As rising temperatures continue to melt arctic permafrost that has been around for thousands of years, tons of carbon locked within this permafrost are released to the atmosphere in the form of carbon dioxide and methane, threatening to accelerate both the melting and global warming in general.
One potential bright spot in this alarming scenario is the plant life that has been appearing on land uncovered by the receding ice. These plants draw carbon from the atmosphere and have the ability to hold it throughout life spans that can run into decades. They can also be used as feedstock for valuable products such as biofuels and carbon fiber. The challenge, though, is that you need lots and lots of biomass to make these processes economically feasible.
Through an Early Career Research Program award from DOE's Office of Science, ORNL quantitative geneticist Wellington Muchero will be working to understand and enhance the ability of arctic plants to capture carbon for long-term storage and conversion into renewable bioproducts. His work focuses on the genus Salix—willows—a widely used bioenergy crop that has emerged as a key species in colonizing land exposed by receding arctic permafrost.
The key to a plant’s ability to capture and store carbon can be found in its relationship with soil microbes, Muchero said.
“My interest is in understanding how plants accommodate symbiotic microbes, which help them perform functions that they cannot perform by themselves,” he explained.
Among these microbes are ones that help the plant grab nutrients from its environment. Not only does the process promote the goal of carbon capture, he said, but also helps the plant thrive, much like chemical fertilizers would. The challenge is that plants have a love–hate relationship with soil microbes; they have very strong defenses to ward off those they regard as harmful, but they can relax these defenses for microbes they deem helpful. The choices they make are genetically coded and differ from species to species.
Muchero’s goal in this project is to identify plant–microbe combinations that promote carbon capture, identify plant genes that play nice with those microbes, and use these genes to enhance other willow species. In the project, he is going to work with willow collections at West Virginia University and New York’s Cornell University, as well as research sites in the arctic.
The process will be painstaking. First, Muchero and his colleagues must collect samples from each location, identify microbes that interact most closely with individual species, and analyze the genome of each species. Once they identify differences in the genome, they must find those that promote plant–microbe interactions and carbon capture.
“When we look at differences in genomes among willow species, that’s where things get very exciting but also very challenging,” Muchero said. “Some of the differences will have nothing to do with plant–microbe interactions. They may be responsible for things like differences in leaf shape or whether one species prefers direct sunlight or shade. So, we’ll be trying to disentangle those differences that are just random from differences that actually control beneficial interactions.”
Muchero, who grew up in Zimbabwe, was attracted to science, especially biology, from a very early age. His enthusiasm was stoked when he learned about the world’s first cloned animal, Dolly the sheep, born in 1996.
“This was right at the time when I was trying to make long-term career choices after a brief stint working as an administrator in the life insurance industry and realizing that finance wasn’t my calling,” he said. “It really captured my imagination—that this thing called DNA could be manipulated in such amazing ways to do all these things we could really never conceive of.”
From Zimbabwe he moved to California, earning a bachelor’s degree at Cal Poly Pomona and a Ph.D. from the University of California at Riverside.
He has been a staff member at ORNL since 2010. As he grows in his career, he would like to find ways for himself and other researchers to more effectively follow through on the insights of their research.
“I would really love to find an avenue where we see more of our findings actually making a difference in the real world," he explained, "and DOE missions are typically directed at that more so than those of academic institutions. ORNL has an unparalleled legacy in translating fundamental discoveries into practical solutions, so I’m in the right environment for finding applications for my research.”
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