Assessing potential environmental effects of genome-editing applications for plants

The current EU biosafety regulation framework requires a mandatory environmental risk assessment (ERA) of genetically modified (GM) products prior to the authorisation of individual GMOs for environmental release or marketing in the EU.

Considering the different characteristics of specific examples of genome edited plants and the respective risk issues relevant for genome edited plants, a recently published paper states that it is neither appropriate nor scientifically justified to draw general conclusions for whole groups of genome-editing applications.

The paper contends that genome editing and conventional breeding are two fundamentally different approaches. With a view to the significant differences concerning the relative frequencies of mutational events at specific genomic locations, the authors argue that a general “likeness” between genome-editing approaches and conventional breeding techniques cannot be assumed until such claims are supported by ERA results.

The paper concludes that a case-specific risk assessment approach is needed for genome-edited plants, based on the characteristics of the individual applications, taking into account their use and interaction with the receiving environment. Furthermore, a robust risk assessment approach is required, in particular for genome-edited plants with novel and/or complex traits as well as traits with limited existing experience from practical use. Finally, a robust assessment of unintended modifications and possible adverse consequences of such modification needs to be maintained, based on an adequate molecular characterisation of genome-edited plants and an appropriate comparative assessment.

Source of commentary: Third World Network.
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Recommendations for the Assessment of Potential Environmental Effects of Genome-Editing Applications in Plants in the EU
Eckerstorfer M.F. et al.
Plants 2023, 12(9), 1764
https://doi.org/10.3390/plants12091764
https://www.mdpi.com/2223-7747/12/9/1764
25 April 2023

Abstract

The current initiative of the European Commission (EC) concerning plants produced using certain new genomic techniques, in particular, targeted mutagenesis and cisgenesis, underlines that a high level of protection for human and animal health and the environment needs to be maintained when using such applications. The current EU biosafety regulation framework ensures a high level of protection with a mandatory environmental risk assessment (ERA) of genetically modified (GM) products prior to the authorisation of individual GMOs for environmental release or marketing. However, the guidance available from the European Food Safety Authority (EFSA) for conducting such an ERA is not specific enough regarding the techniques under discussion and needs to be further developed to support the policy goals towards ERA, i.e., a case-by-case assessment approach proportionate to the respective risks, currently put forward by the EC. This review identifies important elements for the case-by-case approach for the ERA that need to be taken into account in the framework for a risk-oriented regulatory approach. We also discuss that the comparison of genome-edited plants with plants developed using conventional breeding methods should be conducted at the level of a scientific case-by-case assessment of individual applications rather than at a general, technology-based level. Our considerations aim to support the development of further specific guidance for the ERA of genome-edited plants.

Conclusions

In conclusion, we argue that a case-specific risk assessment approach is needed for genome-edited plants, based on the characteristics of the individual applications, taking into account their use and interaction with the receiving environment. Relevant for such an approach is the nature of the respective trait(s) developed in a particular genome-edited plant. A robust risk assessment approach is required in particular for genome-edited plants with novel and/or complex traits as well as traits with limited existing experience from practical use. Furthermore, a robust assessment of unintended modifications and possible adverse consequences of such modification needs to be maintained, based on an adequate molecular characterisation of genome-edited plants and an appropriate comparative assessment.

On the way forward, several challenges have to be mastered, though. Further specific guidance for the ERA of genome-edited plants needs to be developed, as noted in the recent EFSA statement published in October 2022. However, the criteria for risk assessment proposed by the EFSA in this statement must be considered as the beginning of a discussion process rather than as an already suitable solution. The previous EFSA opinions on genome-editing applications, which were not aimed to establish specific guidance, are insufficient for that task, in our opinion. Appropriate data requirements for an ERA need to be established, taking into consideration available scientific data and existing experience for cultivated plants with similar properties. However, a robust molecular and phenotypic assessment is needed for plants with novel and/or complex traits. The basic data set currently required for GMOs could serve as a minimum requirement for such applications, with additional testing of possible environmental and/or food safety effects according to the characteristics for plants with novel and/or complex traits.

From a risk assessment viewpoint, generalising conclusions on the assumed safety of broad groups of genome-editing applications and their “likeness” with conventional breeding approaches are not warranted using current scientific evidence. With a view to the existing uncertainties, rather a broad, but flexible risk assessment approach according to the case-by-case principle needs to be implemented to sufficiently address relevant biosafety issues of genome-edited plants. For plausible hazards associated with NGT and, in particular, genome-editing applications, the level of robustness in the evidence currently required for the ERA of GMOs needs to be maintained.

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