Breeding Causes More Changes In Plants Than Genetic Engineering

It is often maintained that genetic interventions may have unintended consequences for the metabolism of modified plants and by implication for human health and the environment as well. A recently completed research project compared gene expression and plant substances in different conventional and transgenic barley lines. GMO Safety discussed the findings with Uwe Sonnewald, one of the project leaders.
 
GMO Safety: What were the aims of your research project?
Uwe Sonnewald: In our joint project with the University of Giessen and the State University Washington we aimed to test the extent to which different varieties of barley differ from one another, the extent to which transgenic and non-transgenic barley plants differ from one another and the impact of environmental factors. To this end we studied gene expression in the plants and the composition of the metabolites, i.e. the metabolic products. We originally intended to study the leaves and the grains but as it turned out we were unable to complete the grain studies due to repeated crop vandalism in Giessen.

GMO Safety: What are your most important findings?
Uwe Sonnewald: Firstly, we found virtually no differences between the genetically modified barley plants under investigation and their non-transgenic parent lines, either in terms of metabolites or gene expression. We then found that colonisation of the barley plants by mycorrhizal fungi produced virtually no changes in gene expression, but did change the metabolites. This demonstrates the value of combining both approaches. We also discovered that differences between conventional varieties can be considerable. Approximately 1,600 genes in the two conventional varieties that we compared are differentially regulated. We don't even know the function of many of these genes.