Researchers can’t remove foreign DNA – so it's back to the drawing board 

Rothamsted Research’s GM gene-edited low acrylamide wheat has hit problems. An article in Euro News reports that the researchers are having trouble removing foreign DNA from the wheat – a step that they deem important to enable the wheat to evade GMO regulations, including risk assessment, traceability requirements, and GMO labelling, in different regions of the world.

Euro News reports: “Once the edit is complete, the GM components are bred out, leaving a genome-edited but GMO-free plant. Removing the GM elements, however, turned out to be challenging. The project was not initially designed with the removal of GM elements in mind. As a result, the team is now repeating the experiment in a different wheat cultivar and considering alternative transformation methods to simplify the removal process.”

The development exposes the fakery of widespread claims that gene-edited products don’t contain foreign DNA – not to mention the other claims that gene editing can quickly bring important products to market that would take far longer using conventional breeding.

Commenting, Prof Michael Antoniou said, “It is well known among genetic engineering scientists that foreign DNA, either in the form of complete genes or fragments introduced during the gene editing process, is very difficult to remove from gene-edited products. That is especially the case if the foreign DNA has inserted near the gene or genes that are important to the trait the researchers are trying to introduce – in this case, genes responsible for the asparagine biosynthetic pathway. Many developers of gene-edited products get around this problem by not looking properly for the foreign DNA. It is to the credit of the Rothamsted researchers that they did look. But it is highly uncertain as to whether they will succeed in removing the foreign DNA without impacting the viability of their intended trait and other aspects of the gene-edited wheat.”

Not the first problem to hit gene-edited wheat

Rothamsted’s GM gene-edited wheat is genetically engineered using the CRISPR gene editing tool to contain low amounts of the acrylamide precursor asparagine. Asparagine is an amino acid that plays a crucial role in plant nitrogen metabolism and transport, but it can form the “probable carcinogen” acrylamide when wheat products are cooked at high temperatures, leading Rothamsted to try to develop the low acrylamide wheat.

The foreign DNA issue is not the first roadblock to impact the gene-edited wheat project. Previously it ran into another problem – poor germination rate of the gene-edited seeds. The researchers claimed that this “can be reversed by treatment with low concentrations of asparagine”. But it’s ironic that a wheat genetically engineered to contain a low amount of asparagine has to be “rescued” by... adding asparagine!

Prof Antoniou commented, “It is well documented that when the gene editing process is considered as a whole, it is highly mutagenic – that is, it results in hundreds or thousands of sites of unintended DNA damage throughout the organism’s genome. This can result in disturbed gene functions, which can cause poor crop performance. So I don’t find it surprising that a complex trait such as seed germination rate can be disrupted following a gene editing procedure.”

GMWatch co-director Claire Robinson said, “It’s back to the drawing board for the Rothamsted gene-edited wheat. This project has already swallowed hundreds of thousands of pounds in taxpayer money at a time when ordinary people are struggling to pay for food and heating. How many more problems will the project encounter, and how much more public money will be thrown at it before politicians realise they are backing a losing horse?”

The wheat in question

In spite of the problems, Rothamsted has claimed a field trial of the wheat as a success that has delivered on its promises. By using gene editing rather than older-style GM techniques, Rothamsted has also previously claimed that the wheat contains no foreign DNA and that therefore it isn’t a GMO.

In the UK, the 2023 Genetic Technology (Precision Breeding) Act enables any GM plant or animal that the developer declares could have arisen by traditional processes like breeding to evade the GMO regulations and be treated the same as a conventional organism. On the issue of foreign DNA, the Act is silent, but a guidance document suggests that the presence of foreign DNA may be allowed in “precision bred" GMOs under certain circumstances (see section 3.2). A government research briefing also says it is allowed, as long as it is not functional (pp. 86-87).

The EU has never defined a GMO on the basis of whether or not it contains foreign DNA. However, if the GMO deregulation proposal that is working its way through the EU institutions is finally adopted, successfully excluding foreign DNA from a gene-edited plant may more easily allow it to be exempted from most or all of the regulatory safeguards that currently apply to all GMOs.

The Rothamsted researchers appear to be taking precautions to ensure that their gene-edited wheat avoids being regulated as a GMO in as many jurisdictions as possible. That’s if the public funding flow keeps up and if it ever comes to market.

GM low acrylamide wheat not needed

Back in 2021, GMWatch wrote of this wheat:

“The low-asparagine GM wheat is yet another white elephant from the pro-GMO lobby. Naturally low asparagine non-GM wheat varieties have long been available to farmers. But genetics is just one factor. Growing conditions and environmental stresses also have a large effect on the asparagine content of wheat – in particular, sulphur deficiency in soils leads to raised levels of asparagine in the crop.

“What causes sulphur deficiency? Intensive farming and a lack of organic matter in soils.

“So once again, a risky GM crop is being promoted as the ‘solution’ to a problem caused by bad practices – this time, in agriculture and cooking.”

As for the supposed cancer-preventing benefits of a low asparagine wheat, Cancer Research UK has been scathing, even describing the idea that acrylamide in burnt food causes cancer as a “food myth”.

It would be instructive to see an analysis of the cancer risk posed by more obvious culprits, such as pesticide residues in foods, compared with the acrylamide content of burnt or overcooked wheat products. However, there is no urgency on the part of our political leaders to tackle the pesticide issue, but plenty of support for the uncertain prospect of a still-experimental GMO that is likely to have little or no effect on the cancer epidemic. While this might appear contradictory, both are completely in line with Big Ag’s goals.

Image: Shutterstock. Licence available on request.