Researchers at the University of Georgia’s Warnell School of Forestry and Natural Resources are the first in the world to modify a tree’s genome using a method known as CRISPR.
CRISPR, a naturally occurring genetic mechanism that, put simply, allows bacteria to remember and fight viruses by cutting up the invader’s DNA and incorporating small segments into its own genome. Now, this mechanism is being adapted into a highly efficient and precise method of genetic modification. Research lead by professor C.J. Tsai of Warnell is using CRISPR to modify trees in ways that nobody has ever been able to before.
Previous methods of genetic modification were relatively sloppy, affecting large chunks of DNA at a time.
“[Such methods] never led to complete silencing [of a gene] since they act after a gene has been transcribed,” says Tsai. “Previous methods also tend to have non-specific effects, e.g., silencing more than the target gene.”
CRISPR, on the other hand can precisely target genes, or even just a few nucleotides (letters in the code). Using this, Tsai silenced genes associated with the production of lignin, a component of the tree’s cell walls, which turned the wood completely red, an indication of success.
“CRISPR is more specific. As we mentioned in the paper, red stem is a known side effect of lignin modification. Previous methods typically led to sporadic discoloration (due to incomplete silencing), whereas every single CRISPR mutant we generated has complete discoloration.”
More than just a proof of concept, this research went on to show what types of organisms might be created in the future with this technology.
“Lignin impedes biomass utilization for pulping or biofuels. Condensed tannins in forage crops negatively affect digestibility [by livestock], and hence slowing their growth.”
In the future, this technology could lead to advanced, systematically designed organisms highly specialized for use in biofuels, feedstocks, bioprocessing and more.
This article was originally published by the The Red & Black, the University of Georgia’s student newspaper, on June 14, 2015. Click here to view the story at redandblack.com →