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receiving a great attention as it addresses concerns related to dwin-
dling oil supplies, energy independence, and climate change. The etha-
nol in the United States is produced mainly from corn starch. The U.S.
Congress envisioned a 30 percent replacement of the current U.S.
petroleum consumption with biofuels by 2030. Accomplishing this
goal would require approximately 1 billion dry tons of biomass feed-
stock per year. The current production of corn could not meet this
anticipated demand, which could mean that less grain will become
available for food and feed purposes. A study by Perlack et al. (2005)
found over 1.3 billion dry tons per year of biomass potential—enough
to produce biofuels to meet more than one-third of the current
demand for transportation fuels. This annual potential is based on a
more than sevenfold increase in production from the amount of bio-
mass currently consumed for bioenergy and biobased products.
About 368 million dry tons of sustainably removable biomass could
be produced on forestland, and about 998 million dry tons could
come from agricultural lands.
Although wood has been used many years in broad areas, there
are a lot of disadvantages and problems during wood process and in
use. There is a need to engineer forest trees for specific usage or to be
fast growing to provide additional biomass for future bioenergy.

12.2 Overview of Transgenic Woods

12.2.1 Transgenic Trees
In recent years, the rapidly increasing knowledge of plant genomes
has raised the possibility of genetically manipulating trees and other
woody plants at a rate faster than that afforded by traditional tree-
breeding programs. Advancements in gene cloning and genomics
technology in forest trees have fostered the introduction of value-
added traits for wood quality and for resistance to biotic and abiotic
stresses into genotypes, adding a new dimension to forest-tree
improvement programs (Koehler and Telewski 2006).
There are many traits being introduced and modified in wood
species, such as spruce, English elm, pine, poplar, yellow poplar, and
aspen. Poplars were the first forest tree to be transformed genetically
(Fillatti et al. 1987) and the first to have a sequenced genome (Brunner
et al. 2004). Pines and spruces as coniferous forest species are the most
studied transgenic trees, primarily due to their substantial economic
importance, particularly in developed countries, for construction
lumber as well as for pulp and paper. In the United States, loblolly
pine is more widely planted than any other species of tree.
A tree’s trunk is the major harvested organ in forest trees, and
breeding programs are usually aimed directly at improving trunk
performance and wood quality. This includes biochemically modifying