A research team led by professor of biochemistry and molecular biology Debra Mohnen has discovered that manipulation of the same gene in poplar trees and switchgrass produced plants that grow better and are more efficiently converted to biofuels:
Due to the composition of plant cell walls, plant material is not efficiently broken down or deconstructed to the basic sugars that are converted to biofuels.
In a paper published today in Nature Biotechnology, the researchers report that reducing the activity of a specific gene called GAUT4 leads to lower levels of pectin, a component of plant cell walls responsible for their resistance to deconstruction.
Mohnen and a team of researchers at six institutions found that reducing the expression of GAUT4 in poplar and switchgrass led to a 70 percent reduction in pectin content and produced a 15 percent increase in sugar release. Unexpectedly, it also led to an increase in the growth of both plant species, an added benefit.
“We increased the amount of biomass yield of field-grown switchgrass sixfold, and we increased the amount of ethanol yield sevenfold per plant,” Mohnen said. “We also observed increased growth and sugar release in poplar.”
The increase in plant yield and sugar release—demonstrated in both greenhouse and field trials for switchgrass—bodes well for creating biofuels, an important alternative to fossil fuels. Switchgrass and poplar previously were identified by the U.S. Department of Energy as two biofuel feedstocks that can be grown on land that would not profitably support food crops.
Important new progress on a longtime challenges for biofuel production. The need to replace not just transportation fuels but many other petrolueum-based products remains a priority and this new research a great sign that progress is achievable through diligence, hard work and collaboration.
Image: University of Georgia Assistant Research Scientist Ajaya Biswal and professor of Biochemistry and Molecular Biology Debra Mohnen in greenhouse with young populus plants.