Applied and Environmental Microbiology (2015) 81, 3699-3705

Can Zhao, Juan Luis Jurat-Fuentes, Heba M. Abdelgaffar, Hongyu Pan, Fuping Song and Jie Zhang (2015)
Identification of a new cry1I-type gene as a candidate for gene pyramiding in corn to control Ostrinia species larvae
Applied and Environmental Microbiology 81 (11), 3699-3705
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 ¹²⁵I-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.
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Link to article at publishers website
Database assignments for author(s): Jie Zhang, Juan L. Jurat-Fuentes, Hongyu Pan

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ostrinia nubilalis	Maize/corn (Zea mays)
	Ostrinia furnacalis	Maize/corn (Zea mays)
Bacillus thuringiensis Cry1I-toxin (entomopathogen)	Ostrinia nubilalis	Maize/corn (Zea mays)
Bacillus thuringiensis Cry1I-toxin (entomopathogen)	Ostrinia furnacalis	Maize/corn (Zea mays)