The pressure sensor of the venus flytrap

December 11, 2020

All plant cells can be made to react by touch or injury. The carnivorous Venus flytrap (Dionaea muscipula) has highly sensitive organs for this purpose: sensory hairs that register even the weakest mechanical stimuli, amplify them and convert them into electrical signals that then spread quickly through the plant tissue.

Researchers from Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany, have isolated individual sensory hairs and analysed the gene pool that is active in catching insects. "In the process, we found for the first time the genes that presumably serve throughout the plant kingdom to convert local mechanical stimuli into systemic signals," says JMU plant researcher Professor Rainer Hedrich.

That's a fine thing, because virtually nothing was known about mechano-receptors in plants until now. Hedrich's team presents the results in the open-access journal PLOS Biology.

Sensory hairs convert touch into electricity

The hinged trap of Dionaea consists of two halves, each carrying three sensory hairs. When a hair is bent by touch, an electrical signal, an action potential, is generated at its base. At the base of the hair are cells in which ion channels burst open due to a stretching of their envelope membrane and become electrically conductive. The upper part of the sensory hair acts as a lever that amplifies the stimulus triggered by even the lightest prey.

These micro-force-touch sensors thus transform the mechanical stimulus into an electrical signal that spreads from the hair over the entire flap trap. After two action potentials, the trap snaps shut. Based on the number of action potentials triggered by the prey animal during its attempts to free itself, the carnivorous plant estimates whether the prey is big enough - whether it is worth setting the elaborate digestion in motion.

From genes to the function of the touch sensor

To investigate the molecular basis for this unique function, Hedrich's team "harvested" about 1000 sensory hairs. Together with JMU bioinformatician Professor Jörg Schultz, they set out to identify the genes in the hairs.

"In the process, we noticed that the fingerprint of the genes active in the hair differs from that of the other cell types in the trap," says Schulz. How is the mechanical stimulus converted into electricity? "To answer this, we focused on the ion channels that are expressed in the sensory hair or are found exclusively there," says Hedrich.

In search of further ion channels

The sensory hair-specific potassium channel KDM1 stood out. Newly developed electrophysiological methods showed that without this channel, the electrical excitability of the sensory hairs is lost, i.e. they can no longer fire action potentials. "Now we need to identify and characterise the ion channels that play an important role in the early phases of the action potential," Hedrich said.

University of Würzburg

Related Genes Articles from Brightsurf:

Are male genes from Mars, female genes from Venus?
In a new paper in the PERSPECTIVES section of the journal Science, Melissa Wilson reviews current research into patterns of sex differences in gene expression across the genome, and highlights sampling biases in the human populations included in such studies.

New alcohol genes uncovered
Do you have what is known as problematic alcohol use?

How status sticks to genes
Life at the bottom of the social ladder may have long-term health effects that even upward mobility can't undo, according to new research in monkeys.

Symphony of genes
One of the most exciting discoveries in genome research was that the last common ancestor of all multicellular animals already possessed an extremely complex genome.

New genes out of nothing
One key question in evolutionary biology is how novel genes arise and develop.

Good genes
A team of scientists from NAU, Arizona State University, the University of Groningen in the Netherlands, the Center for Coastal Studies in Massachusetts and nine other institutions worldwide to study potential cancer suppression mechanisms in cetaceans, the mammalian group that includes whales, dolphins and porpoises.

How lifestyle affects our genes
In the past decade, knowledge of how lifestyle affects our genes, a research field called epigenetics, has grown exponentially.

Genes that regulate how much we dream
Sleep is known to allow animals to re-energize themselves and consolidate memories.

The genes are not to blame
Individualized dietary recommendations based on genetic information are currently a popular trend.

Timing is everything, to our genes
Salk scientists discover critical gene activity follows a biological clock, affecting diseases of the brain and body.

Read More: Genes News and Genes Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to