Scientists at the University of Bristol have discovered a previously unknown route by which GM genes may escape into the natural environment thus affirming what many have been saying for years, namely, that before GMOs are deregulated and commercialized, we must have a far better understanding of the process of genetic modification.
At the center of the study was Agrobacterium tumefaciens, a bacterium known for its gene transfer mechanism which allows it carry foreign genes into new plants. It is widely used as a transferring agent in the recombinant DNA process for genetic modification of plants.
Bacterial cells naturally carry plasmids, circular pieces of genetic material that can easily cross cell boundaries, and plasmids inside Agrobacterium tumefaciens make it an ideal tool for genetic modification techniques in plants. Scientists use plasmids as vehicles or vectors for carrying engineered genes and depositing them into the nuclei of targeted cells where these genes are sometimes incorporated thus transferring new characteristics.
The success of this process relies on hormones and sugars exuded by plants and, in particular, on the plant wound hormone acetosyringone, which attracts Agrobacterium and triggers transformation mechanisms that allow foreign genes to modify targeted cells. This hormone is secreted when the plant tissues are damaged.
In this study, Professor Gary Foster and his colleagues looked at whether latent Agrobacterium, left in plant tissues from the process of modification, can be used then to transfer synthesized genetic material from modified plants to other organisms in natural environment. The study results clearly demonstrated that when fungi are placed together with damaged plant tissues, Agrobacterium readily transforms associated fungi enabling a pathway for patented genes to escape.
Professor Foster stated: “This study suggests that the encounter between Agrobacterium and a fungus on the plant surface may lead to gene flow in a previously overlooked way, potentially leaking GM genes into the natural world.” In other words, contrary to what GMO proponents would have us believe, genetic modification is not a precise process and may readily have unintended consequences.
This raises a new concern for geneticists and regulators who will need to focus on elimination of any Agrobacterium material prior to release of the GM plant to prevent later escape of proprietary genes. It also raises concerns as to, what, if any, preventive measures may be sufficient to stop unintended gene flow.