"Horizontal" gene transfer from a transgenic potato line to a bacterial pathogen (Erwinia chrysanthemi) occurs--if at all--at an extremely low frequency.
The frequency of possible "horizontal" gene transfer between a plant and a tightly associated bacterial pathogen was studied in a model system consisting of transgenic Solanum tuberosum, containing a beta-lactamase gene linked to a pBR322 origin of replication, and Erwinia chrysanthemi. This experimental system offers optimal conditions for the detection of possible horizontal gene transfer events, even when they occur at very low frequency. Horizontal gene transfer was not detected under conditions mimicking a "natural" infection. The gradual, stepwise alteration of artificial, positive control conditions to idealized natural conditions, however, allowed the characterization of factors that affected gene transfer, and revealed a gradual decrease of the gene transfer frequency from 6.3 x 10(-2) under optimal control conditions to a calculated 2.0 x 10(-17) under idealized natural conditions. These data, in combination with other published studies, argue that horizontal gene transfer is so rare as to be essentially irrelevant to any realistic assessment of the risk involved in release experiments involving transgenic plants.
Schlüter
K
K
Institute of Plant Sciences, Swiss Federal Institute of Technology (ETH), Zürich, Switzerland.
Fütterer
J
J
Potrykus
I
I
D000667:Ampicillin / Q000494:pharmacology; D003470:Culture Media; D053938:DNA Fragmentation; D016974:Dickeya chrysanthemi / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D022761:Gene Transfer, Horizontal; D030821:Plants, Genetically Modified; D010957:Plasmids / Q000235:genetics; D011198:Solanum tuberosum / Q000235:genetics*; D014169:Transformation, Bacterial; D001618:beta-Lactamases / Q000235:genetics
D003470:Culture Media; D000667:Ampicillin; D001618:beta-Lactamases