Did you know veggies can hear you eat them! And you thought being a carnivore was bad

Yes, it true! Plants can identify sounds near them and react to threats in the environment. Scientists at University of Missouri in the US studied various behavioral changes in plants and found that they try to protect themselves from being eaten up.

They can identify sounds nearby and then react to the threats. “Previous research has investigated how plants respond to acoustic energy, including music,” said 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 MU.

Moreover, researchers in Germany have found plants also release a gas when under “attack”. Super-sensitive microphones picked up a “bubbling” sound from a healthy plant which was attacked intentionally.

"The more a plant is subjected to stress, the louder the signal,” said Frank Kühnemann.

Plants do not actually scream in pain, but sounds could be heard when they emit the gas.

This research is the first example of how plants respond to an ecologically relevant vibration. It was found that "feeding vibrations" signal changes the plant cells’ metabolism and create more defensive chemicals that can repel attacks from caterpillars too.

Appel collaborated with Rex Cocroft, professor in the Division of Biological Sciences at MU.

To draw conclusions, caterpillars were placed on Arabidopsis, a small flowering plant related to cabbage and mustard.

Cocroft measured the movement of the leaf in response to chewing with the help of a laser and a tiny piece of reflective material on the leaf of the plant.

Cocroft and Appel then played back recordings of caterpillar feeding vibrations to one set of plants, but the other set of plants was not exposed to any noise.

When caterpillars later fed on both sets of plants, the researchers found that the plants previously exposed to feeding vibrations produced more mustard oils, a chemical that is unappealing to many caterpillars.

“What is remarkable is that the plants exposed to different vibrations, including those made by a gentle wind or different insect sounds that share some acoustic features with caterpillar feeding vibrations did not increase their chemical defenses,” Cocroft said.

This proves that plants can distinguish feeding vibrations from other common sources of environmental vibration.

“Plants have many ways to detect insect attack, but feeding vibrations are likely the fastest way for distant parts of the plant to perceive the attack and begin to increase their defenses,” Cocroft said.

This research provides an opportunity to scientists to study their 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.

The study, 'Plants respond to leaf vibrations caused by insect herbivore chewing,' was funded in part by the National Science Foundation and was published in Oecologia.

(Image: Reuters)