NOTE: A response from Dr. Doug Gurian-Sherman of the Union of Concerned Scientists, and a former biotech specialist at the EPA, to the article we circulated: Drought resistant GM crops ready 'in four years'
James Randerson, Science correspondent
The Guardian, October 8 2008
http://www.guardian.co.uk/environment/2008/oct/07/gmcrops.food
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Re: Drought resistant GM crops ready 'in four years'

This example illustrates several possible weaknesses of genetic engineering as a way to solve complex agricultural problems, as well as weaknesses in the regulatory system that leave us vulnerable when problems with GE crops are not detected.

The gene targeted by this company has been reported by them in the science literature to provide significant drought tolerance, and to provide normal yields under adequate moisture - an important consideration. But genes and proteins often have multiple functions - a lesson learned both from the last decade of genomic studies, and classical population genetics previously, and this is often true of enzymes like those engineered by this company. Those other functions, where they exist, might have important negative consequences for agriculture, the environment, or public health, but are often very
difficult to identify - especially by regulatory systems that are not very rigorous.

In this case, a recent study (by a different group of scientists) has determined that the same gene as is used by this company to confer drought tolerance also makes plants more susceptible to a variety of important plant disease organisms. The gene may be a basic part of plant disease resistance. It may confer some drought tolerance - but at the
expense of making the crop substantially more susceptible to diseases, which could result in crop loss and higher pesticide use. At this point, the implications are not entirely clear.

This example also illustrates weakness in environmental regulation of GE crops. In the U.S. (and elsewhere) there are no requirements to test for particular types of environmental harm for non-pesticidal GE crops (such as ones developed for drought tolerance). Crop developers are supposed to report changes in pest susceptibility during field trials, but because pest presence can be very hit-or-miss during field trials, they may easily miss something like increased susceptibility to some diseases or insects. It is often not until commercialization and widespread cultivation that problems emerge.

Some might argue that the reporting of disease susceptibility of drought-tolerant crops to pathogens shows that problems with GE crops will be detected and addressed. But this is a very haphazard - and therefore unreliable - way of ensuring safety.

- Doug

Doug Gurian-Sherman, Ph.D.
Senior Scientist
Food and Environment
Union of Concerned Scientists
1825 K Street, NW
Suite 800
Washington, DC 20006-1232
phone: 202-331-5436
fax: 202-223-6162
www.ucsusa.org ( http://www.ucsusa.org/ )