Wang Xingliang, Yue Yujin, Zhai Yuqian, Wang Falong, Zhuang Xuna, Wu Shuwen, Yang Yihua, Tabashnik Bruce E, Wu Yidong
State Key Laboratory of Agricultural and Forestry Biosecurity, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
Department of Entomology, University of Arizona, Tucson, AZ.
Proc Natl Acad Sci U S A. 2025 Apr 22;122(16):e2503674122. doi: 10.1073/pnas.2503674122. Epub 2025 Apr 17.
Crops genetically engineered to produce insecticidal proteins from the bacterium (Bt) have been used extensively to control some major crop pests, but their benefits decrease when pests evolve resistance. Better understanding of the genetic basis of resistance is needed to effectively monitor, manage, and counter pest resistance to Bt crops. Resistance to Bt proteins in at least 11 species of Lepidoptera, including many important crop pests, is associated with naturally occurring mutations that disrupt one or more of three larval midgut proteins: cadherin and ATP-binding cassette proteins ABCC2 and ABCC3. Here, we determined how CRISPR/Cas9-mediated mutations disrupting cadherin, ABCC2, and ABCC3 singly and in pairs affect resistance to Bt proteins Cry1Ab and Cry1Fa in the Asian corn borer (), which is the most damaging pest of corn in Asia and is closely related to the European corn borer (), a major pest in Europe and North America. The results from bioassays of six knockout strains and their parent susceptible strain support a model in which Cry1Ab can kill larvae via one path requiring ABCC2 or another path requiring cadherin and ABCC3, whereas Cry1Fa uses only the first path. The model's predictions are generally supported by results from genetic linkage analyses and responses to Cry1Ab and Cry1Fa of Sf9 cells and oocytes modified to produce cadherin, ABCC2, and ABCC3 singly or in pairs. The functional redundancy identified here for Cry1Ab could sustain its efficacy against and may exemplify a widespread natural strategy for delaying resistance.
经过基因工程改造以产生来自苏云金芽孢杆菌（Bt）杀虫蛋白的作物已被广泛用于控制一些主要的作物害虫，但当害虫进化出抗性时，其益处就会降低。为了有效地监测、管理和应对害虫对Bt作物的抗性，需要更好地了解抗性的遗传基础。至少11种鳞翅目昆虫对Bt蛋白产生抗性，其中包括许多重要的作物害虫，这种抗性与自然发生的突变有关，这些突变会破坏三种幼虫中肠蛋白中的一种或多种：钙黏蛋白以及ATP结合盒蛋白ABCC2和ABCC3。在这里，我们确定了CRISPR/Cas9介导的分别破坏钙黏蛋白、ABCC2和ABCC3以及成对破坏它们的突变如何影响亚洲玉米螟对Bt蛋白Cry1Ab和Cry1Fa的抗性。亚洲玉米螟是亚洲玉米最具破坏力的害虫，与欧洲玉米螟密切相关，而欧洲玉米螟是欧洲和北美的主要害虫。对六个基因敲除品系及其亲本敏感品系的生物测定结果支持了一个模型，即Cry1Ab可以通过一条需要ABCC2的途径或另一条需要钙黏蛋白和ABCC3的途径杀死幼虫，而Cry1Fa仅使用第一条途径。该模型的预测通常得到遗传连锁分析结果以及对单独或成对产生钙黏蛋白、ABCC2和ABCC3的Sf9细胞和卵母细胞对Cry1Ab和Cry1Fa反应的支持。此处确定的Cry1Ab的功能冗余可以维持其对亚洲玉米螟的效力，并且可能是一种广泛存在的延缓抗性的自然策略的例证。
