoreception of Floral Scent in Adelphocoris lineolatus

“…Among these ligands, methyl salicylate, butyl acrylate and 4-ethylbenzaldehyde excited the strongest response to AlinOR59 in TEVC recordings. Although TEVC values do not represent behavioral activity, we still propose that methyl salicylate, butyl acrylate and 4-ethylbenzaldehyde are behaviorally active. Methyl salicylate was an important semiochemical to insects.…”

“…A single OR could detect multiple odors, whereas multiple ORs could also detect one odor . Our previous work indicated that AlucOR80 in Apolygus lucorum tuned to 21 ligands and shared four ligands with AlinOR59 including cis -3-hexenyl acetate, hexyl acetate, acetophenone, and ethyl butyrate . Similarly, EsemOR1 in Eriocrania semipurpurella shared the same ligand, β-caryophyllene, with AlinOR59 .…”

“…It has been suggested that ORs are functionally characterized as responding to plant volatile compounds . In recent years, a reverse chemical ecology strategy has been proposed and widely used in the management of the olfactory behavior of agricultural pests. − Different from traditional chemical ecology, the reverse chemical ecology method focuses on the understanding of the molecular mechanism of insect olfactory recognition and the high-throughput screening of candidate ligands with ORs or OBPs as targets . On the basis of this strategy, AlinOR59 from A.…”

“…After being injected with 27.6 ng of AlinOR59 cRNAs and 27.6 ng of AlinORco cRNAs, the oocytes were incubated for 3–5 days at 18 °C. TEVC recordings were performed following the previous protocols . The stimulated currents were recorded using an OC-725C amplifier (Warner Instruments, Hamden, CT).…”

“…TEVC recordings were performed following the previous protocols. 21 The stimulated currents were recorded using an OC-725C amplifier (Warner Instruments, Hamden, CT). Data acquisition and analysis were carried out with Digidata 1440A and pCLAMP 10.3 software (Axon Instruments Inc.).…”