Plants are dumb – many believe. But the opposite is the case: trees, flowers and bushes communicate with each other and also with animals. But how does it work exactly?
Like humans, plants have certain signals that they use to communicate. Plants use fragrances where the spoken and written word is used as a communication medium. With up to a hundred scented vocabulary you can send and exchange surprisingly complex information.
Plants don’t speak like we do, but rather through chemical substances that they give off through leaves and roots. These messenger substances reach other plants in the vicinity through the air or the soil. Scientists are finding out more and more about how sophisticated and sophisticated this chemical communication is.
This ability is particularly useful in self-defense. Since plants cannot flee from their voracious enemies, they resort to a trick: They call for help by luring the enemy’s enemies with the help of fragrances. The maize plant, for example, pursues such a strategy: if it is attacked by a caterpillar, it emits an odor that attracts parasitic wasps. These are considered the natural enemy of the caterpillar and eliminate the pest on the corn plant.
Plants warn of tight spaces
The message from maize plants in the current study by the University of Uppsala in Sweden could be in human language: “Pretty close here. Someone nudges me all the time. So neighboring plants, think carefully about where you are growing.”
Touch is an important signal for plants
In the study, the researchers simulated touching the leaves of different maize plants and were able to show that the maize plants notice when they are touched. In previous studies it had already been shown with other plants such as tomatoes or herbs that touching them influences the growth of the plants. They change the metabolism.
Seedlings like it undisturbed
With their experiments on maize plants, the researchers have now been able to show that the roots of plants that are often touched emit chemical signals. These substances are transferred through the soil and moisture. So the plants not only perceive that they are being touched, they also talk about the roots. And the plants in the area react.
Agree on who will grow where
If a young seedling’s root had the opportunity to grow either in the direction of another plant that was touched or in the direction of a plant that was not touched, then it grew significantly more frequently in the direction of the untouched plant. The contact messenger substances thus had a deterrent effect on the seedling. They seem to warn of tightness in the ground.
Corn roots send out messenger substances
The researchers still have to analyze these experiments and the messenger substances in more detail. However, it is conceivable that the plants actually use chemical substances to coordinate which plant grows where and thus make better use of the habitat.
But plants don’t just rely on communication with insects to defend themselves. The green bodies are also in contact with one another. For example, if a plant notices that it is being eaten, it sends out a scent signal that can be perceived by other plants. This alerts them and can activate defense mechanisms. This strategy is by no means just altruistic – after all, an infected plant attracts vermin and thus becomes a danger to its neighbors.
Useful for pest control?
In the meantime, science is even working to make the communication skills of plants useful for biological pest control. The researchers hope that the intelligent and at the same time natural defensive tricks of the plant world could perhaps be used in agriculture. It is precisely here that many cultivated plants have forgotten how to send out calls for help, summon beneficial insects or put pests to flight with biochemical defense strategies. The aim of the researchers is therefore to teach these plants how to “speak” again – because this would reduce the use of pesticides in the future or even do without them entirely.