|Wild rice. CC photo by Denrdoica cerulea on Flickr|
The vast majority of GM crops now being grown commercially have had a gene inserted to make them resistant to glyphosate herbicide.
After spraying with glyphosate, the yield of the GM crop is protected because the weeds competing for nutrients are killed.
Gene escape from glyphosate-tolerant crops into wild relatives has never been considered an important problem because unless the wild GM derivatives are sprayed with the herbicide, they will have no special fitness advantage and no reason to run riot. But, this 'wisdom' has been challenged by a team of Chinese scientists.
Glyphosate kills plants by inactivating an enzyme, 'EPSPS'*. EPSPS is vital to a number of key metabolic processes because it's responsible for generating a class of essential amino acids (the building block of proteins). These amino acids are vital to the formation of, for example, the plant's supportive material (lignin), plant growth hormone, and a huge range of immune-system substances, which together can account for as much as 35% of a plant's biomass.