Identification And Analysis Of Mirnas Involved In Detoxification In The Diamondback Moth, Plutella Xylostella

The diamondback moth (DBM), Plutella xylostella, is one of the most destructive members of the insect pest complexes that attack Brassica vegetable crops in various parts of the world. DBM has developed resistance to almost all major classes of insecticides and the biopesticide Bacillus thuringiensis (Bt). MicroRNAs (miRNAs) are a group of small, noncoding RNA molecules that play an important role in gene regulation via base-pairing with complementary target gene sequences.Published reports show that the prime detoxification gene families in insects include, cytochrome monooxygenases (P450), carboxylesterase (CarEs), glutathione S-transferase (GSTs), and ATP-binding cassette transporters (ABC transporters). Detoxification genes are responsible for metabolically based resistance to pesticides. At present, the metabolism of miRNAs involved in detoxification metabolism is unclear. In the present study, we screened and identified miRNAs that may regulate the detoxification in P. xylostella from the transcriptome data of susceptible and resistant DBM strains. The results we obtained are outlined below1. We screened seventeen miRNAs that are expressed based on the transcriptome data of the susceptible and resistant strains of P. xylostella. The resulting phylogenetic tree shows that these miRNAs are highly conserved and that their evolutionary distance is related to the phylogenetic relationship of the species.2. We obtained a total of 1,072 target genes based on the prediction of several bioinformatics software programs. Next, we further screened 48 genes from detoxification families and 6 miRNAs. Finally, after an analysis of the digital gene expression profiles and binding sites, we chose 5 miRNAs and 9 target genes for further study.3. The transcription expression profile of miRNAs and target genes shows that the expression profile trend of the five miRNAs is consistent with that of the digital gene expression. We found that expression of 9 target genes is upregulated in chlorpyrifos resistant strains, but there is upregulation in expression of 8 target genes and down-regulation in expression of a gene in fipronil resistant strains.The results of our study will facilitate our understanding of the role of miRNAs in detoxification in P. xylostella and provide new research pathways into insect resistance and controlling pests.