News Release

Arabidopsis study to help understand wood formation

Grant and Award Announcement

Virginia Tech

BLACKSBURG, Va., -- The molecular biology of wood formation is poorly understood. Current efforts to identify the genes that are important to wood quality and quantity in economically important tree species are hampered by the large size, long life span, and incomplete genome sequence data for tree species. A tiny wildflower is expected to help.

Eric Beers, associate professor of horticulture at Virginia Tech and a researcher in the Virginia Agricultural Experiment Station, has received a $345,000 grant from the National Science Foundation for a three-year study of wood formation. He expects to define the roles of some of the protein-degrading enzymes (proteases) important to wood formation and, eventually, to identify genes that regulate that process.

Beers has developed a method for using the annual weed thale cress (Arabidopsis thaliana) as a model for understanding how wood is formed. The basic developmental processes that lead to the formation of xylem, the wood-forming tissue in plants, should be the same in Arabidopsis as in trees, so Beers expects his findings to be applicable to all woody plants. Beers is working with Arabidopsis because it is a small plant that can be easily grown in the lab and has a short life cycle. In addition, the entire Arabidopsis genome has been sequenced, further increasing the value of Arabidopsis for identifying genes important to wood formation.

Since beginning work in this area in 1998, Beers has narrowed his focus to just three genes that code for proteases specific to wood-forming tissue. Currently he is attempting to use techniques for gene silencing and gene knockouts to define the functions of these three genes.

"We silence a specific gene, and then infer the function of the gene by observing the new phenotype, he says.

Woody xylem is a tissue that consists of three cell types, and all three are formed from a population of stem cells known as the vascular cambium. " I am interested in the fundamental question of how cell fate in the xylem is specified at the vascular cambium," Beers says. "How do these cells know what to do? What tells them what to become?"

The expression of the protease genes Beers is studying is limited to specialized water-conducting cells within the xylem, known as tracheary elements. With a technique known as one-hybrid analysis and using genetic analyses of mutants that express the xylem proteases incorrectly, Beers intends to use these protease genes as "molecular handles" to get hold of other genes that act earlier in the sequence of events leading to tracheary element differentiation.

"By identifying the genes that regulate the expression of our tracheary element protease genes, we will be taking the first steps toward the long-term goal of identifying the master regulators that control wood formation," he says.

Such information could have important implications for forest product development and would represent an important contribution to the understanding of this fundamental aspect of plant development.

Candace Haigler of Texas Tech University in Lubbock, Texas, is co-principle investigator for the work supported by the NSF grant. Haigler is a professor in the Biological Sciences Department and director of the Texas Tech University Electron Microscope Facility.

###

Researcher: Eric Beers, 540-231-3210, ebeers@vt.edu
PR Contact: Netta Benton 540-231-7638 netta@vt.edu


Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.