Abstract
Abstract About 20 years after the market introduction of the first GM plants, we review whether or not uncontrolled spread occurred. We summarise cases documented in the scientific literature and derive conclusions for the regulation of the authorisation of new events. Several cases documented in North and Central America and Japan show that transgenes have spread beyond cultivation areas. Important examples are bentgrass (Agrostis stolonifer a), oilseed rape (Brassica napu s) and cotton (Gossypium hirsutum). Several factors can be identified as relevant for transgene dispersal in the environment. Grasses (Poaceae), in particular, show a high potential for persistence and invasiveness, and wild relatives that can cross with the crop plants are a major factor in the unintended spread of the transgenes. There are significant uncertainties in predicting which transgenes will escape and how they will interact with the environment. For example, climate change is likely to have a major impact on the invasive potential of some plant species. The uncontrolled spread of transgenes is therefore a remaining challenge for regulators. We discuss some of these issues in the context of EU regulations since these regulations explicitly refer to the precautionary principle in the assessment of uncertainties. We found the that the precautionary principle as established in EU Directive 2001/18 can only be applied where efficient measures are available to remove genetically engineered organisms from the environment should this become necessary. If a removal from the environment would not be practically feasible, undesirable developments could not be mitigated.
Highlights
There have been many known cases of transgenes moving into the environment since the large-scale commercialisation of genetically engineered plants started around 20 years ago
Though we briefly address issues such as transgenic contamination of seeds and the food chain, we focus on the presence of genetically engineered cultivars and their offspring that can carry transgenes outside areas of intended presence, either as feral plants or as introgression into wild populations
Evidence that transgenes have escaped from agricultural fields We examined publications referring to various regions where genetically engineered plants are grown, both within and outside of the EU and in particular considering regions where wild relatives are native and genetically engineered plants might introgress into natural populations
Summary
There have been many known cases of transgenes moving into the environment since the large-scale commercialisation of genetically engineered plants started around 20 years ago. In a follow-up to this study [26], it was found that 93 out of 100 tested feral oilseed rape plants growing along field edges or on roadsides in Manitoba were positively tested for transgenic constructs. Survey of other related cases of gene flow From existing data, it can be concluded that maize (Zea mays) in Mexico [3,4,38,39,40,41] and oilseed rape (B. napus) in the USA [42], Australia [43,44] and Europe [45,46,47] are likely to have escaped regulatory control, but it is unclear to which extent gene flow to wild relatives has already occurred.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
