agronomic and physiological traits and protein expression were compared between non-bt glandless upland cotton variety-zhong5629 and its bt-transgenic near-isogenic lines differing in cryiac gene. results showed that the bt isogenic line had higher plant height and rate of effective bolls, more internal bolls but lower yield, than the non-bt line. the bt isogenic line had lower chlorophyll cont...

Th e development of resistance to Bacillus thuringiensis (Bt) in insect populations in agriculture not only depends on the level of resistance conferred by a selected resistance mechanism, but also on the fi tness cost associated with the resistance mechanism under specifi c ecological and environmental conditions. Bt resistance in the cabbage looper (Trichoplusia ni), which was identifi ed by ...

The primary strategy for delaying the evolution of pest resistance to transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) entails refuges of plants that do not produce Bt toxins and thus allow survival of susceptible pests. Recent advances include using refuges together with Bt crop 'pyramids' that make two or more Bt toxins effective against the same pest, and ...

Bacillus thuringiensis (Bt) was first described by Berliner [10] when he isolated a Bacillus species from the Mediterranean flour moth, Anagasta kuehniella, and named it after the province Thuringia in Germany where the infected moth was found. Although this was the first description under the name B. thuringiensis, it was not the first isolation. In 1901, a Japanese biologist, Ishiwata Shigeta...

The cotton bollworm Helicoverpa armigera is the major insect pest targeted by cotton genetically engineered to produce the Bacillus thuringiensis toxin (transgenic Bt cotton) in the Old World. The evolution of this pest's resistance to B. thuringiensis toxins is the main threat to the long-term effectiveness of transgenic Bt cotton. A deletion mutation allele (r(1)) of a cadherin gene (Ha_BtR) ...

Natural variability in susceptibility of field collected rice yellow stem borer (Scirpophaga incertulas) and rice leaffolder (Cnaphalocrocis medinalis) to Bacillus thuringiensis (Bt) δ-endotoxins was investigated to establish a geographic baseline for comparison of future population responses to the increased use of Bt based insect control products like Bt transgenic rice and commercial formula...

The sustainable deployment of resistant crop varieties is a critical issue for the implementation of biotechnology in crop pest management. Feeding, biomass accumulation, and mortality were evaluated for susceptible, insecticide-resistant, and Bacillus thuringiensis (Bt) Cry 3A-selected Colorado potato beetle ( Leptinotarsa decemlineata Say) (Coleoptera, Chrysomelidae) larvae fed on: cultivated...

Transgenic crops producing Bacillus thuringiensis (Bt) toxins kill some key insect pests and thus can reduce reliance on insecticides. Widespread planting of such Bt crops increased concerns that their usefulness would be cut short by rapid evolution of resistance to Bt toxins by pests. Pink bollworm (Pectinophora gossypiella) is a major pest that has experienced intense selection for resistanc...

The Bacillus cereus group consists of closely related species of bacteria and is of interest to researchers due to its importance in industry and medicine. However, it remains difficult to distinguish these bacteria at the intra- and inter-species level. Bacillus thuringiensis (Bt) is a member of the B. cereus group. In this work, we studied the inter-species structure of five entomopathogenic ...

The major virulence factor produced by the bacterium Bacillus thuringiensis (Bt) is a pore‐forming toxin called crystal (Cry) toxin, which targets and kills insects and nematodes. To understand how this bacterial toxin interacts with its invertebrate hosts, a genetic screen in C. elegans for nematodes resistant to Bt toxin was carried out. Four of the five genes that mutated to toxin resistance...