Sesamia nonagrioides is one of the most damaging pests of corn in Spain and other Mediterranean countries. Bt corn expressing the Bacillus thuringiensis Cry1Ab toxin is being grown on about 58,000 ha in Spain. Here we studied the mode of action of this Cry protein on S. nonagrioides (binding to specific receptors, stability of binding, and pore formation) and the modes of action of other Cry pr...

The resistance to the Bacillus thuringiensis (Bt) toxin Cry2Ab in a greenhouse-originated Trichoplusia ni strain resistant to both Bt toxins Cry1Ac and Cry2Ab was characterized. Biological assays determined that the Cry2Ab resistance in the T. ni strain was a monogenic recessive trait independent of Cry1Ac resistance, and there existed no significant cross-resistance between Cry1Ac and Cry2Ab i...

This document provides a comprehensive review of information and data relevant to the environmental risk assessment of Cry1Ac and presents a summary statement about the environmental safety of this protein. All sources of information reviewed herein were publically available and included: dossiers presented to regulatory authorities; decision summaries prepared by regulatory authorities; peer r...

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 D...

Transgenic cotton was developed using two constructs containing a truncated and codon-modified cry1Ac gene (1,848 bp), which was originally characterized from Bacillus thuringiensis subspecies kurstaki strain HD73 that encodes a toxin highly effective against many lepidopteran pests. In Construct I, the cry1Ac gene was cloned under FMVde, a strong constitutively expressing promoter, to express ...

The use of conventional chemical insecticides and bacterial toxins to control lepidopteran pests of global agriculture has imposed significant selection pressure leading to the rapid evolution of insecticide resistance. Transgenic crops (e.g., cotton) expressing the Bt Cry toxins are now used world wide to control these pests, including the highly polyphagous and invasive cotton bollworm Helico...

Abstract Background During field surveillance in Gujarat, India, 2009, scientists found that pink bollworm was surviving the first generation of Bollgard cotton, which contains a single protein. This survival observed four districts Gujarat. From 2012 to 2014, surveys revealed larvae had higher rates on II cotton Amreli and Bhavnagar districts. In 2016, outbreak Maharashtra caused significant l...

we investigated the effects of interaction between cotesia plutellae (kurdjumov) and bacillus thuringiensis berliner on parasitism and an immune effector (phenoloxidase activity) of a bt-susceptible and a bt-resistant population of plutella xylostella (linnaeus) in laboratory. parasitism success of c. plutellae varied depending on the use of b. thuringiensis or its toxin, and the timing of appl...

Background: Transgenic plants inhabiting single Bt gene are prone to develop insect resistance and this resistance has been reported in case of some important yield-devastating insect larvae of commercial crops, such as cotton and rice. Therefore, it has become essential to adapt new strategies to overcome the problem of insect resistance and these new strategies should be sophisticated enough ...