Scientists at The Samuel Roberts Noble Foundation, Ardmore, OK, have uncovered a gene responsible for controlling key growth characteristics in plants, specifically the density of plant material.
Denser plants have more biomass, so farmers and ranchers can produce more plant material from the same-sized field. Plants that have increased density hold great potential to be used to produce biofuels, electricity and even advanced materials like carbon fiber.
“This is a significant breakthrough for those developing improved plants to address pressing societal needs,” says Richard Dixon, director of the foundation’s Plant Biology Division. “This discovery opens up new possibilities for harnessing and increasing the potential of crops by expanding their ranges of use. These plants will be part of the next generation of agriculture that not only impacts food, but many other vital industries as well.”
Huanzhong Wang , a postdoctoral fellow in Dixon’s lab, found a gene that controls the production of lignin in the central portions of the stems of Arabidopsis, and Medicago truncatula, species commonly used as models for the study of plant genetic processes. When the newly discovered gene is removed, there is a dramatic increase in the production of biomass, including lignin, throughout the stem.
Researchers have historically focused on reducing lignin production in plants consumed by livestock. However, increasing lignin in non-food crops such as switchgrass may be desirable for increasing the density of the biomass and producing more feedstock per plant and per acre.
“In switchgrass, as the plant matures, the stem becomes hollow like bamboo,” says Dixon. “Imagine if you use this discovery to fill that hollow portion with lignin. The potential increase in biomass in these new plants could be dramatic. This technology could make plants better-suited to serve as renewable energy sources or as renewable feedstocks to produce advanced composite materials that consumers depend on every day.”
Further research with collaborators at the University of Georgia revealed that removal of the gene also can increase the production of carbohydrate-rich cellulose and hemicellulose material in portions of the plant stem. These are the components of a plant that are converted to sugars to create advanced biofuels, such as cellulosic-derived ethanol or butanol. More celluloses and hemicelluloses mean more sugars to use for carbohydrate-based energy production.
“Science often progresses in increments,” Dixon says. “Every once in a while, though, you have a significant breakthrough that helps redefine the research. This is certainly one of those moments for our advanced feedstock program.”
The project is supported by the U.S. Department of Energy and the Oklahoma Bioenergy Center.