Wheat grains less able to germinate

Research centering on genetically engineered wheat meant to form less acrylamide during baking is being carried out in England. Acrylamide is a substance which is thought to cause cancer. The CRISPR/Cas gene scissors were used to switch off a specific gene that is crucial for the production of the amino acid, asparagine, and thus ultimately of acrylamide during baking. However, asparagine is also important for germination, plant growth, stress tolerance and defence against plant diseases.

CRISPR/Cas gene scissors made it possible to reduce the content of freely available asparagine in grains by up to 90 percent. This involved blocking the function of several copies (alleles) of a gene (TaASN2 gene). However, it was found that many the CRISPR wheat grains were no longer able to germinate or showed weaker growth.

In addition, the genetically engineered wheat has other unexpected characteristics: for example, the concentration of several amino acids was unintentionally changed. There were also major fluctuations in the asparagine content. Whether other undesirable changes were caused in the metabolism of the plants still needs to be investigated in more detail.

Initial results of field trials were presented in February 2023. According to these, the acrylamide content in baked goods was reduced. However, it was noticeable that the wheat formed smaller grains. The asparagine content was also higher in some cases than in the variants tested in the greenhouse. For comparison, wheat plants with reduced asparagine content, derived from random mutagenesis but with a lower expression of the desired characteristics, were also tested. Since important data are missing, it is unclear to what extent these comparisons are actually meaningful. The trials are to be continued. It is clear from the manner in which the preliminary data were published that the institutions themselves are also interested in influencing the regulation of new genetic engineering.

This example shows: New Genetic Engineering can be used to produce extreme characteristics in plants and animals that go beyond what can be achieved with conventional breeding. Unintended side effects and interactions in the complex network of genes, proteins and other biologically active molecules can occur even if the intervention in the genome is targeted and precise. While methods of new genetic engineering have great potential for altering the genome of crops, it is not easy to translate this potential into actual benefits. Whatever the case, unintended effects caused by the processes of New Genetic Engineering have to be assessed in detail.