title: Effects of tobacco genetically modified to express protease inhibitor bovine spleen trypsin inhibitor on non-target soil organisms.
abstract: 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.
authors.affiliation: Biocontrol, Biosecurity and Bioprocessing Section, AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch, New Zealand. maureen.ocallaghan@agresearch.co.nz
authors.forename: Maureen
authors.initials: M
authors.lastname: O'Callaghan
authors.forename: Michael
authors.initials: M
authors.lastname: Brownbridge
authors.forename: Wendy B
authors.initials: WB
authors.lastname: Stilwell
authors.forename: Emily M
authors.initials: EM
authors.lastname: Gerard
authors.forename: Elisabeth P J
authors.initials: EP
authors.lastname: Burgess
authors.forename: Emma I
authors.initials: EI
authors.lastname: Barraclough
authors.forename: John T
authors.initials: JT
authors.lastname: Christeller
mesh_terms: D000818:Animals; D001181:Arthropods / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D002417:Cattle; D005298:Fertility / Q000187:drug effects; D009835:Oligochaeta / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D030821:Plants, Genetically Modified; D013154:Spleen / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics*; D014361:Trypsin Inhibitors / Q000235:genetics / Q000494:pharmacology*
chemical_list: D014361:Trypsin Inhibitors