New bacteria toxins against resistant insect pests

[OKIsItJustMe]

http://www.mpg.de/4607123/bacteria_toxins_against_insect_pests

New bacteria toxins against resistant insect pests

Scientists have developed Bt toxins for the management of Bt resistance in European corn borer and other crop pests.

October 19, 2011

Toxins from Bacillus thuringiensis bacteria (Bt toxins) are used in organic and conventional farming to manage pest insects. Sprayed as pesticides or produced in genetically modified plants, Bt toxins, used in pest control since 1938, minimize herbivory in crops, such as vegetables, maize or cotton. Since 1996, Bt producing transgenic crops have been grown, which successfully control pests like the European corn borer, the tobacco budworm, the Western corn rootworm, and the cotton bollworm. Over the years, Bt resistant insects have emerged in organic and conventional farming. Scientists have therefore modified the molecular structure of two Bt toxins, Cry1Ab and Cry1Ac, in order to overcome resistance. The novel toxins, Cry1AbMod and Cry1AcMod, are effective against five resistant insect species, such as the diamondback moth, the cotton bollworm, and the European corn borer. Cry1AbMod and Cry1AcMod can be used alone or in combination with other Bt toxins for plant protection.

…

“When we studied the new Bt toxins in twelve resistant and non-resistant strains of five major pest species, the results of our experiments were encouraging but surprising. The new toxins are also effective against strains whose Bt resistance is not based on cadherin mutations,” says David G. Heckel, director of the Department of Entomology at the Max Planck Institute for Chemical Ecology in Jena, Germany, and co-author of the study. Especially interesting was the finding that the new toxins were specifically effective against a super-resistant strain of tobacco budworm carrying both the cadherin mutation and another mutation affecting an ABC transporter which was discovered by the Max Planck researchers last year.

Particularly striking was the effect of Cry1AbMod and Cry1AcMod on a Bt resistant corn borer and a resistant diamondback moth strain that was 350 times stronger compared to that of the natural toxins. On the other hand, the new toxins had only a weak effect on some strains whose Bt resistance is due to a mutated cadherin.

If both novel Bt toxins prove to be useful in agriculture, they can be used in combination with different Bt toxins to guarantee a reliable effect on herbivorous pests. Biologists also agree that measures to reduce the occurrence of resistant insect pests must be strictly adhered to and that farmers should be informed in detail. Such measures would mainly include the use of different pesticides, crop rotation, and simultaneous sowing of non-Bt plants in fields, where transgenic Bt varieties are grown.

http://dx.doi.org/10.1038/nbt.1988

[mattvermont]

1. source please..thanks

[OKIsItJustMe]

2. Source added…

(Thanks.)

[Nihil]

3. Good luck with that ...

> Biologists also agree that measures to reduce the occurrence of resistant
> insect pests must be strictly adhered to and that farmers should be informed
> in detail. Such measures would mainly include the use of different pesticides,
> crop rotation, and simultaneous sowing of non-Bt plants in fields, where
> transgenic Bt varieties are grown.

Yeah right ... no chance of developing resistance to the new varieties is there?

[OKIsItJustMe]

4. The same could have been said of the original varieties of course

i.e. if they had been managed properly…

[Nihil]

5. Agreed ...

... which makes it even more stupid that people haven't learned the
lesson yet ...
:shrug:

[Tumbulu]

6. At the ESA meeting of 1986 or '87 the genetic engineers

PUBLICLY PROMISED all of us who were in the business of producing the bacterial Bt that they WOULD NEVER engineer into plants the same toxin that the bacteria produced because we all knew that in a short time the bacterial Bt toxin would be inactivated by resistance.

Of course, big surprise , the business people wanted to push these gmo plants through the EPA and so the toxin had to be the same so that no new testing would be required and we all know how hard they fought any and all public testing.

The culture of lying, right from the beginning