TWN Info Service on Biosafety
7 January 2022
Third World Network
www.twn.my
Dear Friends and Colleagues
Risks of SDN-1 Plants Obtained from New Genetic Engineering
The use of site-directed nucleases (SDNs) in crop plants to alter market-oriented traits is expanding rapidly. SDN-1 applications, such as CRISPR/Cas, can be used to induce small changes in the genome of target organisms. These small changes can however be applied multiple times and in combination, and thus lead to significant changes in the metabolism and ingredients of plants. SDN-1 applications are also used to simultaneously modify several genes (i.e. multiplexing) or several gene variants at the same time.
A recent review (Item 1) demonstrates the potential of SDN-1 applications to induce complex alterations in plant genomes that are relevant to generic SDN-associated risks. Nearly half of plants with so-called market-oriented traits contain complex genomic alterations induced by SDN-1 applications, which may also pose new types of risks. Thus, the review highlights the need for plants developed using these new genetic engineering techniques to undergo case-specific risk assessment, taking both the properties of the end product and risks posed by the applied procedures into account.
In addition to the intended genetic changes that SDN-1 applications can achieve, the study also presents specific and partly novel risks associated with gene scissors and caused by unintended effects, both off-target and on-target (Item 2). Many of these unintended effects are triggered by the multi-step procedures used during the application of these techniques. Therefore, risk assessment must examine in detail the unintended changes both in the genome and in the metabolism of the respective plants.
The publication is of particular relevance in the context of current discussion on the future regulation of new genetic engineering methods. The EU Commission has presented a document proposing far-reaching deregulation of, amongst other things, SDN-1 applications in plants if they can also be produced conventionally. In doing so, however, it is largely disregarding current scientific findings on the risks of the new methods.
With best wishes,
Third World Network
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Item 1
The Generic Risks and the Potential of SDN-1 Applications in Crop Plants
by Katharina Kawall
Plants 2021, 10(11), 2259
22 Oct 2021
https://doi.org/10.3390/plants10112259
https://www.mdpi.com/2223-7747/10/11/2259/htm
Abstract
The use of site-directed nucleases (SDNs) in crop plants to alter market-oriented traits is expanding rapidly. At the same time, there is an on-going debate around the safety and regulation of crops altered with the site-directed nuclease 1 (SDN-1) technology. SDN-1 applications can be used to induce a variety of genetic alterations ranging from fairly ‘simple’ genetic alterations to complex changes in plant genomes using, for example, multiplexing approaches. The resulting plants can contain modified alleles and associated traits, which are either known or unknown in conventionally bred plants. The European Commission recently published a study on new genomic techniques suggesting an adaption of the current GMO legislation by emphasizing that targeted mutagenesis techniques can produce genomic alterations that can also be obtained by natural mutations or conventional breeding techniques. This review highlights the need for a case-specific risk assessment of crop plants derived from SDN-1 applications considering both the characteristics of the product and the process to ensure a high level of protection of human and animal health and the environment. The published literature on so-called market-oriented traits in crop plants altered with SDN-1 applications is analyzed here to determine the types of SDN-1 application in plants, and to reflect upon the complexity and the naturalness of such products. Furthermore, it demonstrates the potential of SDN-1 applications to induce complex alterations in plant genomes that are relevant to generic SDN-associated risks. In summary, it was found that nearly half of plants with so-called market-oriented traits contain complex genomic alterations induced by SDN-1 applications, which may also pose new types of risks. It further underscores the need for data on both the process and the end-product for a case-by-case risk assessment of plants derived from SDN-1 applications.
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Item 2
NEW SCIENTIFIC PUBLICATION ON NOVEL RISKS AND APPLICATIONS OF GENE SCISSORS
Testbiotech
26 Oct 2021
https://www.testbiotech.org/en/news/new-scientific-publication-novel-risks-and-applications-gene-scissors
Need for a case-specific risk assessment of plants obtained from new genetic engineering
A new study published in the scientific journal, Plants, presents the specific risks of new genetic engineering techniques and gives an overview of possible gene scissor applications. Inducing supposedly small alterations in the genome of crop plants can nevertheless generate complex changes. The results of the study highlight the need for plants developed using New Genetic Engineering techniques to undergo case-specific risk assessment, taking both the properties of the end product and risks posed by the applied procedures into account.
The study was published in a special issue “Potential Unintended Effects of Genetic Technologies in Plants” of the scientific journal, Plants. The study focuses on so-called SDN-1 gene scissor applications, such as CRISPR/Cas, which can be used to induce small changes in the genome of target organisms. These small changes can be applied multiple times and in combination, and thus lead to significant changes in the metabolism and ingredients of plants.
The study concludes that in slightly more than half of the examined studies on crop plants, individual genes are knocked out by small changes. Among them is the ‘CRISPR tomato’ which has already been approved in Japan and has an increased content of an antihypertensive ingredient (i.e. GABA). This case highlights the fact that conventional breeding was not able to change the relevant genes in the way that was possible using gene scissors.
SDN-1 applications are also used to simultaneously modify several genes (i.e. multiplexing) or several gene variants at the same time. In camelina, for example, 18 gene copies of the target genes were knocked out simultaneously in order to produce plants with a higher oleic acid content. Such interventions would have been practically impossible to achieve with conventional methods. They can, however, lead to new biological properties in the respective plants.
In addition to the intended genetic changes that SDN-1 applications can achieve, the publication also presents specific and partly novel risks associated with gene scissors and caused by unintended effects. On the one hand, these so-called off-target effects can result from the fact that the gene scissors cut at unintended regions of the genome, and thus induce changes at these sites. On the other hand, the gene scissors can also cause unintended changes at the target sequence (also called on-target effects). Many of these unintended effects are triggered by the multi-step procedures used during the application of New Genetic Engineering techniques. Therefore, risk assessment must examine in detail the unintended changes both in the genome and in the metabolism of the respective plants.
The publication is of particular relevance in the context of current discussion on the future regulation of new genetic engineering methods. At the end of September, the EU Commission presented a document proposing far-reaching deregulation of, amongst other things, SDN-1 applications in plants if they can also be produced conventionally. In doing so, however, it is largely disregarding current scientific findings on the risks of the new methods.
Contact:
Christoph Then, Tel +49 151 54638040, info@testbiotech.org