Coming into the study, the researchers expected a relatively uniform distribution of chemicals. Instead, with their chemical roadmap in hand, they found that TCA metabolites are clustered in patches across the root.
“I was surprised by how many chemicals are featured in really distinct patterns,” said Dickinson. “We can see that the plant is doing this on purpose—it needs these molecules in specific regions to grow properly.” The Dickinson lab showed that these TCA metabolites have predictable effects in development, not only in maize, but in another plant species as well (Arabidopsis). This is likely because TCA metabolites are highly conserved—they are made in all plants as well as animals.
Also emerging from the new images were previously unidentified chemical compounds. Dickinson says the mystery compounds could be critical for plant growth since they also are grouped in patterns at specific locations, suggesting a prominent role in development. Dickinson and her colleagues are now investigating these compounds and comparing varieties of maize that have different levels of stress resistance for adverse threats such as severe climate conditions and drought. The new information will help them develop novel chemical and genetic strategies for improving plant growth and stress resilience.
“We’re looking at different maize plants that have drought resistance to see if we’ve already found chemicals that are specific to that variety that we haven’t seen in other varieties,” said Dickinson. “We think that could be a way to find new compounds that can promote growth, especially in harsh conditions.”
The study’s full author list includes: Tao Zhang, Sarah Noll, Jesus Peng, Amman Klair,
Abigail Tripka, Nathan Stutzman, Casey Cheng, Richard Zare and Alexandra Dickinson.
This work was supported by the National Science Foundation (Collaborative EAGER 2028649, 2028776), the National Institutes of Health (NIGMS 1R35GM147216, NIGMS 1T32GM127235-01, NIGMS 1T32GM133351-01), the Hellman Scholars Foundation, the McElroy Fellowship, the Revelle Provost Summer Research Scholarship and the Genentech Scholars Program.