Science - April 26, 2010

Environment affects maize plant more than gene technology

The impact of genetic manipulation on maize plants is no greater than that of regular breeding methods. Environment differences are far more influential, research by Rikilt and partner institutes suggests.

The researchers compared the gene expression and protein production of two transgene maize varieties with those of a variety obtained through traditional breeding.  They assessed the functioning of sixty thousand genes and the presence in the plant of a comparable number of proteins and chemical substances known as metabolites. They are publishing their findings in the next edition of Plant Biotechnology Journal.
Variation
The researchers compared the gene expression over three growing seasons of a traditional variety and two transgene ones: one with resistance to the pestiferous European maize borer, and one with resistance to the herbicide Roundup. They also determined the natural variation in the gene expression by comparing the varieties at one location. And thirdly, they identified the effect of growing conditions by comparing the maize varieties at several locations during one season. The researchers concluded that the environmental influences led to a far greater variety in gene expression, proteins and metabolites than did the different genotypes.
Safety
'This suggests that genetic modification has no more drastic side effects than traditional breeding', says Van Dijk. 'But that does not yet mean that this applies to other crops too, or that GM technology is safe. We have found a few differences between the GM varieties and the traditional crop. Further research should show whether these differences affect the safety of the product. There were no indications of any harmful effects on health.' Yet Van Dijk does think this model study will help researchers to make a rational assessment of the safety risks. 'With this broad analytical approach, certain toxicological studies will probably become unnecessary in the long term.'

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