Environ. Biosafety Res.
Volume 6, Number 3, July-September 2007
|Page(s)||183 - 195|
|Published online||16 November 2007|
Effects of tobacco genetically modified to express protease inhibitor bovine spleen trypsin inhibitor on non-target soil organisms
Biocontrol, Biosecurity and Bioprocessing Section, AgResearch,
Lincoln Research Centre, Private Bag 4749, Christchurch, New Zealand
2 Previous address: University of Vermont, Entomology Research Lab, 661 Spear St, Burlington, VT 05405, USA
3 HortResearch, Private Bag 92 169, Auckland, New Zealand
4 HortResearch, Private Bag 11 030, Palmerston North, New Zealand
Corresponding author: firstname.lastname@example.org
Effects of tobacco genetically modified to express the protease inhibitor bovine spleen trypsin inhibitor (BSTI) were examined in laboratory assays against three earthworm and one collembolan species. BSTI is a serine protease inhibitor that can bind to the digestive trypsins of insects feeding on modified plants, resulting in reduced growth and survival. Protease inhibitors are active against a broad range of insects, so may have a large impact on non-target organisms. Survival and fecundity of the collembolan Folsomia candida were unaffected by consumption of artificial diet containing BSTI-expressing tobacco leaf or powdered freeze-dried BSTI-expressing tobacco leaf that was added to soil. Similarly, mortality and growth of earthworms Aporrectodea caliginosa and Lumbricus rubellus did not differ significantly between soil augmented with BSTI-expressing tobacco leaves or unmodified control leaves. The redworm Eisenia fetida gained less weight when provided with BSTI-expressing leaves in one assay, but when the experiment was repeated, there was no significant difference between treatments. BSTI-expressing tobacco and unmodified control leaves decomposed at the same rate, indicating that the inhibitor had no effect on the overall function of the decomposer community of micro-flora and fauna in soil.
Key words: environmental impacts / earthworms / protease inhibitor / GM plant / Collembola / decomposition
© ISBR, EDP Sciences, 2007