Combined use of lipopolysaccharide-binding protein dsRNA and Gram-negative bacteria for pest management of Coptotermes formosanus

Abstract

BACKGROUND: RNA interference (RNAi) technology is an environmentally friendly strategy for controlling insect pests. Lipopolysaccharide-binding protein (LBP) recognizes lipopolysaccharides, which are a major outer membrane constituent of Gram-negative bacteria. We propose that the LBP gene is a potential target for termite management; however, to date, no studies have examined this gene in termites. RESULTS: In this study, we cloned the LBP gene of Coptotermes formosanus (Cf) and found that the mortality rate of termite workers significantly increased, and the repellence of these workers to Gram-negative bacteria was suppressed after knockdown of CfLBP using double-stranded RNA (dsRNA) injection and feeding. Moreover, the mortality rate of termite workers fed with CfLBP dsRNA and three Gram-negative bacteria (provided separately) was over 50%, which was much higher than that of termites treated with either CfLBP dsRNA or Gram-negative bacteria. Finally, we found that CfLBP impacts the IMD pathway to regulate the immune response of C. formosanus to Gram-negative bacteria. CONCLUSION: CfLBP plays a important role in the immune defense of termites against Gram-negative bacteria. It can be used as an immunosuppressant for RNAi-based termite management and is an ideal target for termite control based on the combined use of RNAi and pathogenic bacteria. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.