HomeNewsDisease-resistant pigs and oily plants – why UK scientists seek to alter food genes
Disease-resistant pigs and oily plants – why UK scientists seek to alter food genes
May 15, 2022
On 24 July 2019, Boris Johnson stood outside 10 Downing Street and delivered his first speech as prime minister. Among the many pledges he made was a promise that he was going “to liberate the UK’s extraordinary bioscience sector from anti-genetic modification rules”. Such a move would allow the nation to “develop the blight-resistant crops that will feed the world”, he added.
Almost three years later, Johnson’s government has eventually got round to outlining, in last week’s Queen’s speech, how it hopes to achieve this goal. This will be done through the forthcoming genetic technology (precision breeding) bill. The proposed legislation has been welcomed by leading UK biologists, although they also warned last week that a long battle lies ahead before UK plant and animal science is at a stage to save the world.
“This bill will let us take a few baby steps,” said Prof Nick Talbot of the Sainsbury Laboratory, a plant research institute based in Norfolk. “It is good news, of course, but we will still need a lot more public debate about the issues involved before we can really progress.”
Examples of the problems that lie ahead are illustrated by novel products created by UK scientists, such as blight-resistant potatoes and crops rich in omega-3 nutrients. These are still unlikely to get approval through the proposed new regulatory framework and will remain stalled in the regulation purgatory that has enclosed them for the past few years.
A basic problem is that there are two different genetic technologies that are used to create new crop varieties. The first is known as genetic modification (GM) and typically involves taking an entire gene from one plant and inserting it into another.
In this way, the host plant acquires the characteristic displayed by the original plant – protection against a particular disease, for example. Developed in the 1990s, GM crops became the focus of virulent campaigning that was based on the unfounded claim that “Frankenfoods” made from such plants were “unnatural” and a danger to health and the environment.
The second technology is more recent and is known as gene editing. Two of its creators, French researcher Emmanuelle Charpentier and Jennifer Doudna, from the US, won the 2020 Nobel prize in chemistry for their work on developing CRISPR-Cas9, a key gene-editing technique. It allows scientists to alter the makeup of a gene without adding new DNA. They merely tinker with an organism’s existing genetic makeup, allowing them to create crop strains with new attributes – such as drought resistance – but without adding genetic material.
It is this technique that was highlighted in the Queen’s speech last week. By contrast, GM technology is unlikely to be included, scientists have concluded. “The government seems to be saying there is a problem with GM plants but these nice gene-edited crops will be exempt and not caught up in tight regulation,” said Prof Jonathan Jones, who is also based at the Sainsbury Laboratory.
For two decades, Jones and his team have worked to create a blight-resistant potato known as the PiperPlus. In every respect it is identical to the Maris Piper, the most commonly grown potato in the UK – except for one key difference. It is resistant to blight, a devastating agricultural scourge that costs UK farmers tens of millions of pounds every year.
“Farmers have to spray their fields 15 times a year to protect their potatoes,” Jones told the Observer. “Their tractors spew carbon dioxide into the atmosphere and compact the soil in the fields, and the chemicals they spray can get into the water supply.”
The PiperPlus could sidestep these issues – but faces a major problem: it was created by GM technology and, at present, there are no signs the new bill will provide a regulatory framework for approving plants created this way. According to the Department for Environment, Food and Rural Affairs, the new bill will create a regulatory regime for plants and animals that “have genetic changes that could have arisen through traditional breeding or natural processes”. That definition would allow gene-edited crops and animals to be raised on UK farms but not those derived from GM techniques.
Thus crop varieties are still going to be regulated not on their properties, but on the method used to create them. “Regulation of genetic technologies should be based on the outcome of any genetic changes rather than the current focus on the technology used to make a genetic change,” warned Prof Dame Linda Partridge, vice-president of the Royal Society.
This point was backed by Prof Johnathan Napier, of Rothamsted Research. “The problem is that GM is a more powerful technology. There are some things that gene editing cannot do but GM can, and that is going to be a problem if we want to develop new strains of crops that can withstand droughts and heatwaves and also provide us with new sources of nutrition.”
As an example, Napier pointed to his team’s work in creating plants that make omega-3 fatty acids. These nutrients have been shown to help prevent heart disease and stroke, and may also play protective roles in cancer and other conditions. The world’s principal source of omega-3 nutrients is fish, but as global stocks dwindle, the planet faces a critical shortage.
“Our omega-3 crops have been trialled and tested and would be a solution but are considered tainted because they were created using GM techniques,” added Napier. “We need the government to kickstart a new approach to plant science. This bill should be seen as just a start to that process.”
Other scientists were careful to stress the benefits of creating regulations for controlling the release of genetically edited crops and animals. At the Roslin Institute, outside Edinburgh, scientists have used this technology to delete sections of a gene in pigs, a move that has created a breed that is resistant to porcine reproductive and respiratory syndrome, a serious ailment that can cause widespread deaths on pig farms.
“We have been working on creating resistant pigs this way and are now ready to pass it on to breeding companies, so this proposed legislation comes at a very good time,” said Prof Alan Archibald, who is based at Roslin. “We could also consider using this technology to breed pigs that are resistant to African Swine Fever, a major killer across the world.”
Roslin’s work raises another issue, however. The new legislation outlined in the Queen’s speech will apply only to England. Scotland has devolved control of such regulations, and given that the SNP maintains its majority control in the Scottish government through a coalition with the Green party, it is not at all certain that similar legislation will be passed north of the border. As Archibald put it: “It could get messy.”
In short, the UK is still a long way from liberating its “extraordinary bioscience sector”, although an encouraging start has been made. What is also clear is the urgency of the need to pursue new plant and animal research and ensure new products get into fields and farms as soon as possible.
As scientists have warned, the world’s population is likely to reach 10 billion by 2050 and new disease-resistant strains of crops and breeds of farm animals will be needed to feed the world. At the same time, global heating threatens to devastate crops as the world warms up. Crops that can survive droughts are also urgently needed, say researchers.
“Agriculture has a major impact on the environment,” said Prof Dale Sanders, director of the John Innes Centre in Norfolk. “It produces far more carbon emissions than the aviation industry, for example. In addition, fertilisers are made from fossil fuels and, along with pesticides, they can also have a major, damaging effrect on local ecology. Only science can save us from these sorts of problems.”