Key laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China.
Rice Technology Research and Development Center, China National Rice Research Institute, Stadium 359, Hangzhou 310006, China.
J Agric Food Chem. 2024 Jan 24;72(3):1779-1786. doi: 10.1021/acs.jafc.3c02495. Epub 2024 Jan 12.
Four P450s were reported to be important for imidacloprid resistance in , a major insect pest on rice, which was confirmed in this study in an imidacloprid-resistant strain (ImiR). Here we found that only two ( and ) from these four P450 genes were overexpressed in a nitenpyram-resistant strain (NitR) when compared to a susceptible strain (SUS). RNAi reduced nitenpyram and imidacloprid resistance in NitR and ImiR strains, with a greater reduction in nitenpyram resistance. The transcription factor FoxO mediated nitenpyram resistance in NitR and ImiR strains, but it was not differentially expressed among strains. The potential reason for the differential regulation of FoxO on expression was mainly from sequence differences in the promoter between susceptible and resistant insects. In six FoxO response elements predicted in the promoter, the single-nucleotide polymorphisms were frequently detected in over 50% of NitR and ImiR individuals. The luciferase reporter assays showed that two mutations, -650T/G and -2205T/A in two response elements at the positions of -648 and -2200 bp, mainly contributed to the enhanced regulation on expression by FoxO in resistant insects. The frequency was over 69% for both -650T/G and -2205T/A detected in NitR and ImiR individuals but less than 20% in SUS insects. In conclusion, overexpression importantly contributed to nitenpyram resistance in , and two mutations in the promoter of resistant insects led to an enhanced regulation on expression by FoxO.
四种 P450 被报道在 中对吡虫啉的抗性很重要，这是水稻上的一种主要害虫，本研究在吡虫啉抗性菌株（ImiR）中得到了证实。在这里，我们发现，在一种耐吡虫脒菌株（NitR）中，与敏感菌株（SUS）相比，这四个 P450 基因中只有两个（ 和 ）过表达。RNAi 降低了 NitR 和 ImiR 菌株对吡虫脒和吡虫啉的抗性，对吡虫脒抗性的降低更为显著。转录因子 FoxO 介导了 NitR 和 ImiR 菌株对吡虫脒的抗性，但在不同菌株之间没有差异表达。FoxO 对 表达的差异调控的潜在原因主要来自于敏感和抗性昆虫之间 启动子序列的差异。在 启动子中预测的六个 FoxO 反应元件中，在超过 50%的 NitR 和 ImiR 个体中经常检测到单核苷酸多态性。荧光素酶报告基因检测表明，两个突变，-650T/G 和-2205T/A，位于-648 和-2200bp 的两个反应元件的位置，主要导致 FoxO 在抗性昆虫中对 表达的调控增强。这两个突变在 NitR 和 ImiR 个体中的频率均超过 69%，而在 SUS 昆虫中的频率均低于 20%。综上所述， 过表达对 中吡虫脒的抗性很重要，而抗性昆虫 启动子中的两个突变导致 FoxO 对 表达的调控增强。
