scholarly journals Cross-resistance and mechanism of resistance to Cry1Ab toxin from Bacillus thuringiensis in a field-derived strain of European corn borer, Ostrinia nubilalis

2011 ◽  
Vol 107 (3) ◽  
pp. 185-192 ◽  
Author(s):  
André L.B. Crespo ◽  
Ana Rodrigo-Simón ◽  
Herbert A.A. Siqueira ◽  
Eliseu J.G. Pereira ◽  
Juan Ferré ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
Cross Resistance ◽  
Corn Borer ◽  
Mechanism Of Resistance ◽  
Cry1ab Toxin

On-plant survival and inheritance of resistance to Cry1Ab toxin from Bacillus thuringiensis in a field-derived strain of European corn borer, Ostrinia nubilalis

2009 ◽  
Vol 65 (10) ◽  
pp. 1071-1081 ◽  
Author(s):  
André LB Crespo ◽  
Terence A Spencer ◽  
Analiza P Alves ◽  
Richard L Hellmich ◽  
Erin E Blankenship ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
Inheritance Of Resistance ◽  
Plant Survival ◽  
Corn Borer ◽  
Cry1ab Toxin

scholarly journals Analyses of Cry1Ab Binding in Resistant and Susceptible Strains of the European Corn Borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae)

2006 ◽  
Vol 72 (8) ◽  
pp. 5318-5324 ◽  
Author(s):  
Herbert A. A. Siqueira ◽  
Joel González-Cabrera ◽  
Juan Ferré ◽  
Ronald Flannagan ◽  
Blair D. Siegfried
Keyword(s):  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
Membrane Vesicles ◽  
Immunoblot Analysis ◽  
Corn Borer ◽  
Toxin Binding ◽  
Real Time Analysis ◽  
Binding Analysis ◽  
Cry1ab Toxin ◽  
Resistant Strains

ABSTRACT Cry1Ab toxin binding analysis was performed to determine whether resistance in laboratory-selected Ostrinia nubilalis strains is associated with target site alteration. Brush border membrane vesicles were prepared using dissected midguts from late instars of susceptible and resistant strains (Europe-R and RSTT) of O. nubilalis. Immunoblot analysis indicated that three different proteins bound to Cry1Ab toxin and were recognized by an anticadherin serum. In a comparison of resistant and susceptible strains, reduced Cry1Ab binding was apparent for all three bands corresponding to cadherin-like proteins in the Europe-R strain, while reduced binding was apparent in only one band for the RSTT strain. Real-time analysis of Cry1Ab binding to gut receptors using surface plasmon resonance suggested slight differences in affinity in both resistant strains. Additional binding analysis was conducted using 125I-labeled Cry1Ab, Cry1Ac, and Cry1Aa. Slight differences were again observed between the resistant and susceptible strains for Cry1Ab binding. However, when binding of 125I-labeled Cry1Aa was tested, a 10-fold reduction in the concentration of binding sites was observed in the Europe-R strain. Expression of the O. nubilalis cadherin gene was similar in both the resistant and susceptible strains and did not account for differences in binding. In combination, the results of the present work suggest that differences in susceptibility to Cry1A toxins in the Europe-R strain of O. nubilalis are associated with altered receptor binding, although the precise nature of this mechanism is still uncertain.

Survival of Ostrinia nubilalis (Hübner) After Exposure to Bacillus thuringiensis Berliner Encapsulated in Flour Matrices2

1994 ◽  
Vol 29 (4) ◽  
pp. 496-508 ◽  
Author(s):  
Michael R. McGuire ◽  
Robert L. Gillespie ◽  
Baruch S. Shasha
Keyword(s):  
Bacillus Thuringiensis ◽  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
Significant Loss ◽  
The Other ◽  
Field Site ◽  
Corn Flour ◽  
Corn Borer ◽  
Natural Infestation ◽  
Corn Plants

Two types of pregelatinized corn flour were used to produce granules containing Bacillus thuringiensis Berliner subsp. kurstaki and various additives for control of the European corn borer, Ostrinia nubilalis (Hübner), in the whorl of corn plants. Laboratory-reared larvae were applied to corn whorls in the greenhouse and field, and a high natural infestation occurred at one field site (Champaign). In the greenhouse and at all three field sites, five of these formulations were just as effective as Dipel 10G, a commercially available B. thuringiensis product, for control of European corn borer larvae. In all greenhouse studies and at one of the three field sites (Champaign), the dose of B. thuringiensis could be reduced by as much as 75% when a phagostimulant was added to flour granules without significant loss of corn borer control. The phagostimulant dose response was not observed at the other two field sites in which larval infestations were relatively low. Flour type had no significant effect on European corn borer control under greenhouse and field conditions. Greenhouse evaluations provided results significantly similar to results from two of the field sites indicating the usefulness of the technique. The data presented highlight the versatility and potential for using novel formulation techniques for enhancing the efficacy of B. thuringiensis.

