Jinhua Luo

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. 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 sucessfully 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 genetically modified plants for the control of this pest.

The diamondback moth (Plutella xylostella) is a devastating global pest of cruciferous crops. This study explores the potential of targeting the vacuolar ATPase subunit E (PxvATPaseE) for its control. We demonstrate that PxvATPaseE is essential for larval development, showing high expression levels in the midgut. RNA interference (RNAi)-mediated silencing of PxvATPaseE resulted in severe growth retardation and dose-dependent mortality, with higher dsRNA doses inducing more sustained effects. Furthermore, computational virtual screening of natural compound libraries identified a high-affinity binder of PxvATPaseE, such as periplocoside D. Our results demonstrate that PxvATPaseE is a promising molecular target for controlling P. xylostella, supporting a dual-strategy approach combining RNAi and targeted chemical inhibition for future pest management solutions.

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.

Epicauta gorhami is a hypermetamorphic insect that mainly forage soybeans during the adult stage. However, the lack of appropriate references hinders our studying of the gene function in E. gorhami. In this study, referring to five computational tools (Ct value, geNorm, NormFinder, BestKeeper and RefFinder), the stability of 10 housekeeping genes (GAPDH, ACT, RPL4, RPL27, α-TUB, RPS18, EF1α, RPS28, RPL13 and SOD) was assessed by qRT-PCR under three different conditions (adult ages, tissues/organs and temperatures). The findings suggested that SOD and RPS18 were the most ideal references for examine gene transcripts among diverse adult ages and at various temperatures; a pair of RPS18 and RPS28 was the most reliable genes to assess gene expressions in diverse adult tissues. Finally, the relative expression levels of EgUAP were computed after normalization RPS18 and RPS28 with across diverse adult tissues. As expected, EgUAP expression was abundant in the foregut, trachea and antenna and scarce in the midgut, hindgut and epidermis. These findings will lay a solid foundation for analyzing the gene expression of E. gorhami.

Although rapeseed (Brassica napus L.) is known to be affected by waterlogging, the genetic basis of waterlogging tolerance by rapeseed is largely unknown. In this study, the transcriptome under 0 h and 12 h of waterlogging was assayed in the roots of ZS9, a tolerant variety, using digital gene expression (DGE). A total of 4432 differentially expressed genes were identified, indicating that the response to waterlogging in rapeseed is complicated. The assignments of the annotated genes based on GO (Gene Ontology) revealed there were more genes induced under waterlogging in “oxidation reduction”, “secondary metabolism”, “transcription regulation”, and “translation regulation”; suggesting these four pathways are enhanced under waterlogging. Analysis of the 200 most highly expressed genes illustrated that 144 under normal conditions were down-regulated by waterlogging, while up to 191 under waterlogging were those induced in response to stress. The expression of genes involved under waterlogging is mediated by multiple levels of transcriptional, post-transcriptional, translational and post-translational regulation, including phosphorylation and protein degradation; in particular, protein degradation might be involved in the negative regulation in response to this stress. Our results provide new insight into the response to waterlogging and will help to identify important candidate genes.