State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
Pestic Biochem Physiol. 2022 Jun;184:105119. doi: 10.1016/j.pestbp.2022.105119. Epub 2022 May 14.
Chilo suppressalis is a major target pest of transgenic rice expressing the Bacillus thuringiensis (Bt) Cry1C toxin in China. The evolution of resistance of this pest is a major threat to Bt rice. Since Bt functions by binding to receptors in the midgut (MG) of target insects, identification of Bt functional receptors in C. suppressalis is crucial for evaluating potential resistance mechanisms and developing effective management strategies. ATP-binding cassette (ABC) transporters have been vastly reported to interact with Cry1A toxins, as receptors and their mutations cause insect Bt resistance. However, the role of ABC transporters in Cry1C resistance to C. suppressalis remains unknown. Here, we measured CsABCC2 expression in C. suppressalis Cry1C-resistant (Cry1C-R) and Cry1C-susceptible strains (selected in the laboratory) via quantitative real-time PCR (qRT-PCR); the transcript level of CsABCC2 in the Cry1C-R strain was significantly lower than that in the Cry1C-susceptible strain. Furthermore, silencing CsABCC2 in C. suppressalis via RNA interference (RNAi) significantly decreased Cry1C susceptibility. Overall, CsABCC2 participates in Cry1C mode of action, and reduced expression of CsABCC2 is functionally associated with Cry1C resistance in C. suppressalis.
二化螟是中国转 Bt 水稻的主要靶标害虫。该害虫对 Bt 水稻的抗性进化是对 Bt 水稻的主要威胁。由于 Bt 通过与靶标昆虫中肠 (MG) 中的受体结合发挥作用，因此鉴定 C. suppressalis 中的 Bt 功能受体对于评估潜在的抗性机制和制定有效的管理策略至关重要。已有大量报道表明，ATP 结合盒 (ABC) 转运蛋白作为受体与其突变可导致昆虫对 Cry1A 毒素产生抗性。然而，ABC 转运蛋白在 C. suppressalis 对 Cry1C 的抗性中的作用尚不清楚。在这里，我们通过定量实时 PCR (qRT-PCR) 测量了二化螟 Cry1C 抗性 (Cry1C-R) 和 Cry1C 敏感品系 (在实验室中选择) 中 CsABCC2 的表达;Cry1C-R 菌株中 CsABCC2 的转录水平明显低于 Cry1C 敏感菌株。此外，通过 RNA 干扰 (RNAi) 沉默 C. suppressalis 中的 CsABCC2 显著降低了 Cry1C 的敏感性。总的来说，CsABCC2 参与了 Cry1C 的作用模式，CsABCC2 的表达降低与 C. suppressalis 对 Cry1C 的抗性在功能上有关。
