Functional characterization of chemosensory proteins in response to artificial light treatment in Thalassodes...

Chemosensory proteins (CSPs) play a vital role in the response to environmental stimuli in insects. However, the involvement of insect CSPs in the stress response to night-time environmental changes has not been examined.

In the current study, four TiCSP genes were first cloned from Thalassodes immissaria by transcriptome and RACE-PCR techniques. TiCSPs had typical characteristics of insect CSPs, including a highly conserved four-cysteine motif and olfactory-specific protein D (OS-D) or OS-D superfamily domains. TiCSP1-4 were clustered classified within different clades in a phylogenetic analysis and were differentially expressed at all developmental stages. Under night-time artificial light stress, the expression levels of TiCSP1 in males were significantly decreased at 24 h, and those of TiCSP2 were decreased in both adult sexes at 48 h. In a molecular docking analysis, TiCSPs showed relatively higher binding affinities with sex pheromone components than with host plant volatile molecules.

Taking the reduced expression levels of TiCSPs and binding affinities into account, TiCSP1 and TiCSP2 are involved in the stress response processes of T. immissaria under light treatment. Our study supplies basic data for the evaluation of the effects of light interference control technology - an emerging physical control measure on nontarget pests of lychee orchards. © 2023 Society of Chemical Industry.