While most people rip weeds from their front yards without a second thought, Bethany Zolman spends her time studying one virtually unknown weed, Arabidopsis thaliana. “If you saw it, you wouldn’t look twice at it,” jokes the assistant professor of biology at the University of Missouri-St. Louis.
Why focus on a plant that seemingly doesn’t merit a double-take? As Zolman explains, this “little weed” serves as a perfect model organism for research because it grows quickly, is easily manipulated, and is comparable to the systems of crop plants. Her research centers around the plant hormone auxin, which controls root development, from length to the number of secondary roots. Auxin can be stored as indole-butryic acid, or IBA, and proteins convert it to the active form of indole-acetic acid, or IAA. Zolman is working to identify the factors involved in the conversion, from when and where it occurs to what cues induce the transformation.
Taking a “genetics approach,” Zolman uses a chemical to induce mutations in the DNA of many wild-type seeds. After altering the seeds’ DNA, she examines the differences between mutants and wild-type plants. Understanding the connections between altered DNA and growth changes in the model system is crucial to the overall goal of enhancing crop plants, a result that would not only lead to economic gains but would also increase seed and food yields.
The IBA-to-IAA conversion occurs in a small unit within the cell called the peroxisome, which houses several metabolic reactions that help plants establish themselves as adults. These peroxisomal protein mutations also reveal a commonality between plants and humans. Some human diseases, such as adrenoleukodystrophy (ALD), explains Zolman, “are basically mutations in the same proteins that are disrupted in our plant mutants.” Examining these protein mutations in plants is easier than studying them in human cells and often better than working with other models such as yeast, because plant systems are more complex. By studying the metabolism of higher organisms, inter-species connections can be made.
Zolman is also involved in a research collaboration with colleague Dr. Wendy Olivas, who runs a molecular genetics lab at UMSL. While Dr. Olivas studies protein-RNA interactions in yeast, Zolman studies the same proteins in Arabidopsis thaliana. Through the collaboration, she hopes to uncover whether the proteins act in a “general pathway” or specific, different components act in plants and others in yeast.
In addition to collaborating with colleagues, Zolman also works closely with graduate and undergraduate students. Graduate students proceed independently, while undergraduates earn research credit by characterizing mutants and completing assays. This arrangement not only helps to move her research program forward, but also benefits the students themselves. Coming from a small institution that didn’t offer many opportunities for biological research, Zolman especially recognizes the need for undergraduate participation, which is “a great way to figure out where you want to go, what you want to do, if this is what you like.” Because “research thinking and classroom thinking are different,” she seeks to gives students experience in the research lab “before they try to find a job.” In addition, she notes, because “a lot of the big companies are looking for students with research experience, it’s important that we’re able to provide that experience at as high a level as we can.”
As a professor and researcher, Zolman takes student interests to heart. Her commitment to providing high-level research opportunities for undergraduates is evidenced by the CAREER Grant she received from the National Science Foundation (NSF) in 2008. Designed to help junior faculty integrate their research and teaching, the five-year award has funded Zolman’s work on IBA and its conversion using three mutant plants. In addition, the proposal included the creation of a lab component for an existing course, in order to engage students to take part in her current investigations.
A grant from the University of Missouri Research Board, which funded supplies and students to work in the lab, enabled Zolman to collect crucial preliminary data. “For [the National Science Foundation] to fund a grant for five years, they have to be very convinced that a lot of the experiments are really going to work,” she explains. “The Research Board award was critical in getting the data that we needed to acquire higher-level funding.” She also received a UMRB Special Opportunities Grant, which was awarded to four Biology Department faculty members at UMSL. This support funded improvements in the greenhouses, including the purchase of new growth chambers and the modification of old ones. This equipment, which is used to control growth conditions, reassured NSF reviewers that Zolman had the overall set-up necessary to conduct her experiments. Just as importantly, the grant supported other faculty members and UMSL students: “It’s helping all of us in our research. Now it’s something that the teaching labs have started using as well, so it’s helping many students on campus.”
Over the years, Zolman has maintained the same sense of awe that made her fall in love with research in the first place. “I never intended to go into research,” she admits, “but I ended up here, and now it’s one of the things I really like about my job. It’s very open-ended. Just being able to look at things that we can’t figure out and do experiments is very interesting to me.” In these experiments, “whatever is wrong with the mutant” controls the direction of her investigation. Though she can't be sure what will happen next, or in what direction the plant may guide her research, one thing is certain: Zolman will let the plants do the talking.