The Effects Of RVA Interference Targeting Bactrocera Dorsalis Ds-Bdrpl19on The Gene Expression Of Rpll9in Non-target Insects

RNA interference (RNAi) is a gene silencing mechanism triggered by double-stranded RNA, dsRNA designed to target pest genes emerges as a promising strategy for improving pest control. Therefore, it is necessary to assess the effects of dsRNA on non-target insects, such as native enemies and beneficial insects, to determine the environmental safety of such treatments.In this paper, we investigated the effects of dsRNA targeting rpl19from Bactrocera dorsalis on non-target insects in citrus ecological systems by feeding the dsRNA to Bactrocera minax, Apis mellifera and Diachasmimorpha longicaudata. Using Real-time PCR and molecular biology techniques detecting the transcript levels of rpl19gene, provide a reference basis for RNAi used for pest control.We isolated the full-length cDNA sequence of rpl19from B. Dorsalis, B. minax, D. longicaudata and, A. Mellifera. rpl19ORF nucleotide sequence of B. dorsalis shared the following identities with the other insect rpl19ORFs:93%identity with B. minax,72%identity with D. longicaudata and70%identity with A. mellifera. Analysis of corresponding amino acid sequence using CLUSTAL X2.0indicated, A homology search revealed that the rpl19acid sequences of Bdrpl19, Bmrpl19, Dlrpl19and Amrpl19are high similarity more than90%.We have found feeding Bdrpl19dsRNA to adult B. dorsalis led to a marked rpl19gene down-regulation over50%, B. minax adults feeding with Bmrpl19dsRNA, marked rpl19gene down-regulation over90%, D. longicaudata feeding with Dlrpl19dsRNA, marked rpll9gene knockdown over38%, A. mellifera feeding with Amrpl19dsRNA, marked rpl19gene down-regulation over50%.Feeding the Bdrpl19CDS dsRNA to adult B. minax and D. longicaudata caused their respective rpl19genes to be knocked down over50%-70%and40%, respectively, but it had no effect on the expression of the rpl19gene in A. mellifera. The Bdrpl193UTR dsRNA did not have any silencing effects on the expression levels of rpl19in non-target insects. The gene homology may be able to explain this result:the nucleotide sequence of Bdrpll9CDS shares two sections of19-21bp overlap, when compared with the Bmrpl19CDS, but only one section of19-21bp overlap, when compared with Dlrpl19CDS. Thus, the level of RNAi in B. minax was more than that of D. longicaudata. This study provides evidence that dsRNA can impact non-target organisms, The results of this study have shown that it is very difficult to design an interference sequence that avoids effects in all non-target insects, but the3UTR dsRNA may not have effects in non-target organisms.