Why I'm happy to `play God' with your food

Prince Charles has condemned genetic engineers for manipulating nature. But scientists argue that their work will benefit us all. By Jonathan Jones

Prince Charles has given voice to widespread public concern about transgenic crop plants. We genetic engineers are "playing God" and threatening "living pollution that cannot be recalled". But is there real cause for concern?

I've worked with transgenic plants for 15 years, in the US and the UK. The more I do it, the less I worry about it. It's striking that in contrast to the nuclear and chemical industries, there are no whistleblowers; people who work with the technology do not experience alarm about how it is being deployed.

Remember when nuclear power was going to make electricity "too cheap to meter"? We've all been disappointed. But that doesn't mean that everything every scientist says is untrue. Much is made of the BSE scare, but scientists said they could not be sure if brains of BSE cattle were safe to eat, and MAFF perversely took this to mean there was no need for caution. Blame MAFF, not the scientists.

Environmental concern led me to a career in plant biology; we cannot take our high-tech society back to a low-tech agriculture. There is no doubt that increased human populations throughout the globe are extremely destructive to the environment. It simply is appalling how rainforests are cut down, fisheries fished out and water resources are overutilized and polluted. But the solutions require more science, not less. Science of course is not the only solution; strong and effective laws are needed to prevent environmentally destructive practice.

I'm proud to work on how plants resist disease. As a consumer, I worry about fungicides and insecticides in the food I and my children eat. The solution? Agriculture based on genetics, rather than chemistry. Delivering crop protection inside the plant is less polluting than spraying chemicals.

Early deployment of transgenic plant technology includes herbicide resistance and insect resistance. Not surprisingly, herbicide manufacturers seek to engineer varieties that resist their herbicides. Herbicides are not all the same: some are persistent and toxic to animals, and others are rapidly inactivated on soil contact and non toxic. Monsanto's Roundup is a less undesirable herbicide than those it replaces. Soybean farmers in the US have broadly embraced Roundup-ready soybeans, because it makes it easier for them to prevent weeds over-running their crop.

In cotton, insect damage is severe and 60 per cent of all US insecticide applications go on this crop. Very substantial reductions are now being made in cotton insecticide application by engineering insect resistence. With the same technology, big yield increases in maize have also been obtained, with more effective insect control. How can this possibly be a bad thing?

Roundup resistance is accomplished by slightly modifying an enzyme that is present in all plants, and which is a target of the herbicide, to a form that is insensitive to the herbicide. In every other respect the plant is identical. A typical plant carries 20,000 genes, most of which we do not understand the function of.

Genetic engineering of plants involves adding two or three genes to this complement of 20,000, and the genes that are added are extremely well understood. I do not believe the statements we so often hear that "we cannot predict the consequences of our actions". We can predict them very well. We can also predict the consequences of large scale application of agrichemicals, and I know which I prefer.

Is this technology signficantly different from traditional plant breeding? Yes. Is it worryingly different? No. In fact it's better. It's more precise, it's easier to control, it enables one to take the properties of a plant more directly towards a specific goal.

Contrary to popular belief, there are no tomatoes out there in stores with fish anti freeze genes in. But I would be unfazed if there were. After all, every time we eat fish we eat a lot of fish DNA and it doesn't seem to have done us any harm so far.

When we eat tomatoes we are eating material that carries disease resistance genes that have been bred in from wild relatives of tomato, and perhaps 2,000 other genes unavoidably brought in at the same time that are not the same as in the cultivated plant. This is a much less well controlled exercise, with less easily forseen consequences, because we don't know what these genes are. Nevertheless, the human population continues onward and upward.

We have always been making substantial changes to the environment through agriculture, and not every change has been a disaster. For example, it is quite unnatural to grow potatoes, tomatoes and sunflowers in Europe. These are American plants. Doubtless they displaced many local varieties; so what? It is irrational to fetishise transgenic plant technology as a technology where protracted public consultation is required. Why not also have a public enquiry every time a new fungicide or insecticide is released?

There's an irony about the complaints about engineering herbicide resistance. The worst possible outcome about which alarms are sounded is that the herbicide resistance will "get out" and give rise to "superweeds". But without the resistance gene in the crop, the herbicide would not be applied. If it did get out, so that the weeds were also resistant, we would simply revert to the status quo ante, and the herbicide would not be used.

This is surely precisely the outcome that opponents of herbicide use are seeking. It is also precisely the outcome that the herbicide manufacturers would wish to avoid; the last thing they would wish is for farmers to have to apply their competitors herbicides for weed control! So they have an incentive to insist on sensible use.

What about consumer choice? I think the realistic answer is that most food products will potentially derive from GM plants, but in the same way as there is an organic shelf in the store, there will be a "non GM" shelf. It is tragic that the organic movement has adopted the view that no GM food can be regarded as organic, since GM plants are the most realistic approach to reducing agrichemical applications.

Ultimately, whether GM foods qualify as organic is a theological argument. I, and I think most sensible consumers, will prefer agriculture based on genetics to agriculture based on chemistry. Genes are a lot safer than organophosphates.

Jonathan Jones is a professor at the Sainsbury Laboratory, Norwich.