Where did the genetic material that is injected into GM corn come from?

Expert response from Stephen Moose

Professor of Plant Functional Genomics, Department of Crop Sciences, University of Illinois

Friday, 05/06/2015 14:04

The genetic material that is used to produce GM corn comes from other genes found in nature that have been shown to program desirable traits. There are many genetic traits that have been introduced into GM corn, but the two most common ones are production of a protein toxic to certain insect pests, and resistance to certain herbicides.

For the insect toxins, the genes come from a common soil bacterium named Bacillus thuringiensis, nicknamed Bt. These bacteria were initially discovered to cause sickness in silkworm caterpillar colonies, and cultures of these bacteria have been sprayed as an organic pesticide for more than 50 years. In the 1980s, scientists discovered the exact genes that made the Bt toxins, and in the 1990s scientists added certain Bt genes to crops like corn.

For herbicide-resistant GM corn, the genes come either from bacteria known to survive in the presence of the herbicide or even from other plants that are naturally resistant to the herbicide. Usually these genes break down the herbicide chemical, but in some cases they just provide an alternative gene insensitive to the herbicide if the plant’s own version of that gene is sensitive.

The Bt insect toxin or herbicide-resistance genes typically have no impact on the plant, except when it is eaten by an insect or sprayed with an herbicide. Ongoing research is testing genes for improved tolerance to environmental stresses like drought, or improved nutrition, or improved efficiency in making bio-energy. These types of genes may benefit the plant or have no effect, but they will not be detrimental to plant performance. Otherwise, the seed companies would be selling an inferior product and customers wouldn’t buy it.