“Soil is not a dead material,” Kaundal said. “One gram of soil can contain around 10 billion microbes, and living soil is more fertile because of these bacteria. They help plants take up nutrients, fix atmospheric nitrogen, and even act as biocontrol agents. While chemical fertilizers and pesticides kill these microbes, PGPB increase not only plant health and crop production but also soil health.”
The project builds on Kaundal’s previous research and is a collaboration involving USU Professor and Extension Agronomist Earl Creech, environmental engineering Professor Ramesh Goel from the University of Utah, and Devinder Sandhu from the U.S. Salinity Laboratory in Riverside, California.
Kaundal and her fellow researchers chose to examine native plants near the Great Salt Lake to isolate salt-tolerant PGPB. For drought-tolerant bacteria, they will focus on snowbrush and mountain mahogany. Both plants are native to Utah, the second-driest state in the United States, and they quickly proved to be home to the bacteria the team is looking for. Once these microbes are isolated, they can offer new ways to help plants adapt to drier, saltier soil conditions.
“Gene-edited crops take a long time to create, and they have to be studied extensively before we release them for public use,” Kaundal said. “With PGPB, we know they don’t have side effects because they’re already present in the soil and helping plants. Why not use them as fertilizer?”
Gathering the bacteria requires going out to where mountain mahogany and snowbrush grow naturally.
“It’s a hike, so it’s fun,” said Kaundal. “And we don’t kill the plants. We just dig 30 centimeters down and expose the roots, which we collect carefully without messing anything up, and the bacteria are either inside these roots or on their surface in the attached soil.”
The root samples are brought back to the lab and sliced into pieces from which the bacteria are extracted. Researchers use different combinations of nutrients to grow and then isolate varieties of bacteria, which they identify with DNA sequencing.
From there, promising isolates are tested in growth chambers on thale cress, a plant often used in experiments because it is well understood and has a relatively short lifecycle.
Bacteria that show further potential are then tested on crops like corn, wheat and watermelon. If successful, they graduate to tests in greenhouses and then fields. Once the team is certain a strain is safe and productive, they can ask farmers to test it on their crops.
Kaundal and her colleagues are in the early stages of the project. Each step takes time, and there are many factors to consider along the way. For instance, in a potato plant grown with PGPB, the team looks for tuber growth, while in a leafy crop like spinach, they focus on foliage. Even so, Kaundal is optimistic about her work.
“Nature already has an answer for everything, only we don't always know what that is,” she said. “That’s why we need to make these discoveries.”
Source : usu.edu