Volatile lactone of Hymenoscyphus pseudoalbidus inhibits germination of ash seeds
The leaves wilt, the crown dies off, the bark exhibits lesions, the wood becomes discolored – the ash forests of Europe are under threat. The perpetrator is an Asian fungus, and its progress is unstoppable. In order to develop effective countermeasures, the transmission pathway, progression of the disease, and propagation of the fungus must be clarified. German researchers have now identified a metabolic product of this killer fungus that inhibits the germination of ash seeds. In the journal Angewandte Chemie, they report on possible mechanisms for this activity.
Hymenoscyphus pseudoalbidus looks almost identical to its harmless relative, Hymenoscyphus albidus, but it causes heavy damage to the common ash, Fraxinus excelsior. Over the last two decades, this killer fungus from the Far East has rapidly spread from east to west across Europe, reaching the British Isles in 2012. There is no decline of the disease in sight. Only a small subpopulation of European ash trees seems to be resistant to this fungus, but it is unclear whether this portion is large enough to ensure the survival of this ecologically and economically important tree species, which is found in nearly all of Europe and parts of Asia around the Black Sea.
A team led by Jeroen S. Dickschat at the Technische Universität Braunschweig has extracted the volatile and nonvolatile metabolic products of the fungus and studied them by spectroscopic methods. The researchers found a suspect among the volatile compounds: in laboratory experiments, the lactone 3,4-dimethylpentan-4-olide inhibits the germination of ash seeds and causes necrosis.
Surprisingly, this compound is also found in nonpathogenic fungi. “Metabolites from the plants may play a role here by regulating the production of the lactone differently in different species of fungus,” suggests Dickschat. “This could also explain why Japanese ash trees are not affected by this fungus and some individuals of the European ash are also relatively resistant.” Another explanation could be the interaction between the lactone and certain microorganisms that are found in the European ash. “Such a mechanism would allow endophytes to act as mediators between the plant and its pathogen,” explains Dickschat. “A comparable mechanism has previously been discovered in another case: Lactones in the smoke produced by burning plants promote germination through a process in which interactions with plant bacteria might play a critical role.”
These new discoveries are important milestones in understanding ash dieback and possible mechanisms of resistance in the unaffected populations of ash. Says Dickschat: “The identification of the lactone as the virulence factor will hopefully pave the way for control of a pathogen that currently threatens the entire population of ash trees in Europe.”
About the Author
Dr. Jeroen S. Dickschat is Assitant Professor of Organic Chemistry at the Technical University of Braunschweig and recipient of the Dechema Young Scientists' Award for Natural Product Research 2014. His research interests focus on the biosynthesis and function of volatile natural products from microorganisms.
Author: Jeroen S. Dickschat, Technische Universtiät Braunschweig (Germany), http://www.oc.tu-bs.de/dickschat/jdickschat_de.html
Title: A Volatile Lactone of Hymenoscyphus pseudoalbidus, Pathogen of European Ash Dieback, Inhibits Host Germination
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201402290
Jeroen S. Dickschat | Angewandte Chemie
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction