Development of an immunochromatographic assay for the specific detection of Bacillus thuringiensis (Bt) Cry1Ab toxin

2019 ◽  
Vol 567 ◽  
pp. 1-7 ◽  
Author(s):  
Sa Dong ◽  
Yuan Liu ◽  
Xiao Zhang ◽  
Chongxin Xu ◽  
Xianjin Liu ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Immunochromatographic Assay ◽  
Specific Detection ◽  
Cry1ab Toxin

scholarly journals No Evidence of an Impact on the Rhizosphere Diazotroph Community by the Expression of Bacillus thuringiensis Cry1Ab Toxin by Bt White Spruce

2007 ◽  
Vol 73 (20) ◽  
pp. 6577-6583 ◽  
Author(s):  
Josyanne Lamarche ◽  
Richard C. Hamelin
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacterial Communities ◽  
White Spruce ◽  
Sequencing Analysis ◽  
Nitrogen Fixing ◽  
Cloning And Sequencing ◽  
Insecticidal Toxin ◽  
Soil Bacterial Communities ◽  
Cry1ab Toxin ◽  
Natural Stands

ABSTRACT Nitrogen fixation is one of the most important roles played by soil bacterial communities, as fixation supplies nitrogen to many ecosystems which are often N limited. As impacts on this functional group of bacteria might harm the ecosystem's health and reduce productivity, monitoring that particular group is important. Recently, a field trial with Bt white spruce, which constitutively expresses the Cry1Ab insecticidal toxin of Bacillus thuringiensis, was established. The Bt white spruce was shown to be resistant to spruce budworm. We investigated the possible impact of these genetically modified trees on soil nitrogen-fixing bacterial communities. The trial consisted of untransformed controls, GUS white spruce (transformed with the β-glucuronidase gene), and Bt/GUS white spruce (which constitutively expresses both the Cry1Ab toxin and β-glucuronidase) in a random design. Four years after planting, soil samples from the control and the two treatments from plantation as well as from two natural stands of white spruce were collected. Diazotroph diversity was assessed by extracting soil genomic DNA and amplifying a region of the nitrogenase reductase (nifH) gene, followed by cloning and sequencing. Analysis revealed that nitrogen-fixing communities did not differ significantly among the untransformed control, GUS white spruce, and Bt/GUS white spruce. Nevertheless, differences in diazotroph diversity were observed between white spruce trees from the plantation site and those from two natural stands, one of which grew only a few meters away from the plantation. We therefore conclude, in the absence of evidence that the presence of the B. thuringiensis cry1Ab gene had an effect on diazotroph communities, that either site and/or field preparation prior to planting seems to be more important in determining diazotroph community structure than the presence of Bt white spruce.

scholarly journals Rearrangement of N-Terminal α-Helices of Bacillus thuringiensis Cry1Ab Toxin Essential for Oligomer Assembly and Toxicity

Toxins ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 647
Author(s):  
Sabino Pacheco ◽  
Jean Piere Jesus Quiliche ◽  
Isabel Gómez ◽  
Jorge Sánchez ◽  
Mario Soberón ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Conformational Changes ◽  
Membrane Integrity ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Membrane Vesicles ◽  
Insect Midgut ◽  
Cry Proteins ◽  
Cry1ab Toxin ◽  
Domain I

Cry proteins produced by Bacillus thuringiensis are pore-forming toxins that disrupt the membrane integrity of insect midgut cells. The structure of such pore is unknown, but it has been shown that domain I is responsible for oligomerization, membrane insertion and pore formation activity. Specifically, it was proposed that some N-terminal α-helices are lost, leading to conformational changes that trigger oligomerization. We designed a series of mutants to further analyze the molecular rearrangements at the N-terminal region of Cry1Ab toxin that lead to oligomer assembly. For this purpose, we introduced Cys residues at specific positions within α-helices of domain I for their specific labeling with extrinsic fluorophores to perform Föster resonance energy transfer analysis to fluorescent labeled Lys residues located in Domains II–III, or for disulfide bridges formation to restrict mobility of conformational changes. Our data support that helix α-1 of domain I is cleaved out and swings away from the toxin core upon binding with Manduca sexta brush border membrane vesicles. That movement of helix α-2b is also required for the conformational changes involved in oligomerization. These observations are consistent with a model proposing that helices α-2b and α-3 form an extended helix α-3 necessary for oligomer assembly of Cry toxins.

Southern analysis of BT-R 1, the Manduca sexta gene encoding the receptor for the Cry1Ab toxin of Bacillus thuringiensis

1997 ◽  
Vol 256 (5) ◽  
pp. 517-524 ◽  
Author(s):  
S. E. Franklin ◽  
L. Young ◽  
D. Watson ◽  
A. Cigan ◽  
T. Meyer ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Manduca Sexta ◽  
Southern Analysis ◽  
Gene Encoding ◽  
Cry1ab Toxin

scholarly journals The pre-pore from Bacillus thuringiensis Cry1Ab toxin is necessary to induce insect death in Manduca sexta

Peptides ◽  
2008 ◽  
Vol 29 (2) ◽  
pp. 318-323 ◽  
Author(s):  
N. Jiménez-Juárez ◽  
C. Muñoz-Garay ◽  
I. Gómez ◽  
S.S. Gill ◽  
M. Soberón ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Manduca Sexta ◽  
Cry1ab Toxin

Nitric oxide participates in the toxicity of Bacillus thuringiensis Cry1Ab toxin to kill Manduca sexta larvae

Peptides ◽  
2015 ◽  
Vol 68 ◽  
pp. 134-139 ◽  
Author(s):  
Carolina Chavez ◽  
Benito Recio-Tótoro ◽  
Biviana Flores-Escobar ◽  
Humberto Lanz-Mendoza ◽  
Jorge Sanchez ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Bacillus Thuringiensis ◽  
Manduca Sexta ◽  
Cry1ab Toxin ◽  
Manduca Sexta Larvae
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