Osa-miR162a Enhances the Resistance to the Brown Planthopper via α-Linolenic Acid Metabolism in Rice (Oryza sativa)

The brown planthopper (BPH) is the most serious pestcausing yieldlosses in rice. MicroRNAs (miRNAs) are emerging as key modulatorsof plant-pest interactions. In the study, we found that osa-miR162ais induced in response to BPH attack in the seedling stage and tunesrice resistance to the BPH via the & alpha;-linolenic acid metabolismpathway as indicated by gas chromatography/liquid chromatography-massspectrometry analysis. Overexpression of osa-miR162a inhibited thedevelopment and growth of the BPH and simultaneously reduced the releaseof 3-hexenal and 3-hexen-1-ol to block host recognition in the BPH.Moreover, knockdown of OsDCL1, which is targetedby osa-miR162a, inhibited & alpha;-linolenic acid metabolism to enhancethe resistance to the BPH, which was similar to that in miR162a-overexpressingplants. Our study revealed a novel defense mechanism mediated by plantmiRNAs developed during the long-term evolution of plant-hostinteraction, provided new ideas for the identification of rice resistanceresources, and promoted a better understanding of pest control.

Automated summary

In this study, it was found that osa-miR162a is induced in response to BPH attack in rice. This miRNA regulates rice resistance to the BPH by affecting the alpha-linolenic acid metabolism pathway. Overexpression of osa-miR162a inhibits the development and growth of BPH, while knockdown of the target gene OsDCL1 enhances resistance to the pest. This study reveals a novel defense mechanism mediated by plant miRNAs and provides new insights into pest control.