Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How plants conserve water

03.12.2009
Less rainfall, higher temperatures: plants are also suffering the effects of climate change. How, despite this, they survive longer periods of drought is the subject of research by Rainer Hedrich, a biologist at the University of Würzburg. He presents his findings in the latest issue of the journal Proceedings.

When the heads of government of the UN Member States meet in Copenhagen in December for the world climate summit, one topic will be on the agenda again: climate change. The struggle by politicians to find a way of limiting global warming will also be followed with interest by plant researchers and experts in farming. After all, these people are already seeing the effects of the rise in temperature.

Modern cultivated plants have forgotten how to conserve water

Rainer Hedrich, Chairman of the Department of Molecular Plant Physiology and Biophysics at the University of Würzburg, is among those interested in the consequences of protracted periods of drought and rising temperatures for the plant world. "Having been subjected to centuries of cultivation, today's cultivated plants have lost some of their vitality. To put it bluntly, our crops have forgotten how best to conserve water," says Hedrich. This means they would not be able to withstand a global change in climate with lengthy periods of heat and drought.

Hedrich has researched the water balance of plants. His most recent findings are reported in the latest issue of the journal Proceedings of the National Academy of Sciences (USA).

Dilemma attached to water shortage and water loss

Plants extract water from the soil and carbon dioxide from the air, which they use during photosynthesis to produce carbohydrates and oxygen. They release water into the environment in the form of water vapor.

"The release of water vapor as an unavoidable consequence of photosynthesis does not constitute a problem for the plant as long as it has enough water at its disposal," explains Hedrich. However, if rain does not materialize, the plant cannot absorb any more water through its roots and, at the same time, it loses more water to the increasingly dry atmosphere.

However, the plant is not completely defenseless against this dilemma. "Its outer skin, the so-called epidermis, is covered with a layer of wax which is impermeable to water and carbon dioxide," says Hedrich. It is only through microscopically small, controllable pores that the plant can absorb carbon dioxide and release water vapor.

Sensory cells register the water content of the plant

How does this work? "These pores consist of two guard cells. When these expand, the pore opens; when they contract, the pore closes again," explains Hedrich. This process is controlled by the plant drawing specific salts - the positively charged potassium ion and the negatively charged chloride ion - into and out of the guard cell through special channels.

"The anion channels of the guard cells have a crucial role to play in water conservation," comments Hedrich. The plant perceives that the soil is drying out and sends a hormone to the guard cells. Once there, this hormone activates a signal chain that causes the anion channels to open and to set a process in motion that ends with the pores closing.

The sensory cells which are able to recognize water stress also have the ability to measure the concentration of carbon dioxide in the leaf as well as the intensity and composition of sunlight. "This means that the plant is able to keep the pores closed and only open them to absorb carbon dioxide when there is sufficient water and light available for the production of carbohydrates," explains Hedrich.

Consequences for farming

Using precise knowledge of the metabolic processes in plants, Hedrich hopes that it will be possible to make modern cultivated plants able to cope with the requirements of climate change. His interest therefore extends to plants which, like the famous "Rose of Jericho", have become real experts at surviving water shortage. "These extremophiles can even survive after being dried out completely," he says. An exact understanding of this ability could help us to optimize useful plants and crops specifically so that they can cope with global warming.

Activity of guard cell anion channel SLAC1 is controlled by drought-stress signaling kinase-phosphatase pair. Dietmar Geiger, Sönke Scherzer, Patrick Mumm, Annette Stange, Irene Marten, Hubert Bauer, Peter Ache, Susanne Matschi, Anja Liese, Khaled A. S. Al-Rasheid, Tina Romeis, and Rainer Hedrich. PNAS, 2009, doi/10.1073/pnas.0912021106

Contact

Prof. Dr. Rainer Hedrich, phone +49 931 3186100, hedrich@botanik.uni-wuerzburg.de

Robert Emmerich | idw
Further information:
http://www.uni-wuerzburg.de

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>