COM 0882.045 2006-2008 - Laserfiche WebLink

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Chinese taro transformed with an oxalate oxidase gene completely arrested the spread of the pathogen Phytophthora colocasiae which is the organism responsible for leaf blight. In comparison, untransformed Chinese taro was almost dead at 12 days after inoculation with the pathogen. Other preliminary tests showed that Chinese taro transformed with an oxalate oxidase gene or a chitinase gene slowed the spread of the fungal pathogen Sclerotium rolfsii but the disease eventually killed the plants. How do the products of these disease resistance penes work? Oxalate oxidase catalyzes the breakdown of oxalate to produce hydrogen peroxide which inhibits growth of pathogens. Remember the hydrogen peroxide your mother used to cleanse your skinned knees? Chitin is a hard, semitransparent material that's found in the cell walls of some fungi and molds. Chitinases degrade the chitin found in the cell wall of fungal pathogens, causing the fungi to die. Stilbene synthase catalyzes the production of resveratrol, a compound that is found naturally in grapes and peanuts. Resveratrol stops the growth of fungal pathogens. Could these disease-resistance genes accidentally move from GE Chinese taro? Not likely. First, Chinese taro variety Bun long rarely flowers under the environmental conditions of Hawaii. Second, traditional Hawaiian taro varieties rarely produce viable seed in Hawaii without human intervention. Taro breeders must manually move the pollen from one taro flower to another flower when its female part is ready because the insect that naturally pollinates taro flowers is not found here. Also, since taro is vegetatively propagated, it would be easy to maintain traditional taro varieties without a high risk of accidental transfer of disease-resistance genes from GE Chinese taro. How might these disease-resistance genes affect the nutrition of taro? The health risk of GE food is so low that after more than 10 years of experience, GE crops have been grown on more than a billion acres and been consumed by millions of humans without a single negative health issue 4. The federal government requires intensive testing of genetically engineered crops for possible health and environmental hazards prior to approval. The official position of the American Dietetic Association is that "Agricultural and food biotechnology can enhance the quality, safety, nutritional value, and variety of food available for human consumption and increase the efficiency of food production, food processing, and food distribution, and environmental and waste management"5. Did you know that if you eat cheese made in the United States, almost certainly you are eating the product of a genetically modified organism? 4 International Service for the Acquisition of Agri-Biotech Applications, 2006, Brief No. 34-2005. 5 Journal of the American Dietetic Association, Feb. 2006, p. 285-293.