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Different mechanisms of resistance to Bacillus thuringiensis toxins in the indianmeal moth.
Appl Environ Microbiol. 2001 Mar; 67(3):1085-9.AE

Abstract

Susceptibility to protoxin and toxin forms of Cry1Ab and the binding of (125)I-labeled Cry1Ab and Cry1Ac has been examined in three Plodia interpunctella colonies, one susceptible (688(s)) and two resistant (198(r) and Dpl(r)) to Bacillus thuringiensis. Toxicological studies showed that the 198(r) colony was 11-fold more resistant to Cry1Ab protoxin than to Cry1Ab activated toxin, whereas the Dpl(r) colony was 4-fold more resistant to protoxin versus toxin. Binding results with (125)I-labeled toxins indicated the occurrence of two different binding sites for Cry1Ab in the susceptible insects, one of them shared with Cry1Ac. Cry1Ab binding was found to be altered in insects from both resistant colonies, though in different ways. Compared with the susceptible colony, insects from the Dpl(r) colony showed a drastic reduction in binding affinity (60-fold higher K(d)), although they had similar concentrations of binding sites. Insects from the 198(r) colony showed a slight reduction in both binding affinity and binding site concentration (five-fold-higher K(d) and ca. three-fold-lower R(t) compared with the 688(s) colony). No major difference in Cry1Ac binding was found among the three colonies. The fact that the 198(r) colony also has a protease-mediated mechanism of resistance (B. Oppert, R. Hammel, J. E. Throne, and K. J. Kramer, J. Biol. Chem. 272:23473-23476, 1997) is in agreement with our toxicological data in which this colony has a different susceptibility to the protoxin and toxin forms of Cry1Ab. It is noteworthy that the three colonies used in this work derived originally from ca. 100 insects, which reflects the high variability and high frequency of B. thuringiensis resistance genes occurring in natural populations.

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Authors+Show Affiliations

Herrero S
Department of Genetics, University of Valencia, 46100-Burjassot (Valencia), Spain.
Oppert B
No affiliation info available
Ferré J
No affiliation info available

MeSH

AnimalsBacillus thuringiensisBacillus thuringiensis ToxinsBacterial ProteinsBacterial ToxinsBinding, CompetitiveEndotoxinsHemolysin ProteinsInsecticide ResistanceInsecticidesLarvaMicrovilliMothsProtein Precursors

Pub Type(s)

Journal Article

Language

eng

PubMed ID

11229895

Citation

Herrero, S, et al. "Different Mechanisms of Resistance to Bacillus Thuringiensis Toxins in the Indianmeal Moth." Applied and Environmental Microbiology, vol. 67, no. 3, 2001, pp. 1085-9.
Herrero S, Oppert B, Ferré J. Different mechanisms of resistance to Bacillus thuringiensis toxins in the indianmeal moth. Appl Environ Microbiol. 2001;67(3):1085-9.
Herrero, S., Oppert, B., & Ferré, J. (2001). Different mechanisms of resistance to Bacillus thuringiensis toxins in the indianmeal moth. Applied and Environmental Microbiology, 67(3), 1085-9.
Herrero S, Oppert B, Ferré J. Different Mechanisms of Resistance to Bacillus Thuringiensis Toxins in the Indianmeal Moth. Appl Environ Microbiol. 2001;67(3):1085-9. PubMed PMID: 11229895.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Different mechanisms of resistance to Bacillus thuringiensis toxins in the indianmeal moth. AU - Herrero,S, AU - Oppert,B, AU - Ferré,J, PY - 2001/3/7/pubmed PY - 2001/9/8/medline PY - 2001/3/7/entrez SP - 1085 EP - 9 JF - Applied and environmental microbiology JO - Appl Environ Microbiol VL - 67 IS - 3 N2 - Susceptibility to protoxin and toxin forms of Cry1Ab and the binding of (125)I-labeled Cry1Ab and Cry1Ac has been examined in three Plodia interpunctella colonies, one susceptible (688(s)) and two resistant (198(r) and Dpl(r)) to Bacillus thuringiensis. Toxicological studies showed that the 198(r) colony was 11-fold more resistant to Cry1Ab protoxin than to Cry1Ab activated toxin, whereas the Dpl(r) colony was 4-fold more resistant to protoxin versus toxin. Binding results with (125)I-labeled toxins indicated the occurrence of two different binding sites for Cry1Ab in the susceptible insects, one of them shared with Cry1Ac. Cry1Ab binding was found to be altered in insects from both resistant colonies, though in different ways. Compared with the susceptible colony, insects from the Dpl(r) colony showed a drastic reduction in binding affinity (60-fold higher K(d)), although they had similar concentrations of binding sites. Insects from the 198(r) colony showed a slight reduction in both binding affinity and binding site concentration (five-fold-higher K(d) and ca. three-fold-lower R(t) compared with the 688(s) colony). No major difference in Cry1Ac binding was found among the three colonies. The fact that the 198(r) colony also has a protease-mediated mechanism of resistance (B. Oppert, R. Hammel, J. E. Throne, and K. J. Kramer, J. Biol. Chem. 272:23473-23476, 1997) is in agreement with our toxicological data in which this colony has a different susceptibility to the protoxin and toxin forms of Cry1Ab. It is noteworthy that the three colonies used in this work derived originally from ca. 100 insects, which reflects the high variability and high frequency of B. thuringiensis resistance genes occurring in natural populations. SN - 0099-2240 UR - https://www.unboundmedicine.com/medline/citation/11229895/Different_mechanisms_of_resistance_to_Bacillus_thuringiensis_toxins_in_the_indianmeal_moth_ DB - PRIME DP - Unbound Medicine ER -
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