Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How plants counteract against the shade of larger neighbours

20.12.2010
The molecular basis of shade avoidance reaction
PNAS report on a collaborative study involving RUB scientists

Plants that “lose the battle” during competitiveness for light because they are shaded by larger neighbours, counteract. They adapt by rapid shoot elongation and stretch their leaves towards the sun. The molecular basis of this so-called shade avoidance syndrome had been unclarified to date. Research scientists from the Utrecht University in the Netherlands and the Ruhr University in Bochum have now been able to unravel a regulation pathway.

A specific transport protein (PIN3) enables the accumulation of the plant hormone auxin, which plays an important role during this adaptation process, in the outer cell layers of the plants, thus enhancing the growth process. The international group of researchers, which includes the plant hormone specialist Prof. Stephan Pollmann from the RUB, has published its observations in the current edition of the Proceedings of the National Academy of Science PNAS.

Suddenly in the shade: plants counteract

Plants often grow in very complex ecosystems, implying that they are in danger of being overgrown and thus shaded by adjacent larger neighbours. Plants have a number of adjustment mechanisms enabling them to register competing neighbours and enhance their competitive reaction. This ensures flexible reaction. Permanent perception of the light intensity and quality is imperative for this process. Prof. Pollmann explained that chlorophyll, the photosynthetic pigment in the leaves, absorbs almost all shades of blue and far red, only allowing dark red light to pass through the leaves. There is a significant change in the red to far-red ratio if a plant is shaded by foliage. If the light receptors in the plants register this change, they initiate a number of adjustment mechanisms in their growth and development program. Taken together these constitute the so-called shadow avoidance syndrome. They enhance the growth of shoots and the upward movement of the leaves (i.e. the hyponastic response).

Auxins play a significant role

Vascular plants produce an entire series of different small signalling molecules, so-called phytohormones, which regulate growth and differentiation processes. Auxins, one of the best-known plant growth factors, have an extremely wide spectrum of activity, and are particularly important. They play a decisive role in almost all plant growth processes, including the shade avoidance reaction. To date, the underlying mechanism was however not fully comprehended. Prof. Pollmann stated that it had been known that the effect of auxin is based on an interaction of auxin formation, transportation and signal transduction. These processes are all influenced by a low red to far-red ratio, but the exact mechanisms were not understood.

Protein distribution ensures directional the flow of hormones

A group of research scientists working under the auspices of the ecophysiologist Dr. Ronald Pierik at the Utrecht University (NL) has now managed to shed light on the matter and further clarify the growth processes in the shoots during the shade avoidance syndrome. They made an interesting observation, namely that shoot growth during a low red to far-red ratio is subject to an intact auxin perception mechanism and is dependent on the accumulation of auxin in the shoot. The auxin transport protein PIN-FORMED 3 (PIN3) is primarily responsible for this accumulation. The formation of PIN3 is enhanced when the ratio between red to far red is low. It primarily accumulates in the lateral endodermal cell walls. This distribution of PIN3 leads to an auxin flow towards the epidermal cell layers, which are responsible for the elongation growth of the shoot.

Comparison between plants in light and shade

This working hypothesis could be experimentally verified by collaboration with Prof. Stephan Pollmann, an expert for phytohormones at the Ruhr University in Bochum. Using state-of-the art mass spectrometry, he succeeded in quantifying and comparing the auxin content in wild-type and genetically created pin3 mutants, which are not capable of producing the transport protein. The shade avoidance syndrome was not present in the genetically altered plants without PIN3. Prof. Pollmann summarized that it is thus possible to deduce the important role of PIN3 controlled auxin accumulation during the shade avoidance reaction.

Title

Keuskamp, D.H., Pollmann, S., Voesenek, L.A.C.J., Peeters, A.J.M., Pierik, R.: Auxin transport through PIN-FORMED 3 (PIN3) controls shade avoidance and fitness during competition. In: Proc. Natl. Acad. Sci. USA, doi: 10.1073/pnas.1013457108

Further Information

Dr. Ronald Pierik, University of Utrecht, F.A.F.C. Wentgebouw, Sorbonnelaan 14-16, Room: Z407, 3584 Utrecht, Netherlands, Tel.: +31 30-2536838, Fax: +31 30-2518366, e-mail: r.pierik@uu.nl

Prof. Stephan Pollmann, Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Campus de Montegancedo, Crta. M-40, km 38, 28223 Pozuelo de Alarcón, Madrid, Spain, Tel.: +34 91 336-4589, Fax: +34 91 715-7721, e-mail: stephan.pollmann@upm.es

Editor: Meike Drießen

Dr. Josef König | idw
Further information:
http://www.ruhr-uni-bochum.de/

More articles from Life Sciences:

nachricht Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University

nachricht Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

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...

Im Focus: Tracing down linear ubiquitination

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...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

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...

Im Focus: Researchers Imitate Molecular Crowding in Cells

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>