Most people have heard the theory that plants grow better when classical music is played for them.
While that claim is still unproven, a new study coming from the University of Missouri has shown that plants can ‘hear’ and react to certain things.
Specifically, they can detect the sounds that are made when they are being eaten, and react to them.
This may sound far-fetched, but it certainly seems to be true.
The study was set up by using a small piece of reflective tape that was placed on a leaf.
This tape could then be hit with specialized lasers to measure the leaf’s movements that were made when a caterpillar consumed the leaf.
Once they recorded several hours of this sound, they set up an experiment using two Arabidopsis plants.
One was in a quiet room, and the other in a room where they played the sounds using specialized speakers to precisely recreate the sound made from the leaf being eaten.
Rex Cocroft, one of the study authors, said of this process:
“It’s a delicate process to vibrate leaves the way a caterpillar does while feeding, because the leaf surface is only vibrated up and down by about 1/10,000 of an inch. But we can attach an actuator to the leaf with wax and very precisely play back a segment of caterpillar feeding to recreate a typical 2-hour feeding session.”
After the sounds were played, the leaves from both the control plant and the tested them for several key chemical compounds. The other author of the study, Mizzou Heidi Appel, explained:
“We looked at glucosinolates that make mustards spicy and have anticancer properties and anthocyanins that give red wine its color and provide some of the health benefits to chocolate. When the levels of these are higher, the insects walk away or just don’t start feeding.”
This remarkable finding shows that plants can detect some types of sound (or at least vibration) and respond to it.
Interestingly, the study noted that when other sounds were played, including those of wind and insects that don’t eat the plant, the defensive chemicals did not increase in the leaves.
Appel commented on the future of this type of study, saying:
“This research also opens the window of plant behavior a little wider, showing that plants have many of the same responses to outside influences that animals do, even though the responses look different.”
While this study does seem to indicate that plants have the ability to ‘hear’ (or something similar to hearing), they have not yet determined the mechanism for how this is done. That will undoubtedly be the subject of future study.
It looks like the lives of plants are much more complex than previously thought.
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