title: Identification of a New cry1I-Type Gene as a Candidate for Gene Pyramiding in Corn To Control Ostrinia Species Larvae.
abstract: Pyramiding of diverse cry toxin genes from Bacillus thuringiensis with different modes of action is a desirable strategy to delay the evolution of resistance in the European corn borer (Ostrinia nubilalis). Considering the dependency of susceptibility to Cry toxins on toxin binding to receptors in the midgut of target pests, a diverse mode of action is commonly defined as recognition of unique binding sites in the target insect. In this study, we present a novel cry1Ie toxin gene (cry1Ie2) as a candidate for pyramiding with Cry1Ab or Cry1Fa in corn to control Ostrinia species larvae. The new toxin gene encodes an 81-kDa protein that is processed to a protease-resistant core form of approximately 55 kDa by trypsin digestion. The purified protoxin displayed high toxicity to Ostrinia furnacalis and O. nubilalis larvae but low to no activity against Spodoptera or heliothine species or the coleopteran Tenebrio molitor. Results of binding assays with (125)I-labeled Cry1Ab toxin and brush border membrane vesicles from O. nubilalis larvae demonstrated that Cry1Ie2 does not recognize the Cry1Ab binding sites in that insect. Reciprocal competition binding assays with biotin-labeled Cry1Ie2 confirmed the lack of shared sites with Cry1Ab or Cry1Fa in O. nubilalis brush border membrane vesicles. These data support Cry1Ie2 as a good candidate for pyramiding with Cry1Ab or Cry1Fa in corn to increase the control of O. nubilalis and reduce the risk of resistance evolution.
authors: College of Plant Science, Jilin University, Changchun, Jilin, China State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
authors: Can
authors: C
authors: Zhao
authors: Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, USA jzhang@ippcaas.cn jurat@utk.edu.
authors: Juan Luis
authors: JL
authors: Jurat-Fuentes
authors: Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, USA.
authors: Heba M
authors: HM
authors: Abdelgaffar
authors: College of Plant Science, Jilin University, Changchun, Jilin, China.
authors: Hongyu
authors: H
authors: Pan
authors: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
authors: Fuping
authors: F
authors: Song
authors: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China jzhang@ippcaas.cn jurat@utk.edu.
authors: Jie
authors: J
authors: Zhang
mesh_terms: D000818:Animals; D001407:Bacillus / Q000235:genetics / Q000378:metabolism*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000633:toxicity*; D001665:Binding Sites; D004731:Endotoxins / Q000737:chemistry / Q000235:genetics / Q000633:toxicity*; D006460:Hemolysin Proteins / Q000737:chemistry / Q000235:genetics / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D007915:Lepidoptera / Q000187:drug effects*; D008970:Molecular Weight; D011485:Protein Binding; D016019:Survival Analysis; D013712:Tenebrio / Q000187:drug effects; D003313:Zea mays / Q000469:parasitology
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis