Analysis of UB and L40, related to deltamethrin stress in the diamondback moth, Plutella xylostella (L.).

Pests have been subjected to heavy selection by insecticide pressure, producing greater and more serious resistance. It is extremely valuable to identify the resistance genes that are relevant for pest control. In our previous studies, we reported that UBL40 is the deltamethrin resistance-associated gene. UBL40 is cleaved by specific endopeptidases to release UB and L40. Therefore, further we compared the expression of UB and L40 in different tissues from larvae of the diamondback moth using a deltamethrin-resistant (DR) strain and a deltamethrin-sensitive (DS) strain. The results showed that both UB and L40 knockdown significantly reduced the level of resistance to deltamethrin and clearly decreased the survival rate in P. xylostella after 72 h. These results provide evidence that UB and L40 both play roles in the regulation of deltamethrin resistance, which could help elucidate the resistance mechanisms and identify new target genes associated with deltamethrin resistance in P. xylostella.