NEW YORK (GenomeWeb) – Scientists from the University of Georgia have reported the first successful use of CRISPR/Cas9 gene editing in trees.
In a paper published recently in New Phytologist, scientists led by Xiaohong Zhou and Chung-Jui Tsai demonstrated the ability of a CRISPR/Cas9 method to reduce concentrations of lignin and condensed tannin in the genus Populus, which includes poplar, aspen, and cottonwood trees. Lignin traps sugars and starches inside the tree's cell walls and condensed tannin is a substance in leaves and bark that deters animals from feeding on the tree.
The modified Populus plants contained about 20 percent less lignin and 50 percent less condensed tannins than wild trees. Each of the 36 poplar plants produced from the experiment targeting lignin genes had red-colored wood, which is a well-known side effect of lignin modification. "This is one of the highest efficiencies ever reported, even in mouse and other animal models where the technology has been more extensively tested," co-author Thomas Jacobs said in a statement.
CRISPR/Cas9 gene editing could greatly accelerate research in tree genetics according to the researchers. Trees often take a long time to grow, making experimental breeding time consuming. "For woody perennials with long generation cycles, accelerated breeding is finally within reach using CRISPR genome editing," the authors wrote in the paper.
The Populus experiment has already provided new directions for research. "We thought we knew what genes control lignin and condensed tannin production, and we did target the right genes, but the work showed us that there are other genes with overlapping roles," Tsai, a senior co-author, said. "The CRISPR system can now guide researchers seeking to identify these previously unknown gene family members."