Cornell researchers have identified the herbicide as an amino acid called meta-tyrosine, or m-tyrosine, that these lawn grasses exude from their roots in large amounts. This amino acid is a close relative of para-tyrosine (p-tyrosine), one of the 20 common amino acids that form proteins.
Reporting on the discovery in the current issue of the Proceedings of the National Academies of Science, Frank Schroeder, the paper's senior author and an assistant scientist at the Boyce Thompson Institute for Plant Research on Cornell's campus, said, "We at first didn't believe m-tyrosine had anything to do with the observed herbicidal activity, but then we tested it and found it to be extremely toxic to plants but not toxic to fungi, mammals or bacteria."
Co-author Cecile Bertin, Ph.D. '05, research director for PharmAfrican, a Montreal-based bio-pharmaceuticals company, made the initial discovery that fescue grasses inhibit plants from growing around them.
While m-tyrosine itself is too water soluble to be applied directly as a herbicide, this research may lead to development of new varieties of fescue grasses that suppress weeds more effectively, which could reduce the need for synthetic herbicides, said Schroeder. By increasing our understanding of basic plant biology, the discovery of m-tyrosine's herbicidal properties could also help researchers discover more sustainable ways to control weeds or completely new herbicides, Schroeder added.
He and his colleagues are now conducting experiments to understand how m-tyrosine works as a plant killer. Plants depend on the production of large amounts of another common amino acid, phenylalanine, which is essential for the biosynthesis of wood, cell walls and lignin.
"Phenylalanine, m-tyrosine and p-tyrosine are structurally all very similar," said Schroeder. "Because of this similarity, we think that m-tyrosine might simulate high concentrations of phenylalanine, which would normally provide negative feedback for phenylalanine biosynthesis" and, thereby, suppress plant growth.
Schroeder and colleagues are also trying to understand why fescue grasses do not succumb to the toxin themselves. They found that when phenylalanine was added to plants dying from m-tyrosine exposure, they recovered. As a result, the researchers suspect that these fescue varieties may overproduce phenylalanine to save themselves from their own toxin.
People have not recognized how effective some fescue varieties are at suppressing weeds because m-tyrosine production appears to be highly dependent on environmental conditions, Schroeder said, which is another area that the researchers are currently investigating.This work was supported by the National Institutes of Health, New York State Turfgrass Association, the National Science Foundation and Triad Foundation.
Blaine Friedlander | EurekAlert!
Alkaline soil, sensible sensor
03.08.2017 | American Society of Agronomy
New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences