In an orchard in western Canada, genetically enhanced fruit trees kill insects on contact without pesticide sprays. Soon they will bear apples whose crispy white flesh won't turn brown even hours after being cut.
In Israel, poplar trees have been made to grow so fast that they could eliminate the need to log old-growth forests, while gobbling enough carbon dioxide to help slow global warming.
In North Carolina and Minnesota, experimental trees containing novel woody fibers can be digested into pulp without the tons of toxic chemicals that today poison the rivers around paper mills.
These dream trees and others with equally attractive traits are growing on scores of test plots around the world, part of a little-noted biotech revolution in forestry that experts predict will hit its commercial stride in the next five years.
Building on a decade of practice in crops such as soybeans and cotton, researchers at universities and at a few biotechnology companies have been perfecting the art of injecting novel genes into the cells of trees. Now, scientists say, they are poised to harness the enormous economic potential of the biggest, longest-lived and most biologically productive land plants on Earth.
Yet for all the promise that foresters see in the newly dawning era of genetically engineered trees, others see an ecological crisis in the making.
Trees can live hundreds of times longer than the biotech food crops already on the market, critics note. That makes it difficult to predict the long-term impact of genetically altered trees on the countless species that depend on them, including the soil-dwelling fungi and microbes that are the foundation of the planet's terrestrial food chain.
Opponents fear that biotech trees, to which scientists have added genes from bacteria, chickens and even humans, will provide poor habitats for beneficial insects and birds, transforming biologically diverse woodlands into sterile "Frankenforests."
They also warn that genes conferring resistance to leaf-chewing pests and chemical herbicides, which researchers are adding to tree DNA, may spread via windblown pollen to related tree species, creating woody weeds with unnatural advantages over their ancient cousins.
The emerging debate over genetically modified trees echoes the one already plaguing biotech agriculture, but with added scientific concerns unique to trees. The issue also strikes an emotional chord not engendered by genetically altered farm crops because it focuses on some of the most beloved and majestic life forms on Earth.
The stakes in the looming battle over biotech trees are high. Wood products amount to a $400 billion global industry, and the demand for paper and pulp products is expected to increase by 50 percent in the next two decades, exceeding supplies by 2010. At the same time there is growing pressure to save the world's remaining forests for wilderness and recreational purposes.
That fundamental conflict between consumption and conservation has both sides of the molecular forestry debate waving environmental banners. Proponents say biotech trees offer the only way to increase the production of lumber, paper and other wood products without decimating existing forests and exacerbating global warming.
"For every tree farm that produces twice the usual amount of wood on an acre of land you can leave an acre of natural forest alone," said Ron Sederoff, director of the forest biotechnology group at North Carolina State University.
In the past decade, about 130 outdoor tests of genetically modified trees have gotten the go-ahead from the Agriculture Department's Animal and Plant Health Inspection Service (APHIS), which has primary responsibility for regulating bioengineered trees in this country--more than half of them in the past 2 1/2 years. The first applications for permission to grow large commercial tracts of the new trees are expected to come around 2005.
Dozens of additional outdoor tests are underway in at least 16 countries, notably Chile, Uruguay and Indonesia, according to the World Wide Fund of Britain, an environmental group that has called for tighter regulation of tree engineering and a global moratorium on commercial releases.
In many cases, it's impossible to say exactly what scientists are putting into the trees. Although APHIS's Web site summarizes every application for field tests, many say simply "CBI," for "confidential business information," in the column that is supposed to describe which gene is being studied and which organism it came from.
But available government records and interviews with scientists indicate that research is largely focused on aspens and cottonwoods, both members of the poplar family, which are favorites of the paper and pulp industry. Of particular interest are genes that reduce the amount of a substance called lignin, or that weaken lignin's chemical structure. Lignin is the tough arboreal "connective tissue" that today must be chemically degraded at enormous expense in the process of turning trees into paper.
Researchers also are adding genes that spur faster growth and increase the concentration of cellulose, the ingredient of prime commercial value in trees. "The idea is to change the tree's genetic regulation to put more available light energy into cellulose production," said Michael Moynihan of InterLink Biotechnologies LLC in Princeton, N.J., which is part of a Chilean biotechnology concern.
And scientists are learning how to block the growth of flowers, pine cones and seeds in trees to focus more of the plants' energy on wood fiber production and to keep novel packets of DNA from spreading to other trees--a concern not only of environmentalists but also of corporate patent lawyers who don't want to lose control of their proprietary genes.
Fast-growing forest trees could do more than increase the world's supply of lumber and pulp. They might also help reduce global warming.
Through photosynthesis, trees consume large amounts of carbon dioxide (CO2), a greenhouse gas produced by automobiles and other industrial sources whose emissions the world's countries have pledged to reduce under the terms of the pending Kyoto Protocol.
Amid growing uncertainty that the signers of that accord will be able to achieve its goals, there is talk of creating a system of "carbon credits" that might allow countries with many CO2-gulping forests to sell their excess air-scrubbing capacity to nations falling short of their clean-air goals. The approach is supported by some in the oil and automotive industries, including Japan's Toyota Motor Corp., which has its own forest biotechnology program.
"Our laboratories are working to develop strains of trees that are especially efficient at photosynthesis," states a Toyota summary of the company's efforts. Once those carbon-consuming trees are developed, the company explains, "we can clone thousands more exactly the same. Eventually, while paying close attention to the ecological balance, we hope to have whole forests of these extra-efficient trees, to help purify the atmosphere."
