Transcription factor CncC potentially regulates the expression of multiple detoxification genes that mediate indoxacarb resistance in Spodoptera litura

The xenobiotic transcription factor cap‘n’collar isoform C(CncC)is considered the central regulator of antioxidant and detoxification genes.Previous research indicated that CncC regulates three-phase enzymes responsible for insecticide resistance.In this study,the SlituCncC gene from Spodoptera litura was obtained and characterized.Quantitative polymerase chain reaction(qPCR)analysis showed that SlituCncC was expressed in all developmental stages and tissues,but was highly expressed in 3rd-and 4th-instar larvae,and in the Malpighian tubule,fat body,and midgut.In addition,SlituCncC was up-regulated and more highly induced with indoxacarb treatment in the indoxacarb-resistant strains compared with the susceptible strain.RNA interference-mediated gene silencing of SlituCncC significantly increased mortality of S.liura when exposed to in-doxacarb.Furthermore,comparative transcriptome analysis showed that 842 genes were down-regulated and 127 genes were up-regulated in SlituC"ncC knockdown S.litura.Further analysis indicated that 18 three-phase enzymes were identified in the down-regulated genes,of which seven were associated with indoxacarb resistance in S.litura.qPCR analysis confirmed that expression of six of these seven genes was consistent with RNA se-quencing data.All six detoxification genes were induced by indoxacarb,and the expression patterns were similar to that of SlituCncC.Finally,the CneC-Maf binding site was predicted in all six gene promoters.This study indicates that the transcription factor SlituCncC may regulate multiple detoxification genes that mediate indoxacarb resistance in S.litura.

Systematic identification and functional analysis of long noncoding RNAs involved in indoxacarb resistance in Spodoptera litura

Long noncoding RNAs(lncRNAs)are noncoding transcripts that are more than 200 nucleotides long.They play essential roles in regulating a variety of biological processes in many species,including insects,and some lncRNAs have been found to be associated with insecticide resistance.However,the characteristics and biological func-tions of lncRNAs involved in indoxacarb resistance are unknown in Spodoptera litura.We performed RNA sequencing in the SS,InRS,and FInRS of S.litura and identified 11978 lncRNAs,including 3136 intergenic lncRNAs,7393 intronic lncRNAs,and 1449 anti-sense lncRNAs.Compared with the SS,51 lncRNAs were upregulated and 134 lncRNAs were downregulated in the two resistant strains,and 908 differentially expressed mRNAs were predicted as the target genes of the 185 differentially expressed lncRNAs.Further analysis showed that 112 of differentially expressed lncRNAs may be associated with in-doxacarb resistance by regulating the expression of 14 P450s,seven CCEs,one GST,six UGTs,five ABC transporters,and 24 cuticle protein genes,and 79 of differentially ex-pressed lncRNAs may regulate the expression of 14 detoxification genes and 19 cuticle protein genes to participate in indoxacarb resistance by sponging 10 microRNAs.Interest-ingly,47 of differentially expressed lncRNAs may mediate indoxacarb resistance through both lncRNA-mRNA and lncRNA-miRNA-mRNA regulatory pathways.Furthermore,quantitative PCR,RNA interference,and indoxacarb bioassay analyses indicated that over-expressed LNC_004867 and LNC_006576 were involved in indoxacarb resistance.This study provides comprehensive information for lncRNAs of S.litura,and presents evidence that lncRNAs havekey roles in conferring insecticide resistance in S.litura.