The Seeds Of Genetic Modification
February 18th, 2013
by Amy Mayer
The vast majority of the corn and soybeans in the United States grow from seeds that have been genetically modified. The technology is barely 30 years old and the controversy surrounding it somewhat younger. But how did it even become possible?[audio:https://kvnonews.com/wp-content/uploads/2013/02/2-18-13.mp3]
First, a note about terminology. Genetic modification, gene transformation and genetic engineering, even biotechnology in an agricultural context, all refer to the same thing: taking a gene from one organism (usually bacteria) and inserting it into another.
The scientists who discovered this technology back in the 1980s werenâ€™t even looking for ways to improve plants. Iowa State University agronomy professor Kan Wang was on the laboratory frontline then, working with biochemists studying agrobacteria and plant tumors.
â€œTheir motivation [was] to cure human disease,â€ she said. â€œBy working on the plant disease, they hoped [they] would get some knowledge, but they completely opened up a different can of worms.â€
Scientists discovered certain agrobacteria could infect a plant, cause a tumor, and then leave the disease behind even after the bacteria was removed. Itâ€™s like if you had strep throat â€” a bacterial infection â€” but then after your course of antibiotics, the strep is gone but the sore throat remains â€”forever. Sounds horrible, right? The researchers figured out the evil bacteria had a particular plasmid that did the dirty deed.
â€œWhat happens is a piece of the DNA comes off of this plasmid and it goes through [the] bacteria cell wall and cross[es] through [the] plant cell wall and then gets into [the] plant cell nucleus,â€ Wang said.
Once inside, it integrates into the plant cell chromosome and permanently transforms the plantâ€™s genetics. This understanding changed the course of the research, Wang said.
â€œThe light bulb switched on and we say, hey, we have a tool!â€ she said.
The research focus moved away from human cancer. Scientists in both academic and industry labs set about determining how they could harness this tool to move good traits. St. Louis-based Monsanto emerged early as a leader in biotech. The company demonstrated successful gene transfer in tomato plants in 1987.
â€œWe have scientists that figured out that gene that the bacteria moved? [We] take that gene out and we put a gene into the bacteria that weâ€™d like to have moved, and the bacteria move the gene for us,â€ said Tom Hoogheen, a tour guide at Monsantoâ€™s Chesterfield Village Research Facility near St. Louis.
In a long dimly lit hallway, he pointed to a large flat-screen monitor showing an illustration of the soybean genome. He said the key is to identify a protein that has a desired effect on a plant and then figure out what gene to transfer to force the plant to produce that protein.
â€œWhat if I can find a protein that slows down sap flow in a corn plant? Doesnâ€™t need as much water â€”drought,â€ he said. â€œWhat if I can find a protein that allows a plant to photosynthesize a new way? So I can spray RoundUp over the top and not kill it?â€
RoundUp is Monsantoâ€™s widely used herbicide, which previously farmers had to be careful not to spray on their crop plants, because it would kill everything. But inserting the bacterial gene in the soybean seed made the plants resistant to RoundUp. Hoogheen noted the researchers working on RoundUp resistance found the vital gene in bacteria living in the wastewater treatment plant at the place where RoundUp was made.
In 1996, after meeting newly established regulatory requirements, RoundUp Ready soybeans hit the market. So from â€œa-haâ€ moment to farmersâ€™ fields took less than 10 years.
Today, genetic engineering is ubiquitous and controversial. With young technology, there is only so much data about safety and long-term implications. And now that the technology is out of the lab and in peopleâ€™s pantries, many people are skeptical of the science and fearful of the implications.
â€œSome people call it like Frankenseeds,â€ said Mike Stahr, manager of the Seed Lab at Iowa State University, adding public perceptions vary by culture. In Europe, GMO products remain more closely regulated than in the U.S.
â€œThereâ€™s just more of a concern for some reason in Europe about youâ€™re messing with the genetics. Iâ€™ve done a great deal of testing and people ask me whether Iâ€™m concerned about biotech seeds,â€ he said. â€œWell, Iâ€™m not.â€
Stahr has a small farm. Even during last yearâ€™s drought, heâ€™s seen good results from seeds containing modern traits, including genetically engineered ones. Within the scientific community, though, there is some recognition the safety demonstrated today canâ€™t predict the ultimate impact on humans, plants or the environment.
Several states, including Iowa and Missouri, are considering mandatory labeling of foods containing genetically modified organisms â€” which is many. More than 90 percent of the countryâ€™s corn and soybeans contain GMOs, which means theyâ€™re in products from cereal to candy to soda.
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