Purdue News

Agriculture's new horizon Biotechnology's course moves into the mainstream Tom Milligan, a row-crop farmer in Dana, Ind., a small town near the Indiana-Illinois border, grows genetically engineered crops, and he admits to being worried about what people might think. Not the people in his small hometown of 900 people--"Nobody here in Dana really has made any comment about it," he says. Instead, the soft-spoken Milligan is concerned about the people in Europe and Japan, and their views on genetically enhanced crops. "I'm worried that some of our customers don't want to accept our crops," he says. In the modern world of agriculture, the high-tech, globalized future that has been predicted for decades finally arrived about three planting seasons ago. Off and running Central to this new world of agriculture are genetically enhanced methods of production in both crops and animals. The fact is that if in the past year you've topped a sandwich with cheese or margarine, gobbled down a bowl of cereal, or swilled a soft drink, you've probably ingested foods that came from genetically engineered crops. Although people in agriculture have been heralding the promise of genetically enhanced crops for 20 years, for most of that period, few products made it to market. Quietly, over the past three years, that has changed in a major way. Marshall Martin, professor of agricultural economics and director of Purdue University's Center for Agricultural Policy and Technology Assessment, says that many common foods now use biotechnology in their production and processing. "The genetically engineered enzyme chymosin is used in more than three-quarters of the cheese produced," Martin says. "Bt-corn, which allows the corn plants to resist the corn borer, has found wide acceptance in 1998. So everyone is already eating foods produced through biotechnology." In fact, the use of genetically enhanced corn has increased from 400,000 acres in 1996 to three million acres in 1997 to an estimated 17 million acres in 1998. Each year, approximately 80 million acres of corn is planted in the United States. Biotechnology is used to produce some of our most common foods: Corn produced through biotechnology is being used in many familiar foods, such as breakfast cereals and taco shells. It also is used to make corn syrup, which is used as a sweetener in many foods, such as soft drinks, baked goods, candies and many others. Soybeans are used in hundreds of food products, including cooking oil, candies and margarine. In 1997, about 20 percent of the soybeans planted in the United States were genetically enhanced. Dairy farms use biotechnology to produce hormones to increase milk production per cow. This biotechnology-derived hormone, bovine somatatropin, is used in about one-third of the dairy cattle in the United States. "We are at the same stage in biotechnology as the personal computer industry was in 1981," says Purdue Dean of Agriculture Victor Lechtenberg. "We're just starting to see the first products come on the market." The code of life The comparison between computers and biotechnology is one that works on several levels. For one thing, both computers and living organisms organize their essential information in a similar fashion. Computers are directed by a series of ones and zeroes, which is known as the binary code. Living organisms all use a code made up of four parts, a quaternary code. Instead of ones and zeroes, the information is conveyed by a series of four chemicals, adenine, thymine, guanine and cytosine, which geneticists simply call A, T, G and C. Like a computer code, the arrangement of these four chemicals strung together forms genes, which contain the information that tells cells whether you are to be a linebacker-sized human or a lemming. Scientists first learned that they could manipulate these four chemicals to form new genes in the mid-1970s. "Recombinant DNA was first developed in 1974," says Mark Hermodson, head of the biochemistry department at Purdue. "Today, even high school kids can stitch genes together. The development of the science has been mind boggling. The rise of the industry in the United States has also been mind-boggling." According to Hermodson, biotechnology began when some scientists noticed that certain strains of bacteria were resistant to viruses whereas other strains of the same bacteria weren't. By investigating the problem, the scientists found that the resistant bacteria contained enzymes that could cut sequences of DNA at specific sites, leaving large portions of DNA intact. These enzymes, which go by the unwieldy name of "restriction endonucleases," allowed scientists to isolate specific genes. "It was basic research, scientists trying to understand the process that didn't have anything to do with animals or plants or humans at all. But it led to a whole industry and the ability to manipulate and sequence DNA," Hermodson says. "It was completely unpredictable." The science accelerated in the early 1980s. In 1982, a somewhat eccentric scientist from California was driving home from a day spent surfing and realized that one of the basic properties of DNA is that it synthesizes itself. (The story, especially the surfing connection, may be apocryphal, but it has become a legend in U.S. laboratories.) Scientists knew that they could separate the strands of DNA by heating it. By