No abstract

Diamondback moth (DBM), Plutella xylostella, is an important pest of crucifers worldwide. The extensive use of diamide insecticides has led to DBM resistance in the world, and this presents a serious threat to vegetable production. In the present study, transcriptomic and proteomic analyses were combined to investigate the potential flubendiamide-resistance mechanism in DBM. The lab-selected (R h) and field-collected (R b) flubendiamide-resistant lines of P. xylostella with resistance ratios of 1889.92-fold and 1250.97-fold, respectively, were used, as well as a lab-reared flubendiamide-susceptible line (S). Compared with the S group, the transcriptomic analysis revealed 151 upregulated and 287 downregulated gene messengers in the R h group and 432 upregulated and 565 downregulated gene messengers in the R b group. The most frequently enriched pathways of differentially expressed genes (DEGs) were mainly involved in metabolic pathways. Metabolism related genes, including two P450, two ABC transporters, and three trypsins, were upregulated in the R h line. Additionally, some P450 genes, trypsin, juvenile hormone (JH), and mucin genes were also upregulated in the R b line. In proteomic analysis comparisons with the S group, there were 78 upregulated and 90 downregulated proteins in the R h group and 221 upregulated and 155 downregulated proteins in the R b group. Further analyses found that three CYP and 11 CYP proteins were over-expressed in R h and R b lines, respectively. Four glutathione S-transferase (GST) and four UGTs were over-expressed in R b line. So, we deduced that the detoxification metabolism may be the main mechanism of flubendiamide resistance in P. xylostella.

Abstract The diamondback moth (Plutella xylostella, DBM) is an important pest of cruciferous vegetables. The use of chlorantraniliprole has been essential in the management of the DBM. However, in many countries and areas, DBM has become highly resistant to chlorantraniliprole. Three different DBM strains, susceptible (S), chlorantraniliprole-selected (Rc), and field-collected (Rb) resistant strains/populations were studied for the role of phenoloxidase in resistance development to the insecticide. By assaying the activity of phenoloxidase (PO) in the three different DBM strains, the results showed that the PO activity in the Rc strain was increased significantly compared with the S strain. The synergistic effects of quercetin showed that the resistant ratio (RR) of the QRc larvae to chlorantraniliprole was decreased from 423.95 to 316.42-fold compared with the Rc larvae. Further studies demonstrated that the transcriptional and translational expression levels of PxPPO1 (P. xylostella prophenoloxidase-1 gene) and PxPPO2 (P. xylostella prophenoloxidase-2 gene) were increased to varying degrees compared with the S strain, such as the transcriptional expression levels of PxPPO2 were 24.02-fold that of the S strain. The responses of phenoloxidase were significantly different in chlorantraniliprole-resistant DBM.

No abstract