Unlocking the secrets of plant energy
Kent Chapman, Regents Professor and director of the UNT BioDiscovery Institute, is questioning decades-old assumptions in plant biochemistry to find better ways of utilizing lipids, the energy molecules found in all plants.
“Biofuels are the future, and lipids are the key,” Chapman says. “The same energy molecules a plant uses to power itself can also be used to power a home or a city. Lipid molecules in plants are actually very similar in structure to molecules in petroleum. But, unlike petroleum molecules, the lipids in plants can be a more efficient, sustainable fuel.”
Lipids are among the most energy-dense organic molecules on Earth and, in the form of fossil fuels, make up the basis of global energy usage. But while society uses the ancient organic lipids contained in coal and oil, these fuels are limited in supply and release carbon dioxide that was captured by plants millions of years ago. Burning these fuels results in a net increase of CO2 levels in the atmosphere. But, by using the lipids from crop plants grown and harvested for biofuels, the release of CO2 is in balance because the gas released was recently captured.
Chapman’s work involves understanding the methods plants use to package and store lipids. He says 30 years ago, scientists believed that plants used a single protein to package and store lipids in their seeds. But by going back to the beginning and using today’s knowledge and technology, Chapman and his co-workers have found at least eight more proteins that are involved in the process. He believes this fundamental research will be used by plant scientists looking to solve a broad range of problems.
One example would be manipulating plants to store more lipids in their stems and leaves. In soybean plants, most of the lipids are contained in the beans, and the stems and leaves are considered waste products. But, if lipids can be stored in the stems in addition to the soybeans, a farmer would suddenly have one super-efficient crop that could be used both as food and fuel. The same sort of reasoning can be applied to livestock feed.
“Imagine an alfalfa plant that stores lipids in the leaves and stems (the parts of plants that livestock animals eat) rather than in the seeds,” Chapman says. “Ranchers often add seed oil, such as soybean or canola, to forage feeds to balance protein calories for livestock. But, by manipulating where lipids are stored, alfalfa could become the perfect animal feed right out of the ground.”
Chapman is the principal investigator in this study, along with collaborating researchers from the U.S. Department of Agriculture, the Agriculture Research Service in Maricopa, Arizona, and the University of Guelph in Canada. The project recently received $800,000 from the U.S. Department of Energy.
Chapman, Director of UNT’s Biodiscovery Institute, also received a grant for enhancements to the institute’s microscopy instrumentation, which is already very advanced in the field of plant science.
“We have a unique capability to image the actual chemicals of lipid molecules in seeds using mass spectrometry, which is something that our lab has been doing for about a decade,” Chapman says. “We are recognized for our ability to do this, and it provides insight into how oils are being made in the seeds.”