In the EU, the authorisation and mandatory labelling of "new genetic engineering" (NGT) is being discussed. Professor Dr Kai Voss-Fels, Head of Vine Breeding at Hochschule Geisenheim University, wants to work intensively with the new methods at in the future. He talks to Raffaella Usai and Alexander Lupersböck about new opportunities and unfounded fears.
New genetic engineering (NGT), also known as "gene scissors" or Crispr/Cas9, often triggers scepticism and fear of unforeseeable effects on the environment. It differs from the technology introduced in the 1990s in that no genes from other organisms are used to "implant" desired characteristics. In NGT, certain traits are enhanced or switched off by directly modifying the genetic material of the plants. This targeted intervention is intended to lead to rapid breeding results. "Natural mutations, i.e. changes in the genetic material, are the driver of evolution and therefore also the basis of breeding," explains Prof Voss-Fels. "Even in classic breeding, changes in genetic information are triggered by crossing or genetic information from related species is deliberately introduced into the plants."
He gives an example: "Varieties such as Riesling or Pinot Noir have been propagated exclusively by cuttings for centuries. In this process, we have accumulated millions of mutations that have formed randomly and characterise today's grape varieties. We could continue to propagate as before and hope that the desired changes will occur by chance in the coming years or centuries - and that we will also find and utilise them. Or we could use NGT methods to specifically trigger such mutations."
In traditional breeding, genetic material is changed by crossing. These mutations cannot be controlled.
HS GeisenheimThe grape varieties modified in this way are indistinguishable from the others. Voss-Fels talks about his work in Geisenheim: "We recently analysed around 250 clones of the white Riesling and red Riesling varieties. We found around 1.2 million mutations in the genetic material of these 250 clones, i.e. 1.2 million differences in the gene code. This means that short snippets of genetic material are present in some clones and not in others." This is precisely where the NGT methods come in: "In the simplest case, only one or two parts of the vine's genetic material, which comprises several hundred million parts, are changed." For example, vine characteristics such as loose berries or lower must weight with a lower alcohol yield can be promoted. "We no longer have to wait decades or centuries for a random mutation to occur that gives the variety more favourable characteristics. However, we first have to go to great lengths to identify these in the vineyard. The conventional method of clone selection in vine breeding is basically based on chance and a bit of luck. We could do this much more precisely and quickly with modern methods."
Voss-Fels admits that the use of NGT is still in its infancy and is difficult to realise under current legislation. His team is currently not allowed to carry out field trials with genetically modified material. However, the scientists would need these in order to gather sufficient knowledge. "We only want to bring into circulation what has already proven itself in well-controlled field trials," he emphasises. At present, all results are based on laboratory work.
Critics argue that genetic research has not yet produced any useful resistance mechanisms in vines, but that traditional vine breeding is already much further advanced. Voss-Fels replies: "With the same arguments, we could have cancelled every innovation that mankind has produced shortly after the start. On the one hand, our research is extremely strictly regulated. We are hardly allowed to develop anything further. On the other hand, we are accused of not delivering anything useful. That's too black and white for me. I never think in terms of either/or."
He clarifies his approach: "My breeding goals are clearly defined, I use the tools that are available to achieve them in the best possible way. If you want to turn a screw in the wall, you need a screwdriver. Today, we can use various tools for breeding. Genetic engineering is an extremely interesting tool for precisely defined areas of application. However, there are also areas of research where I would not use this tool because we can achieve our goal more quickly with other methods such as cross-breeding."
For example, NGT is probably not suitable today for better resistance to drought and water shortage. "It's not just a single gene that is responsible for this. It is the complex interplay of thousands of genes interacting with the environment. I probably can't do much here with genetic engineering or precision breeding because I would theoretically have to change 5,000 genes at the same time. That's not technically feasible, so we resort to classic cross-breeding."
At present, field trials with genetically modified material are not permitted.
Woody T. HernerWhat does he say to the critics who fundamentally reject genetically modified plants? What danger could a Riesling, for example, pose if a gene for resistance to peronospora was also crossed into it? "By all scientific standards, the processes are safe. I have discussed these myths about genetic engineering and environmental hazards often enough. I don't know of a single danger that could come from these clones. If someone believes that bees will mutate into zombies as a result: There is no basis for that. The only danger could possibly be that resistance is not effective enough. The new Riesling would then be just as susceptible to Peronospora as the old one. But the winegrowers will say: 'I don't need that because the new material offers no added value'."
The NGT only accelerates classic mutation breeding, the results of which we have all been living with for many decades. "I firmly assume that you have already eaten something this week that was produced from a crop such as grain or rice that was bred using mutation breeding," says Voss-Fels. "This involves the use of ionising radiation or chemicals that have a strong mutagenic effect but are directly harmful to humans. Mutation breeding hopes that useful variants will emerge by chance. With genetic engineering, you can significantly increase the hit rate and work much more precisely."
Genetic engineering methods are currently not authorised in organic farming. Voss-Fels has a clear opinion on this: "Nobody should be forced to work with such plants. But nobody should be prevented from doing so either. Interventions such as more intensive plant protection and the use of copper preparations are also not the last word in wisdom," he emphasises, adding: "If dangers are only talked up for ideological reasons that go beyond what has developed naturally over centuries, then I don't understand it." He would welcome mandatory labelling for maximum transparency, but this would have to apply to all products: "In organic farming, chemical plant protection is not used, which is why mycotoxins from ergot, for example, are more frequently detected in cereals. This can be dangerous to humans even at relatively low concentrations and can even cause miscarriages. This should be noted on the label, as should the fact that products have been produced using genetically engineered varieties. So that consumers can form a judgement and the declaration is not exploited for marketing purposes." The categorical exclusion of planting material produced with the help of NGT is not scientifically justified.
Although NGT is currently only possible in the laboratory in vine breeding, it has arrived in everyday life in other areas.
HS GeisenheimAccording to Voss-Fels, genetic engineering and organic farming are a perfect match. "There is nothing more elegant than using genetically modified material that copes better with stress conditions than conventional varieties and therefore needs to be sprayed less frequently." With clear labelling, consumers could decide for themselves at some point in the future whether to buy a wine from a variety bred with NGT, which would require significantly less plant protection, or a variety that is genetically unchanged but requires more treatment in the vineyard.
NGT has also long since arrived in our everyday lives. There are currently hundreds of medicines on the market with well over 300 active ingredients that have been produced using genetic engineering methods. Of these, 60 are produced in Germany. "I don't believe that many patients suffering from insulin or cancer will say: 'No, I won't take this drug because I don't want genetic engineering to be used for research. In connection with green genetic engineering, people and society perhaps need to be made more aware of the direct benefits it offers and how safe it is in order to increase acceptance and allay any fears."