There are things you hear from your parents even as an adult, and somehow you still don’t question them. For me, it was cherry tomatoes. My mother insists that only the perfectly round ones are “natural”, and that any other shape must be a sign of genetic modification. Of course, I could have found the evidence to prove her wrong – tomatoes naturally come in many shapes and colours, and labels like “GMO-free” exist for reassurance. Yet the question lingered: how sure can any of us be that the food we buy was not genetically modified, in a world where technology evolves far faster than regulation?

A changing landscape of genetic transformation

EU legislation defines a GMO as any organism whose genetic material has been altered in a way that does not occur naturally. Traditionally, this referred to the insertion of foreign DNA – something clearly distinguishable in a laboratory. But since 2001, when this definition was adopted, biotechnology has undergone a revolution. New genomic techniques (NGTs), such as CRISPR-Cas9, no longer insert exogenous material. Instead, they precisely edit the organism’s own DNA. “NGTs involve transformations that cause mutations in the target genome through a particular process, which may occur, although generally with less efficiency, even without inserting exogenous genes into the plant genome,” explains Ugo Marchesi, senior biologist at the Istituto Zooprofilattico Sperimentale del Lazio e Toscana (IZSLT), the Italian veterinarian public health control institution appointed as National Reference Centre for GMO detection.

In 2018 the European Court of Justice ruled that plants obtained with these techniques fall under GMO legislation. But unlike classical GMOs, some NGT-induced mutations can resemble those that occur spontaneously in nature. This complicates both detection and regulation, and has led the EU to propose two categories. Category 1 NGT plants: edits that could occur naturally or via conventional breeding. These would be exempt from the main GMO rules and not labelled (except seeds). Category 2: all other NGT plants, regulated and labelled like GMOs.


The challenge: changes that are hard to see

Distinguishing natural mutations from engineered ones is scientifically complex.

“That is precisely the challenge,” says Marchesi. “For GMOs, it is easier to find an extraneous genetic sequence. For NGTs, since there may be no insertion of exogenous material, what must be searched for are sometimes single mutations or modifications in very small portions of the original sequence. And this is not to mention that it is even more difficult to determine whether these alterations occurred naturally or were produced using genetic engineering techniques.” Only recently has the scientific community begun developing methods to detect such subtle alterations. Meanwhile, uncertainty clouds policy debates, consumer choices, and the ability to enforce regulations.

Building the tools for transparency

This is where the European project Darwin steps in: helping to ensure that the rules for NGT’s decided by regulators can be implemented. “The aim is simply, on a technological level, to develop detection methods for these new genome-edited plants,” explains its coordinator and research director at the Norwegian Research Centre, NORCE, Odd-Gunnar Wikmark. “The implications are much bigger: it allows a transparent food system and the enforcement of whatever regulation society decides on.” The scientists involved are not taking a position on whether NGTs are desirable. Their mission is to give decision-makers and consumers reliable information. Just like my mother deciding which tomatoes to buy, every consumer filters food choices through personal values – country of origin, local producers, allergens, sustainability, or a preference to avoid GMOs. As Wikmark notes: “Some people may eat food that are GMOs and some may not want to do that. And we believe they should have the option to choose what they want to have on their plate.” But choice requires trust. And trust requires detectable, verifiable information.

From edited plants to detection methods

The research process is hands-on. “Some project partners perform genetic improvement of crops such as rice and tomato using NGTs and make these edited genetic lines available to test whether existing methods can identify the altered sequences or whether new ones need to be developed,” explains Marchesi. “In this process, as a research institute involved in method validation, our role is essentially to help developers verify the performance of their detection methods.” And detection depends heavily on the size and type of modification. Larger alterations, such as those in earlier generations of GMOs, are comparatively easy to spot. Smaller ones, however, can be as tiny as a single base-pair change. “The DNA is a string of letters,” says Wikmark. “Changing one letter – or removing or adding one – is maybe the smallest thing.” Yet such a tiny tweak can have major consequences. In “knockout” edits, for example, removing a small DNA fragment can make a plant resistant to specific diseases. A rapeseed variety became herbicide-tolerant by modifying only two letters. Detecting these microscopic changes is the frontier on which European labs are now working.

Still a long way to go

“I think it’s important to say that even though we have good results in certain aspects, there is still a long way to go,” Wikmark emphasises. “Technologies evolve so rapidly that detection research struggles to keep pace. “I really wish we had started this ten years ago,” he admits. Marchesi agrees: “Publications appear from time to time, but the methods we are developing will probably be among the first to reach a level of validation.” Beyond detection itself lies a wider question of biosafety – a field Wikmark hopes will receive far more attention. The arrival of AI in genetic research, he notes, will only accelerate the pace and complexity of innovations, raising new scientific and ethical debates. Because the real question is not the shape of cherry tomatoes.
It is whether we, as consumers and citizens, can access trustworthy information about why our food looks, grows and tastes the way it does – and decide for ourselves whether we want it on our plates.

Article by Katalin Tornai

About DARWIN 

DARWIN is an EU-funded project to foster the transition to a more sustainable and fair food system by co-developing an innovative detection strategy for products obtained through NGTs, as well as digital solutions.