Researchers at the University of Georgia have used a gene editing tool known as CRISPR/Cas to modify the genome of a tree species for the first time. Their research, published recently in the early online edition of the journal New Phytologist, opens the door to more rapid and reliable gene editing of plants.
By mutating specific genes in Populus — a genus of deciduous trees that includes poplar, aspen and cottonwood — the researchers reduced the concentrations of two naturally occurring plant polymers. One is called lignin, which traps sugars and starches used for biofuel production inside the tree’s sturdy cell walls. The other is known as condensed tannin, and its presence in leaves and barks of the tree deters feeding by ruminants, such as deer, cattle, goats and sheep.
CRISPR technology is derived from a defense mechanism evolved by bacteria and other single-celled organisms. When a bacterium is attacked by an invader like a virus, it captures some of the virus’s DNA, chops it up into pieces and incorporates a segment of the viral DNA into its own genome.
As the bacterium experiences more threats, it accumulates a bank of past infections in a special part of its genetic code called CRISPRs — short for clustered regularly interspaced short palindromic repeats — which act as a kind of immune system to protect against future invasions.
“This is a mechanism that evolved naturally, but we can borrow the bacteria’s gene-cutting abilities and use it to edit very specific genes in all kinds of organisms, including plants and animals,” says C.J. Tsai, director of UGA’s Plant Center. “It’s like using a pair of scissors with GPS tracking to locate and snip out tiny bits of DNA — enough to nullify the gene you don’t want, while leaving everything else unchanged.”
More information is available here: http://news.uga.edu/releases/article/researchers-edit-plant-dna-using-mechanism-evolved-in-bacteria-0615/
