DURHAM, N.C. Tinkering with a single gene may give perennial grasses more robust roots and speed up the timeline for creating biofuels, according to researchers at the Duke Institute for Genome Sciences & Policy (IGSP).
Perennial grasses, including switchgrass and miscanthus, are important biofuels crops and can be harvested repeatedly, just like lawn grass, said Philip Benfey, director of the IGSP Center for Systems Biology. But before that can happen, the root system needs time to get established.
"These biofuel crops usually can't be harvested until the second or third year," Benfey said. "A method to improve root growth could have a major role in reducing the time to harvest for warm season grasses."
Benfey's team appears to have found a way to do just that. They took a directed genomic approach aimed at identifying genes that become active when cells stop dividing and start taking on the characteristics of the mature, adult cell they are to become. "We systematically looked for those genes that come 'on' precisely when cells transition from proliferation to differentiation and then turn 'off' again just as quickly," Benfey said.
That genome-wide search in the roots of the familiar laboratory plant Arabidopsis and subsequent screening of mutant lines turned up a single gene, which the researchers call UPBEAT1 (UPB1). Further study showed that UPB1 controls the gene expression of enzymes known as peroxidases.
They then showed that these peroxidases control the balance of free radicals between the zone of cell proliferation and the zone of cell elongation where differentiation begins. (Although free radicals are probably most familiar as agents of stress to be combated with antioxidants, Benfey noted that the balance of free radicals has also been implicated in the control of a similar transition from proliferation to differentiation in animals.)
When the researchers experimentally disrupted UPB1 activity
|Contact: Kendall Morgan|