Find Paper, Faster
Example:10.1021/acsami.1c06204 or Chem. Rev., 2007, 107, 2411-2502
A female-biased odorant receptor tuned to the lepidopteran sex pheromone in parasitoid Microplitis mediator guiding habitat of host insects
Journal of Advanced Research  (IF12.822),  Pub Date : 2022-03-07, DOI: 10.1016/j.jare.2022.03.006
Shuang Shan, Xuan Song, Adel Khashaveh, Shan-Ning Wang, Zi-Yun Lu, Khalid Hussain Dhiloo, Rui-Jun Li, Yong-Jun Zhang

Introduction

The parasitoid wasp Microplitis mediator is an important natural enemy of the turnip moth Agrotis segetum and other Noctuidae pests. In our field observation, it was fortuitously discovered that sex pheromone traps used for A. segetum also attract female wasps, verified by a simulated field condition dual-choice laboratory assay. Therefore, it was hypothesized that olfactory recognition could be crucial in this process. In this regard, a female-biased odorant receptor of the wasp, MmedOR49, attracted our attention.

Objective and method

Expression analysis (fluorescence in situ hybridization (FISH); quantitative real-time PCR), in vitro (Xenopus oocyte expression and two-electrode voltage-clamp recordings) and in vivo (RNAi combined with behavioral assessments) functional studies, and bioinformatics (structural modeling and molecular docking) were carried out to investigate the characteristics of MmedOR49.

Results

MmedOR49 mRNA expression was detected in the antennae of females by FISH. Quantification using qPCR indicated that the expression level of MmedOR49 increased significantly after adult emergence. In vitro functional study revealed that MmedOR49 was specifically tuned to cis-5-decenyl acetate (Z5-10:Ac), the major sex pheromone component of A. segetum. Molecular docking showed that Z5-10:Ac strongly bound to the key amino acid residues His 80, Ile 81, and Arg 84 of MmedOR49 through hydrogen bonding. Behavioral assays indicated that female wasps were significantly attracted by Z5-10:Ac in a three-cage olfactometer. RNAi targeting further confirmed that MmedOR49 was necessary to recognize Z5-10:Ac, as female wasps lost their original behavioral responses to Z5-10:Ac after downregulation of the MmedOR49 transcript.

Conclusion

Although M. mediator is a larval endoparasitoid, female wasps have a behavioral preference for a sex pheromone component of lepidopteran hosts. In this behavior, for female M. mediator, MmedOR49 plays an important role in guiding the habitat of host insects. These data provide a potential target for enhancing natural enemy utilization and subsequent pest control.