The effect of Bacillus thuringiensis toxin Cry1Ac on the behaviour of a laboratory-selected resistant population (72-fold) of Helicoverpa armigera on Bt-cotton was evaluated. Compared with non-Bt-cotton and Cry1Ac toxin incorporated in semi-synthetic diet, resistant larvae reared on Bt-cotton had only 0.13% survival and slower development. The results suggest that Cry1Ac from Bt-cotton exerts a...

*Correspondence: Md. Mozammel Hoq, Laboratory215, Department of Microbiology, University of Dhaka, Dhaka1000, Bangladesh e-mail: [email protected] Bacillus thuringiensis (Bt) biopesticides, a recognized eco-friendly pest control agent, can be used to reduce many problems associated with indiscriminate use of chemical pesticides such as environmental pollutions, public health problems, emergence ...

The members of the Bacillus thuringiensis group, commonly known as Bt, produce a huge number of metabolites, which show biocidal and antagonistic activity. B. thuringiensis is widely known for synthesizing Cry, Vip and Cyt proteins, active against insects and other parasporins with biocidal activity against certain types of cancerous cells. Nevertheless, B. thuringiensis also synthesizes compou...

Which genes have been incorporated into the Marucaresistant cowpea? The Maruca-resistant cowpea contains the cry1Ab (Bt) and nptII genes. The Bt gene was derived from the soil bacterium Bacillus thuringiensis subsp. kurstaki. The Bt protein produced in modified cowpea plants has been shown to be identical to the naturally occurring protein, and equivalent to the protein used as a biopesticide b...

Insecticidal cry and vip genes from Bacillus thuringiensis (Bt) have been used for control of lepidopteran insects in transgenic crops. However, novel genes are required for gene pyramiding to delay evolution of resistance to the currently deployed genes. Two PCR-based techniques were employed for screening of cry2-type genes in 129 Bt isolates from diverse habitats in India and 27 known Bt str...

Chitinase plays a positive role in the pathogenicity of Bacillus thuringiensis to insect pests. We used touchdown PCR to clone the chitinase (Schi) gene from Bacillus thuringiensis serovar sotto (Bt sotto) chromosomal DNA. Our DNA sequencing analysis revealed that the Bt sotto Schi gene consists of an open reading frame (ORF) of 2067 nucleotides with codes for the chitinase precursor. We also f...

Bt maize technology involves developing hybrid maize crops that incorporate genes developed from the soil dwelling bacteria Bacillus thuringiensis (Bt). The primary benefit of Bt maize technology is the heightened crop protection from stem borers, which are maize pests that can inflict serious crop losses. Bt maize has been grown in Mexico, South Africa and several countries in the EU, with mor...

The bacterium Bacillus thuringiensis widely used as bio-pesticide. The specific toxic activity to insects and another microbe(s) regarding the existing of crystals that have different morphologies, sizes, numbers and compositions, as Bt strains the crystals have more different proteins, which contain encoded Cry distinct genes. In this work we isolated 334 colonies from 59 soil samples in 13 lo...

Although scores of experiments have examined the ecological consequences of transgenic Bacillus thuringiensis (Bt) crops, debates continue regarding the nontarget impacts of this technology. Quantitative reviews of existing studies are crucial for better gauging risks and improving future risk assessments. To encourage evidence-based risk analyses, we constructed a searchable database for nonta...

This document reviews the safety assessment for Bacillus thuringiensis (Bt) delta-endotoxin proteins that have been introduced into agricultural crops to provide protection against insect pests. Information is provided on the scientific basis for U.S. EPA approvals for the introduction of Bt proteins into agricultural crops. Relevant to these approvals is the extensive data base on Bt protein s...