dsRNA-mediated interference with RcβGRPs significantly reduced the resistance of Reticulitermes chinensis Snyder...

Reticulitermes chinensis Snyder (Blattodea: Termitidae) is a highly destructive social insect. In comparison with traditional chemical control, pathogen-based microbial control provides benefits, including environmental friendliness, although its application is frequently constrained by the robust immune system of termites. β-1,3-glucan recognition proteins (βGRPs), a key class of pattern recognition receptors, play a central role in initiating insect immune responses. Therefore, we investigated the functions of RcβGRPs in R. chinensis against infection by three pathogenic microbes, aiming to elucidate the molecular mechanism by which RcβGRPs mediate the immune defense of this termite against pathogen invasion.

This study investigated the functions of RcβGRP1 and RcβGRP2 in R. chinensis regarding defense against infections caused by Bacillus thuringiensis (Bt), Serratia marcescens (SM1), and Beauveria bassiana (Bb). The results showed that pathogenic infections induced upregulation of RcβGRP1 and RcβGRP2. Following interference with these two genes, the expression of multiple immune genes downstream of the Toll pathway was variably altered. Additionally, interference with RcβGRPs resulted in a significant decrease in the frequency of mutual allogrooming behavior among termites. Furthermore, as RcβGRPs were interfered with, the resistance of R. chinensis to pathogens significantly decreased.

These findings suggest that the functions of RcβGRPs may extend beyond immune signaling at the individual level and also serve as a crucial link between individual physiological immunity and collective behavioral immunity. This study demonstrates potential roles of RcβGRPs in regulating individual and group immunity in R. chinensis and provides a theoretical foundation for enhancing termite biocontrol efficacy by targeting immune genes. © 2026 Society of Chemical Industry.