Application Of The LC MS/MS Technical Analysis And Compare The Ubiquitinated Proteins In The Larval Diamondback Moth, Plutella Xylostella L.

The diamondback moth, Plutella xylostella belongs to the Lepidoptera, Plutella. It is one of the most destructive pests of cruciferous crops all over the world. As the diamondback moth occurred in many generations, generation overlapping, high propagation coefficient lead to chemical drug use frequency. Therefore, Plutella xylostella has developed a robust resistance to many chemical and biological pesticides. Then, it is important to understand its mechanisms of insecticide resistance.In our previous work, Cheng LG obtained one different expressed sequence with relatively high homology to the ubiquitin gene as assessed via cDNA representational difference analysis (RDA). Ubiquitin is a 76-amino acid protein that is ubiquitously distributed and highly conserved throughout eukaryotic organisms. Regulation of proteins by post-translational modification with ubiquitin plays an important role in a variety of cellular processes including protein degradation, stress response, cell-cycle regulation, protein trafficking, endocytosis, signal transduction and transcriptional regulation. To identify the potential effects of pesticide deltamethrin on the diamondback moth protease system, we used LC MS/MS method to determine the different expression of ubiquitinated proteins in the 3rd larvae of diamondback moth between deltamethrin-resistant (DR) strain and deltamethrin-sensitive (DS) strain. What we achieved are mainly:1. LC MS/MS approach was chose to identify the different expression of ubiquitinated proteins between the DR strain and DS strain of diamondback moth. Twenty-six ubiquitinated proteins were identified from the DR and DS of the diamondback moth. The number of up-regulated proteins between DR and DS was seventeen, meanwhile, five proteins were significantly down-regulated. The results showed that the deltamethrin stress obviously changed diamondback moth ubiquitinated protein system.2. Protein function result showed that:these differentially expressed proteins include Carbonic AnHydrase family member, ADP ribosylation factor 102F CG11027-PA, dihydrolipoamide dehydrogenase,19.8kDa Heat shock protein et al. These proteins function include protein binding, catalytic activity, molecular transducer activity. But the relationship between insect resistance needs to be further verified.3. As resistance strain was obtained from the sensitive strain through several generations of selection, so these differential ubiquinated proteins indicated that the selection of pharmacy led to the changes in protein expression of diamondback moth. Therefore this study is helpful to understand the mechanism of insecticide resistance and design novel strategies to prevent, or minimize the spread of resistance.