Other genetically modified trees may help clean up contaminated land. The one tree listed by APHIS as having been endowed with a human gene is a poplar with a stretch of human DNA that can break up cancer-causing dioxins and the toxic breakdown products of polychlorinated biphenyls (PCBs).
Orchard growers have their own reasons for tinkering with genes, and APHIS has approved field trials of more than 50 genetically altered variants of apples, grapefruits, pears, persimmons, plums and walnuts in 18 states, most on small sites of an acre or two.
USDA scientists, for example, recently created a plum containing viral DNA that makes the fruit resistant to plum pox, a fruit-deforming disease that has cost growers millions of dollars in Europe and arrived in the United States last fall. "The trees essentially vaccinate themselves," said Ralph Scorza, who led the work in West Virginia at a location he keeps secret because of fears that protesters will damage the site.
Another priority is the creation of patented specialty fruits with improved flavors or other consumer-friendly traits.
"Everyone recognizes that the money in the tree fruit industry of the future is going to come from new varieties with exclusive rights," said Neal Carter, president of Okanagan Biotechnology of Summerland, B.C. Carter has planted about 800 genetically altered trees, the oldest of which are just a year short of fruit-bearing age.
Next fall, with great anticipation, Carter will cut into the first of his genetically altered apples endowed with DNA to block the chemical reaction that makes the flesh turn brown after the fruit is bitten or cut. If the gene works, he said, "you'll be able to cut this apple up and put it in the lunch bag and the kid might actually eat it."
Among the other new fruits Carter foresees coming to market in the next decade are peaches engineered to ripen more slowly and deliciously after harvest and cherries in a variety of fashionable new colors.
That's assuming, he adds, that the research is allowed to move forward.
In fact, advocates opposed to biotech trees are becoming increasingly vocal and active. In March, the Boston-based Native Forest Network, the Rainforest Action Network of San Francisco and a Uruguayan ecology group launched an international public relations campaign against genetically engineered trees. Other activists have conducted nighttime raids on tree test plots in the United States, Canada and Europe, destroying years of work and contributing to the decision by at least one corporation to drop its efforts.
Zeneca Plant Science, a major European biotechnology concern, recently abandoned its foray into biotech forestry, saying it became disenchanted after protesters ruined its sole stand of trees last summer. St. Louis-based Monsanto and Royal Dutch Shell also quit the field in the past two years, citing unspecified "business" considerations.
"The main risk of working with engineered trees is not a biological risk, it's a political risk because of the hysteria around the world," said Steven Strauss, who is developing genetically modified trees at Oregon State University in Corvallis.
Like the conflict over genetically altered crops, the war of words over genetically altered trees tends to be extremely polarized. Opponents warn of irreversible genetic pollution, while proponents claim that new traits are unlikely to persist in the wild.
Nonetheless, even biotech-friendly foresters agree that some concerns cannot just be waved away.
Some suspect, for example, that low-lignin trees may prove especially vulnerable to insect infestation, which could harm surrounding forests. And if low-lignin genes do spread, then surrounding trees might degrade faster than usual and deprive many species of the crucial habitat now afforded by slowly rotting wood.
Opponents also predict that plantations of fast-growing trees will require large amounts of water, fertilizer and pesticides, undercutting their usefulness as a hedge against global warming. They're asking whether genetically altered trees will cause allergies in people not usually bothered by tree pollen. And they wonder what will happen to the birds, insects and other wildlife that depend on tree pollen, nectar and seeds if scientists plant large expanses of sterile trees whose reproductive energies have been diverted to fuel extra growth.
Assessing the Risks
Ultimately, questions about safety will have to be resolved by data, not debate. But opponents say regulatory standards are not tough enough.
The restrictions on outdoor testing of genetically modified trees are virtually identical to those already in place for annual crops, they note. In most cases, growers must simply sign a statement promising they will follow general guidelines to protect the environment.
"The current rules are not very stringent and are not well policed, and there are a lot of different risk issues that ought to be addressed thoroughly before these trees get commercialized," said Jane Rissler of the Union of Concerned Scientists.
Unfortunately, federal funding of experiments to assess risks of engineered trees is scant, said Dave Ellis, who conducted seminal work on genetically altered spruce trees at the University of Wisconsin and is now at CellFor Inc., a biotech tree company in Victoria, B.C. Ellis tried several times to get federal money for ecological studies of low-lignin wood while he was at Wisconsin, he said, but to no avail.
Federal regulators say they are on top of the issue.
"USDA recognizes that there are environmental, scientific and other issues that need to be carefully considered and addressed before genetically engineered trees are used commercially," said Michael Schechtman, the agency's biotechnology coordinator. When the USDA receives its first request for commercial approval of a biotech tree, he said, it will be considered "in an open and public process."
The department may also soon ask a special committee of the National Academy of Sciences to investigate the risks and benefits of biotech trees.
And biotech foods such as fruits and nuts will have to pass additional muster with the Food and Drug Administration, Schechtman said--and with the Environmental Protection Agency if they contain any insect-killing genes.
If activists have their way, that will be a long process.
But every year of delay can only hurt what's left of Earth's remaining forests, said Kenneth Munson of ArborGen in Savannah, Ga., a biotech tree venture that includes woodland-product giants International Paper and Westvaco and two New Zealand companies.
"We have great confidence in the American people," Munson said. "We think they are knowledgeable and pragmatic and we look forward to a rational discussion of this."
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Last Updated on 8/5/00
By Karen Lutz Benbrook