EXTRACTS: The potato carries a gene, neomycin phosphotransferase II (nptII), that bestows on the potato resistance to a number of antibiotics, including kanamycin and neomycin. Both the World Health Organisation and the European Medicines Agency (EMEA) have judged those antibiotics 'critically important' for human health, says Contiero.

The GM potato war
Colin Barras explains the latest row triggered by genetic modification
Daily Telegraph, 23 November 2007 http://www.telegraph.co.uk/earth/main.jhtml?view=DETAILS&grid=A1YourView&xml=/earth/2007/11/23/scigm123.xml

Where genetic modification of crops is concerned, environmental groups are as vehemently opposed today as they were at the height of the GM food controversy of the 1990s.

But is GM science now in a position to allay some of the fears of environmental groups?

The GM food controversy looks likely to re-ignite in the coming months, as the European Union is poised to give the green light to commercial cultivation of a genetically modified potato. BASF is expected to begin commercial growing of Amflora, their GM potato, early in 2008.

Although Amflora is intended primarily for industrial purposes - it contains a starch that is useful in the paper industry - it may also be used in animal feed, which is where the controversy begins, says Marco Contiero, Policy Director of Genetic Engineering at Greenpeace's European Unit.

The potato carries a gene, neomycin phosphotransferase II (nptII), that bestows on the potato resistance to a number of antibiotics, including kanamycin and neomycin. Both the World Health Organisation and the European Medicines Agency (EMEA) have judged those antibiotics 'critically important' for human health, says Contiero.

He worries that if the gene passes to bacteria in the environment or in the gut of animals that eat the potato, antibiotic-resistant bacterial strains could appear with the potential for a negative impact on human and animal health.

'Under EU law, genes of this kind which 'may have adverse effects on human health and the environment' should have been phased out by December 2004,' Contiero says.

The fact that, in February, the European Food Safety Authority (EFSA) judged BASF's potato safe for commercial planting despite the presence of nptII is evidence that the EU is pushing for a commercial license regardless of the scientific evidence, thinks Kirtana Chandrasekaran, Real Food Campaigner at Friends of the Earth.

'There is tremendous pressure at the EU level to approve these crops for cultivation and a lot of attempts to push the application through,' she says. 'Member States have consistently rejected GM applications [but] they tend to be approved at the Commissions' level.'

But Peter Oakley, a member of BASF's Board of Executive Directors, disagrees. 'There's always a scepticism to new technology,' he says. Amflora is likely to be granted a commercial license because it has been shown to be safe by the most stringent of tests, says Oakley.

'If we tried to register a kiwi fruit [for commercial planting] in the EU today we would fail,' Oakley says. The kiwi fruit has so many proteins that are foreign to the European palate that, despite its natural origins, it would be refused a license under the EU's rigorous rules because of its potential to cause allergic reaction, he says.

Arno Krotzky is Managing Director of Metanomics, a subsidiary of BASF Plant Science, the company that has produced the potato. He says that Amflora can pass the tough tests required by EU law because genetic modification of crops has become a precise science in recent years.

GM science is often described as a crude tool with unpredictable consequences, but Krotzky thinks that, following a decade of study, GM scientists can offer greater precision than their critics realise.

'Back in the 1990s everyone was sequencing genes,' he says. There were projects to map every gene in anything from bacteria to humans, but there was little emphasis on studying how those genes worked, says Krotzky.

'At BASF we were actually looking at the function of genes,' he says. 'Now we not only know that the gene is there, we know what it does.'

Studying the function of genes in crops is a lengthy process that involves removing one gene at a time from the plant genome and growing the modified crop in controlled greenhouse conditions through a number of generations, says Krotzky.

Over this time, researchers can assess the precise impact each gene has on plant growth, and identify those that increase yield or benefit agriculture in some other way.

The information from this new technique offers the prospect of GM crops tailor-made for specific situations, and because the science is controllable, such crops will carry minimal risk of unwanted side effects, says Krotzky.

For BASF's GM potato, the modification process involved turning off a gene responsible for the production of an uneconomic form of starch.

Amflora contains only the form of starch that is useful for the paper industry. 'GM plant technology is now about doing something in a well-defined, directed way,' says Oakley.

But Contiero worries that, even if BASF researchers can control the precise properties of the GM crop, they have conducted too little research into the environmental impact that their GM crops could have.

[The] effects [Amflora has] on biodiversity were not considered by BASF,' he says. 'And the data analysed [by EFSA during their assessment of Amflora] concern the effects of surrounding wildlife on the potato, rather than the impact of the potato on the environment.'

Contiero thinks that this is why BASF included the nptII gene in their GM potato. The gene will help protect the potato from the environment, but the impact that nptII may have on the environment was not fully considered, he says.

Oakley admits that the addition of the gene has worried environmentalists, but says the scientific evidence suggests the gene is safe. 'The types of antibiotics [that nptII offers resistance to] are found all over agriculture and have been used of 20-30 years,' he says.

'We could replace nptII with another gene, but it would take 6-7 years and double the cost of development of Amflora. That's why we don't just replace it.'

Oakley argues that the environment poses a much greater threat to the GM potato than the potato does to the environment. 'Cultivated crops [including GM crops] only survive because you farm them,' he says.

'If you stopped farming, most crops would disappear; they're just not competitive [in the natural world].'

But GM crops are [not?] so vulnerable, or incapable of impacting on the environment, says Chandrasekaran. She points to evidence that pesticide resistant GM crops are passing their resistance to weeds by pollen transfer. 'This results in a vicious circle of escalating use of weed killers to tackle the resistant weeds,' she says.

'Given its failure to deliver on any of the benefits promised so far, there is no reason to believe that we need GM to face the current challenges,' says Chandrasekaran.

She says that conventional breeding programmes are helping to produce drought-resistant crops, often touted as a goal of genetic modification.

'A team of Japanese Researchers at Shizuoko University has been experimenting with crossing African and Asian rice to produce strains that perform well under drought conditions,' she says. 'The crossing is by conventional breeding techniques only; no genetic modification or other forms of biotechnology are involved.'

Colin Barras of Imperial College London was one of the winners of the 2007 Bayer/Telegraph Science Writer awards. Open to those aged 15-28, click for details of the 2008 competition.

http://www.science-writer.co.uk/

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