Brauer Puts Her Degree to Work against Wheat Disease

Elizabeth Brauer, a former graduate student at BTI, is using her degree and her experience working with researchers at BTI, Cornell and the USDA, to fight Fusarium head blight, a devastating disease that strikes wheat and barley.

Brauer completed her doctoral research in the lab of Sorina Popescu at BTI, studying stress signaling pathways in plants. Now, Brauer is a postdoctoral fellow at Agriculture & Agri-Food Canada at the Ottawa Research and Development Center. She works with Rajagopal Subramaniam to study the molecular interactions between wheat and the fungal pathogen that causes Fusarium head blight (Fusarium graminearum), to understand how to develop wheat that is resistant to this devastating disease.

Fusarium head blight causes the wheat plant to produce bleached grains that shrink and wrinkle over time. The fungus also produces mycotoxins, making the grain unmarketable. The blight is a serious risk for growers in many parts of North America.

“There’s no full resistance against this particular pathogen, so it’s a wide open field to really understand what’s happening there at the molecular level,” said Brauer.

Brauer’s work at Agriculture & Agri-Food Canada builds on her previous research on plant immunity with Popescu at BTI. They recently published part of this work in the journal Plant Physiology. In the paper, they present evidence that when plants detect the presence of bacteria, they trigger the rapid release of potassium ions.

“The plant is basically spitting out tons of potassium into its environment and from individual cells. We found that those potassium fluxes, and potentially the potassium reabsorption, seem to be essential for the plant to generate the full spectrum of defense responses,” said Brauer.

This discovery was madewhile studying a gene called ILK1, which is involved in immunity and salt stress. ILK1 regulates an important potassium ion transporter called HAK5. Blocking potassium ion transport can stop some immune responses, such as growth inhibition, indicating that the fluxes are necessary for triggering their defenses.

“We’ve known that potassium ion fluxes are important for signaling in animals but haven’t seen that they’re also important in plants until now,” said Brauer. “It’s specifically important for plant immunity.”

Though Brauer has moved on to her wheat research, Popescu is continuing this line of research in her lab, now located at Mississippi State University (MSU). Graduate and undergraduate students in her lab study the contribution of ILK to the changes in the global gene transcription profiles of diverse plant tissues that are under salt stress or undergoing an immune response against a bacterial pathogen. The work on the Arabidopsis ILK1 will be expanded into crop plants.

“The exciting concept that signaling pathways can be edited to modify a plant’s behavior to environmental stress—an idea emerged from the work performed at BTI—will be tested,” said Popescu.

A winner of Cornell’s Barbara McClintock Award, Brauer credits the intersection of the research communities at BTI, Cornell and the USDA with making the work possible. Because plant immunity and ion fluxes are such disparate research topics, she consulted experts in both fields. Additionally, co-author Miguel Piñeros in Leon Kochian’s lab at the USDA Holley Center, to his electrophysiology lab—a rare resource that enabled her to measure the ion fluxes within the plants and their cells.

“Being able to collaborate with people at Cornell who are working on similar things and with overlapping interests was really important for my project,” said Brauer. “What I had at BTI was access to so many different techniques and methods, because of the postdocs and the experience of the people who work there.”