RNAi of vATPasea Affects Survival and Larval-Pupal Development in Plutella xylostella.

The diamondback moth, Plutella xylostella, is a major pest of brassica vegetables and oilseed crops, posing a serious threat to China's grain and oil production. RNA interference (RNAi) has been developed as an efficient strategy to control pests. In this study, the effects of RNAi on P. xylostella were evaluated by injecting two doses of synthesized dsPxvATPasea. The transcripts of PxvATPasea were widely transcribed during different developmental stages from egg to adult. They were abundantly expressed in the hindgut and Malpighian tubules, compared with other tissue types. Introduction of 800 ng dsPxvATPasea in the fourth-instar larvae greatly reduced corresponding mRNA levels by 3.1 and 1.4 times on day 2 and 3, respectively, causing 66.6% mortality and 33.4% treated larvae pupated. Silencing PxvATPasea by injecting 1200 ng dsRNA significantly decreased the expression level by 5.0 and 2.0 times on the second and third day, leading to 79.2% larval lethality and 20.8% depleted larvae pupated. Moreover, introducing 800 ng or 1200 ng dsPxvATPasea finally reduced larval fresh weight by 22.1% and 28.8%, respectively. The results indicated that the silencing efficiency of PxvATPasea worked in a dose-dependent way. Consequently, PxvATPasea is a potential molecular target gene. Our findings will facilitate the application of RNAi technology to manage P. xylostella.