Genetically Engineered Bt Corn

Farmers don't just plant a crop and then wait for the profits to roll in at harvest time. They must manage the crops in order to get a good yield. They invest in herbicides (glossary id 82) to keep weeds from choking out crops, and insecticides (glossary id 83) to protect their crops from pests like the European cornborer. The cornborer attacks corn plants, reducing the yield. Chemical insecticides are one effective way to combat this pest, but scientists have hit upon another solution.

· Scientists know that a soil bacterium Bacillus thuringiensis (Bt) is a natural pesticide.
· Scientists isolated the blueprint for a protein within the bacteria's DNA. This protein kills insects.
· This Bt gene was combined with the recombinant DNA (glossary id 27) of corn. By inserting the Bt DNA into the corn gene, the makeup and heredity of the corn was changed. The Bt protein that kills insects is now made by the corn plant. It is a hereditary trait that can be passed on to its offspring, which will be resistant to the European corn borer.
· Genetic engineering created a new type of corn.

Other genes and the proteins made by Bt have been combined and used effectively against potato beetles and cotton boll worms to protect against pests and help increase potato and cotton yields.

It is important to understand that pests can become reistant to pesticides like Bt. In the future, cornborers could become resistant to Bt corn.

x-axis: year
y-axis: percent of genetically engineered Bt crops.
Bt Corn -first available in 1995, 8% in '97, 26% in '99, 19% in 00'-01'

Source: U.S. Department of Agriculture. "Adoption of Bioengineered Crops." (Online.) September 2002.

Explore More: Genetic Engineering
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