Pine Tree Genome is Largest Genome Ever Sequenced

The genome of the most commercially important tree species in the US has been sequenced for the first time, producing what researchers report as the largest genome sequence completed to date, according to the University of California, Davis.

Loblolly pine trees, also known as southern yellow pines, are used to make most of the paper products manufactured in the US, and the tree is the second-most widely occurring in the nation, behind the maple tree.

The tree's genome is enormous, about seven times larger than the human genome, and researchers were able to sequence it relatively quickly thanks to a novel new technique that yields a faster and more efficient analytical process, UC Davis reported.

David Neale, a professor of plant sciences at UC Davis, led the research, which is published in two journals, the March 2014 issue of GENETICS and in the open-access journal Genome Biology.

Neale said that the genome's huge size was not nearly as daunting as assembling the sequence into the right order. To tackle the huge amount of data at hand - which had been an obstacle to sequencing this genome in the past - the researchers used a new method that can speed up the raw data processing 100-fold.

This new sequencing technique was developed by researchers at the University of Maryland. It was tested for the first time in this genome study, allowing researchers to bring order to the 16 billion separate DNA fragments in the loblolly pine genome.

"The size of the pieces of consecutive sequence that we assembled are orders of magnitude larger than what's been previously published," Neale said.

The genome data is publicly available and could be used for future genomic studies and by scientists and land managers.

"The fusiform rust mapping that our scientists did as part of this project provides significant information for land managers, since more than 500 million loblolly pine seedlings with these resistance genes are planted every year," said Dana Nelson, project leader at the Forest Service Southern Institute for Forest Genetics. "The group selected loblolly pine for sequencing because of the relatively long history of genetic research from the institute and others on the loblolly's complex traits such as disease resistance," he said.

The research was funded by the USDA's National Institute of Food and Agriculture. The group's director, Sonny Ramaswamy, said that the genome of the loblolly pine can play an important role in American forestry.

"Now that we've unlocked its genetic secrets, loblolly pine will take on even greater importance as we look for new sources of biomass to drive our nation's bio-economy, and ways to increase carbon sequestration and mitigate climate change," Ramaswamy said.