Analysis Of UB And L40 Related To Deltamethrin Stress And Resistance

The diamondback moth, Pluttela xylostella L., is one of the most destructive pests in cruciferous vegetables such as cabbage and pakchoi. Now pesticides control has become an important means for pest control. But widespread use of pesticides induced resistance and impede its prevention seriously. The study and discovery of new resistance related gene could help us to understand the molecular basis of drug resistance, and find new targets for resistance management.In the previous studies, the UBL40 has been reported the deltamethrin resistance-associated gene. UBL40 is cleaved by specific endopeptidases to release UB and L40. Whether UB or L40 participates in deltamethrin resistance requires further study. In this paper, We have done the experiment as follows:1) We stimulated the Drosophila cells with different concentrations of deltamethrin. The results of quantitative real-time PCR shown that UB and L40 were both up-regulated in Drosophila Kc cells after deltamethrin stimulation. Then we selected a suitable concentration of deltamethrin to stimulate the Drosophila Kc cells in different time, we also found that UB and L40 were both overexpressed. This was the foundation for the next experiment.2) The full length of UB and L40 were cloned and transfected to the Drosophila Kc cells. The transfection efficiency were detected at the level of gene and protein. After successful transfection, the cells were stimulated with different concentrations of deltamethrin. We found that Drosophila Kc cells conferred a degree of protection against deltamethrin3) The dsRNA of UB and L40 were synthesized with RNAi kit and interfered the Drosophila Kc cells. The interference efficiency were detected at the level of gene and protein. After successful interference, the cells were stimulated with different concentrations of deltamethrin. We found that UB or L40 knockdown both significantly reduced the level of resistance.4) The UB and L40 gene were interfered in the larvae of deltamethrin resistant diamondback moth with the RNAi technology, then the mortality of diamondback moth was detected. We found that UB and L40 knockdown both significantly reduced the level of resistance.According to the above experiment, we conclued that in the fusion gene UBL40, the UB and L40 all participated in deltamethrin resistance. This provides an important clues for further study the mechanism of drug resistance.