Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plants are „biting“ back

19.05.2016

Calcium phosphate is a widespread biomineral in the animal kingdom: Bones and teeth largely consist of this very tough mineral substance. Researchers from Bonn University could now for the first time demonstrate the presence of calcium phosphate as a structural biomineral in higher plants. The substance provides the necessary “bite” to the stinging hairs of representatives of the rock nettle family (Loasaceae). It hardens the trichomes, which serve as a herbivore defense. Conversely, our native stinging nettles have stinging hairs hardened by glass-like silica. The results of the study are now published in the journal „Scientific Reports“.

Animals only eat them once: When the tongue touches the minute trichomes of rock nettles (Loasaceae), the tips of the stinging hairs break off and a painful cocktail pours out into the sensitive tissue. These well-defended plants have their centre of diversity in the South American Andes.


The colourful flower of the rock nettle Blumenbachia insignis in the Botanical Gardens of Bonn University.

(c) Photo: M. Weigend/Uni Bonn


Under the scanning electron microscope: Detail of the lower leaf surface of Loasa pallida. The red areas are mineralized (here not differentiated between different minerals).

(c) Image: H.-J. Ensikat und M. Weigend/Uni Bonn

„The mechanism is very similar to that of our well-known stinging nettles“, says Prof. Dr. Maximilian Weigend of the Nees-Institut for Biodiversity of Plants at Bonn University. There are additional differences between the only stinging nettles and rock nettles – which are only distantly related - apart from their different appearance: Native stinging nettles fortify their needle-like hairs with silica, while their spectacularly flowering South American counterparts employ calcium phosphate for that purpose.

Calcium phosphate has never previously been documented as a structural biomineral in higher plants. “The mineral composition of the stinging hairs is very smilar to that of human or animal teeth“ says Prof. Weigend, who has been researching the highly diverse rock nettles for the past 25 years.

Many scientists previously noted the strikingly rough hairs of this plant group, but nobody ended up researching their chemical composition. The botanists investigated the stinging hairs – built like hypodermic syringes - with their own electron microscope and in collaboration with colleagues from the Steinmann-Institute for Geology, Mineralogy and Paleontology and the Institute of Inorganic Chemistry of Bonn University.

Tips of the stinging hairs structurally similar to reinforced concrete

It could be shown that especially the mechanically highly stressed tips of the hairs are incrusted with calcium phosphate. „This is essentailly a composite material, structurally similar to reinforced concrete“, explains Prof. Weigend. The fibrous cellulose as the typical material of plant cell walls provides the scaffolding and is densely incrusted with tiny crystals of calcium phosphate. The scientist of Bonn University is convinced „This renders the stinging hairs unusually rigid”.

It is still unclear why rock nettles evolved this particular type of biomineralization, while most plants use silica or calcium carbonate as structural biominerals. „A common reason for any given solutions in evolution is that an organism possesses or lacks a particular metabolic pathway“, says Prof. Weigend. However, rock nettles are able metabolize silica and use it as a structural biomineral – side by side with calcium phosphate. It is not currently understood why it is particularly calcium phosphate that is used in the stinging hairs tips, the very substance that the mouthparts of their enemies also consist of. „At present we can only speculate about the adaptive reasons for this. But it seems that rock nettles pay back in kind – a tooth for a tooth” chuckles the biologist of Bonn University.

Bionics: plant trichomes as templates for bone substitutes

Additional research projects are directed towards investigating which other plants may use structural calcium phosphate to face challenges in their natural environment and which biomechanical advantages this material conveys to the plants. The discovery is also of potential relevance for bionic applications. „Surgical bone substitutes have to be highly tissue compatible, cellulose-composite are likely to meet that criterion“, says Prof. Weigend. First attempts at producing artificial cellulose-calcium phosphate composite have been made by other researchers, but so far a natural template was unknown. The cellulose-calcium phosphate composite in rock nettles could be just such a template.

Publication: Hans-Jürgen Ensikat, Thorsten Geisler & Maximilian Weigend: A first report of hydroxylated apatite as structural biomineral in Loasaceae – plants‘ teeth against herbivoren, Scientific Reports, DOI: 10.1038/srep26073

Media contact:

Prof. Dr. Maximilian Weigend
Nees-Institut for Biodiversity of Plants
Bonn University
Tel. ++49-(0)228-732121
Email: mweigend@uni-bonn.de

Johannes Seiler | idw - Informationsdienst Wissenschaft
Further information:
http://www.uni-bonn.de

More articles from Life Sciences:

nachricht Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)

nachricht CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

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...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

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...

Im Focus: Studying fundamental particles in materials

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...

Im Focus: Designing Architecture with Solar Building Envelopes

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>