taking enzymes that copy DNA from heat-loving bacteria that had been isolated from the geysers of Yellowstone National Park, it was possible to copy each of the two strands of DNA together again, doubling the number of copies. Now the procedure is automated with machines that help reproduce the DNA. By repeating that cycle of separating the strands and then copying each of them 10 times, over 1,000 copies are produced--20 cycles produces one million copies of the DNA. Hermodson says this technique often is encountered in sensational crime trials. "When they talk about looking at DNA from a crime scene, they amplify it up using this technique and compare it with other DNA," he says. "They extract the DNA from a drop of blood at the scene, and then run it through 30 cycles or so, and they get enough DNA to compare with the DNA of the suspects." Hermodson says that this technique has allowed breakthroughs in the laboratory to come at incredible speed. "The beauty of biotechnology is that it has speeded up biological research enormously," he says. "It's given us understanding of how things are regulated in living organisms that we couldn't have approached 10 or 15 years ago." This ability to produce small amounts of substances found in the body is bringing about a marriage between the pharmaceutical industry and agriculture. One direction is the development of nutriceuticals, foods that contain pharmaceutical products. For example, by using DNA cloning techniques, William Langridge of Loma Linda University has developed a potato that contains an antigen for cholera. Cholera kills as many as one million people each year in developing countries. Simply by eating the raw potato, people are able to be immunized against the disease. Langridge's next step is to put the antigen into a banana. Why? Bananas taste better than raw potatoes. Promises, promises Peter Goldsbrough, professor of horticulture at Purdue, says that recent well-publicized failures of biotech crops have led some people to mistakenly think that agricultural biotechnology is struggling to gain acceptance. That isn't the case, he says. "Biotechnology has had setbacks recently," Goldsbrough says. "Flavr-Savr tomatoes, which were the best-known biotech product, were pulled from the market, and a virus-resistant squash also was pulled from the market. But this is not the death knell of agricultural biotechnology." According to Goldsbrough, Flavr-Savr tomatoes failed because of unexpected requirements of a new product, not because of concerns over biotechnology. Introduced in 1994, the Flavr-Savr tomatoes promised the taste of home-grown tomatoes from the grocer's cooler. Because they had a long shelf-life, they could be allowed to ripen on the vine and then shipped to the supermarkets. "The problem was that they were using the same equipment to pick and ship the ripe, soft Flavr-Savr tomato as they had the hard, green tomatoes," Martin says. "The loss from damage to the crop was as much as 30 percent. By the time they tried to adapt peach-packaging equipment to handle the tomatoes, it was too late." Fresh-tasting, genetically enhanced tomatoes may be headed to market finally in 1999 ("It's called 'Endless Summer.' Aren't those marketing people clever?" Goldsbrough laughs), but the bumpy introduction of crops is still leaving some users feeling like they are trying to view Web pages on an old Commodore 64. For example, Milligan says that many farmers in his part of Indiana are upset that some seed companies have tacked a surcharge, which they call a "technology fee," onto the price of genetically enhanced seed. Not surprisingly, this isn't popular. "I only planted Bt-corn this spring because my seed dealer gave me 10 bags of seed," Milligan says. "I wouldn't buy it, so he finally just gave it to me." At more than $100 per bag (including the technology fee) the free seed was worth more than $1,000. But Milligan questions more than the price strategies. "It doesn't yield as well as the other new seed, especially the soybeans," he says. "I think what they've done is enhance some old seed lines that don't perform as well as the new lines." Despite the problems, Milligan says that he expects to plant more genetically enhanced seed in the future. "I think they'll soon put the enhancements into their top seed lines," he says. "And, I think there are some good new varieties on the horizon. I've been told that they've just about developed a corn variety that resists rootworm, and that will be worth waiting for. We are just seeing the beginning of a mountain of possibilities for genetically enhanced crops." Goldsbrough agrees that many new crops soon will be coming to market to address most, if not all, of the major pests. "Biological processes are so complex and diverse that somewhere there's an organism that can kill the soybean cyst nematode, the leading soybean pest," he says. "We will find that organism, isolate the relevant genes and put them into our soybean crops." Gold rush is on Such optimism is reflected on Wall Street, where the attractiveness of the marketing opportunities that exist, coupled with the enormous potential for new products, has led to a sort of gold rush as investors and companies try to position themselves for maximum profit. Like the frenzy over Internet companies, everybody wants to be in on biotech. The field is so