Sentences with phrase «bt proteins»

Importantly provides key data substantiating the ~ million-fold safety margins for Bt proteins

In an article in the February issue of Environmental Entomology, researchers used caterpillars that were known to be resistant to Bt proteins and fed them Bt maize and Bt cotton...

Organic growers have used Bt proteins in sprays for decades because they kill certain pests but are not toxic to people and most other organisms.

«Many mechanisms of resistance to Bt proteins have been proposed and studied in the lab, but this is the first analysis of the molecular genetic basis of severe pest resistance to a Bt crop in the field,» said Bruce Tabashnik, one of the paper's authors and the head of the Department of Entomology in the UA College of Agriculture and Life Sciences.

That's because refuge crops provide fodder for insect pests that are not resistant to Bt proteins.

Although Bt proteins provide environmental and economic benefits, these benefits are cut short when pests evolve resistance.

Scientists from the UA and the U.S. Department of Agriculture worked closely with cotton growers in Arizona to develop and implement resistance management strategies such as providing «refuges» of standard cotton plants that do not produce Bt proteins and releasing sterile pink bollworm moths.

However, insect pests have shown the ability to evolve resistance to Bt proteins.

The new study revealed that pest resistance to Bt crops is evolving faster now than before, primarily because resistance to some Bt proteins causes cross-resistance to related Bt proteins produced by subsequently introduced crops.

While organic farmers have used Bt proteins in sprays successfully for more than half a century, some scientists feared that widespread use of Bt proteins in genetically engineered crops would spur rapid evolution of resistance in pests.

All other Bt proteins in genetically engineered crops are in another group, called crystalline, or Cry, proteins.

Because these two groups of Bt proteins are so different, cross-resistance between them is low or nil, according to the authors of the study.

The caterpillar pest Helicoverpa zea (also known as cotton bollworm and corn earworm) has evolved resistance to four Bt proteins produced by biotech crops.

When crops genetically modified to express the Bt protein started hitting the market, the anti-GMO activists, including Greenpeace, claimed that the plant produced too much Bt and that it could be harmful to people.

An encouraging development is the recent commercialization of biotech crops producing a novel type of Bt protein called a vegetative insecticidal protein, or Vip.

«Same pest, same crop, same Bt protein, but very different outcomes.»

Not exact matches

The stakes are especially high for defining and managing insect resistance to corn and cotton plants genetically engineered to produce proteins from the bacterium Bacillus thuringiensis (Bt).

Since 1996, farmers worldwide have planted more than a billion acres (400 million hectares) of genetically modified corn and cotton that produce insecticidal proteins from the bacterium Bacillus thuringiensis, or Bt for short.

Comparing proteins produced by normal genes to those produced by mutant Bt resistant ones, the team discovered that enzymes play a key role in determining whether or not a worm succumbs to the toxin.

[Editors» note: Bt crops have been genetically modified to produce a bacterial protein that kills certain insect pests.]

Bt produces a protein that is deadly to a very narrow category of pests, including the corn borer worm.

But there may be a silver lining: Once researchers have cloned the gene and studied the protein it codes for, Tabashnik says, they might be able to use that knowledge to make better Bt plants.

The finding, published in today's issue of the Proceedings of the National Academy of Sciences, boosts fears that some insects could quickly develop resistance to these pesticides, bacterial proteins known as Bt toxins, and render them useless.

Bt crops, including corn, are genetically engineered to produce proteins from the Bacillus thuringiensis (Bt) bacterium.

Their findings, reported in the May 19 issue of the journal PLOS ONE, shed light on how the global caterpillar pest called pink bollworm overcomes biotech cotton, which was designed to make an insect - killing bacterial protein called Bt toxin.

Like many other transgenic crops, Bt maize synthesises its own pesticide: a toxic protein produced in its leaves and stems, which kills pests in a matter of days.

Genetically engineered maize is created by introducing a gene into the plant genome that expresses a toxic protein from a bacterium, i.e. Bacillus thuringiensis (Bt).

Crops genetically engineered to produce proteins from the bacterium Bacillus thuringiensis — or Bt — were introduced in 1996 and planted on more than 180 million acres worldwide during 2013.

A LARGE body of literature has shown that genetically modified (GM) plants that produce proteins from the bacterium Bacillus thuringiensis (Bt) to protect themselves from insect pests have little to no effect on a wide range of non-target insects.

Different strains of Bt produce proteins that target different species of insect.

A breakthrough came in 1996 with the introduction of Bt cotton, a genetically engineered crop containing a gene transferred from the bacterium, Bacillus thuringensis, endowing the plants with a protein that kills some, but not all insects.

Experts have attributed these kinds of changes to impurities in the bacterial preparation — it is important to recognize that some bacteria that produce Bt make several toxic proteins.

Mouse feeding tests show GM technology is a safer way of delivering protection of crops from insects with the Bt - protein insect than is the traditional delivery method.