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
Immune Defense Without Collateral Damage
23.01.2017 | Universität Basel
The interactome of infected neural cells reveals new therapeutic targets for Zika
23.01.2017 | D'Or Institute for Research and Education
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
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...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Health and Medicine
23.01.2017 | Physics and Astronomy
23.01.2017 | Process Engineering