An-Najah Staff

Transgene flow from biotech crops to other organisms is an issue that should be properly addressed when considering biosafety. Transgene flow can be countered by either establishing containment mechanisms to keep the transgenes within the crop, or by employing mitigation techniques aimed at minimizing the environmental effects of the primary transgenic trait should it escape.  Jonathan Gressel and Hani Al-Ahmad of the Weizmann Institute of Science, Israel, review transgenic mitigator strategies in their article “Mitigating Transgene Flow from Crops”, published in the latest issue of the Information Systems for Biotechnology News Report. In transgenic mitigation, genes (termed mitigator genes) that lower the competitive ability of transgenic hybrids are linked to the primary transgene. Such mitigator genes are neutral or positive to the crop, and may confer traits such as dwarfism, inhibited dormancy, and non-shattering of seedpods. These traits would confer a competitive disadvantage in wild populations, ensuring escapes would not survive.  Researchers co-cultivated TM transgenic oilseed rape (with a mitigator gene for dwarfism) with its wild counterpart and found that the TM rape was suppressed, unable to grow normally, and hardly set seed. TM-weed hybrids, as well as further backcrosses, were also found to be “exceedingly unfit and unable to compete with wild type weed.” Thus, researchers conclude, transgenic mitigation is clearly advantageous to a crop grown alone, while disadvantageous to a crop-weed hybrid living in a competitive environment.