What kinds of traits have been engineered into agricultural crops?
Most of the commercial genetically engineered (“GE”) crops grown in the United States contain genes that provide either pest resistance or herbicide tolerance. GE corn and cotton contain Bt genes from the soil bacterium Bacillus thuringiensis. The proteins produced from those genes kill certain insect pests when the proteins are ingested by those insects, eliminating the need to kill those pests with chemical pesticides. GE soybeans, corn, canola, and cotton contain one of several bacterial genes that protect the crop from particular herbicides. Those genes allow certain herbicides to be applied to the crop without harming it, giving farmers more flexible use of herbicides to control weeds. Finally, some varieties of squash and papaya have been engineered with plant virus genes that render those crops resistant to those plant viruses.
