The Bt concept
A gene from a soil bacterium has been transferred to maize using genetic engineering methods. This maize now produces a Bt toxin, an active substance that is poisonous for the plant’s chewing pests. Chewing insects that are sensitive to the toxin variety in question ingest the deadly substance with the plant parts.
Background
- Bacterial arsenal to combat chewing insects
- Bacillus thuringiensis: Profile of a bacterium
- Jörg Romeis interview: "Bt technology has given new impetus to Integrated Pest Management" (11/2005)
Pest: European corn borer
The European corn borer is the primary target organism of genetically modified Bt maize. The Bt toxin produced in the maize plants also attacks the pest’s larvae where they used to be safe – inside the stem.
Background
Pest: Western corn rootworm
Brought over from North America, a new maize pest is spreading across Europe: the Western corn rootworm (Diabrotica virgifera). Genetically modified Bt maize which is resistant to the pest is pending authorisation in Europe.
Background
- Pest conquers Europe
- Interview with Stefan Vidal (University of Göttingen): "In regions where we grow one maize crop after another there will be problems." (03/2003)
Risk assessment for Bt plants
The authorisation of Bt plants has to consider complex ecological interrelationships. The question is: Are separate investigations needed for each plant and the non-target organisms it might affect? Or is it possible to develop suitable standard tests? GMO Safety spoke to Angelika Hilbeck and Jörg Romeis.
Background
Toxin levels in Bt maize
The level of Bt toxin in genetically modified Bt plants is not the same in all plant parts. It varies according to the variety and stage of development, but also according to the site and weather conditions. What is the range of such variations and do they pose problems for safety assessments?
Research info
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