Fast-growing tree would be used for paper production

By MATEUSZ PERKOWSKI

Capital Press

A tree seedling developer has revived its push to commercialize genetically engineered eucalyptus trees.

Arborgen, based in Summerville, S.C., has submitted an updated request to USDA to deregulate its eucalyptus cultivar, which was modified to withstand freezing temperatures.

The company withdrew a previous petition submitted in 2008 to include more data about the biotech cultivar's flowering.

If approved, the variety would be the first commercial introduction of biotechnology to the forestry sector. The USDA has previously deregulated transgenic papaya and plum trees, but these are not used for forestry.

Though some varieties of conventionally bred eucalyptus are already freeze-tolerant, they typically grow 40 percent to 60 percent slower than trees native to tropical climates, the petition said.

Arborgen sees a potential demand for fast-growing eucalyptus in the southeastern U.S., a major producer of hardwood trees for paper production.

Regeneration of native tree stands takes up to 50 years, while eucalyptus trees can be harvested on a rotation of about five to seven years, the petition said.

Eucalyptus trees are currently grown on plantations in the U.S., but production is limited to central and southern Florida.

Arborgen has developed a fast-growing tree that can withstand lower temperatures by inserting genetic sequences linked to cold tolerance from Arabidopsis thaliana, or thale cress, into a Brazilian eucalyptus variety.

The tree would be most suited for cultivation in a hardiness zone that includes northern Florida and the southernmost portions of Louisiana, Mississippi, Alabama, Georgia and South Carolina.

According to the company, the possibility of genetically engineered eucalyptus crossing with conventional trees is minimal because sexually compatible species aren't adapted to the region.

The cultivar has also been genetically modified to prevent pollen formation, which "could have value in reducing public concerns" about gene flow, the petition said.

Even so, Arborgen's eucalyptus trees have already run into legal opposition.

Last year, several environmental groups filed a legal complaint against the USDA for permitting the company to establish several experimental plantings of the cultivar.

According to the complaint, plaintiffs fear the cultivar may become an invasive species and that the tree's large water needs will distort the hydrology of the area.