Volume 6 Number 4
April 12 - May 3 2010
Part of an international project to sequence the Eucalyptus tree genome (its full DNA sequence) the team from Creswick has recently submitted tissue from trunks and leaves containing genetic information for growth processes during wood and leaf formation. The contribution was led by Dr Antanas Spokevicius from the Department of Forest and Ecosystem Science, School of Land and Environment.
“Information gained from the material collected will be vital for fast-tracking the development of plantation trees with desired properties for biofuel or pulp and paper production, as well as giving clues to how Eucalypts have adapted to past climate change and became the dominant tree species in Australia,” says Dr Spokevicius.
Australia’s forest and wood products industry, has an annual turnover of almost $19 billion, making it vital to understand which genes are important in determining wood property, growth and development traits as well as stress tolerance and pest resistance.
The hope is that with this knowledge, saplings with the gene(s) for important traits can be selected and grown on for higher quality timber and help forest growers develop diagnostics for assessing which seedlings will produce higher quality timber.
This knowledge will also be valuable in attempts to understand the impact of climate change by providing insights into the mechanisms that allow plants to deal with stresses such as drought and heat. Not only will such information be useful in tree growth improvement efforts but could be used to gauge the effect that changes in climate might have on eucalypt populations in our native forests for conservation efforts.
“Whilst the species targeted are of commercial significance they are also important species within the genus Eucalyptus,” says PhD candidate Lynette Taylor, who assisted in the collection.
“Information gained as part of these efforts can soon be used to understand the biology of our native trees and how they have adapted to the Australian landscape.”
The completed genome sequence is expected to be released in late 2010, however, much of the assembled information is already available for use by the research community.
The international sequencing effort was initiated in 2007 by the Eucalyptus genome network, Eucagen, a consortium of Eucalyptus researchers from around the globe with support from the Community Sequencing Program at the US Department of Energy (DoE) Joint Genome Institute (JGI).
Eucalyptus is only the second tree species in the world to have its genome sequenced, and is the first commercially relevant plantation species based on its significant economic importance worldwide. The Poplar which was the first is mainly used as a research species in understanding tree development, as it has little economic relevance.
Efforts are focused on two species: Eucalyptus grandis or flooded gum, an important commercial species in tropical and sub-tropical regions and Eucalyptus globulus or blue gum, an important commercial species in temperate regions, particularly in south-east Australia.
The material provided by the University of Melbourne will provide insights into the coding parts of the eucalypt genome (those parts of the genome that represent genes, also called the transcriptome), and determine a tree’s development, form and function.
“While the genome sequence can tell us what the genetic code is, the transcriptome tells us which part of the genome contains the genes that direct tree growth. Having information on every gene present in a Eucalyptus tree is certainly a powerful tool for assisting our tree improvement efforts.”
One of the big challenges to studying trees is their long life cycle, some taking up to 20 years to produce seed. This has led Dr Spokevicius to also investigate methods which alter the gene expression in trees in order to observe changes in wood formation in acceptable time frames.
Working with the CSIRO and Sappi, a South African forestry products company, the group led by Associate Professor Gerd Bossinger previously demonstrated for the first time how a commercially important complex wood trait can be strongly influenced by a single gene (called beta tubilin gene).
The findings were an important step towards the production of wood fibres with altered tensile strength, stiffness and elastic properties, enabling growers to choose trees for different uses such as timber and wood pulp.