title: Knockdown of the MAPK p38 pathway increases the susceptibility of Chilo suppressalis larvae to Bacillus thuringiensis Cry1Ca toxin.
abstract: 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.
authors.affiliation: 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.
authors.forename: Lin
authors.initials: L
authors.lastname: Qiu
authors.affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Fan
authors.affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Lang
authors.initials: L
authors.lastname: Liu
authors.affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Boyao
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Wang
authors.affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Chaoliang
authors.initials: C
authors.lastname: Lei
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Wuhan, China.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Lin
authors.affiliation: 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.
authors.forename: Weihua
authors.initials: W
authors.lastname: Ma
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000633:toxicity*; D003001:Cloning, Molecular; D004731:Endotoxins / Q000633:toxicity*; D020869:Gene Expression Profiling; D055785:Gene Knockdown Techniques; D006460:Hemolysin Proteins / Q000633:toxicity*; D007814:Larva / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D007915:Lepidoptera / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D048670:MAP Kinase Kinase 4 / Q000037:antagonists & inhibitors / Q000235:genetics; D020935:MAP Kinase Signaling System; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000235:genetics; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000235:genetics; D034622:RNA Interference; D016019:Survival Analysis; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4