scholarly journals Characterization of Chimeric Bacillus thuringiensis Vip3 Toxins

2006 ◽  
Vol 73 (3) ◽  
pp. 956-961 ◽  
Author(s):  
Jun Fang ◽  
Xiaoli Xu ◽  
Ping Wang ◽  
Jian-Zhou Zhao ◽  
Anthony M. Shelton ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Trichoplusia Ni ◽  
European Corn Borer ◽  
Insect Pest ◽  
Chimeric Protein ◽  
Fall Armyworm ◽  
Terminal Region ◽  
Cabbage Looper ◽  
Cross Resistance ◽  
Corn Borer

ABSTRACT Bacillus thuringiensis vegetative insecticidal proteins (Vip) are potential alternatives for B. thuringiensis endotoxins that are currently utilized in commercial transgenic insect-resistant crops. Screening a large number of B. thuringiensis isolates resulted in the cloning of vip3Ac1. Vip3Ac1 showed high insecticidal activity against the fall armyworm Spodoptera frugiperda and the cotton bollworm Helicoverpa zea but very low activity against the silkworm Bombyx mori. The host specificity of this Vip3 toxin was altered by sequence swapping with a previously identified toxin, Vip3Aa1. While both Vip3Aa1 and Vip3Ac1 showed no detectable toxicity against the European corn borer Ostrinia nubilalis, the chimeric protein Vip3AcAa, consisting of the N-terminal region of Vip3Ac1 and the C-terminal region of Vip3Aa1, became insecticidal to the European corn borer. In addition, the chimeric Vip3AcAa had increased toxicity to the fall armyworm. Furthermore, both Vip3Ac1 and Vip3AcAa are highly insecticidal to a strain of cabbage looper (Trichoplusia ni) that is highly resistant to the B. thuringiensis endotoxin Cry1Ac, thus experimentally showing for the first time the lack of cross-resistance between B. thuringiensis Cry1A proteins and Vip3A toxins. The results in this study demonstrated that vip3Ac1 and its chimeric vip3 genes can be excellent candidates for engineering a new generation of transgenic plants for insect pest control.

Enhancement of Activity of Bacillus thuringiensis Berliner Against Four Lepidopterous Insect Pests by Nutrient-Based Phagostimulants1

1995 ◽  
Vol 30 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Robert R. Farrar ◽  
Richard L. Ridgway
Keyword(s):  
Bacillus Thuringiensis ◽  
Ostrinia Nubilalis ◽  
Helicoverpa Zea ◽  
European Corn Borer ◽  
Insect Pests ◽  
Diamondback Moth ◽  
Lethal Dose ◽  
Corn Earworm ◽  
Corn Borer ◽  
Whole Plants

To help improve control of insect pests with microbial insecticides, we investigated the interactions of four commercial, nutrient-based phagostimulants (Pheast [AgriSense], Coax [CCT Corp.], Gusto [Atochem North America, Inc.], and Entice [Custom Chemicides] with Bacillus thuringiensis Berliner and four lepidopterous insect pests (gypsy moth, Lymantria dispar [L.] [Lymantriidae]; corn earworm, Helicoverpa zea [Boddie] [Noctuidae]; European corn borer, Ostrinia nubilalis [Hübner] [Pyralidae]; and diamondback moth, Plutella xylostella [L.] [Plutellidae]). Comparisons were made of treated foliage in Petri dishes in the laboratory and of sprayed whole plants in a greenhouse. In general, phagostimulants increased mortality of all species tested, but no consistent differences among phagostimulants were found for any species. Food consumption was generally lower on the treatments that contained phagostimulants causing the highest rates of mortality, possibly as a result of more rapid ingestion of a lethal dose on these treatments. Reduced rates of feeding by insects on treatments with B. thuringiensis alone were seen, probably due in part to intoxication and, possibly, to behavioral effects as well. Indications of potentially significant interactions between host plants and both B. thuringiensis and phagostimulants also were seen.

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