Guy Poppy, University of Southampton
Firmly outside the EU, where regulations are considered tighter, the UK government plans to revise regulations on gene editing in agriculture in England, enabling field trials of crops which have had their DNA spliced to accentuate particular qualities, like resistance to disease or drought. This will be followed by a broader review of rules on genetically modified organisms.
The British public has traditionally been sceptical of genetically manipulating food, but should it be? What could new technology offer farming? And what are the risks? We asked professor of ecology at Southampton University, Guy Poppy.
What actually is gene editing? How does it differ from genetic modification?
Humans have been genetically modifying plants and animals ever since we stopped being hunter-gatherers. It’s just the way in which we modify the genes of an organism which has changed.
Random mutations occur in the DNA of organisms all the time. When a variation emerged in the past which a farmer happened to like, such as a tomato plant which produced juicier fruit, they were likely to breed that plant to ensure the trait was passed on. Repeating this process over generations created organisms with more of the characteristics people like. Human hands have directed evolution through this process of selective breeding since the dawn of agriculture.
Genetic modification (GM) typically involves inserting genes into the genome of a plant or animal. The outcome can be similar to selective breeding, but the results are more immediate and precise. Genetic modification can also create characteristics which would be unlikely through any form of selective breeding.
Take transgenic organisms. These are the products of transferring a gene from one organism’s genome to another, like a GM crop spliced with insecticidal proteins found in soil bacteria.
Gene editing (GE) is the result of more recent technology, such as CRISPR-Cas9, which can quickly, precisely and (relatively) cheaply edit parts of a genome by removing, altering or adding sections of DNA. Gene editing typically doesn’t involve introducing genes from other species, but these techniques allow quite complex control of an organism’s genome.
What is CRISPR, the gene editing technology that won the Chemistry Nobel prize?
Gene editing can direct the evolution of plants and animals to yield varieties that would have taken conventional breeding many generations to produce. As a result, many countries are revising their regulations for genetically modified organisms (GMOs) to reflect the capabilities of this new technology, and in the case of the UK, when the technology is used to develop a crop which could not have been produced through conventional breeding.
Could these field trials lead to the widespread use of gene-edited crops?
No. The current proposals allow researchers or food firms to conduct field trials of gene-edited crops in England with the approval of the Department for Environment, Food and Rural Affairs (Defra). The costs and some of the barriers to starting research have been lifted, but we’re still waiting for new legislation which would govern the wider use of gene editing in the UK. Only then might we see the sale of gene-edited crops, which would be considered by the Food Standards agency.
Some may see Defra’s decision to allow research as approving gene-edited crops by the back door. Others might fear that it will lead to the wider consideration of all genetic technologies available for editing plants, animals and even humans.
A simpler approval process is likely to encourage more scientists to undertake field trials.
What are some of the potential benefits of gene editing food crops?
Gene editing can make plants and animals more nutritious or resilient to climate change, for example. Many plants contain anti-nutrients – substances which restrict the availability of nutrients to the human body during digestion. Gene editing could target and remove these, making the plant more nutritious.
Gene editing can also change a plant’s water requirements, producing crops that need less water to grow. In 2018, scientists discovered that by altering the expression of a gene that is found in all plants, they could make tobacco plants 25% more water-efficient. Now they are testing this technique on food crops, like lettuce. The idea is to make crops more resilient to droughts, which are likely to become more frequent and severe in many growing regions as the world warms.
I have written before about removing food allergens with gene editing, by effectively silencing genes associated with allergens. IngateyGen, a biotechnology company based in the US has patented a process for making hypoallergenic peanut plants. The company hopes to produce other plants as part of a partnership with nearby Fayetteville State University.
Clearly, the future of gene editing could involve much more than just increasing crop yield or reducing the use of pesticides, but it needs to be developed thoughtfully.
What worries do you have?
The safety and environmental impact of GM foods is important, and there are well developed scientific processes to assess and manage these risks. I do fear the government is avoiding some of the real issues raised by gene editing but relevant to how we grow food in the future, such as the business models of current food producers and how affordable gene-edited food will be, particularly for the world’s poorest people.
I’m also concerned about issues which are somewhat hard to predict. Civilisation already relies on obtaining much of its calories from a few staple crops, which represent a fraction of 1% of the total biodiversity which exists. One criticism of GM technology is that it encourages the expansion of a few varieties of staple crops, otherwise known as cultivars. This narrows genetic variation between crop plants even further. A diverse genome is more resilient to pests, diseases and climate change. Repeatedly breeding just a handful of cultivars can lead to widescale crop failure, as occurred with sugar cane in the 1970s.
Gene editing could make crop species more diverse if it could result in farmers using more species and cultivars, as gene-editing becomes more available and accepted. Because CRISPR has made this technology cheaper, gene editing could be used to improve the genomes of mutliple cultivars and many different crop species, injecting some diversity into farm fields.
But regulation of GM plants and animals is complex, expensive and increasingly seen as a barrier to innovation by both scientists and industry. If the regulation of gene-edited crops were made simpler, it could mean the editing of more crop species and cultivars. This would also diversify access to gene-edited products and the number of organisations with products on offer, preventing a few, large corporations from monopolising the process.
What do you think could be the future of this technology?
Too often in the past, people have heard about scientific revolutions which have failed to deliver. It takes more than clever technology for these things take off. That’s why I believe some of the bigger issues about food and farming need addressing.
Defra’s proposals are a proportionate way to move beyond the current system of regulations, while accepting that gene editing is different from the GM technology which developed transgenic organisms. It would be a great shame to waste this opportunity by mishandling the debate.
Should we genetically edit the food we eat? We asked two experts
Scientists enjoy an even greater level of respect and trust among the public as a result of the pandemic and the success of multiple vaccines, some of which are the products of genetic modification. The Oxford/AstraZeneca vaccine, for example, uses an adenovirus, a type of pathogen that causes a common cold, to serve as the vehicle for getting a genetic sequence into your cells. In effect, that adenovirus is a GMO. It’s important that we maintain this trust by engaging with the public about what science is trying to achieve and what we can and can’t say, without overpromising or cherry-picking evidence.
Feeding the world while improving human and planetary health is not easy and will require more than the odd tool in the farming toolbox. There needs to be a debate about food and farming which can tackle multiple issues, including gene editing. I accept that it’s important to consider gene editing on its own, but it is also part of a complex food system. Gene editing could help to feed the world in a changing climate, but this is only realistic if these wider issues are discussed and considered. Otherwise we will be sifting through claims and counter-claims, like during the GM debate of the 1990s and early 2000s, when two sects argued and argued rather than explore what people need from a food and farming system.
Guy Poppy, Director of Multidisciplinary Research and Professor of Ecology, University of Southampton
This article is republished from The Conversation under a Creative Commons license. Read the original article.