Over half of the world’s calories come from grasses, but imagine generating enough fuel from grass to run a car or even light up a house. Actually, the dream of turning a blade of grass into usable energy is not as far-fetched as it might seem. Doing her part toward realizing this goal, Elizabeth Kellogg, Professor of Biology at the University of Missouri-St. Louis, is researching the history behind switchgrass and its relationship with other grasses.
Besides switchgrass, Kellogg studies such cereal grasses as wheat, maize, rice, sorghum, barley, and sugar cane. Rice is one of the most important grains, feeding about 50 percent of the world’s population. But all of these grasses are significant both economically and ecologically. In her investigations Kellogg seeks answers to the same general questions: from where did the plant come, and in what kind of environment does it thrive? "If you want to understand the biology of a species," says Kellogg, “you need to understand something about where and how it originated.” For example, scientists know that the domestication of wheat occurred over a period of thousands of years and required innumerable trial-and-error attempts to make it work.
With switchgrass, this kind of background information still needs to be developed. Once scientists have a better grasp of its history and the environments in which it thrives, they may be able to “create a new crop.” As a Missouri native, switchgrass is abundant throughout the state and covers roughly two-thirds of the eastern United States. Fortunately, it can grow in a lot of different environments and does not require the most fertile, high-quality land.
Moreover, as a source of bio-fuel, switchgrass could well provide a viable alternative to corn. “Corn feeds people and animals,” notes Kellogg. “Why would you want to use your best agricultural land for making fuel?” In addition, she explains that because only the corn seed is needed in creating bio-fuel, the majority of the plant is wasted, making corn-derived fuel an inefficient energy solution. With switchgrass, on the other hand, the whole plant would be used and efficiency would be significantly enhanced.
With funding from the University of Missouri Research Board, Kellogg has been able to reconstruct the switchgrass family tree. Using comparative genomics, she compares the DNA sequence of the plant to that of other grasses. Perhaps surprisingly, Kellogg describes DNA extraction as a relatively easy process: “You can do it with things you actually have in your own kitchen!”
Here's how it works. The plant cells are enclosed in a very firm cell wall made of cellulose. To extract DNA, one must break down those cell walls, employing either a blender or a mortar and pestle. The next step is to dissolve away all the fats in the cell membrane by introducing soap. Finally, one must get rid of proteins with a substance such as meat tenderizer. As Kellogg puts it, “we sort of gradually break down one piece of the cell after another until we are left with just water and DNA.”
But DNA extraction takes time, she says, “and is just plain physical work.” To increase productivity, the UMRB grant allowed Kellogg to hire a postdoctoral scholar to help run the project in the lab, and his role has been central to the overall operation. “He is generating a lot of data," she observes, "supervising the undergraduate and graduate students and just making sure everything is on track.”
In addition to her pathfinding research, Kellogg teaches a variety of classes on the UMSL campus, ranging from molecular biology and animal physiology to plant biology, ecology, and evolution. “There is something about teaching that makes you think about what you are doing in a much more explicit and general way,” she observes. “Research is very focused. You ask very detailed questions about just one particular system. Teaching is kind of the opposite: you have to think really broadly. They work together to force you both to look at detail and how that detail also fits into the big picture.”