What’s the key to growing resilient crops that can survive tough conditions? Researchers at the University of Missouri are getting to the root of it — literally.
Scientists in the Walter Gassmann lab at Mizzou’s Bond Life Sciences Center have discovered how a specific protein known as SRFR1 plays a critical role in how deeply plant roots grow underground. Even more promising, they unlocked a way to manipulate this protein to encourage longer root growth, a trait that can potentially help plants better withstand drought.
This breakthrough could pave the way for genetically engineered seeds that produce more resilient crops.
“Depending on the environment, plants sometimes need a longer or shorter root, and we discovered that this protein helps regulate that outcome,” said Gassmann, director of the Bond Life Sciences Center and a professor in the College of Agriculture, Food and Natural Resources. “In times of drought, plants need longer roots to reach deeper into the soil in search of water or nutrients. Now that we have learned what this protein does, we can manipulate it to help plants thrive in various environments.”
Into the weeds
In the new study, Gassmann and senior scientist Jianbin Su found the SRFR1 protein forms tiny, gel-like structures in a specific part of the outer root. These loose structures, called condensates, form naturally to help the root grow.
The researchers set out to genetically alter the protein to “super-charge” this condensation process, resulting in plants with longer roots.
Using an AI tool that predicts a protein’s structure, they identified which amino acids form bonds between two molecules of SRFR1. Armed with this knowledge, researchers hypothesized that replacing these amino acids with structurally and chemically different ones could boost the protein’s ability to condense. To test the idea, the team designed a synthetic piece of edited genetic code and combined it with the enzyme DNA polymerase in a test tube to generate new, modified DNA.
The new DNA was then inserted into a bacterium that helps transport the new DNA into a plant’s flowers, so that the new DNA becomes a permanent part of the plant’s seeds.
“Using Mizzou’s Advanced Light Microscopy Core, we could see that our genetically altered plants were forming more of these condensates in the outer root, resulting in even longer roots than the wild-type plant,” Gassmann said. “The bottom line is once we understand these organisms better, we can design, breed or change them in a way that improves agriculture.”
A plant biologist’s playground
Plants are incredibly complex, and scientists still don’t know the exact roles that all of their microscopic proteins play. Gassmann has spent the past quarter century — with federal funding from the U.S. Department of Agriculture and National Science Foundation — uncovering plants’ molecular secrets.
“Mizzou’s reputation as a leader in plant science research and the collaboration with research groups in the Bond Life Sciences Center and the Interdisciplinary Plant Group make this a great place for our work to thrive,” Gassmann said.
Gassmann’s work as a plant biologist involves screening thousands of plants with random mutations or proteins that have been deactivated or “deleted” to learn more about the role they play in a plant’s development or resistance to pathogens. He’s been studying the role of the SRFR1 protein for the past 20 years.
“In order to one day help farmers grow plants that are more resilient, particularly in areas with drought, we have to better understand the underlying cellular biology in the first place, and that is why foundational research at a land-grant university like Mizzou is so important,” Gassmann said. “The interdisciplinary collaboration among scientists in the Bond Life Sciences Center and across campus is what makes Mizzou a leading research university, and it’s what fuels our excitement going forward.”
The study, “Polymerization-mediated SRFR1 condensation in upper lateral root cap cells regulates root growth,” was published in The Plant Cell.
