Researchers at the University of Texas at Austin who specialize in studying switchgrass recently concluded the multi-purpose plant could be a "best of both worlds" tool in the fight against climate change.
The switchgrass is a clean-burning source of renewable fuel and its large root system is known to pull carbon out of the air and store it underground. The researchers studied whether switchgrass could simultaneously grow a large grass plant above ground and a large root system under ground. Typically, plants can develop one or the other but not both, the university's College of Natural Sciences reports on its website.
"Typically, plants are thought to have a limited quantity of resources available for growth, and so their development may exhibit allocation tradeoffs," Tom Juenger, professor of integrative biology at the university and a corresponding author of the paper, said in the university report. "You can imagine that if a plant puts a lot of energy into sinking carbon in the ground for a large root system, it's going to come at the cost of generating tissues above ground.
However, researchers found that it is genetically feasible for switchgrass to have large root systems for sequestering carbon and large plant structures above ground for use as biofuel, the report states. The findings were outlined in the the publication Proceedings of the National Academy of Sciences.
"Our data suggests that you can breed a switchgrass plant with substantial above-ground biomass and it doesn't necessarily come at the cost of a good root system," Juenger said.
Switchgrass can "grow almost anywhere" with little water or human effort, the researchers state in their paper, and can grow up to 12 feet tall, producing large volumes of biomass for fuel. The root systems can also extend 10-12 feet underground; that impressive length can capture a lot of carbon, but is also tough for researchers to dig out for research.
"We found a similar degree of genetic variation for below ground traits as for above-ground structures," Juenger said. "But we know a lot less about below ground traits because they are harder to get to and study."
Funding for the research came from the U.S. Department of Energy, the Advanced Research Projects Agency and the Projects of National Natural Science Foundation of China and Zhejiang Provincial Funds for Distinguished Young Scientists, the university reports.
