PARENT SESSION
Contributed Oral Session 137: Agroecology: Pest Control, Dispersal, and Pollination
Thursday, August 11, 1:30 PM - 5:00 PM, Meeting Room 519 A, Level 5, Palais des congrès de Montréal
GM derived Bacillus thuringiensis endotoxins in the soil.
Moore, Sian*,1, Jones, Thomas1, Symondson, William1, 1 Cardiff University, Cardiff, UK
ABSTRACT- Bacillus thuringiensis is a gram negative soil bacterium which produces a range of endotoxins during sporulation. These endotoxins have insecticidal properties and some crops are genetically engineered to produce these toxins to reduce the use of chemical pesticides. These crops introduce the endotoxin into the soil via root exudates, post harvest incorporation of plant residues and pollen. These toxins can bind to certain soil particles which has lead to concerns about the build up of toxins in the environment to potentially harmful levels. This study investigates the possible effects of GM derived Bt endotoxins on the soil biotic community using genetically modified broccoli plants (Brassica italica) producing the Cry1Ac lepidopteran active toxin. Effects on both target lepidopteran larvae and non-target organisms (for example Folsomia candida (Collembola), Deroceras reticulatum (Gastropoda) and the free living nematode Panagrellus redivivus) have been investigated using microcosm studies and enzyme linked immunosorbent assay techniques to track the endotoxin. Results so far indicate that the Bt toxins can have a direct effect on non-target organisms but effects are species-specific. Indirect effects have also been measured.
Key words: Bacillus thuringiensis, GM crops, non-target effects