MiRNAs regulated overexpression of ryanodine receptor is involved in chlorantraniliprole resistance in Plutella xylostella (L.).

Xiuxia Li,Xiwu Gao,Lei Guo,Pei Liang,Xuguo Zhou

doi:10.1038/srep14095

Abstract

The amino acid mutations in ryanodine receptor (RyR) and elevated activity of detoxification enzymes have been associated with the diamide insecticide resistance in the diamondback moth, Plutella xylostella (L.). The up-regulation of P. xylostella RyR mRNA (PxRyR) expression has also been reported in field populations of different graphical origin. However, whether the up-regulation of PxRyR is involved in diamide resistance remains unknown. In this paper, 2.28- to 4.14-fold higher expression of PxRyR was detected in five field collected resistant populations, compared to that in a susceptible population. The expression of PxRyR was up-regulated 5.0- and 7.2-fold, respectively, after P. xylostella was treated with LC50 and LC75 of chlorantraniliprole for 12 h. Suppression of PxRyR using RNA interference restored the toxicity of chlorantraniliprole against the fourth instar larvae from the resistant population. More importantly, the expression of PxRyR is regulated by two miRNAs, miR-7a and miR-8519. These findings provide an empirical evidence of the involvement of miRNAs in the regulation of insecticide resistance, and shed light on the novel targets for the sustainable management of this devastating insect pest.

Highlights

MicroRNAs, a group of non-coding RNAs, 19–24 nt in length, modulate many biological processes, including development, metabolism, behavior and metamorphosis[16,17,18], through post-transcriptional regulation either by degrading mRNA or blocking its translation[19,20]
Without exposure to any insecticide for two consecutive generations, PxRyR expression decreased by 48% (PY-F3-Un, Fig. 1C)
Target mutations and metabolism mediated insecticide resistance have been extensively studied in diamide insecticides resistant in P. xylostella[4,10,11,12,13,26], while whether the changes of PxRyR expression is involved in resistance remains poorly understood

Summary

Introduction

MicroRNAs (miRNAs), a group of non-coding RNAs, 19–24 nt in length, modulate many biological processes, including development, metabolism, behavior and metamorphosis[16,17,18], through post-transcriptional regulation either by degrading mRNA or blocking its translation[19,20]. As the target of diacylhydrazines insecticides, the expression of ecodysone receptor (EcR) is regulated by miRNA-281 in the silkworm, Bombyx mori[21]. MiRNAs have been surveyed in P. xylostella[22,23], none of them have been associated with the regulation of PxRyR expression. We demonstrated that the overexpression of PxRyR mRNA is involved in chlorantraniliprole resistance in P. xylostella. The expression of PxRyR is regulated by two miRNAs, miR-7a and miR-8519. These findings provide an empirical evidence of the involvement of miRNAs in the regulation of insecticide resistance, and shed light on the novel targets for the sustainable management of this devastating insect pest

Methods

Results

Discussion

Conclusion