[NAFEX] Biotech Trees

Bruce Hansen brucedhansen at sbcglobal.net
Tue Apr 26 08:59:38 EDT 2005

Biotech tree tests rooted in caution
Genetic modification can add helpful traits, but effects on a forest's web
of life call for extra care.
Mike Toner - Staff
Monday, April 25, 2005
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
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." 

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