One of Europe’s leading microbiologists wants EU legislators to follow the UK’s lead and relax the rules for the gene editing of common crops, reports Dermot Martin.
Award-winning Science Director at Belgium’s VIB-UGent Centre for Plant Systems Biology, Professor Dirk Inzé, says that, as things stand, it is easier to conduct field trials on gene edited wheat and maize in the UK than in EU countries.
Inze maintains this is leading to a significant drag in wider scientific research which could pose a threat to future food security.
Asked about the UK’s approach to gene editing Inzé said: “It has become easier in the UK to perform field trials with gene edited plants and this gives both academia and industry a major advantage over continental Europe.”
Inzé’s comments come on the back of the first UK field trial of gene-edited wheat. The trial’s findings are encouraging – preliminary results suggesting no crop yield or agronomic penalties where precision breeding techniques are employed on a wheat strain. The UK Government approved the first trial of genetically edited wheat which had been sown in a dedicated field in Hertfordshire. The results are being hailed as a breakthrough.
The trial, which started in October 2021, involved wheat that had been genetically redesigned using CRISPR-Cas9, creating a strain which displayed low levels of asparagine, an α-amino acid used in the biosynthesis of proteins.
During cooking at high temperature, such as baking or toasting, the asparagine in cereals is converted to acrylamide which scientists believe to probably be carcinogenic.
In 2017 the EU introduced benchmark levels on acrylamide in wheat-based foodstuffs, including breakfast cereals, bread and biscuits.
These restricted levels were rolled over into UK law after Brexit. The EU is already considering going further by imposing maximum levels, above which it would be illegal to sell the product.
Scientists at Rothamsted Research (RR) in Hertfordshire have been exploring the genes of the winter wheat, Cadenza, and have identified one gene responsible for most asparagine accumulation. They now have the ability to knock out that gene using the precision breeding technique.
The difference between genetically modified (GM) and gene edited (GE) organisms is vital in this work. In the case of GM, extra DNA is introduced into the plant, adding one or a small number of additional genes to a plant’s complement of several tens of thousands of genes.
With GE, the CRISPR technique allows for small changes to be made to a precisely targeted gene which is already present in the plant. UK legislation has been introduced to cut red tape for gene editing, so farmers will soon be able to grow more resistant, nutritious and productive crops as well as being able to use less pesticide. These early studies using CRISPR, still a young technique itself, are vital.
Asparagine levels can be reduced substantially in wheat without compromising grain quality
Nigel Halford, Principal Research Scientist – Crop Science Professor
The rule changes, made possible in part by the UK’s departure from the EU, will mean that scientists across England will be freer to undertake plant-based research and development using CRISPR more easily.
These rules will apply to plants where gene editing is used to create new varieties similar to those which could have been produced more slowly through traditional breeding processes.
The work on wheat by Rothamsted Research, led by Principal Research Scientist – Crop Science Professor Nigel Halford, has been revealing.
Asparagine is made by enzymes called asparagine synthetases. Wheat seems to have five genes that make these enzymes, known as ASN1, ASN2, ASN3.1, ASN 3.2 and ASN4.
Halford’s team, in studying this small gene family, discovered ASN2 to be the most active in the grain but it was not active anywhere else in the plant. They chose to knock out the ASN2 gene using the CRISPR Cas9 technique. The idea was that low activity of the other ASN genes in the grain would provide enough asparagine to make proteins but that so-called ‘free’ asparagine would not accumulate in the way that it does when the ASN2 gene is fully expressed. The project is expected to stretch over five years but already it is delivering results.
“Acrylamide has been a serious problem for food manufacturers since being discovered in food in 2002. It causes cancer in rodents and is considered ‘probably carcinogenic’ for humans,” said Halford.
“It occurs in bread and its levels increase substantially when the bread is toasted, but is also present in other wheat products and many crop-derived foods that are fried, baked, roasted or toasted, including crisps and other snacks, chips, roast potatoes and coffee.
“Asparagine levels can be reduced substantially in wheat without compromising grain quality. This would benefit consumers by reducing their exposure to acrylamide from their diet, and food businesses by enabling them to comply with the regulations on the presence of acrylamide in their products.
“That is a long-term goal. Our project aims to assess the performance of the wheat plants in the field and measure the concentration of asparagine in the grain produced under field conditions.”
The scientists at RR studied low asparagine wheat plants and published the data showing that the asparagine concentration in the GE grain was very low.
However, more field testing is required to establish if the low asparagine trait is maintained under real field conditions. Data on how the plants perform in the field in other ways, such as their grain yield and protein content, will also be vital.
The great numbers of plants grown in the five year trial will also enable the team to identify plants that have lost any added genes to establish going forward which plants are GE and not GM.
There is one apparent downside to the low asparagine content seeds. Early tests show that these seeds showed poor germination ability, yet this issue could be overcome by exogenous application of asparagine.
Inzé [pictured] believed the UK approach was welcome: “I wish that the EU would also have a similar relaxed legislation for gene edited crops.”
In a statement the Government’s Chief Scientific Adviser at the Department of Environment, Food and Rural Affairs, Professor Gideon Henderson, commented: “Gene editing is a powerful tool that will help us make plant breeding more efficient and precise by mimicking natural processes that currently take many years to complete. With the new rules formally in place, scientists will be able to assess new crops in real-world conditions more easily. This will increase our ability to harness the potential of gene editing to efficiently help grow plants that are more nutritious, beneficial to the environment, more resilient to climate change, and resistant to disease and pests.”
- Dermot Martin is a freelance journalist who specialises in biological sciences and gene editing