Using genomicsThe study of genes and their functions, John Helgeson and Jiming Jiang created a blightA plant disease that attacks both potatoes and tomatoes. Late blight is caused by a fungal pathogen or germ that survives from one season to the next in infected potato tubers. resistant potato. Sounds like a happy ending, right? Perhaps, but their wonder-spud may run into a different type of resistance in the marketplace. Many consumers are leery of plants that are "genetically modified". Truth be told, humans have genetically changed crops since the beginning of civilization. In fact, ancient peoples in the Americas changed corn so much that it can no longer survive without humans.
Not all genetic modifications are the same. Some involve inserting genes that don't come from plants. It is this idea that scientist have created freaky "Frankenfoods" that generates fear and concern among consumers. Many people remind us that our past is filled with man-made disasters. They question whether scientists really know enough to play with an organismAny living being capable of reproduction, growth, and maintenance's genetic structure to be sure of its safety! These fears place an ethical and political spin on this new science.
Supporters say that GM crops can produce more food with less land, can provide better nutrition, and can be made to resist disease and predatory insects with less herbicides and pesticides. Opponents say that engineered plants could transfer their resistance to weeds; that transferred genes could make their way into the environment with unknown consequences; and that GM crops could hurt plant and animal biodiversity.
However, genomics techniques don't necessarily involve inserting genes into a plant. Another technique, called "marker assisted breedingA process using genetic fingerprinting techniques that allows plant breeders to track genes that produce a desired trait to select plants that will reproduce that trait in their offspring. Marker assisted breeding allows plant breeders to speed up the results of traditional selective plant breeding." identifies, marks and tracks individual genes that produce specific traits from parent to offspring. This method takes the guesswork out of traditional selective breedingThe breeding of animals or plants for desirable traits or characteristics. It also blurs the definition of a GM crop.
Why didn't John and Jiming use marker-assisted breeding for their potato? It turns out the wild potato with the blight resistant gene has a different number of chromosomes than modern domestic potatoes, so they cannot interbreed naturally. The gene had to be inserted into the domesticated potato's genomeAll the genetic material in the chromosomes of an organism, whether animal, plant, or microbe.
The irony of the potato story is that human domesticationThe process of genetically adapting wild animals and plants into cultivated forms that suit the interests of human beings removed potatoes' genetic resistance to blight in the first place. Now, humans have the ability to put it back. Are there any examples of testing genetically modified plants for safety? In spring of 2006, the University of Arizona in Tucson conducted an environmental and productivity study of "BT cotton"—a variety that is genetically modified to produce its own pesticide. The study showed that farmers used half as much conventional pesticide and the effects on the environment were the same as non-BT cotton. There was no difference in the amount of cotton grown, but farmers made 9% more because they spent less on pesticides.
