Analysis of differentially expressed proteins between the spinetoram-susceptible and -resistant strains of Plutella xylostella (L.)

Plutella xylostella (L.), a worldwide vegetable pest, has developed resistance to spinetoram, which was previously effective for the control of P. xylostella (L.). The insecticidal resistance mechanism is essential to develop effective resistance management strategies. To explore the spinetoram resistance mechanism, a comparative proteomics approach was used to investigate the proteomic differences between the spinetoram-susceptible strain (SS) and spinetoram-resistant strain (RS) of P. xylostella (L.). Approximately 280 protein spots were detected on each SDS-PAGE gel. Of these, 19 proteins were successfully identified by MALDI-TOF-MS.·There were 6 significantly down-regulated spots and 13 up-regulated spots in RS, which showed significantly difference compared to that in SS. Based on the gene ontology(GO) system and KEGG database, the 19 identified proteins were classified into 6 groups including metabolisms, signal transduction, chaperones, transcriptional, protein synthesis, structural protein. Meanwhile, the expression profiles of 5 resistant related protein were further analysed by qRT-PCR. The results showed that 60S acidic ribosomal protein P2, glutathione S-transferase isozyme 3 and glutathione S-transferase delta were significantly up-regulated, while phosphoglycerate mutase and receptor for activated protein kinase C homolog were significantly down-regulated. The expression tendency of mRNA was in accordance with which of protein. This study provided evidences that spinetoram induces proteomic changes in P. xylostella (L.), and it is contributed to help us understand the resistance mechanism of P. xylostella (L.) to spinetoram.