Plant Biotechnology and Genetics: Principles, Techniques and Applications

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But there are other techniques for creating genetic variability between the black-
and-white of traditional breeding and genetic engineering. Since the 1940s, mutagenesis
breeding has been used to induce genetic variability, especially in cereals, by exposing
seeds to doses of mutagens—compounds that induce mutations in DNA—such as ionizing
radiation or mustard gas. The practice is still used today, as are other techniques. Should
such products also be regulated? Or is it the process itself of genetic engineering that is
inherently risky?
Proponents and critics have sparred on this point since the advent of genetic engineering,
but the scientific community and North American regulators have consistently maintained
that it is the endproduct, not the process, that should be regulated. Varieties of potatoes and
celery, for example, have been produced through traditional breeding that were later discov-
ered to contain unacceptably high levels of natural compounds. This view that the endpro-
duct should undergo a safety assessment regardless of how it was produced has been
enshrined in the Canadian Novel Food Act (1999) and was reaffirmed by an expert
panel of the US National Academy of Sciences (2000).


15.6.2 Health Concerns

In 1994 the Flavr Savr tomato became the first whole, genetically engineered food to be
approved by the US Food and Drug Administration (FDA) and, subsequently, Health
Canada. Results of rodent feeding trials, submitted as part of the dataset that regulators
reviewed, showed no difference between conventional and genetically engineered tomatoes.
It also showed that rats do not like tomatoes.
The experiment highlighted one of the difficulties in assessing the safety of genetically
engineered foods. For example, the genetically engineered field maize grown in North
America (and now elsewhere) contains a gene from the common soil bacteriumBacillus
thuringiensis, and is known as Bt corn. Regulators and several international scientific
panels reasoned that because humans have been ingesting Bt without effect for decades
(it is also widely used as an organic spray) and because the Bt toxins (in this case specific
to the European cornborer) are proteins—and because any toxin protein remaining after
processing would be quickly digested in the human gut—Bt corn is safe; or, in the
words of the language-challenged, the Bt corn was found to be substantially equivalent
to traditional corn. Any commercial concern wishing to sell a genetically engineered
food, or indeed any new or novel food, must demonstrate substantial equivalence, based
on molecular, nutritional, and toxicological data, to the appropriate regulatory body. If sub-
stantial equivalence is more difficult to establish, then the identified differences, or new
characteristics, would be the focus of further safety considerations. The more a novel
food differs from its traditional counterpart, the more detailed the safety assessment that
must be undertaken. Future products of agricultural biotechnology, where complex path-
ways within a plant are altered to produce more nutritious foods, may require a more
elaborate safety assessment. The genetically engineered foods available today are the
result of relatively simple gene transfers, harnessing systems that are based in nature.
However, the attempt to improve any food can possibly lead to unexpected conse-
quences. For example, in the laboratory, in one instance, a human allergen was transferred
from one crop to another. During the preliminary assessment process, the company immedi-
ately discontinued the experiment. For the critics of biotechnology, the experiment proved
that allergens could be transferred, and therefore, untold risks lay in the manipulation of
food structure. For supporters, the incident showed that the regulatory system worked.


352 WHYTRANSGENICPLANTS ARE SO CONTROVERSIAL
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