Selection of test organisms for the environmental risk assessment of genetically modified plants: applying and testing a new selection procedure

Since almost two decades now, chemical stressors such as pesticides are subjected to a number of standardised ecotoxicity tests for regulatory approval prior to their release to the environment. Since the advent of the technology, genetically modified organisms (GMOs) in general, and genetically modified plants (GMPs) in particular have been a contentious issue  and, very quickly, it was agreed that they have to be subject to regulations. However, up to now no agreed standardised pre-release testing procedures exist.  Regulations and scientifically sound testing procedures must account for the differences between genetically modified plants and chemicals: most importantly, GMOs are capable of self-reproduction. Due to this capability, GMOs can increase and potentially spread in the environment, and exist for – by human standards – largely unlimited time. With the GMOs, transgene products will spread in the environment. Scientifically sound testing strategies and methodologies for the required case-specific risk assessment of GMOs must account for this, and treat a GMO as an integrated biological system consisting – in the case of a GMP – of the plant and the novel trait in contact with the receiving environment. The goal of this project was: (1) to compile and evaluate existing ecotoxicological testing methodologies and – strategies for chemicals regarding their suitability for risk assessment of transgenic plants, and (2) to evaluate currently used ecotoxicological testing procedures for GMPs. Based on these analyses, recommendations for alternative strategies and improvements were made. These include the formulation of specific provisions for ecotoxicological testing strategies for GMPs in order to be in compliance with the legal requirements. An improved testing strategy and risk assessment framework for GMPs were developed.