AUTHOR=Yang Xifa , Liu Shaokai , Lu Wenhui , Du Mengfang , Qiao Zhuangzhuang , Liang Zhen , An Yiting , Gao Jing , Li Xiang 

TITLE=Delta and jagged are candidate target genes of RNAi biopesticides for the control of Nilaparvata lugens

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2022.1023729

DOI=10.3389/fbioe.2022.1023729

ISSN=2296-4185

ABSTRACT=<p>The brown planthopper (BPH; <italic>Nilaparvata lugens</italic>) is an important pest in rice cultivation, and chemical pesticide over-use and ineffectiveness of existing Bt transgenic rice against piercing-sucking insects make novel control methods necessary. RNA interference (RNAi) biopesticide is a new type of product with high efficiency and specificity and are simple to use. The Notch signaling pathway has extensive and important physiological functions and plays a key role in the development of insects. In this study, two key ligand genes of the Notch signaling pathway, <italic>delta</italic> (<italic>dl</italic>) and <italic>jagged</italic> (<italic>jag</italic>), were selected and their lethal effects and functional analysis were systematically evaluated using a stable short-winged population (Brachypterous strain) and a long-winged population (Macropterous strain) of BPHs. The full-length coding sequences of <italic>Nldl</italic> and <italic>Nljag</italic> comprised 1,863 and 3,837 base pairs, encoding 620 and 1,278 amino acids, respectively. The nucleic acid sequences of <italic>Nldl</italic> and <italic>Nljag</italic> were identical between the two strains. The expression levels of <italic>Nldl</italic> and <italic>Nljag</italic> were relatively high in the head of the nymphs, followed by those in the abdomen. Through RNAi treatment, we found that injection of BPH nymphs of both strains with ds<italic>Nldl</italic> (10–50 ng/nymph) or ds<italic>Nljag</italic> (100 ng/nymph) produced lethal or teratogenic effects. dsRNA treatment showed excellent inhibitory effects on the expression of target genes on days 1 and 5, suggesting that RNAi rapidly exhibits effects which persist for long periods of time in BPHs. Taken together, our results confirm the potential of <italic>Nldl</italic> and <italic>Nljag</italic> as target genes of RNAi biopesticides, and we propose optimized dosages for the control of BPHs.</p>