CYP427A1-mediated metabolic resistance to buprofezin and imidacloprid in Nilaparvata lugens from southwestern rice regions of China.

BACKGROUND

Nilaparvata lugens migrates into the inland via the southwestern rice regions of China (SWRR). If pest control fails in this gateway region, it would pose a serious threat to inland rice production. However, due to the historical lack of systematic insecticide resistance monitoring in SWRR, high-level resistance to commonly used insecticides in field populations is continuously and uncontrollably developing.

RESULTS

Compared to the Lab-HZ strain, SWRR populations showed significantly higher resistance to buprofezin and imidacloprid. Specifically, the Wangzhou2024 (WZ24) population from Chongqing exhibited a resistance ratio (RR) of 463.21-fold to buprofezin, while the Dehong2024 (DH24) population from Yunnan showed an RR of 758.75-fold to imidacloprid. In these resistant populations, cytochrome P450 monooxygenase (P450) activity increased by 2.5-6.1-fold, and expression of CYP427A1 was up-regulated by 3.8- and 14.4-fold. RNA interference-mediated silencing of CYP427A1 increased mortality of approximately 90% following exposure to buprofezin and imidacloprid. Molecular docking revealed that the binding free energies of CYP427A1 with buprofezin and imidacloprid were -6.1 and -6.3 kcal/mol, respectively, and recombinant CYP427A1 could metabolize both insecticides in vitro.

CONCLUSION

This study provides a systematic assessment of insecticide resistance levels in N. lugens from SWRR and demonstrates that CYP427A1-mediated metabolism as a key contributor to high-level resistance to buprofezin and imidacloprid in the populations examined. © 2026 Society of Chemical Industry.