Plant sciences student helps research natural fungicide

Cullen Dixon, a plant sciences major, helped to perform research to create a biofungicide from sorghum compounds. Credit: Cullen DixonAll Rights Reserved.

UNIVERSITY PARK, Pa. — It’s common that some people worry about crops that are sprayed with fungicides. But what if the fungicide came from a natural source, such as another plant? 

Sophomore Cullen Dixon is working with a research team to help answer this question. As a plant sciences major with the plant genetics and biotechnology option, Dixon is already exploring the avenues of applied research that the College of Agricultural Sciences offers to students.

Dixon participates in a lab that tests the effectiveness of secondary metabolite compounds produced by sorghum as potential biopesticides in combating foliar diseases of Zea mays, or corn. Sorghum, a cereal grain plant found all over the world — including in India, West Africa and China — contains a compound that acts as a natural fungicide.

Plant-based biofungicides and biopesticides are nontoxic to humans but toxic to microorganisms, are environment-friendly and can reduce the use of chemical fungicides and pesticides. “It’s like a spray-on fungicide, and it’s from another plant,” Dixon said.

The complex process starts with Dixon extracting the compound from the sorghum. Then, it’s purified through various centrifuges and solvents. The product of that is evaporated, re-suspended in water and, finally, applied in an atomized spray onto the plant using carbon dioxide and water.

The fungus also has to be applied to the corn so the lab can test the compound’s effectiveness in inhibiting fungal growth. After the fungus is harvested, the hyphae, the branching filaments that make up the mycelium of a fungus, are strained out so only the spores are left, and then the spores are re-suspended in solution and applied in the same way to the corn.

“I’m happy to go into the lab because I’m doing legitimate research and not busywork. It makes going in to work exciting,” Dixon said.  

Right now, the lab is focused on how these secondary metabolites work on corn. Sorghum and corn are closely related, so there is a greater potential for the compound to work.

Dixon found out about the research while doing an interview for his freshman seminar class. He spoke to Surinder Chopra, a professor of maize genetics, and learned that there was an opportunity for an undergraduate to be on the research team.

The diverse team consists of participants from several countries and at different levels of study. This includes one postdoctoral researcher, Iffa Gaffoor, as well as several graduate and three undergraduate students, including Dixon. One other undergraduate, Janelle Thompson, is also a College of Agricultural Sciences student studying biorenewable systems.

“At first, I was the only undergraduate in the lab," Dixon said. "But I felt like I fit right in. Everyone was so welcoming."

Cullen Dixon, a plant sciences major, performs research related to biopesticides. Credit: Penn StateCreative Commons

Last Updated April 28, 2017