Plants Can Detect the “Moment of Touch” and “Moment of Separation”: Study

Plants know “moment of touch” and “moment of separation”

This time, the research team conducted a total of 84 tactile tests on 12 types of plants, including Arabidopsis thaliana (Arabidopsis thaliana) and tobacco (Nicotiana tabacum).

These plants are pre-grown to contain calcium sensors.

A calcium sensor is a technology that can visualize the movement of intracellular calcium ions when a plant is touched.

In the tactile test, plant leaves were placed under a microscope, and ultra-thin glass rods called microcantilevers were used to stimulate individual cells.

The reaction changed depending on the strength and length of the glass rod,What they all had in common was how they reacted to touch and release.was.

Within 30 seconds, plant cells touched by the glass rod slowly transmitted waves of intracellular calcium ions to neighboring cells.

It was confirmed that the waves of calcium ions spread concentrically from the touched point and lasted for about 3 to 5 minutes.

This happens when touched“Slow waves of calcium ions”is.

When the glass rod was further removed from the contact point, a faster concentric wave was generated almost instantaneously and disappeared within a minute.

This happens when you leave“Rapid waves of calcium ions”is.

The team wondered what caused this wave of calcium ions.“Due to pressure changes in plant cells”points out.

Animal cells are designed so that the applied pressure can pass through the cell membrane, but plant cells have a strong cell wall that cannot be easily broken, so even a light touch can temporarily increase the pressure inside the cell. it rises.

To verify this pressure theory, I inserted a special device into the plant cell and mechanically increased and decreased the pressure.

As a result, it has been confirmed that the same calcium ion waves are generated when the glass rod is touched and removed.

Therefore the plantdiscriminates when something is touched and when something is released through the increase or decrease in pressure within the cellIt seems that.

Lead researcher Michael Knoblauch said:

“Animals, including humans, can sense touch through nerve cells.

However, it is truly amazing that plants without nerves have such a fine sensitivity to detect touch at such a detailed level.”

What are the benefits of discerning touch?

On the other hand, it is not yet clear what merit there is in discerning the difference between when something is touched and when something is removed.

There have been a number of studies on the sense of touch in plants, but most of them have shown that touch is of some benefit to the plant.

For example, when a plant leaf senses that it has been bitten by a caterpillar, it secretes chemicals that are not palatable to insects.

Then, in the research on Mimosa, when a leaf is damaged, it sends an electrical signal to its entire body, and the leaf flaps shut to protect itself from insect damage.

Why does Ojigisou “bow”? Elucidation of the purpose and mechanism that was actually unknown!

Since the new tactile response discovered this time does not appear in a visible form like that of Ojigisou, it may be information exchanged inside the plant.

As the next step, the research team plans to clarify the effects of calcium ion waves generated by touch on plant cells and genes.

However, it is certain that plants sense our body touch.