Plants are More Into Insect Music Than Ours

For the longest time, people have wondered if plants can groove to music the same way we, and several types of animals, clearly do. Everyone has heard at least once in their life that if you sing, or talk to a plant, it makes it grow better. Now I am not actually sure if everyone has heard that, but I certainly did, and spent many hours testing it as a little person. My results were inconclusive, but my curiosity remained to this day. I decided to harness the powers of the internet and did some searching. What I’ve found is a little more complicated than plants just enjoying Michael Jackson (or whoever your favorite musician is). Since it isn’t easy to find human-created music playing naturally in the woods, and since plants and animals adapt to their environments, it is unlikely that plants have evolved to “like” most music (with the exception of the incredible Telegraph plant, which “DANCES” to music and no one seems to know why!!!). But, if you dissect the concept of music and think of it just as vibrations, then yes, there are many varieties of plants that can sense and respond to that, and many of these vibrations are produced by our little insect friends.

Pollinators

An intriguing example of plants visibly reacting to sound/vibration can be found in their relationships with pollinators. The hum created by a bee’s wings creates a very specific pitch, which is sensed by certain flowers, such as those of a tomato plant, or the Orphium frutescens (1). These flowers release their pollen when they feel the bee’s vibration so it can be more sure to attach to the bee, increasing the chance of reproduction. Although this seems less fun than the idea of a plant actually dancing to music, it does have some interesting implications that may lead us to create some bio-mimicked music that plants actually could jam to!

Pests

Another very opposite way that plants respond to vibrations is actually to ward off insects. When a cabbage butterfly caterpillar chews on an Arabidopsis thaliana leaf, the plant recognizes the feeling. At this point, the Arabidopsis releases a toxin (anthocyanin, a water-soluble vacuolar pigment) to get rid of the chewers. BUT, when a gentle breeze or a different insect create a similar vibration, the plant is oblivious and releases nothing. For this reason, this mechanism isn’t yet fully understood (2).

 

Neighboring Plants

It has been claimed that plants can actually also use sound to communicate with one another, as is evidenced by the relationship between chilli and fennel. Fennel plants excrete chemicals that halt the growth of surrounding plants. This phenomenon is called allelopathy. They also coincidentally create a certain vibration with their roots as they grow. When fennel is grown in a box next to a chilli plant, even though the fennel’s chemical can’t reach the chilli through the box, sound can still penetrate, and the chilli grows leaning away from the fennel. Botanists believe that chilli plants may be able to hear the vibration created by fennel roots, hence the growing in the opposite direction (3). This could mean that plants are basically talking to each other all over the place, all the time, and we’d have no idea. Some botanists, such as Dr. Monica Gagliano, think plants could use sound to communicate through fungal connections underground, allowing an entire forest to be on the same page; like an internet for plants (4).

There are probably all kinds of mechanisms that plants have evolved with sound that we still haven’t discovered, so keep your ears open!

1. S. (2012). Bee hits note to unlock flower pollen. Retrieved May 10, 2016.
2. Poecke, R. M., & Dicke, M. (2004). Indirect Defence of Plants against Herbivores: Using Arabidopsis thaliana as a Model Plant [Abstract]. Plant Biology, 6(4), 387-401. doi:10.1055/s-2004-820887
3. Gagliano, M., Renton, M., Duvdevani, N., Timmins, M., & Mancuso, S. (2012). Out of Sight but Not out of Mind: Alternative Means of Communication in Plants.PLoS ONE, 7(5). doi:10.1371/journal.pone.0037382
4. Oskin, B. (2013, March 11). Sound Garden: Can Plants Actually Talk and Hear? Retrieved May 10, 2016.
5. Kim, M. (2014, July 6). Can plants hear? In a study, sound vibrations prompt some to boost their defenses. Retrieved May 10, 2016.
6. Hamilton, E. (2015, April 14). Listening in on Plant Defenses. Retrieved May 10, 2016.