Originally Posted: May 16, 2017
Discovery may someday allow farmers to grow crops in climates where they currently won’t grow and allows scientists to make a subtle, targeted mutation to a specific native plant protein
Findings of a new study solve a key mystery about the chemistry of how plants tell time so they can flower and metabolize nutrients.
The process — a subtle chemical event — takes place in the cells of every plant every second of every day.
The new understanding means farmers may someday grow crops under conditions or in climates where they currently can’t grow, said chemist Brian D. Zoltowski, Southern Methodist University, Dallas, who led the study.
“We now understand the chemistry allowing plants to maintain a natural 24-hour rhythm in sync with their environment. This allows us to tune the chemistry, like turning a dimmer switch up or down, to alter the organism’s ability to keep time,” Zoltowski said. “So we can either make the plant’s clock run faster, or make it run slower. By altering these subtle chemical events we might be able to rationally redesign a plant’s photochemistry to allow it to adapt to a new climate.”
Specifically, the researchers figured out the chemical nuts and bolts of how a chemical bond in the protein Zeitlupe forms and breaks in reaction to sunlight, and the rate at which it does so, to understand how proteins in a plant’s cells signal the plant when to bloom, metabolize, store energy and perform other functions.
Zoltowski’s team, with collaborators at the University of Washington and Ohio State University, have made plant strains with specific changes to the way they are able to respond to blue-light.
“With these plants we demonstrate that indeed we can tune how the organisms respond to their environment in an intelligible manner,” Zoltowski said.
Zoltowski and his colleagues made the discovery by mapping the crystal structure of a plant protein whose function is to measure the intensity of sunlight. The protein is able to translate light intensity to a bond formation event that allows the plant to track the time of day and tell the plant when to bloom or metabolize nutrients.
A plant uses visual cues to constantly read every aspect of its environment and retune its physiological functions to adapt accordingly. Some of these cues are monitored by plant proteins that absorb and transmit light signals — called photoreceptors. The research team specifically studied two key photoreceptors, Zeitlupe (Zite-LOO-puh) and FKF-1.
“Plants have a very complex array of photoreceptors absorbing all different wavelengths of light to recognize every aspect of their environment and adapt accordingly,” said Zoltowski, an assistant professor in the SMU Department of Chemistry. “All their cells and tissue types are working in concert with each other.”
The finding was reported in the article “Kinetics of the LOV domain of Zeitlupe determine its circadian function in Arabidopsis” in the journal eLIFE online in advance of print publication.
Co-author and lead author is Ashutosh Pudasaini, a doctoral graduate from the SMU Department of Chemistry who is now a postdoctoral fellow at the University of Texas Southwestern Medical School, Dallas. Other co-authors are Jae Sung Shim, Young Hun Song and Takato Imaizumi, University of Washington, Seattle; Hua Shi and David E. Somers, Ohio State University; and Takatoshi Kiba, RIKEN Center for Sustainable Resource Science, Japan.
The research is funded through a grant from the National Institute of General Medical Sciences of the National Institutes of Health awarded to Zoltowski’s lab. READ MORE