Plants are stakeholders in a subtle and complex chemical warfare to secure optimal growth conditions. Although it has been known for decades that plants produce and release chemical substances to fight their neighbors, it has remained unclear how exactly these compounds act on other plants. A team of German and French scientists has been able to show that one particular class of plant toxins slows down the development of competing plants by specifically acting on the structure of their genome.
Plants are in a constant competition with their neighbors for limited resources such as light, nutrients and water. Only the fittest survive and reproduce. To defend their territory against invading competitors, plants employ so-called allelochemicals, toxic compounds that can inhibit growth and development of other plants. The existence of this chemical warfare, referred to as ‘allelopathy’, is widespread among many plant species, and has been known for a long time to scientists and agriculturists.
To have an advantage over their neighbors, some plant species release chemicals from their roots (e.g. DIBOA). These compounds can get degraded in the soil and turn into toxic substances.
Claude Becker, Sebastián Petersen (Max Planck Institute for Developmental Biology) and Markus Burkard (University Hospital Tübingen)
Plants are able to release chemical compounds from their roots into the soil, where the substances decay or are modified by microbes. Some of these products are toxic when the roots of neighboring plants take them up. Work by Sascha Venturelli and colleagues now sheds light on the inner workings of this plant chemical warfare (The Plant Cell).
Claude Becker, one of the leaders of the study, explains the importance of the findings: “The phenomenon has been known for years, and many classes of allelochemicals have been identified over the last decades, but for first time we now understand the molecular mechanism of such a ‘territorial behaviour’ of plants”.
The scientists investigated the role a specific class of plant secondary metabolites, the cyclic hydroxamic acids DIBOA and DIMBOA. These are released by several grass species, and their degradation products are well known for their phytotoxicity.
Through structural and biochemical analyses, followed by physiological experiments, Venturelli and colleagues could show that these compounds inhibit the activity of so-called histone deacetylases. These enzymes bind to histones, a group of proteins that together with DNA form the genetic material, also known as chromatin. Histone deacetylases remove acetyl side chains from these histones, causing compaction of the DNA and leading to a reduction in gene expression.
In the model plant Arabidopsis thaliana, the scientists found that inhibition of histone deacetylases by the plant toxins lead to more histone acetylation and an increase in gene expression, ultimately causing plant growth to slow down. The study thus not only presents the first molecular mechanism for allelopathy, but also illustrates how environmental toxins can alter chromatin structure and gene expression.
Allelochemicals are important regulators in natural and agricultural plant communities, and have repeatedly been associated with the success of invasive species in their new habitats. But there is more: “Herbal natural products in general hold great potential for the therapy of human diseases”, says Sascha Venturelli from the University Clinics Tübingen, medical scientist and first author of the study, and continues: “We have found that these particular compounds efficiently inhibit the growth of human cancer cells, too.”
Indeed some inhibitors of histone deacetylases have already been approved as anti-cancer drugs. Michael Bitzer and Ulrich Lauer, initiators and co-advisors of the study explain on-going efforts: “Clinical trials at the University Clinics Tübingen currently assess the efficacy of these plant toxins in cancer patients”. Understanding the mode of action of plant toxins could therefore also be of wider significance for medical research.
Contributing authors and institutes:
Sascha Venturelli, Alexander Berger, Kyra von Horn, Ulrich M. Lauer and Michael Bitzer from the Department of Internal Medicine I, Medical University Clinic, University of Tübingen, Germany;
Regina G. Belz from the Institute of Plant Production and Agroecology in the Tropics and Subtropics, University of Hohenheim, Stuttgart, Germany;
Andreas Kämper, André Wegner and Oliver Kohlbacher from the Applied Bioinformatics Group, University of Tübingen, Tübingen, Germany;
Alexander Böcker from the Evotec AG, Hamburg, Germany;
Gérald Zabulon and Fredy Barneche from the Institut de Biologie de l’Ecole Normale Supérieure (IBENS), CNRS, Paris, France;
Tobias Langenecker, Detlef Weigel and Claude Becker from the Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
Venturelli et al.
Plants release precursors of histone deacetylase inhibitor to suppress growth of competitors
Advance Publication, The Plant Cell, November 2015 tpc.15.00585
Nadja Winter (PR Officer)
Phone: +49 7071 601-444
Nadja Winter | Max-Planck-Institut für Entwicklungsbiologie
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research