Systematic identification and characterization of differentially expressed microRNAs under tetraniliprole exposure in the fall armyworm, Spodoptera frugiperda.

The fall armyworm, Spodoptera frugiperda, is a worldwide agricultural pest and causes huge losses of crop production each year. Tetraniliprole is a novel diamide insecticide with high efficacy against even the insecticide resistant pests of Lepidoptera, Coleoptera, and Diptera. MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression at the posttranscriptional level and play an important regulatory role in the insecticide resistance in insects. However, the effects of miRNAs on the tetraniliprole tolerance in S. frugiperda are poorly understood. In the present research, the miRNAs response to tetraniliprole application in S. frugiperda were systematically investigated by high-throughput sequencing. A total of thirty differentially expressed miRNAs were identified under tetraniliprole treatment in S. frugiperda. The functions of the target genes of these differentially expressed miRNAs were further predicted by Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes database pathway, and the most significantly enriched pathway was MAPK signaling pathway. The expression changes of six differentially expressed miRNAs were validated by quantitative real-time polymerase chain reaction. Furthermore, miR-278-5p had the highest expression in the hemolymph and malpighian tubule and the lowest expression in the gut. Oversupply of miR-278-5p significantly increased the mortality of S. frugiperda following exposure to tetraniliprole. These results will provide the basis for understanding the regulatory roles of miRNAs regarding to tetraniliprole tolerance in S. frugiperda.