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Genetic Engineering of Plants: A Topic for Classroom Debate

    Marie A. C. Langham
    South Dakota State University






    Genetic engineering of plants is a technology that offers an amazing potential to change agriculture and food production. People have been modifying plants throughout history by selection for maximum performance. However, these changes were gradual and primarily based on naturally occurring variation. Genetic engineering has the potential to rapidly change crop plants by incorporating traits that are not a normal part of the plant's genome. Some of these changes have produced plants that yield food products with enhanced storage (shelf life) or other marketing characters (color, size, flavor, etc.). In plant pathology, the insertion of new genes to increase a plant's defenses against pathogens holds the promise of managing pathogens that have not previously had effective control strategies. For example, the insertion of the coat protein gene from certain viruses into a susceptible crop plant has been shown to provide resistance to the target virus where none was available before. However, genetic engineering has engendered debate and controversy since it was first proposed.

    Today's students will be tomorrow's policy makers. Their decisions will determine the final outcome of this debate, and today's educational background will provide the basis for their future decisions. Some topics, which are a part of this continuing debate, provide good foundations for classroom discussion and projects. These issues include the following:

    • Should genetic engineering be utilized in food crops?

    • Which genes should be utilized in genetic engineering?

    • Is it appropriate to insert genes from a plant into another kind of plant?

    • Is it appropriate to insert genes from an animal into a plant?

    • Should we use plants to produce pharmaceuticals and nonfood products or does this endanger our food sources?

    • Should food products manufactured from genetically modified plants be required to state this as part of their food labeling?

    • What rights do farmers have to seed they produced from genetically engineered plants?

    • Will modified plants cross with related wild species and the inserted genes be carried into the progeny by genetic drift? Could this lead to "super" weeds?

    • Will the inserted genes cause a decrease in yield (yield drag) to the modified plants?.


    The following web sites can provide information and materials to assist in highlighting DNA, genetics, and genetic engineering in the classroom:

    • The International Food Information Council has released a new version of its speaker's manual, Food Biotechnology: A Communications Guide to Improving Understanding. A PowerPoint presentation, discussion guide, handouts, and assessment quizzes are provided. The guide is available for $19.95 at the following address: http://www.ific.org/publications/other/biotechcommguide.cfm.

    • DNA from the Beginning is presented by the Dolan DNA Learning Center, Cold Spring Harbor Laboratory. Using Mendel's basic work with peas, it provides animated presentations of the basics of DNA, genes, and heredity. It progresses to feature the work of other scientists on determining what are genes and how they function. This is available at http://www.dnaftb.org/dnaftb/.

    • Found at OLogy Home provided by the American Museum of Natural History, The Gene Scene provides information on basic genetics, the role of nature versus nurture, and the quest for the perfect tomato. A number of activities are included. It is found at http://ology.amnh.org/genetics/index.html.

    • DNA the Easy Way is a laboratory guide that provides an easy technique for isolating DNA from bacterial cells. It is available here through the APS Education Center at.



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    Leaf distortion and stunting of New Guinea impatiens infected with Impatiens necrotic spot virus (INSV). (Courtesy M. Daughtrey). Click image for an enlarged view and more information.