1 Aug 2014

Can plants detect sound?

From Nine To Noon, 9:43 am on 1 August 2014

Cabbage butterfly caterpillar munches on an Arabidopsis leaf Photo by Roger Meissen Bond LSC
This cabbage butterfly caterpillar munches on an Arabidopsis leaf adjacent to a leaf where a piece of reflective tape bounces back a laser beam used to detect the vibrations created by its chewing. Roger Meissen/Bond LSC.

Scientists have proved that some plants do respond to sound.

So was Prince Charles right, and should we be talking to them?

Well, not quite, but it seems the sound of chewing can provoke a response.

Two researchers at the University of Missouri, Heidi Appel and Rex Cocroft recorded the sound of a cabbage butterfly caterpillar chewing a leaf...

They then played the sound to one set of mustard plants and left another set in silence.

The result was remarkable – the plants that heard the recording of chewing vibrations created an increased amount of mustard oil, which they use as a defence to deter insects.

Their study shows that the vibrations produced by a cabbage butterfly caterpillar munching on a leaf of the mustard plant, throws its defenses into high gear.

Heidi Appel, a senior research scientist in the Division of Plant Sciences at Missouri says it's the first study of its kind to find evidence that plants respond to a sound in the environment

She said the plants were also selective about what type of vibrations they responded to – they did not respond to other vibratory sounds, including those from the wind and non-threatening insects.

Listen to Heidi Appel and Rex Cocroft on Nine To Noon, including the sound played to the plants.