Knockdown of vATPase subunit A impairs larval-pupal development in Plutella xylostella.

Plutella xylostella is a destructive pest damaging the cruciferous plants worldwide. Transgenic plants expressing dsRNA can be widely deployed for pest control. However, highly effective lethal target genes are currently lacking. Here, we assessed the efficacy of RNA interference (RNAi) against P. xylostella through microinjection of in vitro synthesized dsRNA targeting PxvATPaseA. The full-length ORF of PxvATPaseA was 1848 bp, encoding 615 amino acids. PxvATPaseA was widely transcribed during different developmental stages from egg to adult. It was abundantly expressed in the foregut, hindgut, and Malpighian tubules, compared with other tissue types. Injecting 800 ng of dsPxvATPaseA into the fourth-instar larvae greatly reduced the corresponding mRNA level by 1.88-fold on day 2, causing 45.8% larval mortality, and lastly 54.2% treated larvae successfully pupated. At a higher dose of 1200 ng of dsPxvATPaseA, RNAi efficacy was significantly enhanced. The expression level of PxvATPaseA was reduced by 2.22-fold and 1.92-fold on day 2 and 3, respectively, leading to 79.2% larval lethality, and only 20.8% of depleted larvae pupated. Our results indicate that PxvATPaseA is an effective target for managing P. xylostella. These findings will facilitate the development of new insecticides and the cultivation of pest-resistant plants.