Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanodomains Made Visible

30.04.2013
In dry conditions, certain areas of the plant cell membrane are subject to significant changes. For the first time, scientists have made these so-called nanodomains visible under the microscope, investigating how they changed.
Plants are generally firmly rooted in the ground so that they cannot just move to a different place when the conditions become too dry or uncomfortable in any other way. Therefore, they must be alert to environmental changes and react appropriately.

When the conditions are favorable, the root absorbs nutrients and life-sustaining water. Above the surface of the ground, the shoot adjusts to the current light conditions, performs photosynthesis and produces components for growth, development and reproduction.

Under stress, the plants switch over from this standard program to survival mode. For this purpose, they need the ability to sense stress factors – such as heat, drought or the presence of pathogens – and to take appropriate action. They are able to do this with the help of sensors, which are each connected to a specific network.

Interconnected platforms in the membranes

"According to current knowledge, the cell membranes contain numerous tiny platforms, where certain signaling proteins interact. To some extent, these platforms possess preset interconnections. Depending on the respective signal, they are then reconfigured," explains Dr. Ines Kreuzer, a plant biologist at the University of Würzburg. Because these membrane platforms are so tiny, they are also known as nanodomains.

Reconfiguration of the nanodomains observed

As reported in the journal PNAS, Kreuzer's study group showed for the first time that the components of the drought stress signaling pathway occupy such nanodomains. In cooperation with Professor Gregory Harms at Wilkes University in Pennsylvania (USA), they were also able to trace the change in the domain composition induced by the hormone abscisic acid (ABA) under the laser microscope.

The ABA hormone is used to communicate changes in the water status between different parts of the plant. In dry conditions, high ABA levels ensure that the plant reduces its loss of water to the minimum.

Several signaling proteins involved

The team of the young Würzburg researcher identified several signaling proteins in the nanodomains as main components of the ABA signaling pathway. Kreuzer: "We are talking about the ion channel SLAH3, which is activated by the protein kinase CPK21. This kinase is controlled by the protein phosphatase ABI1. As soon as the receptor recognizes the presence of the ABA hormone, it deactivates the phosphatase and sends out the kinase to activate the ion channel. The opening of the ion channel converts the 'water shortage' signal into a flow of ions – an electrical response, in other words."

Phosphatase as "doorkeeper"

In this process, the nanodomains are a kind of "meeting place", where the reactants are given the opportunity to meet. In the absence of the drought stress hormone ABA, the phosphatase ensures that the ion channel and the kinase are no longer allowed into the membrane domains – there is no cellular response. "The processing of the hormone signal is obviously regulated on the basis of the fact that certain proteins either have or don't have access to special membrane areas, in which mechanism the phosphatase seems to perform the function of a 'doorkeeper', as Kreuzer summarizes.

The next steps of the research

Further studies are intended to show how the process in the nanodomains impacts on the nucleus. It is conceivable that drought tolerance genes are activated there, ensuring the survival of the plant even when there is a shortage of water.

Ines Kreuzer and her study group conduct research at the Department of Botany I – Molecular Plant Physiology and Biophysics of the University of Würzburg, headed by Professor Rainer Hedrich. Their studies are funded by the German Research Foundation within the Research Training Group 1342 (Molecular and Functional Analysis of Lipid-Based Signal Transduction Systems).

Arabidopsis nanodomain-delimited ABA signaling pathway regulates the anion channel SLAH3. Fatih Demir, Claudia Horntrich, Jörg O. Blachutzik, Sönke Scherzer, Yvonne Reinders, Sylwia Kierszniowska, Waltraud X. Schulze, Gregory S. Harms, Rainer Hedrich, Dietmar Geiger, Ines Kreuzer, PNAS, April 29, 2013, doi 10.1073/pnas.1211667110

Contact persons

Dr. Ines Kreuzer, Department of Botany I – Molecular Plant Physiology and Biophysics, University of Würzburg, T +49 (0) 931 31-86103, ifuchs@botanik.uni-wuerzburg.de

Prof. Dr. Rainer Hedrich, Department of Botany I – Molecular Plant Physiology and Biophysics, University of Würzburg, T +49 (0) 931 31-86100, hedrich@botanik.uni-wuerzburg.de

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

More articles from Life Sciences:

nachricht Show me your leaves - Health check for urban trees
12.12.2017 | Gesellschaft für Ökologie e.V.

nachricht Liver Cancer: Lipid Synthesis Promotes Tumor Formation
12.12.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Long-lived storage of a photonic qubit for worldwide teleportation

12.12.2017 | Physics and Astronomy

Multi-year submarine-canyon study challenges textbook theories about turbidity currents

12.12.2017 | Earth Sciences

Electromagnetic water cloak eliminates drag and wake

12.12.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>