Researchers found an amazing discovery while experimenting with the Thale cress(Arabidopsis thaliana). They put two Thale cress a few centimeters away from each other and cut two small slices in one of the leaves to simulate an attack of an insect.
One day later, the roots of the non-injured neighboring plant had become remarkably long. Also, according to the researchers, they were “more robust”: they had much more smaller side roots.
“It was crazy: I did not believe it first,” says researcher Harsh Bais. “I expected the injured plant to increase energy in growing the roots. But we did not see that. “Just the other plant turned out to grow its roots. “The uninjured plant allows more roots to grow to gather food and to obtain more nutrients needed to defend itself.”
The Thale cress next to the wounded companion suddenly invests in his defense is of course no coincidence. “A wounded plant warns its neighbors for danger. He does not shout and does not send a message, but he is bringing the message. “The plant release chemicals, which are spread through the air. “The plant does not loosen those chemicals to help itself, but to warn the neighbors.” Unclear is how long the odors stay in the sky. “But if you walk through a lawn after it is mowed or by a field of crops shortly after harvest, you smell those substances.”
Bacteria and growth hormones
But what happens now when a Thale cress receives the alarm signals from his wounded neighbor? The researchers found out that the Thale cress seems to invest in an important growth in hormones and a substance that attracts good bacteria. Those bacteria gather around the roots, with as result boosting the plant’s defense.
In recent years there are more and more studies that change our image of plants gradually. Plants appear to be all but passive organisms: they are able to monitor and respond to their surroundings, and also appear to be able to communicate with peers in different ways.