The EU is falling behind in crop improvement because of its outdated policies on gene editing, say crop scientists. Japan, Canada, the US and now the UK all allow some gene editing of crops, but the EU remains lumbered by legislation written two decades ago. Gene editing allows the DNA of crops to be tweaked to boost sustainability.
It could generate crops less thirsty for pesticide and fertiliser inputs, as well as prepare crops for a future of increasing heat and drought stresses due to climate change. Also, pests and diseases are on the move, due to climate change, at a time when we are trying to reduce pesticide use.
The potential of gene editing is not a fringe viewpoint. "It is a breakthrough technology with huge potential," says Dr Ismahane Elouafi, the chief scientist of the Food and Agricultural Organisation (FAO). "As a scientist, I don't see it in the same category as GMOs [genetically modified organisms]." She would like to convince the EU to change its views, and she sees gene editing as crucial for improving food security and reducing global hunger.
Crispr-Cas9 – often illustrated as a scissors cutting DNA strands – is used in some bacteria to record DNA sequences of viruses they've encountered. They then chop them up (with the Cas9 enzyme) whenever the viral sequences reappear. In 2018, Emmanuelle Charpentier and Jennifer Doudna won the Nobel prize in chemistry for its discovery and advancing its potential in gene editing.
"The beauty of it is that it works across kingdoms – so plants, animals, bacteria," says Dr Eoin Lettice, plant scientist at University College Cork. "I am interested in how it can be applied in improving plants, to introduce crop varieties that boost yields or improve resistance to stresses," including plant diseases.
Since the 1940s, crop breeding has involved bombarding seeds with radiation or chemicals to trigger DNA mutations. The resulting plants were grown up and screened for beneficial traits, which is slow and expensive. Many vegetables in our supermarkets were developed this way.
In the 1990s, researchers figured out how to move genes from one species to another, even from a bacterium to a plant. Early GMOs had resistance to herbicides, which were then sprayed with this herbicide to kill off other plants. More recently, in the UK, scientists introduced a gene for omega 3 oils from fish into plants, so that fish oils could be produced on a farm.
The European Commission describes climate change and environmental degradation as 'an existential threat to Europe and the world'
But in the 1990s there was a backlash against such genetic modified organisms (GMOs), dubbed Frankenfoods, because genes from one species were placed into another. “No matter how much you tell people it is safe, in the back of their minds there is a fish gene going into a plant, and there is unease about that,” says Lettice. Also, a plant that allowed better killing of weeds or insect pests did not grab consumers as especially useful. There were concerns about these newfangled crops, and plant scientists failed to convince the public of their merits and safety.
Growing precision
The EU introduced tough regulations for GMOs in 1991 – so tough and expensive that a maize with an insecticide from bacteria was the only ever approved GMO crop in Europe. Subsequently, the discovery of Crispr-Cas9 allowed plant geneticists to delete a few letters of DNA or disable genes. "It is much more precise," says Lettice.
Crop scientists were then left bewildered by a 2019 decision by the European Court of Justice that gene editing should fall under GMO regulations. It meant random crop mutations made by chemicals got a pass, whereas gene-edited crops would be regulated in a way that left them commercially non-viable.
In April a report for the European Commission acknowledged that the EU's policy of treating gene-edited crops as GMOs was not fit for purpose, and that gene editing could help with more sustainable crops. Last month the UK announced that it would diverge from the EU in how it polices gene editing.
The rest of the world is moving on. Earlier this year, Japan launched a gene-edited tomato with high levels of a compound believed to lower blood pressure and anxiety. Field trials in the US are testing a gene edited tomato with resistance to viral diseases. And UK crop scientists have edited wheat to contain less asparagine, an amino acid that gets converted to toxic acrylamide during baking and high-temperature cooking.
“A blanket bank on gene editing doesn’t help us or countries that are struggling globally with climate change and with changing patterns of pests and diseases,” Lettice warns.
He believes Irish potatoes could benefit from gene editing, which must be regularly sprayed with fungicides to protect against late blight, the organism that caused the potato famine in Ireland. "We still haven't been able to produce a potato variety which is commercially viable and resistant to late blight," says Lettice. "Irish farmers must spray their crop 10-15 times in a growing season."
This touches on a conundrum at the heart of European crop policy. The European Commission describes climate change and environmental degradation as “an existential threat to Europe and the world”. Its response is the European Green Deal, an effort to make the continent climate neutral, and its farm-to-fork strategy in food production.
"That's basically Europe's drive to reduce inputs into farming practices – be they fungicides, pesticides – to improve biodiversity levels and increase sustainability of food production," says Dr Ewen Mullins at Teagasc.
Disease resistance
The EU aims to significantly reduce chemical and energy inputs into crops by 2030. But Mullins counters that crop breeders need all the tools available, due to the time it takes for traditional crop breeding – usually 10-15 years.
Ireland has diseases too of barley and wheat, which often necessitate fungicides. Which the EU also wants to reduce the use of. “To reduce those inputs,” says Mullins, “we have to develop new varieties that are able to resist those diseases. Gene editing would be one way of helping to do that.”
Climate change is also expanding some crop pests and diseases geographically, with southern Europe hit hard. In Ireland, barley yellow dwarf virus (BYDV) could be a worsening problem due to our milder winters. The virus is spread by aphids. The aphid population appears to survive better over milder winters, says Mullins, which increases the risk of BYDV infection in our cereal crops.
It seems inevitable that the EU will fall further behind other regions, where a pragmatic approach is being taken in regulating new plant breeding methods
The European Commission realises its regulations are now out of step with the rest of the world. But some large member states are wary of reopening any debate that touches on the GM controversies of yesteryear. Meanwhile, Canada and other countries regulate on the health and environmental safety of the crop itself, rather than the tools used to develop it.
The UK government recently announced it would allow changes via gene editing than could have been done naturally. "The UK government's decision is pragmatic and reassuring," says French crop geneticist Prof Agnes Ricroch at AgroParisTech. "If there is no transfer of foreign genes to the plant genome, the edited plants are not GMOs." She predicts "the British, by developing edited plants or animals, will export their products to the EU".
This could see Europe import gene-edited foodstuffs from the UK. Lettice is pessimistic about a change of course for the EU. “It seems inevitable that the EU will fall further behind other regions, where a pragmatic approach is being taken in regulating new plant breeding methods,” he says.
But crop scientists view the British decision as piling further pressure on the EU to change – especially in the context of climate change, as it will require faster crop breeding to generate crops capable of growing well under new conditions and new stresses.
Anthony King is a science journalist. He can be found on twitter @AntonyJKing
