Unexpected reactions in GE maize

Scientists from Switzerland and Norway have published the results of an investigation into GE maize MON810, which produces an insecticidal protein, a so-called Bt toxin, Testbiotech reports. In the investigation, two varieties of maize MON810 were grown in climate chambers and subjected to defined stress conditions i.e. cold/wet and hot/dry. According to the authors, this is the first study to report on whether there is a relationship between transgene expression and protein production in Bt maize under changing environmental conditions.

The results are surprising: In general, the Bt content was on average higher in one variety compared to the other. Under cold/wet conditions the content of Bt increased in one of the varieties, but not in the other. The activity of the DNA construct inserted into the plants was lowered significantly under hot/dry conditions in one variety, but this had no influence on the Bt content. These results show that the stress reactions of maize containing the DNA for the MON810 event are not predictable in a reliable way.

“These findings are highly relevant for the risk assessment of MON810 or 1507 maize and other genetically engineered plants expressing single or several Bt proteins”, says Christoph Then for Testbiotech. “The paradigm applied in the current risk assessment of genetically plants has to be reviewed. We suggest that all further authorisations for genetically engineered plants producing insecticidal toxins are suspended.” This pilot project was realised with the support of Testbiotech and with funding from the Manfred Hermsen Umweltstiftung. Further funding was made available by Altner-Combecher-Foundation, GEKKO Foundation and Foundation on Future Farming. The full article is available from http://www.testbiotech.org/en/node/1200