A key concern regarding the use of genetically modified crops is the possibility that they will spread their altered genes to wild plants. Research published online this week by the Proceedings of the National Academy of Sciences could help prevent these occurrences. Scientists have engineered a strain of GM plant that propagates successfully on its own, but cannot mix with non-GM plants.

Johann P. Schernthaner of Agriculture and Agri-Food Canada and his colleagues worked with genetically engineered tobacco plants. The researchers first introduced a so-called seed lethality (SL) gene into otherwise normal plants to make the seeds infertile. They then crossed this strain with a second GM strain that carried a gene capable of repressing the SL gene. According to the report, the resulting plants propagated successfully. But when the team tried to breed these plants with normal, wild-type tobacco, germination failed because the repressor gene was no longer active.

The scientists propose that linking a desired new trait to the SL gene "could provide a mechanism to control the unwanted spread and establishment of novel traits within sexually compatible plant species without the need for intervention." They note, however, that further refinements of the technique will be required to optimize it for successful application out in the field.