Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Venus flytrap: from prey to predator

06.05.2016

The carnivorous Venus flytrap recognizes its prey by taste and its cells share similarities with the human intestine. By exploiting common plant defense strategies, the flytrap has completely turned the table; it seeks out and consumes prey rather than being the meal itself.

The Venus flytrap (Dionaea muscipula) feeds on insects. It attracts a meal with its flower-like reddish color and ripe fruity smell on leaves converted to ambush traps. Seeking nectar, an insect will inevitably touch the highly sensitive sensory hairs on the leaves. This causes the trap to snap shut at lightning speed, imprisoning the prey.


A Venus flytrap with its turf of glands and single glands under the microscope.

(Picture: Sönke Scherzer)


A Venus flytrap with its turf of glands and single glands under the microscope. The three layers of a gland with a cartoon showing the three typical cell types.

(Pictures: Dirk Becker / Sönke Scherzer)

Dionaea must then decide how much energy to invest in the capture and consumption. It estimates the size of the prey by counting how often it touches the sensory hairs. Two touches and Dionaea activates a special hormone. With five or more stimuli, the plant produces enzymes and transport proteins for digesting and absorbing the prey.

But what genes make the trap a trap? How did the plant switch to animal food during evolution? Professors Rainer Hedrich (Biophysics) and Jörg Schultz (Bioinformatics) and their teams from Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, have unraveled this mystery. Their results are published in the scientific journal "Genome Research".

The flytrap is a leaf with root function

Surprisingly, the analyses revealed that the Dionaea trap not only had active genes typical of leaves, but also possessed genes normally specific to roots. But how can the trap be both a leaf and root at the same time? The scientists found the answer in the numerous glands that densely populate the trap surface.

The dome-shaped glands are made up of three cellular layers. The outer layer consists of cells responsible for excreting digestive enzymes. The second layer features cells whose envelopes are folded multiple times – similar structures that increase the surface area are found in the intestine of humans. "We assume that this is the place where nutrient uptake takes place," Hedrich supposes.

The cells of the third layer are densely packed with oil bodies. They could supply the fat for the energy used by the two outer cell layers – an idea supported by the gene activation pattern in traps that caught insects.

Trap also recognizes insects by their taste

Insects are protected by a chitin exoskeleton. The Venus flytrap cracks this protective shell using special digestion enzymes that are produced once the sensory hairs register a stimulus. It will ebb away if the hairs are not further stimulated. The researchers found that with repeated stimulation (whether by a trapped insect or experimenter), enzyme production increases for several days.

But what if the prey dies soon after capture? This is not a problem for the Venus flytrap: the presence of a chitin receptor assures continued production of enzymes – the plant is capable of "tasting" the insect. The chitin boosts the enzyme production even more than a mechanical stimulus.

From defending to attacking

So, the presence of chitin tells the Venus flytrap that food is available, causing the digestive juices to flow. "Contact with chitin normally means danger for a plant – insects that will eat it," Hedrich explains. Ordinarily, this triggers defense mechanisms.

"In the Venus flytrap these defensive processes have been reprogrammed during evolution. The plant now uses them to eat insects," the professor further adds. The JMU researchers came to this conclusion by looking at thale cress (Arabidopsis thaliana), a non-carnivorous plant, for exactly the same pattern of gene activation as found in the Venus flytrap when it catches its prey.

The greatest match is found when thale cress is injured mechanically or when insects feed on it. The physiological responses too are similar. Injuring thale cress generates an electrical impulse that activates an important defense hormone called jasmonate. Touching the Venus flytrap's sensory hairs activates the same hormone.

From that point on, the signal paths differ. To fend off insects, the hormone starts the production of substances that poison or deter insects, or make the leaves hard to digest. In this carnivorous plant, the hormone initiates the digestion of the meal and uptake of its nutrients.

Goal of "Carnivorom" EU project achieved

"We have thus achieved our goal of decoding the molecular origin of the Venus flytrap's carnivorous way of living," Hedrich reports with pleasure. He has pursued this goal since 2010 within the scope of the "Carnivorom" project funded by the European Union (EU) to the tune of 2.5 million euros (http://www.carnivorom.org).

"We are now going to compare the genome of carnivorous plants, their protocarnivorous precursors such as Plumbago to plants in which carnivorous and non-carnivorous development stages alternate such as in Triphyophyllum or the tropical liana Ancistrocladus, which has gone on to abandon the carnivorous lifestyle. Ultimately, we want to know what equipment a plants needs to eat and live off animals."

“Venus flytrap carnivorous life style builds on herbivore defense strategies“, Felix Bemm, Dirk Becker, Christina Larisch, Ines Kreuzer, Maria Escalante-Perez, Waltraud X. Schulze, Markus Ankenbrand, Anna-Lena Keller Van der Weyer, Elzbieta Krol, Khaled A. Al-Rasheid, Axel Mithöfer, Andreas P. Weber, Jörg Schultz, Rainer Hedrich. Genome Research, May 4th, 2016. DOI: 10.1101/gr.202200.115

Contact

Prof. Dr. Rainer Hedrich, Chair of Botany I (Molecular Plant Physiology and Biophysics), University of Würzburg, Germany, Phone: +49 931 31-86100, hedrich@botanik.uni-wuerzburg.de

Weitere Informationen:

http://www.bot1.biozentrum.uni-wuerzburg.de/en/startseite/ Prof. Hedrich's homepage

Robert Emmerich | Julius-Maximilians-Universität Würzburg

More articles from Life Sciences:

nachricht At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History

nachricht New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>