Terahertz rays can be used to determine the change in water content of leaves without destroying them.
This is being demonstrated in a recent publication by biologists and physicists from Marburg that appears in a special issue of the journal "Plant Physiology”. Reduced water content leads to increased permeability of the leaves for terahertz waves, the authors say. Thanks to the new method, researchers can measure stress responses in many individual plants over long periods of time.
Global climate change is expected to cause extreme weather conditions – like distinct periods of drought – in the Mediterranean and Central Europe in the future. "Most tree species are very sensitive to drought stress which is caused by lack of water", David Behringer explains; the biologist from Marburg is co-author of the current publication.
To estimate the survival chances of plants under different environmental conditions one has to know the genetic and physiological background of drought stress tolerance in different plants as precisely as possible.
"So far, no methods for the specific investigation of stress responses of plants have been available", adds Professor Dr. Birgit Ziegenhagen, head of conservation biology at the university of Marburg and co-author of the study. "Common measurement methods assess the drought stress either through indirect processes or the measurement leads to the destruction of the plant material."
Therefore, the scientists used terahertz rays – electromagnetic waves in the spectrum between microwaves and infrared light. The biologists in Ziegenhagen’s group used the expertise of their colleagues from the Department of Experimental Semiconductor Physics. "It has been shown that terahertz waves are absorbed almost completely by water while they pass through many solids freely", Professor Dr. Martin Koch explains. The physicist is also involved in the current publication.
Researchers took advantage from another characteristic of terahertz waves, as co-author Norman Born from Koch's working group says: "Since terahertz waves have a much shorter wavelength than microwave radiation, it is possible to measure the thin needles of fir trees."
The authors tested their method on a species of fir trees because conifers with their little leaf surfaces are particularly difficult to study by conventional methods.
For the first time, the researchers from Marburg monitored a great number of plant seedlings over a period of several weeks with the new technique; by doing so, the group has been able to observe, compare and evaluate stress reactions directly. The researchers irradiated a number of plantlets repeatedly by terahertz waves, so that they were able to record the change of water content in the needles accurately and in real time. This was only possible by using the special design of the terahertz spectrometer which was developed in Marburg.
The non-destructive long-term measurements allow accurate prediction of how long a plant can tolerate drought under certain conditions. "Thanks to the new technology, it is possible to expose plants of different genotypes to the same stress to characterize deviant reaction", says conservation biologist and co-author Dr. Sascha Liepelt. Martin Koch as Head of Experimental Semiconductor Physics is looking forward to the continuation of the research work: The "Johannes Hübner Foundation" will support the ongoing work by a scholarship; it will be used to adapt the system to other plant species and conduct in-depth studies.
Original publication: Norman Born, David Behringer & al.: Monitoring plants drought stress response using terahertz time-domain spectroscopy , Plant Physiology 2014 , pp. 113.233601v1 - 113.233601, DOI : 10.1104/pp.113.233601
For more information:
Subject Experimental Semiconductor Physics
Tel : 06421 28-24156
E -mail : firstname.lastname@example.org
Department of Nature Conservation Biology
Tel : 06421 28-23489
E -mail : email@example.com
Press release on Forest Ecology Research (in german): http://www.uni-marburg.de/aktuelles/news/2013d/1213b
Johannes Scholten | idw - Informationsdienst Wissenschaft
A novel synthetic antibody enables conditional “protein knockdown” in vertebrates
20.08.2018 | Technische Universität Dresden
Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
20.08.2018 | Life Sciences
20.08.2018 | Information Technology
20.08.2018 | Power and Electrical Engineering