Identification of an Alarm Pheromone-Binding Chemosensory Protein From the Invasive Sycamore Lace Bug Corythucha ciliata (Say).

Fengqi Li,Ningning Fu,Du Li,Ran Wang,Cheng Qu,Yihua Xu,Hetang Chang,Chen Luo

doi:10.3389/fphys.2018.00354

Fengqi Li, Ningning Fu + Show 6 more

Open Access

https://doi.org/10.3389/fphys.2018.00354

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Abstract

The spread of the exotic insect pest sycamore lace bug Corythucha ciliata (Say) is increasing worldwide. The identification of behaviorally active compounds is crucial for reducing the current distribution of this pest. In this study, we identified and documented the expression profiles of genes encoding chemosensory proteins (CSPs) in the sycamore lace bug to identify CSPs that bind to the alarm pheromone geraniol. One CSP (CcilCSP2) that was highly expressed in nymph antennae was found to bind geraniol with high affinity. This finding was confirmed by fluorescence competitive binding assays. We further discovered one candidate chemical, phenyl benzoate, that bound to CcilCSP2 with even higher affinity than geraniol. Behavioral assays revealed that phenyl benzoate, similar to geraniol, significantly repelled sycamore lace bug nymphs but had no activity toward adults. This study has revealed a novel repellent compound involved in behavioral regulation. And, our findings will be beneficial for understanding the olfactory recognition mechanism of sycamore lace bug and developing a push-pull system to manage this pest in the future.

Highlights

Sycamore lace bug, Corythucha ciliata (Say) (Heteroptera: Tingidae), is an important exotic invasive pest
The nymphs were significantly repelled by geraniol in petri dishes (Table 1) and on plant leaves (Table 5)
The expression levels of c32563_g2 are associated with the differing responses of sycamore lace bug nymphs and adults to geraniol, and this chemosensory proteins (CSPs) was selected as a candidate geraniol-binding protein

Summary

Introduction

Corythucha ciliata (Say) (Heteroptera: Tingidae), is an important exotic invasive pest. The discovery of behaviorally active compounds is an efficient approach to developing pest management strategies (Foster and Harris, 1997) Examples of these types of compounds include alarm pheromones, which affect insect behavior, development and oviposition and are important for insects to defense against dangers such as natural enemies (Ono et al, 2003; Kunert et al, 2005; Dewhirst et al, 2010). Alarm pheromones and other repellent compounds can enhance the efficiency of insecticides (Kuwahara et al, 2011) These types of compounds are important targets in pest management.

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