Mushrooms that don’t brown. Wheat that fights off disease. Tomatoes with a longer growing season.
All of these crops are made possible by a gene-editing technology called CRISPR-Cas9. But its future has been clouded by the European Union’s (EU) top court.
The court recently ruled that gene-edited crops are genetically modified organisms, or GMOs, and therefore must comply with the tough regulations that apply to plants made with genes from other species.
Many scientists responded to the decision with dismay, predicting that countries in the developing world would follow Europe’s lead, blocking useful gene-edited crops from reaching farms and marketplaces. The ruling may also curtail exports from the United States, which has taken a more lenient view of gene-edited foods.
“You’re not just affecting Europe, you’re affecting the world with this decision,” said Matthew Willmann, director of the Plant Transformation Facility at Cornell University.
The ruling also raises a more fundamental question: What does it mean for a crop to be genetically modified?
In its decision, the EU court exempted crops produced through older methods of altering DNA, saying they were not genetically modified organisms. That assertion left many scientists scratching their heads.
“I don’t know why they are doing that,” said Jennifer Kuzma, an expert in genetic engineering at North Carolina State University. “I was thinking, ‘Do they have the right science advice?’ ”
Since the agricultural revolution 10,000 years ago, all crop breeding has come down to altering the genetic composition of plants. For centuries, farmers selected certain plants to breed, or crossed varieties, hoping to pass useful traits to future generations.
In the early 20th century, scientists discovered genes and invented ways to breed crops. Two lines of corn, for example, could be melded into hybrid plants that were superior to either parent.
By the 1920s, researchers realized they didn’t have to content themselves with amplifying the genetic variations that already existed in plants. They could create mutations.
To do so, they fired X-rays at plants or used chemicals that disrupted plant DNA. Mutagenesis, as this method came to be known, introduced random mutations into plants.
Scientists inspected the mutants to find those that were improvements. Thousands of plant breeds in use today, from strawberries to barley, are the product of mutagenesis.
In the 1970s, microbiologists figured out how to insert genes from humans and other species into bacteria. Plant scientists later used recombinant DNA, as the technology came to be known, to develop methods for inserting genes into plants to improve their growth.
Some varieties of corn, for example, received a gene from bacteria that allowed the crops to produce an insect-killing toxin. These came to be known as genetically modified crops, and they sparked controversy.
Environmental groups such as Greenpeace and Friends of the Earth raised concerns that genetically modified crops posed unpredictable dangers.
The plants might escape farmers’ fields and spread through wild ecosystems, for instance, perhaps hybridizing with wild plants and introducing their genes into new species.
Environmental groups also raised the possibility that genetically modified crops could harm human health. Genetically modified crops produce proteins from their own genes and from the genes of other species.
On opposite sides of the Atlantic, the conflict has played out in different ways.
In the United States, the National Academy of Sciences has found no evidence to confirm that gene-edited crops are any more dangerous than conventionally bred ones.
While the government has put in place a number of regulations governing genetically modified crops, the industry has boomed. More than 185 million acres of these crops were planted in the United States in 2017.
In Europe, by contrast, concerns about genetically modified organisms led the EU to issue a directive in 2001. From the early stages of research to the marketplace, these products would have to pass a series of tests for environmental risks and human safety.
The directive made it clear that crops made through older forms of mutagenesis were not genetically modified organisms because they were “conventional” and had “a long safety record.”
The result of the directive has been that Europe grows almost no genetically modified crops. In 2017, only 325,000 acres were planted across the continent.
In the years after the EU’s directive came out, science advanced beyond recombinant DNA. Rather than inserting a gene from another species, researchers learned to snip out a piece of a plant’s DNA, or even rewrite short stretches of genetic material.
Instead of inserting foreign genes, scientists were able to edit a plant’s own DNA in new ways. They could create crops that make more, or fewer, proteins from their own genes, gaining advantageous traits.
When scientists started experimenting with gene-editing on crops, the EU offered no clear guidance. In 2015, a French agricultural union and allies such as Friends of the Earth went to court to have gene-edited crops labeled as genetically modified organisms — and regulated as such.
And now the court has agreed. In a statement, the court said gene-edited crops were GMOs “within the meaning of the GMO Directive.”
Dana Perls, senior food and agriculture campaigner at Friends of the Earth, praised the court for recognizing gene-editing as genetic modification. “We need to call it what it is,” she said.
In March, the U.S. Department of Agriculture said it was not planning to regulate gene-edited crops as it does crops with foreign genes inserted with recombinant DNA.
As a result, CRISPR-edited crops like mushrooms are expected to move quickly into the U.S. marketplace. But these crops may be barred from import into Europe.