Gum tree by the litre, research scientist predicts

The potential of Australian eucalyptus trees to be used as a biofuel and ‘carbon sink’ plantation crop could soon skyrocket, predicts Professor Robert Henry, the director of Southern Cross University’s Centre for Plant Conservation Genetics.

The reason for his prediction is that the humble eucalyptus tree is about to become only the second tree in the world to ever have had its entire genetic sequence mapped. (The poplar was the first.)

Professor Henry said the eucalyptus tree’s genome is about to be decoded by an international consortium – of which Southern Cross University is a founding member.

“Our forestry researchers are in an excellent position to take full advantage of this gene sequence once it becomes available,” he said.

“We plan to be at the forefront of developing eucalypts with improved properties for converting wood to ethanol and other fuels, for storing atmospheric carbon and for the development of more economically profitable and sustainable forestry practices.

“This new data will greatly enhance the current work our researchers in the Forestry Cooperative Research Centre are already undertaking in improving wood properties.”

Australian eucalypts are fast growing, high yield trees which are one of the world’s most valuable fibre and paper producing trees, as well as being good at carbon sequestration – capturing and storing excess atmospheric carbon.

The project to map the DNA sequence of the 600-million-nucleotide tree genome will be coordinated by the Eucalyptus Genome Network, EUCAGEN (www.eucagen.org), which was formed at a meeting initiated by Southern Cross University, the University of Tasmania and the Australian Genome Research Facility. More than 130 scientists from 18 countries are currently involved in EUCAGEN.

Funding for the project will come from the USA Department of Energy Joint Genome Institute and the Community Sequencing Program. The information will be made freely available over the worldwide Web.

The genus Eucalyptus, comprised of over 700 different species, includes some of the fastest growing woody plants in the world and, with approximately 18 million hectares growing in 90 countries, it is one of the most widely planted genuses of plantation forest trees in the world.

“Sequencing the eucalyptus genome will help us overcome many of the major obstacles towards achieving a sustainable energy future,” said Alexander Myburg of the University of Pretoria, in South Africa, who is co-leading the project.

“The eucalyptus genome will provide a window into the tree’s metabolic pathways, shedding light on such traits as cold tolerance, osmotic potential, membrane integrity, and other agronomic features,” said co-lead Gerald Tuskan, of Oak Ridge National Laboratory, in the USA.

Project collaborator Maud Hinchee, chief technical officer of ArborGen (a US company specialising in applying genetics and biotechnology to forestry) said: “This monumental project will enable improved breeding strategies for cellulosic ethanol feedstocks and contribute to environmentally sound improvements in productivity for the global forestry industry.

“This effort will help us advance our goals of producing renewable high-value biomass from a smaller environmental footprint … (and offer) a new source of hardwood in the Southern USA that can play a key role in national energy security and economic development in the region, in addition to providing numerous environmental benefits.”

Already, a considerable amount of carbon is tied up in eucalyptus biomass. Coupled with the emerging economic incentives for carbon sequestration, eucalyptus trees are a prime candidate for increased efforts to remove carbon from the atmosphere.

Project co-leader Dario Grattapaglia, of the Catholic University of Brazil, said that in countries such as Brazil, eucalypts are used as a source of renewable energy for high quality steel production in a way that reduces the net production of greenhouse gases.

“Eucalyptus is capable of sequestering carbon at a rate of 10 tons (9 metric tonnes) of carbon per hectare per year, and has a positive net carbon balance even when it is used to generate energy from charcoal or for pulp and paper production,” he said.

“Furthermore, plantation forestry of eucalypts plays a crucial role in reducing the pressure on tropical forests and associated biodiversity.”

Photo: Professor Robert Henry with Julie Bishop, Federal Minister for Education, Science and Training in a laboratory at the Centre for Plant Conservation Genetics recently.