Genetically Modified Trees: A Blessing or Danger for the World?
Copyright 2000, Washington Post
August 4, 2000
By Rick Weiss Washington Post Service
WASHINGTON - In an orchard in western Canada, genetically enhanced fruit trees kill insects on contact, without pesticide sprays. Soon the trees will bear apples whose crispy, white flesh will not turn brown even hours after being cut open.
In Israel, poplar trees have been made to grow so fast that they could eliminate a 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 processed into pulp without the tons of toxic chemicals that now poison 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 human beings, 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, forest biotechnology director at North Carolina State University.
In the last decade, about 130 outdoor tests of genetically modified trees have got the go-ahead from the Agriculture Department's Animal and Plant Health Inspection Service, which has primary responsibility for regulating bioengineered trees in the United States, more than half of them in the last two and a half years.
The first applications for permission to grow large commercial tracts of the new trees are expected to come in about five years.
Dozens of additional outdoor tests are under way 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 is impossible to say exactly what scientists are putting into the trees. Although the Animal and Plant Service's Web site summarizes every application for field tests, many say ''CBI,'' for ''confidential business information,'' in the column that is supposed to describe which gene is being studied and from which organism it came.
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 great 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, New Jersey, 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 its efforts. Once those carbon-consuming trees are developed, the company says, ''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 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.
Orchard growers have their own reasons for tinkering with genes, and the U.S. Animal and Plant Health Service 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.
Department of Agriculture 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 fear that protesters might damage the site. Another priority is the creation of improved specialty fruits. ''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, who is president of Okanagan Biotechnology in Summerland, British Columbia.