Two populations of Trichoplusia ni that had developed resistance to Bacillus thuringiensis sprays (Bt sprays) in commercial greenhouse vegetable production were tested for resistance to Bt cotton (BollGard II) plants expressing pyramided Cry1Ac and Cry2Ab. The T. ni colonies resistant to Bacillus thuringiensis serovar kurstaki formulations were not only resistant to the Bt toxin Cry1Ac, as prev...

The influence of L-serine on the growth of different strains of the genus Bacillus was investigated. It has been observed that the addition of L-serine to minimal synthetic media results in an inhibition in the growth of certain strains of Bacillus spp. but not B. thuringiensis. Then L-serine-resistance phenomenon was used in isolation of B. thuringiensis strains from soil. An isolation method ...

On June 19, 2003, the Center for Science in the Public Interest (CSPI) issued “Planting Trouble: Are Farmers Squandering Bt Corn Technology?” That report presented data from the United States Department of Agriculture (USDA) that found significant noncompliance by farmers in Iowa (IA), Minnesota (MN) and Nebraska (NE) with the Environmental Protection Agency’s (EPA) refuge requirements for corn...

Two sigma factors, sigma 35 and sigma 28, direct transcription from the Bt I and Bt II promoters of the cryIA(a) gene of Bacillus thuringiensis; this gene encodes a lepidopteran-specific crystal protoxin. These sigma factors were biochemically characterized in previous work (K. L. Brown and H. R. Whiteley, Proc. Natl. Acad. Sci. USA 85:4166-4170, 1988; K. L. Brown and H. R. Whiteley, J. Bacteri...

4 Bacillus thuringiensis (Bt) is an aerobic, spore-forming bacterium that produces, during the sporulation phase, crystalline inclusions composed of proteins known as δ-endotoxins (3). The δ-endotoxins form two multigenic families, Cry and Cyt toxins. Cry proteins are specifically toxic to several orders of insects: Lepidoptera, Coleoptera, Hymenoptera, Diptera, and to nematodes. In contrast, C...

Transgenic cotton (Gossypium hirsutum L.) with Bacillus thuringiensis Berliner δ-endotoxin genes has been widely adopted for suppression of lepidopteran pests. To account for inconsistency of the endotoxin gene expression, we developed a polymerase chain reaction (PCR) for checking the purity of transgenic cotton plants. A total of eight cry1Ac genes were aligned for the PCR primer design. A DN...

A novel assay was developed for the detection of Bacillus thuringiensis (BT) spores. The assay is based on the fluorescence observed after binding an aptamer-quantum dot conjugate to BT spores. The in vitro selection and amplification technique called SELEX (Systematic Evolution of Ligands by EXponential enrichment) was used in order to identify the DNA aptamer sequence specific for BT. The 60 ...

This minireview discusses the risks to humans and large mammals associated with the use of Bacillus thuringiensis var. kurstaki (Btk) in forest, agricultural and urban environments. The first subspecies used for insect control was Bacillus thuringiensis subsp. thuringiensis (Btt), known at the time as Bt Berliner. Much of the early work done with Bt does not identify the subspecies. Btk is regi...

The present research represents the first investigations into the development of crosstolerance in the larvae of Diamondback Moth (DBM) tolerant to Bacillus thuringiensis toxin (Bt-toxin: Dipel) and treated with different concentrations of the entomopathogenic fungus Beauveria bassiana (strain BbGHA). Significant differences (at P = 0.05) were obtained between the fungus concentrations used for...

Insect-specific toxins derived from Bacillus thuringiensis (Bt) provide a valuable resource for pest suppression. Here we review the different strategies that have been employed to enhance toxicity against specific target species including those that have evolved resistance to Bt, or to modify the host range of Bt crystal (Cry) and cytolytic (Cyt) toxins. These strategies include toxin truncati...