MPB's anaerobic work-out

Field testing of genetically modified crops has come to a virtual halt in Europe, and any GM plants that do make it to field trials run the risk of being torn up by protesters. In the U.S., the discovery of StarLink corn in seed corn has raised the issue of "genetic pollution" from modified to unmodified crop products.

MPB Cologne GmbH thinks it may have discovered a solution that avoids the production of recombinant proteins in the field. The company, which is pursuing plants as therapeutic factories rather than as foodstuffs, has developed an anaerobic gene expression system that uses a maize-derived promoter to express recombinant proteins in potato tubers. The promoter is silent under the potato's regular growing conditions, and thus no recombinant protein is produced in the field. But upon harvesting the potatoes and bathing them in nitrogen (or any anaerobic environment), the promoter becomes active and the recombinant protein is made...