CREATING biotech trees
By Pulp & Paper Canada
Scientists are working to create trees that grow fast, contain less lignin and more cellulose and are tolerant to herbicides while being resistant to pests. And if all goes according to plan, experts ...
By Pulp & Paper Canada
Scientists are working to create trees that grow fast, contain less lignin and more cellulose and are tolerant to herbicides while being resistant to pests. And if all goes according to plan, experts predict that commercial plantations of these biotech trees will hit the North American market in five years.
And not too soon for the $500-billion (US)-a-year global forest-products industry. Demand for pulp and paper products is expected to increase by 50% in the next two decades, outstripping fibre supplies by 2010. Alongside industry requirements are environmental demands to save the world’s remaining forests for wilderness and recreational use. (More than half of the wood currently comes from old-growth forests, mostly from developing nations like Indonesia and Brazil.) Proponents say that biotech trees are one of the best ways to meet such conflicting demands, while keeping existing forests intact and reducing global warming.
And the industry is starting to take note. In April 1999, American giants International Paper Company, Westvaco Corp. and Monsanto joined forces with New Zealand-based Fletcher-Challenge to form a $60-million (US) five-year research consortium whose aim is to produce and market eucalyptus, poplar pine and sweet gum seedlings for pulp and paper products. (Monsanto subsequently pulled out, citing that the work did not contribute to its core business.) Since then, New Zealand-based Genesis Research joined the group to form ArborGen of Savannah, GA.
Hundreds of test tracts of genetically modified (GM) trees have been planted in at least 16 countries, particularly Chile, Uruguay, Indonesia and the United States. Canada’s program is modest, limited to a few test plots near Quebec City.
Researchers are experimenting with genetic manipulation to promote faster-growing, more easily managed trees that produce an improved fibre. In pursuit of such goals, scientists are looking to manipulate a tree’s genetic makeup.
The first to commercialize
The biotech revolution is feeding the appetite for research into GM trees. For one, compared to traditional tree breeding programs, modern bioengineering methods are more precise, allowing specific genes to be targeted or manipulated. (See Genetic engineering decoded.)
Using such tools, countries are working feverishly to be the first to commercialize GM trees, and reap the financial rewards by selling patents for the technology. No commercial sites have been reported to date. “[But] there is speculation that in China where distinctions between research and commercial use blur, some commercial plantations are in place,” says Steven H. Strauss, a professor of molecular and cellular biology and director of Oregon State University’s tree genetic engineering research cooperative in Corvallis, OR. In the US and Canada, however, scientists face tighter government regulations.
Scientists argue that the precise methods that biotechnology offers only duplicate what nature does, but at an accelerated rate. “The mutation of trees by nature has occurred over millions of years — that’s genetic engineering at a much slower pace,” says Vincent L. Chiang, professor of plant biotechnology and director at Michigan Technological University’s plant biotechnology centre in Houghton, MI.
In July 1999, researchers at MTU made news when they said they had genetically modified a quaking aspen (Populus tremuloides), reducing the lignin it produced by almost half, while increasing its cellulose content to 15%. As reported in Nature Biotechnology, the lignin:cellulose ratio of the GM aspens is 1:4, double the 1:2 ratio common to natural trees.
Mills could derive direct benefits of lignin-reduced trees, such as lower chemical, energy and environmental costs. “We have produced transgenic trees, which have lignin reduction ranging from 5% to 45%,” Chiang told Pulp and Paper Canada. “As well, the lignin-reduced trees have increased cellulose content.”
In field trials, greenhouse-sheltered GM trees grow almost twice as fast as non-GM trees, and without any ill effects. “They grow normally and are more resistant to insects,” noted Chiang, who theorizes that the tree transfers the energy saved from lignin production to other areas, such as enhanced growth and cellulose production.
Such thinking is behind one of the main ideas of genetic tinkering: shut down one process, and the plant will put its energy to another. “I was working with a company in Australia that put a lot of effort in making sterile eucalyptus and radiata pine trees. They thought that if the tree wasn’t putting some of its efforts into making flowers, it might make more wood,” says Carol Loopstra, a molecular biologist at Texas A&M University in College Station, TX.
Current research is centred on finding the right percentage of lignin that a tree ought to contain. If it contains too little lignin, then it’s no longer a tree, since it not only lacks the structural support that lignin provides but becomes an easy target for pests, says Strauss of Oregon State. “You have to find a balance point between not making the tree such a wimp that it can’t survive and changing it so it’s producing what humans want. We don’t yet know what that point is.”
Michigan Tech holds patents on the process its scientists have developed for aspen, and have licensed the technology to an unnamed forest products company. Although aspen is the model species, Chiang says that the technology is generally transferable to other tree species, including spruce. “We have a contract with a Canadian company for spruce,” he says. “And we have many pulp and paper companies with which we have research contracts.”
