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gene responsible for drought tolerance and insert that gene into a different plant. The new genetically-modified plant will gain drought tolerance as well. Not only can genes be transferred from one plant to another, but genes from non-plantorganisms also can be used. The bestknown example of this is the use of B.t. genes in corn and other crops. B.t., or Bacillus thuringiensis, is a naturally occurring bacterium that produces crystal proteins that are lethal to insect larvae. B.t. crystal protein genes have been transferred into corn, enabling the corn to produce its own pesticides against insects such as the European corn borer. For twoinformative overviews of some of the techniques involved in creating GM foods, visit Biotech Basics (sponsored by Monsanto)http://www.biotechknowledge.monsanto.com/biotech/bbasics.nsf/index or Techniques of Plant Biotechnology from the National Center for Biotechnology Educationhttp://www.ncbe.reading.ac.uk/NCBE/GMFOOD/techniques.
What are some of the advantages
of GM foods?
The world populationhas topped 6 billion people and is predicted to double in the next 50 years. Ensuring an adequate food supply for this booming population is going to be a major challenge in the years to come. GM foods promise to meet this need in a number of ways:
• Pest resistance Crop losses from insect pests can be staggering, resulting in devastating financial loss for farmers and starvation in developingcountries. Farmers typically use many tons of chemical pesticides annually. Consumers do not wish to eat food that has been treated with pesticides because of potential health hazards, and run-off of agricultural wastes from excessive use of pesticides and fertilizers can poison the water supply and cause harm to the environment. Growing GM foods such as B.t. corn can help eliminatethe application of chemical pesticides and reduce the cost of bringing a crop to market4, 5.
• Herbicide tolerance For some crops, it is not cost-effective to remove weeds by physical means such as tilling, so farmers will often spray large quantities of different herbicides (weed-killer) to destroy weeds, a time-consuming and expensive process, that requires care so that the herbicide doesn't harm the cropplant or the environment. Crop plants genetically-engineered to be resistant to one very powerful herbicide could help prevent environmental damage by reducing the amount of herbicides needed. For example, Monsanto has created a strain of soybeans genetically modified to be not affected by their herbicide product Roundup ®6. A farmer grows these soybeans which then only require one application ofweed-killer instead of multiple applications, reducing production cost and limiting the dangers of agricultural waste run-off7.
• Disease resistance There are many viruses, fungi and bacteria that cause plant diseases. Plant biologists are working to create plants with genetically-engineered resistance to these diseases8, 9.
• Cold tolerance Unexpected frost can destroy sensitive seedlings. Anantifreeze gene from cold water fish has been introduced into plants such as tobacco and potato. With this antifreeze gene, these plants are able to tolerate cold temperatures that normally would kill unmodified seedlings10. (Note: I have not been able to find any journal articles or patents that involve fish antifreeze proteins in strawberries, although I have seen such reports in newspapers. I canonly conclude that nothing on this application has yet been published or patented.)
• Drought tolerance/salinity tolerance As the world population grows and more land is utilized for housing instead of food production, farmers will need to grow crops in locations previously unsuited for plant cultivation. Creating plants that can withstand long periods of drought or high salt content in soil...
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