Differentially expressed microRNAs under imidacloprid exposure and identification in Sitobion avenae

Backgroud: MicroRNAs (miRNAs), which are as short single-stranded non-coding RNAs, coudl regulate the expression of target genes, especially regulation or metabolism of endogenous or xenobiotic compounds. Results: The de novo assembly of the transcriptomes was obtained through Illumina short-read sequencing technology in Sitobion avenae. 57 miRNAs, of which 36 were known and 21 were novel were identified. Quantitative expression levels of miRNA showed that the expression of 5 miRNAs were significant up-regulation, and the expression of 11 miRNAs were significant down-regulation in the nymph of S. avenae treated by imidacloprid in comparison with the control, respectively. The candidate transcript target genes in S. avenae that could be regulated by these miRNAs were also carried out. The functions of the miRNAs, which could potentially regulate the target genes participated in the metabolism, regulatory or detoxification of S. avenae were clarified based on Gene Ontology and KEGG pathway. The effects of the miRNAs identified api-miR-1000, api-miR-316, and api-miR-iab-4 on susceptibility of S. avenae to imidacloprid was determined. The abundance of api-miR-1000, api-miR-316, and api-miR-iab-4 modulated by the addition of their own inhibitors to the artificial diet could change significantly the susceptibility of S. avenae to imidacloprid, which further proved that the regulatory affect of these miRNAs on regulation or metabolism of insecticides. Conclusion: It suggested that differentially expressed microRNAs under the stress of imidacloprid could play critical regulatory role in the resistance of S. avenae to imidacloprid.