GM not the only answer
Still, not everyone is convinced that lignin-reduced GM trees would improve the pulping process. “Lignin reduction does not necessarily result in greater rates of lignin removal,” says Paul Watson, group leader of resource evaluation at Paprican in Vancouver. “There is a host of things going on inside a pulp digester, and just because we have reduced a tree’s lignin content, that doesn’t translate to a faster-removing species.”
Watson finds the results from the lignin-reduction trials “overstated.” Paprican, which is not involved in any GM tree program, relies on conventional tree-breeding methods to increase pulp yields, Watson says. “There are rapid-assessment tools that are becoming available, which can identify superior trees in the natural realm.” In effect, Paprican’s approach is monitoring over manipulation. He adds, “We have shown that you can get a 5% swing in pulp yield using natural methods.”
Watson holds little doubt that forestry companies “have to reduce their ecological footprint.” But GM trees are only one way to achieve that, he says. “Research needs to be done in a logical sequential way. We can learn a lot from what has been done on the agricultural side for the last 10 years.”
One of Paprican’s concerns is the escape of genes into the soil. Not enough is known on the long-term effects of altering the genetic makeup of a tree, no matter how precise the process. “The are unexpected side-effects to these changes,” says Simon Potter, a scientist at Paprican in Vancouver. “We don’t fully know or understand these effects.”
So say opponents of GM trees, who fear that such trees will provide poor habitats for beneficial insects and birds, transforming biologically diverse woodlands into sterile “Frankenforests.” For example, lignin plays an important role in the tree’s defence against herbivores — it makes the plant harder to digest. Opponents of GM trees contend that low-lignin trees will become the equivalent of fast food.
And they worry that birds, insects and other wildlife that depend on tree pollen, nectar and seeds will have less places to go, should there be large tracts of sterile trees whose reproductive energies have been diverted to fuel extra growth.
Oregon State’s Strauss says that such statements confuse the issue, and result from poor science. “The opponents think that GM trees will march into a wild forest and take it over. I don’t see any scienti
fic evidence for it,” he notes. In nature, among species and between species, trees vary in the amount of lignin they contain, and breeders breed for that reduction today, he says. “We are already doing this, and it hasn’t resulted in an ecological disaster.”
Still, groups like Greenpeace, Friends of the Earth and Union of Concerned Scientists have mounted well-funded campaigns to slow down the GM train. These political action groups are building on the recent widespread media attention generated by the public unease of transgenic species in agricultural products, or genetically modified organisms (GMO).
Strauss finds their actions make his job “more hellish,” and takes particular aim at the American-based Union of Concerned Scientists (UCS) who, he says, “do science by press release.” He adds, “They are a political action group, and not a scientific group that concludes through scientific consensus. A small group gets together to decide what their programs will be, and then they go straight to the media or to lawyers to press their case.”
In some instances, eco-terrorists in Europe and the US have destroyed saplings of GM trees. And in at least one case, a group vandalized what it thought were GM saplings, but were natural trees undergoing traditional breeding methods. That is why many researchers and companies keep their GM sites secret.
Rigorous controls in place
Like many scientists, Texas A&M’s Loopstra says that although there are sufficient regulatory controls in place to ensure public safety, the industry can play a central role to allay fears of health hazards. “The industry needs to prove that everything is being tested. You can’t allow scientists or companies to do whatever they want.”
One concern of transgenic species is that it might follow the law of unexpected consequences. “There are possibilities of allergies being created,” she says, “But in cases where that has happened, they have been caught — due to good testing and controls.”
Loopstra, who is researching transgenic plants like poplar and tobacco, says that in conferences no scientific debate as to its ethical merits is taking place. “Most scientists say it’s something that’s here and most of the problems associated with GM will eventually be resolved.”
In Canada, things are moving at a slower, more prudent pace (See A modest program). “Yes, we have a program for GM trees,” says Anne-Christine Bonfils, science advisor for the Canadian Forest Service in Ottawa. “But we take a balanced approach. Teams are also working on environmental impact assessments, which are just as important.”
Canada’s current GM program is small compared to that of New Zealand, Brazil and the US. But things might soon change. In the 2000 budget, the federal government set aside $160 million to create Genome Canada, a non-profit organization reporting to Industry Canada. It consists of five regionally based technology centres in Atlantic Canada, Quebec, Ontario, the Prairies and British Columbia. Genome Canada’s mandate “is to make Canada a world leader in genomics research and development.”
Genomics is the science of deciphering and understanding the genetic code of organisms: human, animals, plants and pathogens. The genomics group will also undertake a research program to address the ethical, environmental, legal and social issues associated with genomics research.
Some of that money will eventually flow to researching biotech trees, including to Paprican. And if Canada wants to reap the benefits of biotechnology in the 21st century — the so-called biotech century — it will be forced to quickly act to develop GM plantations, albeit using ethical guidelines. If predictions hold true, there will soon be a tree-growing industry that will support the solid-wood industry and pulp mills. “The technology has matured to the stage that in five to 10 years, engineered trees with desirable traits will be commercially produced,” says Michigan Tech’s Chiang.