FAR knockout significantly inhibits Chilo suppressalis survival and transgene expression of double-stranded FAR in rice exhibits strong pest resistance.

Chilo suppressalis is one of the most prevalent and damaging rice pests, causing significant economic losses each year. Chemical control is currently the primary method of controlling C. suppressalis. However, the indiscriminate use of chemical insecticides increases pest resistance, pollutes the environment and poses a significant health threat to humans and livestock, highlighting the need to find safer, more pest-specific and more effective alternatives to pest control. Plant-mediated RNA interference (RNAi) is a promising agricultural pest control method that is highly pest-specific and has less of an impact on the environment. Using multi-sgRNAs/Cas9 technology to delete Fatty acyl-CoA reductase (FAR) of C. suppressalis in the G0 generation, we show that downregulating FAR transcription may significantly increase the mortality rate and darken the epidermis of C. suppressalis compared with the control. Subsequently, we developed dsFAR transgenic rice lines using Agrobacterium-mediated genetic transformation and then screened three strains expressing dsFAR at high levels using transcriptional level analysis. Using transgenic rice stems, a laboratory feeding bioassay indicated that at least one line (L#10) displayed a particularly high level of insect resistance, with an insect mortality rate of more than 80%. In the field trials, dsFAR transgenic rice displayed high levels of resistance to C. suppressalis damage. Collectively, these results suggest the potential of a new environment-friendly, species-specific strategy for rice pest management.