Oregon State researchers Amy Klocko and Steven Strauss, along with scientists from several universities and agencies, have reported a breakthrough in the field of forest genetics with the development of genetically modified poplar trees, according to a report in the Canadian Journal of Forest Research. The trees have become resistant to insects, grow faster, and retain the characteristics of inserted genes for up to 14 years. The new traits can have major effects on paper, pulp, and biofuel industries.
The researchers injected the trees with a Cry3A protein in order to combat insect attack by stimulating the trees to produce an insecticidal protein. Researchers determined the insect resistance was partnered with increased growth rates of up to 23% (13% on average). They studied 402 trees from 1998 to 2001, and continued research at a clone bank at OSU over the next 14 years. The traits remained viable throughout the study, and results exceeded scientist expectations according to Strauss, a distinguished professor of forest biotechnology in the OSU College of Forestry. Strauss adds that although the trees will be significant in terms of wood yield, health, and productivity, researchers may be underestimating the true value of the trees. Klocko, lead author of the article, explains this value, stating that insects not only kill trees, but also leave them vulnerable to disease. Such decreases in viability and health can be quite expensive to combat in natural poplar varieties.
The researchers have successfully engineered male trees to be sterile in order to keep the GMO traits from spreading to other trees. Female sterility has yet to be achieved, but researchers continue to work toward that goal. The sterile trees could be used commercially without the threat of interbreeding with natural varieties of poplar.
Another aspect of the study involved the development of drought-tolerant poplars, which could be quite significant in the face of climatic changes forecasted for the Pacific Northwest.
The development of these GMO poplars is a major achievement in a field which is much less advanced than the related field of GMO crop development. Since trees can be subjected to insect attack over a period of years as they mature, insect resistance may offer greater commercial value than GMO crop species. This long-term susceptibility is also the reason behind the necessity to ensure modified trait expression over a long time period. The success of this study may lead to significant reductions of pesticide usage and crop loss, but Strauss warns that much more research may be necessary in order to overcome regulatory obstacles to GMO tree commercialization. The development of sterile varieties will also be an important aspect of meeting government regulations for GMO organisms.
By Kristen Daly