US researchers report in the journal Science that they have successfully unlocked the DNA code of a tree. The genome of the black cottonwood (Populus trichocarpa) was completely sequenced by the researchers leading to hope that better quality wood and plant-based products may be available in future.
Researchers said that the poplar tree has very less DNA, but more genes than other mammals or humans. The forest department is also hoping the study may benefit it. "Under optimal conditions, poplars can add a dozen feet of growth each year and reach maturity in as few as four years, permitting selective breeding for large-scale sustainable plantation forestry," said Dr Sam Foster of the US Forest Service. "This rapid growth coupled with conversion of the lignocellulosic portion of the plant to ethanol has the potential to provide a renewable energy resource along with a reduction of greenhouse gases."
Researchers said they chose poplar since it is widely cultivated worldwide. It is estimated that there are some 75 million hectares of poplar in the world. Plus the tree is small in size, so the researchers felt they would be able to sequence it quickly. They said the tree has just 485 million base pairs in its genetic code.
The researchers said about 93 genes of the poplar were involved in cellulose production, which is the most widely available organic material on Earth. This cellulose is important since it can be fermented into alcohol, and distilled to produce fuel-quality ethanol, besides being broken into sugars.
Dr Gerald Tuskan, the lead author of the Science report said biofuels had value since they reduced the environmental impact of emissions. "Biofuels emit fewer pollutants than fossil fuels such as gasoline. In addition, poplar and related plants are vital managers of atmospheric carbon. Trees store captured carbon dioxide in their leaves, branches, stems, and roots," he added. "This natural process provides opportunities to improve carbon removal from the air by producing trees that effectively shuttle and store more carbon below ground in their roots and the soil."
