Oct 28, 2005

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The fructan potato

“We have been unable to find any significant differences.”

The fructan potato, which produces the polysaccharide inulin in its tubers as a result of a genetic modification, has been tested for its environmental effects for a number of years within the context of biosafety research. The findings indicate no noticeable safety problems. GMO Safety spoke to the director of the research group, Bernd Hommel, from the Federal Biological Research Centre (BBA) in Kleinmachnow

Dr. Bernd Hommel of the Federal Biological Research Centre for Agriculture and Forestry (BBA) in Kleinmachnow, directed the fructan potato research group

GMO Safety: The fructan potato has been the focus of field and laboratory studies for three years. Looking at the results, is it fair to conclude that the fructan potato displayed no noticeable problems?

Bernd Hommel: Yes, apart from modified growth patterns that’s a fair conclusion. But that’s not what we expected, since the genetic modification really represented a very dramatic intervention in genetic terms. The strains we studied were double transformants, in other words, genetically modified parent varieties were genetically modified a second time. The carbohydrate metabolism has also been changed to such an extent that a new substance, inulin, is produced

GMO Safety: What changes in growth patterns did you observe?

Bernd Hommel: The plants remained smaller overall and there was an increased density of hairs on the underside of the leaves. We then took a closer look at the possible consequences of these phenotypical changes, particularly with regard to the incidence of pests and diseases. Our working hypotheses were that denser hair growth deterred the female Colorado potato beetle from laying her eggs, and that a sparser canopy reduced the incidence of fungal attack. However we were unable to detect any significant differences in fungal, potato beetle or nematode infestation.

GMO Safety: Feed trials were also conducted. What were the findings?

Bernd Hommel: We wanted to know whether the genetic modification had resulted in any unwanted substances along with the desired production of fructans. Feed trials with pigs and analytical examinations established that the fructan potatoes were equivalent to conventional varieties in terms of content. There was a slight increase in glycoalkaloids, which include solanine, but this was well below the safety threshold. We also traced the DNA from transgenic fructan potatoes in the intestinal tract of the pigs and investigated its possible absorption into the bloodstream. We were in fact able to detect transgene-specific gene sequences in the stomach, but not in the gut. Transgenic DNA sequences were not found either in the blood or the internal organs.

GMO Safety: The fructan potato is no longer being developed at the Max Planck Institute in Golm. Why is this?

Bernd Hommel: Further work is being carried out on the fructan potato in the Netherlands. In Germany a different potato, the genetically modified starch potato, is looking very promising. The starch industry is very interested and the breeding of suitable varieties is well underway.

GMO Safety: Thank you for talking to us.