GMO Regulations: Keeping Killer Plants at Bay

Crops developed through the use of recombinant DNA technology are singled out for a series of safety tests that are not performed on plants modified through other techniques, such as mutagenesis or wide crosses.  Food safety testing ensures that GM crops are as safe as non GM crops, while environmental safety testing ensures that GM crops will not become weeds, turn relatives into weeds through gene flow, or harm beneficial organisms.

The tests are geared towards both intentional and non-intentional changes.  Intentional changes consist of the new protein made by a transgene and its metabolites, which are tested for toxicity and allergenicity. 

Unintentional effects are hypothesized to arise from dormant pathways that are re-activated by DNA insertions or other mutations, to produce toxins.  As unintentional effects are of an unknown nature, they cannot be tested for directly.  Therefore, the presence of novel compounds is inferred from altered plant growth or altered crop composition.  Thus extensive agronomic studies which measure phenological traits are conducted, along with measurements of all key components of the harvested product.  In some cases, animal feeding studies are conducted with the transgenic crop as well.

Thus far, unintentional changes have been elusive.  The most common interpretation is that current evaluations are not rigorous enough to detect these changes, thus leading to ever-increasing testing requirements.  At last estimate, the cost of safety-testing associated with getting one new crop to market was placed at $34 million.