Miracle Grow?

Nancy Marie Brown
September 01, 2001

"A traditional farmer could never cross a fish with a strawberry, wrote Mark Dion, an artist included in the exhibit "Paradise Now" at the Exit Art gallery in New York last year.

chips and cheese curls

Seventy percent of our snacks of genetically modified. Is that good or bad?

It's the kind of comment Nina Fedoroff was expecting at her Frontiers of Science lecture, "Monsters or Miracles? Genetically Modified Organisms in our Food," last January. For the last year or so, all the news about genetically modified or "GM" food had been bad. Threats to the monarch butterflies. Boycotts in Europe. Starlink corn—approved as animal feed, not human food—found in Kraft taco shells. Two days before Fedoroff was to speak, biotechnology giant Monsanto was dissected in a full-page article in the New York Times. There, the FDA scientist in charge of biotech from 1979 to '94 opined glumly, "Food biotech is dead."

If so, Fedoroff would argue, many people in the future will starve.

"This is a subject that really gets people excited, and I really look forward to your questions," Fedoroff said as she clipped the microphone to her collar. She has a nice speaking voice, musical and earnest, and was casually dressed in sneakers and slacks, as if she were just running out to the store, not facing a possibly hostile crowd. She seemed almost disappointed when they proved to be restrained and polite; she believes strongly in the social value of her science and is not afraid to speak out.

Fedoroff studies plants, lately using the techniques of genetic engineering. She's never crossed a fish with a strawberry, and she agrees that many of the first products of biotechnology, like the "ice-minus" bacteria (engineered with a fish gene to protect strawberries from frost) or the "Flavr-Savr Tomato" (which ripens more slowly and so can sweeten on the vine) have been public relations disasters and commercial flops.

She did not mention the fact that genetically modified food is already a mainstay of the American diet: According to the New York Times, 70 percent of all processed foods and soft drinks on our supermarket shelves contain ingredients from genetically modified crops; other GM foods include much of our corn, potatoes, soy, summer squash, tomatoes, canola oil, and beer.

Nor did Fedoroff point out that the first biotech food ingredient to be approved (in 1990, according to the National Agricultural Biotechnology Council) was a substitute for rennet, a protein extracted from the stomachs of calves and necessary for cheesemaking. Produced by genetically modified bacteria, it now has an 80 to 90 percent market share and is considered to be vegetarian, kosher, and halal.

Instead, Fedoroff spoke about those traditional farmers and their crosses. "Traditional plant breeding is not so old," she explained. "It's a product of the 20th century. I'm not here to tell you there are no problems with genetically modified organisms. But are the problems familiar ones, or is there something new here, something discontinuous from anything we've experienced before?

"We've never asked traditional plant breeders to explain to us what they are doing, and they are modifying our food too."

People have been selecting which plant varieties to grow for millennia—ears of corn originally were small, purple, and dry. Broccoli, cauliflower, cabbage, and kale were once all the same plant. But it's only since the late 1800s, when Gregor Mendel's pea experiments were accepted, that we've understood the principles of inheritance, that traits are dominant or recessive, and how to use that knowledge to reach a goal.

Said Fedoroff, "What plant breeders seek to do is to improve the usefulness of the crop. To increase the yield. To identify and bring in disease-resistance or insect-resistance genes. And they've sought to push the limits of what is possible.

"They find a disease-resistance gene in a wild plant and cross it with a crop plant—breeding in 100,000 weed genes. Then they try to get rid of the weedy parent genes they don't want." Those "weedy parent genes" could bring in toxins or allergens, something critics of biotechnology fear from genetically modified crops. For this reason, Fedoroff argued, genetically modified crops are safer than new varieties of traditionally bred crops. With genetic modification, we insert a few genes; with traditional breeding, we add thousands. With genetic modification, we can predict what the inserted genes will do; with traditional breeding, we can't.

"Gene flow" is another risk critics identify with genetically modified crops. But gene flow—the idea that genes inserted into a crop could "flow" into a weed, creating a superweed, such as a weed resistant to insecticides—is just as likely for traditionally bred plants as for genetically modified ones, since the only way genes can "flow" is via the plant's pollen. If the crop and the weed couldn't cross-pollinate before genetic engineering, they can't cross-pollinate now. If they can crossbred, then whatever advantages are bred—or inserted—into the crop will eventually turn up in the weed. "It's a real problem," Fedoroff admitted, "but not a new problem."

A third criticism of genetically modified crops, that they will reduce biodiversity, also is nothing new: most of our traditional crops are already monocultures.

