Shared Midgut Binding Sites for Cry1A.105, Cry1Aa, Cry1Ab, Cry1Ac and Cry1Fa Proteins from Bacillus thuringiensis in Two Important Corn Pests, Ostrinia nubilalis and Spodoptera frugiperda
Open Access
- 5 July 2013
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 8 (7), e68164
- https://doi.org/10.1371/journal.pone.0068164
Abstract
First generation of insect-protected transgenic corn (Bt-corn) was based on the expression of Cry1Ab or Cry1Fa proteins. Currently, the trend is the combination of two or more genes expressing proteins that bind to different targets. In addition to broadening the spectrum of action, this strategy helps to delay the evolution of resistance in exposed insect populations. One of such examples is the combination of Cry1A.105 with Cry1Fa and Cry2Ab to control O. nubilalis and S. frugiperda. Cry1A.105 is a chimeric protein with domains I and II and the C-terminal half of the protein from Cry1Ac, and domain III almost identical to Cry1Fa. The aim of the present study was to determine whether the chimeric Cry1A.105 has shared binding sites either with Cry1A proteins, with Cry1Fa, or with both, in O. nubilalis and in S. frugiperda. Brush-border membrane vesicles (BBMV) from last instar larval midguts were used in competition binding assays with 125I-labeled Cry1A.105, Cry1Ab, and Cry1Fa, and unlabeled Cry1A.105, Cry1Aa, Cry1Ab, Cry1Ac, Cry1Fa, Cry2Ab and Cry2Ae. The results showed that Cry1A.105, Cry1Ab, Cry1Ac and Cry1Fa competed with high affinity for the same binding sites in both insect species. However, Cry2Ab and Cry2Ae did not compete for the binding sites of Cry1 proteins. Therefore, according to our results, the development of cross-resistance among Cry1Ab/Ac, Cry1A.105, and Cry1Fa proteins is possible in these two insect species if the alteration of shared binding sites occurs. Conversely, cross-resistance between these proteins and Cry2A proteins is very unlikely in such case.This publication has 62 references indexed in Scilit:
- Lack of Cry1Fa Binding to the Midgut Brush Border Membrane in a Resistant Colony of Plutella xylostella Moths with a Mutation in the ABCC2 LocusApplied and Environmental Microbiology, 2012
- Specific Binding of Radiolabeled Cry1Fa Insecticidal Protein from Bacillus thuringiensis to Midgut Sites in Lepidopteran SpeciesApplied and Environmental Microbiology, 2012
- Binding Sites for Bacillus thuringiensis Cry2Ae Toxin on Heliothine Brush Border Membrane Vesicles Are Not Shared with Cry1A, Cry1F, or Vip3A ToxinApplied and Environmental Microbiology, 2011
- Interaction of Bacillus thuringiensis Cry1 and Vip3A Proteins with Spodoptera frugiperda Midgut Binding SitesApplied and Environmental Microbiology, 2009
- Specific Binding of Bacillus thuringiensis Cry2A Insecticidal Proteins to a Common Site in the Midgut of Helicoverpa SpeciesApplied and Environmental Microbiology, 2008
- Analyses of Cry1Ab Binding in Resistant and Susceptible Strains of the European Corn Borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae)Applied and Environmental Microbiology, 2006
- Toxicity and Mode of Action of Bacillus thuringiensis Cry Proteins in the Mediterranean Corn Borer, Sesamia nonagrioides (Lefebvre)Applied and Environmental Microbiology, 2006
- Binding analyses of Cry1Ab and Cry1Ac with membrane vesicles from Bacillus thuringiensis-resistant and -susceptible Ostrinia nubilalisBiochemical and Biophysical Research Communications, 2004
- Domain-III Exchanges of Bacillus thuringiensisCryIA Toxins Affect Binding to Different Gypsy Moth Midgut ReceptorsBiochemical and Biophysical Research Communications, 1995
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976