Potential Negative Impacts of Genome-Edited Plants on Ecosystems

THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE

 

Dear Friends and Colleagues

Potential Negative Impacts of Genome-Edited Plants on Ecosystems

A recent scientific publication (Item 1) is one of the first worldwide to focus on ecological risks associated with specific CRISPR/Cas plant applications. Intended alterations induced by genome editing have the potential to unintentionally alter the composition of a plant and/or interfere with its metabolism. This could affect diverse defense mechanisms and inter-/intra-specific communication of plants having a direct impact on associated ecosystems.

The review used genome-edited camelina (Camelina sativa) as an example to illustrate how far biotechnology has come to generate novel, genetic combinations in an agriculturally relevant crop, and the likely and potential ecological impacts. Camelina is an oilseed crop and CRISPR/Cas was used to simultaneously knock out 18 gene copies in the genome to generate plants with a higher oleic acid content. Camelina has a six-fold set of chromosomes and is, therefore, a good example to demonstrate that even small changes in the genome created with CRISPR/Cas can have a huge effect. Unintentional effects on various processes can occur, like effects on the formation of certain messenger substances with which plants communicate and with which they, for example, ‘warn’ of a pest infestation. A change in the composition of fatty acids can affect and influence existing food webs. Apart from this, there is also the possibility that genome-edited plants will hybridise with wild species leading to unintended effects in subsequent generations. At the same time, the genome-edited camelina has the potential to persist in the environment and spread uncontrollably. (Item 2)

The review concludes that with regard to environmental risk assessment, there are additional challenges concerning genome-edited plants that may go beyond current experiences with GM plants. Risk assessment of such novel traits will therefore require additional knowledge of their consequences for the organism and the ecological impacts when released into the environment.

With best wishes,

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Item 1

GENOME-EDITED CAMELINA SATIVA WITH A UNIQUE FATTY ACID CONTENT AND ITS POTENTIAL IMPACT ON ECOSYSTEMS

By Kawall, K.
Environ Sci Eur 33, 38
26 March 2021
https://doi.org/10.1186/s12302-021-00482-2
https://enveurope.springeropen.com/articles/10.1186/s12302-021-00482-2#citeas

‘Genome editing’ is intended to accelerate modern plant breeding enabling a much faster and more efficient development of crops with improved traits such as increased yield, altered nutritional composition, as well as resistance to factors of biotic and abiotic stress. These traits are often generated by site-directed nuclease-1 (SDN-1) applications that induce small, targeted changes in the plant genomes. These intended alterations can be combined in a way to generate plants with genomes that are altered on a larger scale than it is possible with conventional breeding techniques. The power and the potential of genome editing comes from its highly effective mode of action being able to generate different allelic combinations of genes, creating, at its most efficient, homozygous gene knockouts. Additionally, multiple copies of functional genes can be targeted all at once. This is especially relevant in polyploid plants such as Camelina sativa which contain complex genomes with multiple chromosome sets. Intended alterations induced by genome editing have potential to unintentionally alter the composition of a plant and/or interfere with its metabolism, e.g., with the biosynthesis of secondary metabolites such as phytohormones or other biomolecules. This could affect diverse defense mechanisms and inter-/intra-specific communication of plants having a direct impact on associated ecosystems. This review focuses on the intended alterations in crops mediated by SDN-1 applications, the generation of novel genotypes and the ecological effects emerging from these intended alterations. Genome editing applications in C. sativa are used to exemplify these issues in a crop with a complex genome. C. sativa is mainly altered in its fatty acid biosynthesis and used as an oilseed crop to produce biofuels.

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Item 2

GENOME-EDITED PLANTS: NEGATIVE EFFECTS ON ECOSYSTEMS ARE POSSIBLE

By Testbiotech
30 March 2021
www.testbiotech.org/en/news/genome-edited-plants-negative-effects-ecosystems-are-possible

New scientific publication shows the need for detailed investigation of ecological risks

A new scientific publication in the Environmental Sciences Europe journal provides an overview of the unwanted effects the release of genome-edited plants can have on ecosystems. These result from the intended properties induced by genome editing and can contribute to various metabolic processes. The publication is based on Project Genetic Engineering and the Environment (FGU) findings, and is one of the first worldwide to focus on ecological risks associated with specific CRISPR/Cas plant applications.

Genome editing applications predominantly using CRISPR/Cas gene scissors can increase the possibilities and speed with which the genome of plants can be changed. It does not matter whether additional genes are integrated into the genome. Even small genetic changes induced several times and in combination to generate novel properties, can significantly change metabolic pathways and ingredients. Consequently, plants with new properties must undergo risk assessment even if no additional genes are inserted.

The study uses camelina (Camelina sativa) to explain possible unintended effects that the release of a genome-edited crop can have on ecosystems. Camelina is rich in polyunsaturated fatty acids. The CRISPR/Cas application aimed to increase the amount of oleic acid in the camelina seeds and to reduce the amount of easily oxidizable fatty acids. This was intended to extend the shelf life of the oil extracted from camelina.

Camelina has a six-fold set of chromosomes and is, therefore, a good example to demonstrate that even small changes in the genome created with CRISPR/Cas can have a huge effect: gene scissors were used to simultaneously knock out 18 gene copies in the genome of the camelina and thus generate plants with a higher oleic acid content. Such interventions have until now hardly, or not at all, been possible with conventional breeding methods and can give rise to completely new biological properties. In the USA, these plants have already been deregulated without undergoing thorough risk assessment.

Diverse properties can be changed with CRISPR/Cas applications. In the case of camelina, gene scissors have often been used to change the composition of the fatty acids. However, besides the desired properties, unintentional effects on various processes can also occur, e.g. effects on the formation of certain messenger substances with which plants communicate and with which they, for example, ‘warn’ of a pest infestation. A change in the composition of fatty acids can affect and influence existing food webs. Apart from this, there is also the possibility that genome-edited plants will hybridise with wild species leading to unintended effects in subsequent generations. At the same time, the genome-edited camelina has the potential to persist in the environment and spread uncontrollably.

A recent EFSA opinion also comes to the conclusion that plants with complex genetic changes need to undergo risk assessment, even in cases where no additional genes are inserted.

Contact:
Christop Then,
info@testbiotech.org, Tel + 49 (0) 151 54638040

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