They talk together, recognize their family and have a memory. Plants have senses, and research shows that the green geniuses use the same signal substance as mammals to detect dangers.
With gentle movements, a hungry caterpillar slowly crawls up the stem of the plant until it is in the middle of a green leaf, in which it sinks its teeth. It seems like a peaceful scene, but below the surface alarm bells are ringing, and the plant is already in full swing to protect itself from the caterpillar's attack. The bite created an electrical signal of electrically charged ions that rapidly spread from the scene of the crime to the rest of the plant cells to warn them of the hungry danger. The signal is triggered by glutamate - an amino acid that also acts as a signal substance in the nervous system of mammals. Glutamate appears to be the crucial piece of the puzzle that scientists have been looking for for so long to be able to explain how different parts of the plant can communicate with each other so quickly that they can defend themselves against attack.
The discovery happened by accident when American and Japanese researchers from the universities of Wisconsin in the US and Saitama in Japan, among others, wanted to investigate how plants react to gravity. In doing so, they surprisingly concluded that plants have a kind of nervous system similar to that of humans and animals - a conclusion that once again demonstrates that the lives and communication networks of our rooted friends are much more advanced than we have until now. thought.
Attack provokes a signal In the study, the researchers placed genetically engineered plants under a light microscope to monitor the levels of calcium ions in the cells. This often varies in response to, for example, a touch, changes in temperature and changes in the direction of gravity. Because the plants were manipulated in such a way that they produce a protein that lights up at high calcium concentrations, the researchers were able to follow the reaction precisely with the microscope. When the scientists placed a caterpillar on the plants, they saw a wave of light appear around the area it ate, which after a few seconds spread to every corner of the plant. A whole arsenal of toxins was produced to protect the plant from further attacks. But when the researchers blocked the cell-surface proteins that were activated by glutamate, there was no light wave, suggesting that the amino acid plays an important role in the plant's rapid response and defense - just as it does in the nervous system. mammals, where the amino acid also carries signals between cells by opening ion channels.
Plants sleep, see and signal 1234 Research shows that plants can do a lot of what animals do. For example, they can sense their environment with the help of special light-sensitive cells in the leaves, sleep by changing the sap tension in their cells and talk to each other by sending chemical signals through the air. © Ken Ikeda / Shutterstock
But although the cells of the plant and animal communicate via glutamate, there is a big difference in how the two systems work. For example, plants, unlike mammals, do not have real nerve cells and cannot feel pain. That is not surprising; After all, in animals the pain signal indicates that they have to flee, and plants cannot do that, so they do not need to feel pain. Furthermore, the speed of the electrical signals differs greatly. During the experiment, the calcium signal in the manipulated plants spread at a top speed of approximately 1 millimeter per second, which is lightning fast for plants, but extremely slow compared to the signal speed in animals, where the electrical currents sometimes move at 120 meters per second. .
Green memory works well Despite the differences, however, animals and plants use the same signal substance for communication between cells. And it is not the first time that the green multicellular organisms have surprised scientists with their animal properties. A number of studies show that plants can both learn and remember. Researchers at the University of Western Australia trained pea plants in the same way as dogs, for example, to associate the sound of a bell with food: associative learning. In the experiment, cuttings of the pea plants were placed under a simple maze of a water pipe with two outlets. Once the plants reached a certain height, they came to a crossroads where they could grow left or right in the tube.
The mycorrhiza fungus forms enormous networks underground in the extension of the roots, with which the plants share nutrients and warn each other in the event of illness.
The researchers divided the plants into two groups: One group was exposed to wind from a fan followed by blue light from the same side of the tube, while the other group received wind from one side and then light from the other. A subsequent test showed that the pea plants in the first group grew towards the wind, even when there was no light. So they had learned from their previous experiences and linked the wind from the fan to the light. Experiments with mimosa plants confirm this behavior. These plants are very sensitive to touch and quickly fold their leaves as a defense mechanism when touched. The researchers dropped the plants from a height of 15 centimeters several times. On the first three to four times, the plants folded the leaves together, as expected, but on the fifth time they hesitated and after 60 times they stopped responding at all. The plants learned that the trap was not fatal, and so no longer put any energy into the defense, even when the researchers tested them again a month later. And you might think the plants were dead or dead, but if shaken vigorously, they would still crease their leaves.
Signing plants That plants can do much more than we think is not a new theory. As early as 1880, the British naturalist Charles Darwin suggested that plants are intelligent and that their version of a brain lies in the roots - a conclusion that has been confirmed several times, including by the discovery of networks that are an extension of the roots and with which the plants help each other by sending nutrients and warnings through them.
Plants use the same signal substance as animals
When a plant takes damage, it sends a wave of electricity to all of its cells, triggering some sort of immune response. The key to the signal appears to be glutamate, an amino acid also produced by mammals.
protects the plant by triggering all kinds of bitter toxins, such as tannic acid, which can make the caterpillar sick.
Those networks in the roots consist of mycorrhiza fungi, and their total mass on Earth is estimated at 30 billion tons. A large percentage of the plant species on our planet may be connected to the networks more than 400 million years old. By sending chemical signals via the networks, plants can, for example, warn each other about diseases in the immediate vicinity, but they can also transfer carbohydrates to conspecifics who are in the shade and therefore receive too little energy from the sunlight. And by the discovery of glutamate as an important signal substance in plant defense against attack, we can understand how they communicate. https://wibnet.nl/natuur/planten/ook-planten-zijn-gevoelige-wezens
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