Plants develop hearing in an attempt to get rid of attackers, according to a study. The caterpillars are one of the most vicious enemies of leafs and, surprisingly, plants manage to develop a defensive behavior to counter hungry insects. A team at University of Missouri-Columbia discovered the fact after a study. Animal and plant behavior does not cease to amaze us. Last week we reported on monkeys who develop distinct facial traits to avoid interbreeding. Today we will see how plants are more than passive victims.
The researchers used the classical experimental setting. The first phase was to expose one group of Arabidopsis plants to the independent variable, while the control group was supervised in normal conditions. The independent variable in this case was a recording of caterpillars munching on leaves. The second part of the experiment included actual caterpillars eating the plants from both groups. The result was that the plants previously exposed to the munching sound developed a defensive mechanism. A caterpillar repellent chemical was released in large quantities and the insects retreated.
Plants develop hearing but do not listen to music
Plants do not respond by producing this substance when they are facing the wind or other vibrations. The fact lead the team of researchers to the conclusion that plants can hear. The results will probably have massive importance in agriculture. By developing cheap large scale vibration mechanisms, agricultural producers can protect their harvest and yield larger crops.
Other studies meant to understand how plants react to acoustic energy have been performed. The tests involved even reactions to music. But Heidi Appel, senior research scientist in the Division of Plant Sciences in the College of Agriculture, Food and Natural Resources and the Bond Life Sciences Center at University of Missouri says their experiment is a first. “Our work is the first example of how plants respond to an ecologically relevant vibration. We found that feeding vibrations signal changes in the plant cells’ metabolism, creating more defensive chemicals that can repel attacks from caterpillars.”, Appel states.
The leaves performed vibrations for less than one ten-thousandth of an inch, but that was enough proof for the researchers. The next step is to investigate how exactly the plants develop the mechanism. The scientists’ first hunch is that the mechanoreceptors play a large part in how plants develop hearing. Those are proteins found in both animal and plant cells and have the role to assess pressure or distortion. The 1970s research suggesting that plants are more responsive to classical music, rather than rock have been dismissed. Probably the 1970s researchers were more elitist.