Eucalyptus genome sequenced

The Eucalyptus genetic code has been sequenced with  a reference genome for Eucalyptus grandis, commonly known as the flooded gum, being made available.

The project, which started over a decade ago, involved researchers from the University of Tasmania, The University of Melbourne, the Victorian Department of Environment and Primary Industries, the Australian National University, Western Australian Department of Parks and Wildlife and the University of the Sunshine Coast along with international collaborators.

Hundreds of Eucalyptus tree species have been identified so far. According to Dr Antanas Spokevicius of the University of Melbourne, eucalypts have become the hardwood plantation species of choice in many parts of the world for use in the pulp, paper and timber industries and for generating bio-energy.

“This resource will provide a huge boost for breeding and biotechnological tree improvement programs and has put eucalypts on the same footing as many other important crop species, whose improvement programs have benefited greatly from a sequenced genome,” Dr Spokevicius said.

The genomic DNA assembly the team generated spans more than 94% of the predicted 640 million base-pairs of the eucalypt genome, which contains over 36,000 protein-coding genes. About one-third of genes turned up in sequences stemming from tandem duplications, highlighting the importance of repeat sequences in the genome.

The researchers identified 113 genes responsible for synthesising terpenes, the familiar aromatic essential oils of eucalypts. These oils provide chemical defence against pests as well as the familiar aromatic essential oils used in medical or industrial settings.

They may be extremely important in understanding feeding preferences of animals such as the endangered koala, while genome-based research could also one day lead to eucalypt oils being used as a base for jet fuel.

The analysis also revealed an ancient whole-genome duplication event estimated to have occurred in the Eucalyptus lineage about 110 million years ago.

“Duplication of genes may be one of the reasons that eucalypts have been able to adapt to so many diverse environments across Australia,” Dr Dorothy Steane from the University of Tasmania said.

The study was recently published in Nature.