National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Wuhan, China.
Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
Sci Rep. 2017 Mar 6;7:43964. doi: 10.1038/srep43964.
The bacterium Bacillus thuringiensis (Bt) produces a wide range of toxins that are effective against a number of insect pests. Identifying the mechanisms responsible for resistance to Bt toxin will improve both our ability to control important insect pests and our understanding of bacterial toxicology. In this study, we investigated the role of MAPK pathways in resistance against Cry1Ca toxin in Chilo suppressalis, an important lepidopteran pest of rice crops. We first cloned the full-length of C. suppressalis mitogen-activated protein kinase (MAPK) p38, ERK1, and ERK2, and a partial sequence of JNK (hereafter Csp38, CsERK1, CsERK2 and CsJNK). We could then measure the up-regulation of these MAPK genes in larvae at different times after ingestion of Cry1Ca toxin. Using RNA interference to knockdown Csp38, CsJNK, CsERK1 and CsERK2 showed that only knockdown of Csp38 significantly increased the mortality of larvae to Cry1Ca toxin ingested in either an artificial diet, or after feeding on transgenic rice expressed Cry1Ca. These results suggest that MAPK p38 is responsible for the resistance of C. suppressalis larvae to Bt Cry1Ca toxin.
苏云金芽孢杆菌（Bt）产生的一系列毒素对多种害虫都有防治效果。明确导致对 Bt 毒素产生抗性的机制将提高我们控制重要害虫的能力，并加深我们对细菌毒理学的理解。在这项研究中，我们调查了 MAPK 途径在斜纹夜蛾对 Cry1Ca 毒素抗性中的作用，斜纹夜蛾是水稻作物的一种重要鳞翅目害虫。我们首先克隆了斜纹夜蛾丝裂原活化蛋白激酶（MAPK）p38、ERK1 和 ERK2 的全长，以及 JNK 的部分序列（以下简称 Csp38、CsERK1、CsERK2 和 CsJNK）。然后，我们可以测量这些 MAPK 基因在幼虫摄入 Cry1Ca 毒素后不同时间的上调情况。利用 RNA 干扰技术敲低 Csp38、CsJNK、CsERK1 和 CsERK2 后，只有敲低 Csp38 显著增加了幼虫对在人工饲料中或在转 Cry1Ca 水稻上取食后摄入的 Cry1Ca 毒素的死亡率。这些结果表明，MAPK p38 负责斜纹夜蛾幼虫对 Bt Cry1Ca 毒素的抗性。
