Generally, plants adjust their growth to fit in with their local environment, light being easily the most important factor - after all, they need light to live. These responses are not controlled by photosynthesis itself, however, but by specialized photoreceptor proteins including phytochrome and phototropin which respond to red and blue light, respectively.
Whereas phototropin somehow steers growth direction in higher plants, phytochrome controls most aspects of plant development including germination, stem extension, greening and even flowering. Not surprisingly, it has been found that very many plant genes are regulated by phytochrome, and indeed most textbooks say that phytochrome works exclusively in this manner.
That cannot be true, however, because some phytochrome effects occur almost instantaneously whereas it takes at least 10 minutes to activate a gene and produce a protein. Moreover, in lower plants it is phytochrome that steers growth direction – that simply can't be done via gene regulation.
However, writing in the prestigious Proceedings of the National Academy of Sciences USA, Katharina Jaedicke and colleagues from the Institute for Plant Physiology of the Justus Liebig University in Giessen now report that phytochrome binds to phototropin at the cell membrane in both lower and higher plants. In moss filaments, the phytochrome probably uses the phototropin to steer growth towards the light source because no reaction occurs if the phototropin is missing. The association of phytochrome with phototropin in higher plants probably has a different function in relation to direction sensing, however.The discovery is particularly remarkable because elegant experiments with polarized light carried out in the 1960's predicted that phytochrome was attached to the cell membrane – but up to now there had been no direct evidence for this. Scientists will now be able to use the new findings to design experiments which might provide vital information about how phytochrome and phototropin work and thus how plants respond to light – phenomena which are fundamental to agriculture and thus our food supply.
Christel Lauterbach | idw
The secret sulfate code that lets the bad Tau in
16.07.2018 | American Society for Biochemistry and Molecular Biology
Colorectal cancer risk factors decrypted
13.07.2018 | Max-Planck-Institut für Stoffwechselforschung
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...
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...
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...
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....
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...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
13.07.2018 | Event News
13.07.2018 | Materials Sciences
13.07.2018 | Life Sciences