Ludwig-Maximilians-Universität München
print

Language Selection

Breadcrumb Navigation


Content

Green gene technology

Experimenting on nature – a debate

Munich, 11/23/2012

The role of gene technology in agriculture is the subject of passionate debate. In a Research Focus organized by LMU's Center for Advanced Studies, various experts, such as plant biologist Jürgen Soll and sociologist Bernhard Gill, sought common ground.

Source: Jan Greune
Foto: Jan Greune

Some 12% of agricultural land worldwide now bears genetically modified crops. What is the figure in Germany?

Soll: No transgenic crops are currently being cultivated in Germany, not even in field experiments as far as I know. This situation is unlikely to change soon, and one of the largest German agrobiotech firms, BASF, recently moved its research division to the US. However, the volume of imports derived from genetically modified (GM) plants is quite considerable. Germany imports about 75 kg of transgenic soybeans per person per year, mostly for use as animal fodder. But, as I say, not much is grown anywhere in Europe.

Why is that?

Soll: First of all, because society has yet to reach a consensus on the utility and potential of GM crops. We in Germany live in an environment in which enough food can be produced by conventional methods. It is hard to convince the consumer of the advantages that transgenic strains offer.

Let’s take a well-known example, the so-called Bt maize developed by the American concern Monsanto. One variant carries a bacterial gene for a toxin to which the European corn borer, a grain pest, is susceptible. This maize strain has been approved by the EU, but some member states, including Germany, do not allow it to be cultivated. Why?

Soll: That is something I do not understand. The same toxin is sprayed on large areas of strictly controlled, Demeter-certified, organically farmed land. It is harmless to humans and other animals.
Gill: But the pest gradually becomes resistant to it.
Soll: Resistance will ultimately arise no matter what agent or mode of application one chooses. It is true that glaring errors in resistance management have been made in the US, but that does not invalidate the principle.

Monsanto – not exactly famous for reticence or restraint in matters of business – itself advises caution here. The company now recommends that 50%, not 20% as before, of the cultivated area should be given over to so-called refuges, plots planted with conventional maize that cannot produce the toxin, to reduce the selection pressure on the pest and slow the spread of resistance. One doesn’t have to be a diehard ideologist to conclude that Bt maize is not the big breakthrough in pest management.

Soll: As I just said, there is always competition between the plant-protecting effect of a pesticide and the evolution of resistance.
Gill: However, the expansion of Bt maize cultivation to vast areas of cropland will rob the organic farmer of a useful weapon, as the increased selection pressure will ensure that all problem insects eventually become resistant to the toxin.
Soll: If acquired resistance does spread, this could indeed pose a problem for organic farming in the US.

Is the German ban on the planting of Bt maize based on plausible estimates of risk or is it a roundabout way of preventing the cultivation of transgenics altogether?

Soll: The German Research Foundation (DFG) and the Federal Ministry for Education and Research have invested large amounts of money in risk assessment. None of their studies has found evidence that transgenics are a threat to the environment or to human health.

Are all the arguments in favor of the ban then invalid?

Soll: Cultivation of Bt maize is associated with a rise in biological diversity relative to conventional maize fields. The corn borer and some related species suffer, but the plant otherwise promotes diversity and sustainability by reducing the amount of insecticide the farmer needs to apply. The counterarguments are all motivated by the fear of losing votes.
Gill: We have seen Bavarian Prime Minister Horst Seehofer suddenly reverse his stance on the issue. At first, he was all in favor of transgenics, but then his pollsters whispered in his ear that his party, the CSU, might lose electoral support as a result. The more fundamental problem, however, is that EU law leaves no room for a politically motivated ban on the cultivation of Bt maize. So member states bend over backwards to argue that there are risks, although bans are actually inspired by other concerns, touching on the future of rural landscapes, the fate of agricultural traditions and on agricultural policy in the widest sense.

Do you think consumers would be less opposed to gene technology in agriculture if they knew more about it, as many people like to argue?

Soll: Studies have shown that factual knowledge is not what determines whether one is for or against. In places like the Ammersee region, where I live, rejection is popular, but the level of education is above average. So it’s not just a matter of how much a person knows.
Gill: These studies show that people have a particular mindset, which affects how they react to the information on offer, how they filter and interpret it. This makes them more likely to accept some arguments and to reject others. Information campaigns alone do not alter their basic attitudes.
Soll: On the other hand, the public did begin to take a more favorable view of so-called “red gene technology,” i.e. its application in medicine, when doctors were able to offer compelling reasons for its adoption. Why should diabetics use pig insulin when biotechnologically produced human insulin is available? The perceived benefits decided the argument. We are now in a similar position.

Which means more to the consumer? The price, or the nutritional quality?

Gill: Medicine was understood to involve direct intervention in natural processes long before the advent of gene technology. With food, we have the paradoxical situation that, for the past century, the food industry, which in effect “denatures” foodstuffs, has advertised its products as “natural.” So the consumer’s insistence on “naturalness” has a long tradition. In the US, this obviously plays less of a role, and in Northern Europe, the Netherlands especially, the idea of naturalness is not as important as in Southern Europe or German-speaking countries. The Protestant-Catholic divide may have something to do with that. Then in Germany there is a further split. In the South, where farms tend to be smaller, opposition to gene technology is far more widespread than in the North and East.

If the utility of the products on the market was more obvious to the average consumer than in the case of Bt maize or “gene soya,” would that increase their level of acceptance?

Soll: Perhaps. Consider sustainability. Modern agriculture as it is practiced today is not very environmentally benign. Potatoes, for instance, are often sprayed with fungicides to prevent blight, and organic farmers use copper salts containing heavy metals. In this sector gene technology can help the environment, and that might send a more positive message to consumers. We now have transgenic blight-resistant potato varieties. Transgenics of the first generation were herbicide-resistant but, in most cases, did not reduce herbicide use. The second generation focused on pest resistance, and some of these have had very positive social effects in certain regions of the Third World. The next generation could promote sustainable farming in the developed world.
Gill: But to do this, biotechnology must extricate itself from the embrace of the agro-industrial complex and pesticide makers. So far, all agricultural biotechnology has come from the chemical industry; in a sense, it has simply been an extension of chemical agriculture. Biotechnology must become more biological, i.e. more complex. Instead of enabling plants to make substances invented by other organisms, we must modify the plant’s own metabolism to suit local conditions. I can’t imagine that the chemical industry, which has done most to commercialize biotechnology, has any interest in such an approach.
Soll: But one can’t keep industrial firms out. Markets for staples like maize, rice, cereals, oilseed, are so big that they will always attract strong economic interests. Large concerns have less incentive to invest in crops like our local fruits; the scale is too small. A Swiss colleague of mine has used gene technology to generate scab-resistant apples. He isolate the resistance gene from an ancient apple stock that can no longer be crossed with modern varieties. He then used normal breeding methods to eliminate all genetic material derived from organisms other than apple. The result is a socalled cisgenic strain, one that has been modified by genetic transformation but retains no foreign DNA. Clearly, this can contribute to sustainability – particularly when one considers how apples are now grown, on the shores of Lake Constance for instance. For decades, the trees have been exposed to broad-spectrum antibiotics like streptomycin, which are applied in large weekly doses by spraying. Huge amounts leach into the soil, where they induce resistance. Yet debates on green gene technology focus on the far lower risk that soil bacteria might pick up resistances from transgenic plants.