OfGNBP silencing enhances the toxicity of Serratia marcescens Bizio (SM1) to Odontotermes formosanus (Shiraki).

The immunity of insects plays a vital role in their survival. Our experiments found that lipopolysaccharide (LPS) and glucono-δ-lactone (GDL) could influence the virulence of Serratia marcescens Bizio (SM1) to Odontotermes formosanus (Shiraki) by affecting the immunity. Gram-negative binding proteins (GNBPs) are an important pattern recognition proteins that play a crucial role in the innate immune system. Therefore, two OfGNBP s were cloned in O. formosanus. The expression of OfGNBP s was significantly changed by LPS,SM1 and GDL, not prick. In addition, the immune-related gene expression, the phenoloxidase activity and antibacterial activity of donor termites and recipient termites were significantly induced by SM1. Furthermore, the knockdown of OfGNBP by RNA interference reduced not only individual immunity but also social immunity in O. formosanus , which increased the virulence of SM1 to O. formosanus. Importantly, ds OfGNBP alone also had good control effect on O. formosanus. In summary, we concluded that ds OfGNBP s are important termite immunosuppressants. [Display omitted] • Two OfGNBP s play an important role in the individual immunity of O. formosanus. • Two OfGNBP s play an important role in the social immunity of O. formosanus. • Two OfGNBP s were first confirmed to play an important role in resistanting SM1. [ABSTRACT FROM AUTHOR]