enticing that electronic giant Motorola announced in early 1998 that it is thinking of moving the company into biotechnology. "Where the transistor in the 1940s was an extraordinary invention, life sciences are going to change the next millennium that way," Motorola CEO Chris Gavin told USA Today . "It is too fundamental a technology change for us not to find a way to contribute." The excitement over biotech has caused money to fly around Wall Street in a dizzying fashion. In May, chemical giant Dupont sold its oil unit Conoco so that it could plow the $25 billion from the sale into biotechnology products. Also in May, Monsanto bought seed companies DeKalb and Delta Pine & Land for a reported $4.1 billion. In June, the pharmaceutical company American Home Products merged with Monsanto, for a reported $34.6 billion. Analysts say the merger will speed the interweaving of pharmaceutical and agricultural products. Not everyone is buying into this genetically enhanced rosy future, though. Jane Rissler, senior staff scientist with the liberal political group Union of Concerned Scientists, says that increased use of these crops is "a high wire without a safety net." Rissler's group is asking the Environmental Protection Agency to put as much as half of the nation's farmland off limits to genetically enhanced crops. Last winter, the U.S. Department of Agriculture (USDA) proposed standards for organic foods that would have allowed genetically enhanced crops to be labeled organic. After receiving strong public opposition to the proposal, this past spring the USDA withdrew genetically enhanced foods from consideration as organic foods. Milligan says that he and his fellow farmers consider the crops safe. "We're not paranoid about it," he says. This is a view that is shared by most people in the United States. Acceptance varies around the world Thomas Hoban, a professor of sociology at North Carolina State University, has studied the public's acceptance of genetically enhanced foods for the past 10 years and has found that most Americans are comfortable with the technology. "Based on over 5,000 interviews, we consistently have found that between two-thirds and three-fourths of people in the United States are positive about biotechnology, which means that they are willing to buy products, support its use and see benefits to society for its continued use," he says. "This support has stayed very constant for the past decade." Hoban says that although support for biotechnology and its products is high in the United States, it is even higher in Canada and Japan. Hoban says that even in Europe, which is considered hostile to biotechnology, there are some countries that accept the technology. "The Netherlands, Finland, the United Kingdom and a few other countries are also quite positive," he says. Some of the strongest resistance to biotechnology in general, and genetically engineered crops in particular, is in central Europe. Already, Austria and Luxembourg have banned biotech crops completely. Such talk gives farmers like Milligan heartburn. "We will only grow what people will buy," he says. Hermodson says that scientists have to make sure that they are doing safe, ethical science, and leave society to make its own decisions. "All scientists can do is to be concerned about safety, and to be concerned about long-term scientific issues, such as ecological issues," he says. "Sometimes we're not as tuned into those issues as we should be, although I think we're much more conscious of those issues now than we were 20 years ago." Biotechıs next step One of the frequent criticisms of biotechnology is scientists often use genes from bacteria or other organisms in their work. Hermodson says that at the biochemical level, the four chemicals that make up DNA--A, T, G and C--are all the same, whether they originate in a bacterium or in a fish. "Even how genes are expressed and how proteins are produced in different organisms is similar," Hermodson says. "We work in the organism that's most approachable, that's easiest to work in, not the one that everyone thinks about, like cows or corn." Scientists are hoping to take greater advantage of the similarities of gene expression in living organisms. A new area of biology, called genomics, is revolutionizing how scientists conduct genetic experiments. Genomics hinges on the recently discovered fact that certain traits appear on approximately the same location on the chromosomes of similar organisms. For example, drought tolerance in rice is found in about the same location on the chromosome as drought tolerance in corn. "This started 10 years ago with work with corn geneticists," says John Axtell, an agronomist at Purdue and the first chairman of the National Academy of Science's Applied Biology committee. "When the scientists started looking at the genetics of sorghum, we found some interesting things. The similarity to corn, rice and other cereal crops is so great that you can use genetic probes from corn to map genes from sorghum. We mapped the genome of sorghum by using genetic maps of corn. "We're constantly finding genes and discovering what they do," he says. "Now we won't have to go through the 50 years and 500 careers to learn how to improve these crops." Story by Steve Tally Purdue News Service: (765) 494-2096; e-mail, purduenews@purdue.edu To the Purdue News and Photos Page