Recombinant AcMNPV-gp64-EGFP and synergist triphenyl phosphate, an effective combination against Spodoptera frugiperda.

Objectives: AcMNPV is a kind of microbial insecticide that can significantly relieve the resistance of Spodoptera frugiperda to chemical pesticides. TPP is a widely used synergist, which can reduce the use of pesticides by inhibiting carboxylesterase. It is emergently needed to develop a biological control way of Spodoptera frugiperda. Results: GP64 mediates low-pH-triggered membrane fusion during entry by endocytosis and participates in AcMNPV particle budding. We explored the synergistic anti-insect activity of AcMNPV-gp64-EGFP and TPP. AcMNPV-gp64-EGFP could increase progeny virus proliferation and accelerate the transcription of 38k and vp39 genes. TPP could inhibit the carboxylesterase activity in the midgut of Spodoptera frugiperda larvae infected with AcMNPV-gp64-EGFP and enhance the virulence of AcMNPV-gp64-EGFP to Spodoptera frugiperda. Conclusions: TPP targeted carboxylesterase inhibition so that AcMNPV-gp64-EGFP could escape the antiviral response in insect hosts. It provided a novel strategy for the prevention of Spodoptera frugiperda. [ABSTRACT FROM AUTHOR]