From The Atlanta Journal Constitution, by Mike Toner
Behind a locked gate in a quiet corner of a University of Georgia research forest, 30 spindly poplar trees have earned another year of life.
Another spring. Still no flowers. In the rest of the forest, spring is a celebration of new life. For these trees, one of these years the budding of yellowish green blossoms will mean certain doom.
"When that happens, these trees will be destroyed," says UGA forest geneticist Scott Merkle. Flowers, of course, mean pollen. "And these woods are full of yellow poplar," he says. "If the pollen from these trees escaped, it would be out of our control."
Merkle's 15-year-old yellow poplars are among the oldest genetically modified trees ever grown in the open air. The first pollen they produce is expected to prove that engineered traits — in this case an innocuous bacterial marker gene — can be passed to succeeding generations of trees.
And that is precisely why no one wants pollen from these trees drifting on the wind through a landscape where native yellow poplars — a species found from New England to Florida — live to the ripe old age of 300 years.
This spring, farmers across America will plant more than 100 million acres of genetically modified corn, soybeans and cotton. Down on the farm, transgenic crops have become as common as fertilizer and weeds.
In the forest, the brave new world of biotech trees is not so deeply etched. As transgenic trees move out of greenhouses into the open air — and the industry edges closer to large-scale commercial plantings — some vexing questions remain.
"Genetically engineered trees can live for decades, are very closely related to their wild relatives and can spread their pollen for hundreds of miles," says Brian Tokar of the Institute for Society Ecology, one of several environmental groups that this spring asked the U.S. Department of Agriculture to halt further releases of such trees.
Unlike farm crops, trees are part of a natural web of birds, insects, microbes and plants that make up forest ecosystems. A tree designed to resist insect attack or grow faster may have clear advantages for growers, but also unpredictable ripple effects that won't end with the first frost.
"We have many of the same concerns that our critics have," says Merkle. "The difference is that instead of shutting things down, we want to do the experimental plantings that will answer these questions."
Out in the open
Most biotech trees still grow only in laboratory dishes and greenhouses. To answer some of the questions, however, transgenic trees — "frankentrees" to their critics — are increasingly moving outdoors.
So far, the USDA has approved at least 124 open-air tests — ranging from trees that can absorb mercury from contaminated soils around a former hat factory in Danbury, Conn., to a virus-resistant grapefruit with a gene from the snow drop lily in Texas' Rio Grande Valley. Transgenic walnuts, cherries, apples, pears, plums and persimmons are under development.
Although it's gone largely unnoticed by U.S. consumers, most papayas from Hawaii now carry a novel gene designed to resist to a devastating ringspot virus. They're the first transgenic tree fruit to have entered commercial production.
In China, however, foresters are planting hundreds of acres with two strains of poplar trees engineered to produce their own insecticide — more than 1 million trees so far in seven provinces. Brazil is expected to begin planting commercial quantities of transgenic eucalyptus trees within the next year or two.
Most of the tests in the United States are still limited to a few acres and a few years' duration. These experimental plantings encompass several broad goals of biotech forestry — the restoration of vanishing tree species, "improved" trees for the forest and paper industry, and the use of trees as "toxic avengers" for industrial decontamination.
An Arbor Day ceremony in Syracuse, N.Y., this week, for instance, marks the first planting of transgenic American elms outside the laboratory. Scientists at SUNY College of Environmental Science and Forestry hope the 2-foot trees with artificial genes planted in front of the college library will be a symbolic step toward vanquishing Dutch elm disease, which has destroyed millions of elm trees across America since the 1930s.
By this fall, SUNY forester Bill Powell also hopes to plant the first transgenic chestnut trees. The saplings incorporate a wheat gene designed to make them resistant to chestnut blight, which has wiped out the once-dominant tree in eastern forests.
"It will take five years or so to see if our technique works, but if it does, we also have our eye on other things like butternut canker, white pine blister rust and dogwood anthracnose," he said.
Paper industry boon
Commercial foresters are designing trees that grow faster, resist insects and herbicides, and are better suited to their end purpose. The pulp and paper industry, for instance, is eager to try out the "woodless tree" developed by Vincent Chiang of North Carolina State University.
Chiang's aspens are not really woodless, but they have only half the normal amount of lignin — the molecular glue that provides trees with rigidity by binding tree fibers together — and increased volumes of cellulose, the stuff from which paper is made.
"For the pulp and paper industry, removing lignin takes a lot of energy and chemicals, so the savings could be enormous," says John Cairney, associate professor of biology at Georgia Tech's Institute for Paper Science.
Industry studies project that low-lignin trees could save the U.S. pulp industry between $1 billion and $3 billion a year. Field trials of the trees in England and France have so far found no harmful environmental effects, but researchers say more research is needed before the "woodless" trees are ready for large-scale plantings.
Initially, the industry expects to use any "improved" trees on privately owned tree plantations, which currently account for about 34 percent of all trees harvested in the United States. The industry now plants nearly 2 billion new seedlings a year.
In the United States, the leader in transgenic tree experimentation is Charleston-based ArborGen, a $60 million joint venture paper of forest industry giants such as International Paper and MeadWestvaco.
For security reasons, ArborGen won't disclose the exact locations of its field tests, but USDA records show it holds permits for more than 67 open-air experiments on eucalyptus, pine, poplar and sweet gum.
Most of the test plots are in South Carolina, but the company also has tests under way in Georgia, Florida and New Zealand. Anticipating that a key to future commercial plantings is likely to be assuring that engineered traits don't spread from tree plantations into the open forest, Arborgen is working to perfect sterile trees — using what is sometimes known as terminator technology — that would be incapable of pollinating others of the species.
Cleanup role studied
Researchers are also working to perfect trees that could aid in the cleanup of toxic wastes. Massachusetts-based Applied PhytoGenetics, using technology developed at the University of Georgia, is testing the ability of transgenic cottonwoods to remove mercury from the soil at industrial sites in Connecticut and Alabama.
Early indications are that the cottonwoods — engineered with a bacterial gene to detoxify mercury — are prospering in contaminated soils that would be deadly to most trees.
"If this works," says Chief Executive Officer David Glass, "we are doing with genetic engineering something that does not exist in nature."
Industry sources are torn between wanting to publicize the potential of transgenic trees and the need to protect their open-air experiments. Most companies simply won't disclose the locations of their tests for fear their trees will be damaged or destroyed by environmental activists.
The fear is not unfounded. In 2001, the Earth Liberation Front claimed responsibility for two arson attacks aimed at transgenic tree research — a $3 million fire at the University of Washington's Center for Urban Horticulture and a $500,000 fire at an Oregon tree farm.
Few environmental groups — even those opposed to transgenic trees — condone such attacks. But as the industry eyes commercial plantings, even some professional foresters are urging caution.
The Forest Stewardship Council, a group of forest research and management officials that certifies about 100 million acres of "sustainable" forests throughout the world, has flatly prohibited the use of transgenic trees on the lands it oversees.
Without more knowledge about the consequences and better machinery to regulate releases, the group says, any use of the technology outside research settings poses "unnecessary and unacceptable risks."
