26 February 2002

BT TOXIN ACCUMULATES IN SOIL

January 2002 SOIL BIOLOGY AND BIOCHEMISTRY
Year: 2002    Volume: 34
Pages 133-137

Bt toxin is released in root exudates from 12 transgenic corn hybrids representing three transformation events
D. Saxenaa, S. Floresb and G. Stotzky

Abstract
The anti-lepidopteran toxin (Cry1Ab protein) encoded by truncated genes from Bacillus thuringiensis was released in the root exudates from all hybrids of Bt corn studied and which represented three transformation events (Bt11, MON810, and 176). In vitro and in situ studies indicated that the toxin released in root exudates accumulates in soil, as it adsorbs and binds rapidly on surface-active particles (e.g. clays and humic substances), and retains insecticidal activity for at least 180 d, the longest time studied. The results indicated that the release of the Cry1Ab protein by roots is a common phenomenon with transgenic Bt corn and is not restricted to only the one Bt corn hybrid (NK4640Bt) and tranformation event (Bt11) studied initially.