The insect NF-κB pathway is primarily constituted by nuclear factor κB (NF-κB) and the inhibitor of κB (IκB), which plays a crucial role in the innate immune response. Dorsal and Cactus, as NF-κB and IκB factors, are important downstream regulators of the Toll
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The insect NF-κB pathway is primarily constituted by nuclear factor κB (NF-κB) and the inhibitor of κB (IκB), which plays a crucial role in the innate immune response. Dorsal and Cactus, as NF-κB and IκB factors, are important downstream regulators of the Toll pathway in
Plutella xylostella. In this study, the
PxDorsal and
PxCactus genes of
P. xylostella were cloned, and the molecular docking demonstrated that PxDorsal and PxCactus can interact with each other. RT-qPCR results indicated that
PxDorsal and
PxCactus were expressed in all stages, and the expression of
PxDorsal,
PxCactus, and antimicrobial peptides
PxGloverin2,
PxMoricin3, and
PxLysozyme2 were significantly down-regulated under
Bacillus thuringiensis (Bt8010) infection. Interestingly, silencing the
PxDorsal gene by RNA interference (RNAi) significantly down-regulated the expression of
PxGloverin2 and
PxMoricin3 and increased the epidermis melanization of
P. xylostella larvae fed with Bt8010. Our findings indicate that PxDorsal and PxCactus may interact with each other, and silencing
PxDorsal inhibits the expression of downstream antimicrobial peptides, thereby enhance the susceptibility of
P. xylostella to Bt8010. This study contributes a theoretical basis for further research on the Toll pathway of
P. xylostella to pathogens and offers insights for screening effective biological control targets from the perspective of the immune system.
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