The new study, published today (Aug. 23) in the Proceedings of the National Academy of Sciences, identifies the protein targets in cells of a key hormone that controls how plants respond to environmental stresses such as drought, excessive radiation and cold.
The work, which builds on decades of research with a key plant hormone known as abscisic acid, could help underpin the development of new crop plant strains capable of thriving in hotter, dryer climates. The work is considered important in light of the pressing need to expand and intensify agricultural production on marginal lands worldwide, and especially so in the context of global climate change.
"If we can figure out how this works with crops and make them able to resist drought, the benefits would be enormous," notes Michael Sussman, a University of Wisconsin-Madison professor of biochemistry and the senior author of the new study. "These are the first baby steps to understand the effects of dehydration in plants and it may give us the opportunity to develop crops that can withstand this kind of stress in the field."
Working in the model laboratory plant Arabidopsis, the Wisconsin team explored the influence of abscisic acid, a long-studied hormone that, in addition to influencing how plants respond to environmental stress, controls the naturally occurring processes of seed dormancy and germination.
The hormone has been known to science for 50 years, and was believed to influence certain proteins in cells in a complicated cascade of events that aided the ability of a plant to survive such stresses as dehydration, excessive radiation and cold temperatures. But any plant cell, Sussman explains, contains at least 30,000 different proteins, and the identity of the few proteins activated by the hormone was a deep mystery.
"Since they cannot walk or run, plants have developed an interesting and complicated system for sensing and responding very quickly to dehydration and other stresses," says Sussman, noting that, on average, a plant is composed of 95 percent water. "Most plants have what's called a permanent wilting point, where if water content goes below 90 percent or so, they don't just dehydrate and go dormant, they dehydrate and die."
Figuring out how to trigger a dormant state, such as exists naturally in seeds, which are 10 percent water and can in some cases remain viable for hundreds of years, could be key to creating plants that survive drought in the field, Sussman explains.
The team, which includes postdoctoral fellow Kelli G. Kline and scientist Gregory Barrett-Wilt, utilized a new stable isotope technology and mass spectrometry to comb 5,000 candidate proteins in the cells of living plants and found 50 that were influenced by the abscisic acid hormone. The survey is the first of its kind in a living plant and many of the proteins identified were previously not known to be influenced at all by abscisic acid.
Surprisingly, the hormone was found to regulate some of the plant proteins in a completely different way than was known before, by inhibiting their ability to have a phosphate moiety removed from an amino acid, by a type of enzyme called a protein phosphatase. Protein phosphatases are the opposite side of the coin that catalytic enzymes known as protein kinases occupy. In many important biological processes, such as cancer, it is the protein kinases that are the dominant actors.
The finding that phosphatases play a more critical role in a hormonally regulated system is a new idea in biology discovered through work with plants. Sussman's group's findings indicate that the dynamic interplay between the hormone and the proteins it affects is a more complicated process than previously suspected. "The story is far from complete," says the Wisconsin biochemist. "There is something very interesting, and complicated, going on."
The new study was funded through the U.S. National Science Foundation.
Terry Devitt, 608-262-8282, firstname.lastname@example.org
Michael Sussman | EurekAlert!
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy