Scientists have developed a way for crops to detoxify glyphosate, the herbicide trademarked as Roundup by the US-based Monsanto company. It may lead to increased competition and challenge Monsanto's dominance of the genetically modified (GM) crop market.
The researchers first identified a bacterial enzyme that detoxifies glyphosate. Through a process of 'directed evolution' they shuffled the genes that produce the enzyme, making it 10,000 times more efficient. When the genes were inserted into maize plants it enabled them to tolerate six times the concentration of glyphosate normally applied.
Most GM crops grown worldwide are engineered to resist glyphosate through the 'Roundup Ready' technique developed by Monsanto. But the herbicide remains in the plants and can interfere with reproductive development, reducing yields. Preliminary studies suggest that the new approach should also work in other crops.
References: Science 304, 1089 (2004) / Science 304, 1151 (2004)