The Sainsbury Laboratory prepares for blight-resistant GM potato trial
Copyright Archant Norfolk 2016
After gaining government consent to field-test a genetically-modified potato, Norwich-based scientists are seeking to prove the agricultural benefits of GM technology – and win public approval from those who still doubt it.
The subject of genetically-modified (GM) crops – and whether their commercial cultivation should be allowed in the UK – has polarised opinions for many years.
And scientific reports in recent weeks have reignited some familiar arguments.
First, the US National Academies of Science (NAS) concluded that GM crops are safe to eat, after reviewing more than 900 studies and data covering the 20 years since they were introduced in America.
That was quickly followed by a report by the UK’s Royal Society, which also says there has been no evidence of ill health effects – and although it acknowledges engineered crops may cross-breed with closely-related plants in the wild it says GM crops are no more likely to have “unforeseen effects” than those produced using conventional cross-breeding.
But despite those studies, and the length of time which GM has been in the human food chain, opponents still claim the health and environment implications of the technology have yet to be properly tested, and that any benefits have not been sufficiently proven to justify the expense of the research.
And it is within this melting pot of opinion that a Norwich-based research team hopes to make the case for the agricultural benefits of GM potatoes.
The Sainsbury Laboratory (TSL) has won government approval to conduct field trials on a designated site at the Norwich Research Park between 2016 and 2019.
It is part of a project to develop a Maris Piper potato that is resistant to blight infections and nematode pests, bruises less and produces less acrylamide when cooked at high temperatures.
Prof Jonathan Jones, who is leading the project, said: “We have been looking at wild relatives of potatoes for new sources of resistance to potato late blight, a devastating disease which caused the Irish potato famine.
“It necessitates 10-20 chemical sprays per year for potato growers. The thinking is very simple: Would it not be great to replace all these sprays with genes which confer resistance?
“The analogy I use is that it is like antibiotics. If you just rely on one antibiotic to treat a bug, the bug will find a way around it. But if you find multiple sources of resistance to disease it will be much harder for the bug to work around.
“The aim is to find three resistance genes for blight and stack them into a commercial variety – we hope to be able to trial that next year.”
Prof Jones was one of the authors of the Royal Society report, saying he hoped to inform a “rational debate” on new technologies and scientific methods.
He said: “ We want a scientifically-enfranchised public, otherwise it is undemocratic. All of these issues require a degree of understanding , so we want the public to be engaged with it.
“One of the main points of the report is that there is absolutely nothing bad about the method itself. GM is just a method to get DNA into plant cells. The question of what purpose we should be using it for is absolutely an important question to think about, but there is nothing wrong with the method itself.”
In the case of the potato project, Prof Jones said the method involves using a bacterium called agrobacterium, which occurs naturally in soil and typically causes crown gall.
“We have removed the genes (from the bacterium) that have this undesirable trait of causing uncontrolled growth, and replace it with what we want to put in,” he said. “It delivers DNA into the plant cell. It is the Royal Mail of DNA, and the delivery method is completely benign.”
In response to suggestions that genetically-engineered crops have not reached their promised yield potential, Prof Jones said: “It is a bit of a ‘straw man’ argument. “When people talk about yield improvement, they are not talking about the intrinsic performance of the plant. They are talking about the potential to harvest useful output from that crop.
“It (GM) does not improve the intrinsic performance of the soya bean, for example, but it makes it a lot easier to control the weeds in a soy bean crop and get a decent performance. You could get the same result if you used lots of herbicide.
“My question to those who disagree with this is: What is your alternative recommendation to soya farmers about how to control weeds?”
The project team aims to generate enough suitable plants to start testing them in the field in 2017.
A previous field trial in 2011/12 found that a single gene had conferred blight resistance into potatoes, but the aim of the next one will be to assess how that variety performs against potatoes with three sources of resistance to blight, plus other beneficial traits.
TSL researcher Dr Marina Pais said: “We will have our control plants, which are normal Maris Piper potatoes, then we have these transgenic plants with single resistant genes, and then hopefully the stack.
“The idea is we plant them in May and we look at them throughout the season and if late blight comes I want to see if my plants are still alive, while the control plants get infected and die. That would be a good result. In principle, it is best if the infection happens naturally.
“The goal of the field trial is to test the performance of the plants in a real situation, so it will be great to get the plants out of the labs and the glasshouses. I am in plant science to help solve problems. That is what I always wanted to do. So to see plants out in the field is a step towards it.”
Peter Melchett, who runs an organic farm near Hunstanton in west Norfolk, was one of 28 volunteers arrested for ripping out a trial crop of GM maize from a farm in Lyng in 1999 – although all were later acquitted of criminal damage.
Now, as the policy director at the Soil Association, he remains steadfastly opposed to GM technologies, including the Sainsbury Laboratory’s new blight-resistant potato trial.
“The fundamental problem is two-fold,” he said. “Firstly there is no market. You can grow all the potatoes you want, with as many GM-stacked traits you want, but if no-one wants to buy them it is a complete waste of time and money.
“The second problem is that with blight resistance there has been really significant progress by developing through non-GM breeding techniques, and a number of varieties are increasingly resistant. So GM is a solution that no-one wants for a problem that has largely been solved through other methods.
“I think people all over the world are rejecting GM because there is an underlying unease and uncertainty about this technology and what it is doing to our food. This is not the public being frightened or ignorant, this is the public listening to a range of scientific opinions – particularly from those not working with GM research or working for GM companies – who have found reasons to think there may be problems in terms of human health.”
On the scientific claims that there is no evidence of adverse health effects in 20 years of GM consumption, Lord Melchett said: “It is a claim that has been repeated endlessly. It is an extraordinary thing for scientists to say.
“No-one has done any research looking at human health over a period of time to see whether eating a GM diet has any adverse effects on your health. “Yet what the NAS and the Royal Society and government ministers are saying is: ‘Americans have been eating GM food for 15 years so it must be safe.’ But actually American health has got worse over the last 15 years and no-one has done any research to find out if GM is the cause. Absence of evidence is not the same as evidence of absence.
“I am a great supporter of science and there is some wonderful research being done at places the John Innes Centre which could have some practical application for farming, using better techniques than GM. But there are still some scientists stuck in the bygone age of GM.”
The GM potato field trial will take place on a small area of land, no larger than 1,000 sqm, at the John Innes Centre in Colney.
Approval has been granted from 2016 to 2019, and trials will be performed between May and November.
To contain the GM plants and prevent them from mixing with conventional crops, an isolation distance of 20m to other potato varieties will be observed, and a 3m fence will be built to prevent larger animals coming into contact with the plants.
The Sainsbury Laboratory says the field trial site will be visited regularly by trained lab staff to monitor the trial and to “prevent any adverse environmental effects or adverse effects to human health”.
At the end of each season, all harvested material (plant tops and tubers) will be placed in sealed containers and removed to an authorised waste disposal facility. After each season during the three-year trial period, the plot will be left fallow and monitored for volunteer plants and ground-keepers.
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