Explain how trees communicate with each other when they are in danger

Scientists have discovered that when faced with danger such as pests, plants have the ability to spread a volatile compound around to warn healthy plants to activate defense mechanisms.

According to a new study, injured trees emit certain chemical compounds that can penetrate the internal tissues of healthy trees and activate defense mechanisms from within the tree's cells.

Wounded trees can release a compound that acts as a warning signal to their surroundings. (Photo: Getty Images)

For the first time, researchers were able to 'visualize tree-to-tree communication ', said Masatsugu Toyota, lead author of the study published in the journal Nature Communications.

The idea of ​​a 'talking' tree began to form in the 1980s. Two ecologists placed hundreds of caterpillars and spiders on willow branches to observe the tree's reactions. They found that attacked trees began to produce chemicals that made their leaves less palatable and indigestible to deter insects.

But even more surprising, scientists discovered healthy trees of the same species, located 30 or 40 meters away and with no roots connected to the pest-infested trees, also put up similar defenses. to prepare yourself against insect invasion.

These early research groups came up with a new idea: Trees send chemical signals to each other through the air. But no one knew which compounds were important and how they were perceived - until now.

Plants apparently don't have ears or eyes, but previous research has shown they communicate with their surroundings by secreting chemicals called organic compounds that we can smell. .

Trees also have the ability to communicate with each other. (Photo: Getty Images).

But just as humans can speak many words, plants can produce a wide range of compounds for different purposes. Some are used to attract pollinators or as defense against predators.

However, one class of these compounds is released when a plant is injured: green leaf volatiles. As the name suggests, almost any leafy green plant can release this compound when the plant experiences physical damage.

In the new study, Toyota and colleagues manually crushed leaves and placed caterpillars on Arabidopsis or tomato plants to trigger the release of various green leaf volatiles. They then spread these compounds to healthy plants to see if they responded.

To monitor the response of healthy plants, the team genetically modified the plants so that calcium ions would fluoresce when activated inside each cell. Calcium signaling is important for cellular functions in most living organisms on Earth, including humans.

Toyota says calcium signaling plays a similar role in plants. Depending on the type of plant, it can trigger messages to close leaves or digest insects.

Plants activate calcium signals when attacked by leaf-eating insects. (Source: National Geographic)

After testing many volatile substances, the team found only two that appeared to increase calcium ions inside cells. In addition, they found that calcium signaling first increased in guard cells that form holes in the plant's leaves or stomata – an important finding because it showed that the compounds were absorbed into tissues. inside the tree.

'They cannot easily penetrate the surface of the plant,' said Kessler, Professor at Cornell University . They have to pass through stomata, [which] allows the plant to actually inhale carbon dioxide and expel oxygen for photosynthesis'.

Toyota says the calcium signal is like a switch to turn on the plant's defense response. After the signal increased, the team found that the plant increased the production of certain gene expressions for defense. For example, Toyota says plants can produce certain proteins to prevent insects from eating leaves, causing the insects to develop diarrhea.

With the new understanding, researchers say plants can be immunized against threats and harmful agents before they occur - similar to vaccinating plants.

For example, exposing healthy plants to plants invaded by insects or related volatiles may help strengthen their genetic defenses, contributing to limiting pesticide use.

This advance has planted many seeds for future research, the scientist said.

Be kind to the tree

Scientists say plants are no different from animals, they feel pain and endure pressure. So, be gentle with them. (Photo: Guido Mieth/Getty).

Molecular biologist Masatsugu Toyota of Saitama University, Japan, says this communication system is surprisingly similar to what we see in animals, but differs at the cellular level.

Information and methods of transmitting and receiving information are also different. But once they receive the signal, they activate calcium signal waves, similar to how animal cells communicate with each other. And even human cells use calcium signals to exchange information with each other.

So scientists say we should treat our plants gently.

He said: "Plants can sense many types of stimuli in the environment. They can smell, feel by touch and communicate with others. There is no boundary between animals and plants here. I really want everyone, especially children, to understand that plants are very sensitive. Let's be gentle with all the plants around us . "