A new way to explore plant-microbial interactions

Humans benefit greatly from their relationship with plants
.
We rely on them for food, clean air, medicines, fuel and a variety of other products
.
But plants need other partners to thrive
.
Many plants grow better
by establishing relationships with soil microbes.
These microorganisms help plants obtain nutrients such as nitrogen, phosphorus and iron
.
In exchange, plants provide sugars and amino acids
to microorganisms.

Scientists at the U.
S.
Department of Energy's (DOE) Argonne National Laboratory recently received a grant from the Department of Energy's Office of Science, Biological, and Environmental Research (BER) Bioimaging Program to learn about plant-microbe communication and how it promotes plant growth and health
.

"We can use the fantastic capabilities of advanced photonic sources to observe the interface
between microbes and plants at nanometer resolution.

—Gyorgy Babnigg, bioinformaticiologist/molecular biologist at Argonne

"We wanted to know what plants provide for microbes, and what microbes provide plants," says Gyorgy Babnigg, a bioinformatician / molecular biologist at Argonne and principal investigator of the project.

”

On a broader scale, understanding plant-microbe interactions can provide insights
into improving plant growth and enhancing the products and resources on which humans depend.
In a world moving towards renewable energy, the development of plant products that can replace plastics and other fossil-derived products becomes even more important
.

In the three-year project, Babnigg and his colleagues at Argonne, the University of Chicago, and the Department of Energy's Joint Genomics Institute plan to develop a new imaging technique that uses engineered plant growth to promote bacteria as biosensors
.
The improved microorganisms will be able to indicate which resources
are shared by bacteria in the rhizosphere (the area around the plant's root system) and the plant itself.

"Bacterial cells have the ability to sense and respond to nutrients, such as amino acids, sugars, small organic acids, and signaling molecules
in substances secreted by plant roots," Babnigg said.
Once cells sense nutrients, they tell bacteria to use them for energy and growth
.
The researchers' goal was to track the amount
of each nutrient around the root system by adding proteins to microbes that glow under the microscope.
The novelty of this color-changing method is that scientists can measure compounds of low and high abundance underground without sacrificing plants
.

"We can send these biosensors to other scientists, and then they can put microbes into the environment they're studying and measure the dynamics
of rhizosphere compounds.
"

While developing and testing these biosensors, the scientists will also collect microscopic images to further understand the relationship between
plants and microbes.
"We can use the fantastic capabilities of advanced photon sources to observe the interface
between microbes and plants at nanometer resolution," Babnigg noted.
The team also plans to use these images to assess the distribution of components in the rhizosphere during plant-microbe interactions, and how this distribution changes
over time and in different environments.

To speed up the discovery of images, the researchers will partially automate the imaging process
.
They plan to work with Argonne University's Autonomous Discovery Team and Argonne's Leadership Computing Facility to develop artificial intelligence (AI)-guided image acquisition and analysis tools
.
"An automated system based on artificial intelligence may come up with novel ideas or experimental methods
that our scientists can't think of," Babnigg said.