"The notion that we have not been engaged in modifying plants for our own purposes, the notion that the plants we use today are Ônatural,' is absurd," said Fedoroff. "The ability to live in civilizations depends on the ability to modify plants."

Biotechnology, she argued, is just a continuation of traditional plant breeding. At its heart is the clever harnessing of a plant pest, the bacterium Agrobacterium tumefaciens. "You've probably seen it," Fedoroff said. "When limbs are sawed off a tree, a lump grows. This kind of bacterium can get into a wounded plant cell and actually engineer the plant. It subverts the plant cells to make food for the bacterium and, in addition, it slips in a couple of genes that produce growth hormones—so you get a lump."

Agrobacterium acts by inserting a plasmid—a small ring of DNA—into the plant cell. To engineer a plant, scientists modify this plasmid. First they take out the genes that produce growth hormones and create food for the bacterium. Then they insert the genes they want the plant to express. Genes, for example, to make corn resistant to the herbicide Round-Up or to produce Bt, a popular insecticide.

"Then you return the plasmid to the bacterium and allow the bacterium to get into the plant cell." An easy way to do this is to cut up the leaves, dip them into a solution containing the bacteria, screen the leaf pieces to see which ones have picked up the bacteria and which haven't, and put the infected leaves on a special medium that encourages them to grow.

"And then—I have never gotten over the wonder of this part—it regenerates into a plant," Fedoroff said. "The little shoots get bigger, you can remove them and root them, and they turn into plants. It's quite remarkable."

Using this or similar techniques, scientists are working on breeding rice rich in vitamin A, bananas that deliver the hepatitis B vaccine, poplar trees that can clean up mercury pollution, sunflowers that make an oil to replace petroleum. As Gregg Easterbrook wrote in a New York Times editorial, The transgenic crops in the news today are just the first manifestations of a fundamental new idea. Much better versions are coming.

"Why do we care about genetically modified organisms?" Fedoroff asked. "In America, the reason is not apparent to us. We live in a wealthy country, blessed with arable land and a temperate climate."

We worry about monarch butterflies dying if they eat pollen from Bt corn. "How big a risk is that compared to the loss of their overwintering habitat in Mexico? Probably not even close by an order of magnitude," said Fedoroff. And why is the habitat for monarchs and other wildlife disappearing? So people can grow more food.

The population of the world is exploding. "Everybody's guess is that it will not be less than eight or nine billion before it stops growing," a third again as many people as the six billion reached in 2000, while the average amount of food produced per person peaked in 1985 and has been dropping since. "Looking forward, it's not at all clear that we'll be able to feed people, especially as their expectations rise."

By one estimate, humankind is farming the same amount of land—six million square miles—that was farmed 40 years ago, but feeding 80 percent more people. "And we're constantly losing land to salinization, desertification, overuse. Where are our productivity increases to come from?"

Nina Fedoroff, Ph.D., is director of the Life Sciences Consortium and the Biotechnology Institute. She is the Willaman Professor of Life Sciences in the Eberly College of Science, 219 Wartik Lab, University Park, PA 16802; 814-863-5717; nvf1@psu.edu.


Floral Genes

A flower’s shape and how it grows affect all aspects of a plant, says Penn State biologist Claude dePamphilis: pollination, gene flow, predation, and seed dispersal, as well as fruit and seed production.

More than 100 genes that control flowering are known, but most were found in a handful of laboratory plants—Arabidopsis, maize, and snapdragon (Antirrhinum). These do not begin to represent the many different species—around 300,000, says dePamphilis, who is proposing a Floral Genome Project. Scientists from Penn State, the universities of Florida, Michigan, and Alabama, and Cornell will identify genes for flowering in a wide range of species, 15 in all, including poppy, avocado, blueberry, asparagus, gooseberry, magnolia, and yellow poplar; they will build on data from plants whose genomes are to be sequenced soon, including rice, soybean, and tomato.

They hope to discover the origin of genes for flower development and to fill in the "missing links" of flower evolution. Among the results will be a Virtual Flower Web site for public use.

Claude W. dePamphilis, Ph.D., is associate professor of biology in the Eberly College of Science, 208 Mueller Lab, University Park, PA 16802; 814-863-6412; cwd3@psu.edu. Photo by Gerald Lange (gxl7@psu.edu) and Jennifer Anne Tucker of the Digial Photography Studio, which is suppported by Apple Computer, Calumet Photographic, Eastman Kodak, Megavision, Photographic Supply, M&T Mank and Rockwell Foundation.

—Jenai Young

Last Updated September 01, 2001