Unless your plant yells, "Feed me Seymour," you've never heard a plant cry out. But according to a new study, plants can feel when they are being chewed on, and they aren't big fans of it. Vibrations make plants react by putting up their dukes against predators, according to Ag Web.
So could a farmer play a song for his crops so they release chemicals to ward off pests? Could be.
Professor of Biological Sciences at the University of Missouri Rex Cocroft recorded the sound of caterpillars with a vibration microphone and lasers to gauge the speed of the surface's vibrations. When the vibrations were played, the Arabidopsis plant defended itself by producing mustard oil, which in high doses, could poison a caterpillar, according to Ag Web.
Plants aren't always ready to defend themselves in an instant. Sometimes, they have to "prime" themselves. Heidi Appel, senior research scientist of plant sciences at the University of Missouri, compares it to cocking a gun, according to Ag Web.
"That's what we found in this case: a priming response to the feeding vibration," Appel explained to Ag Web. "If a plant had received feeding vibrations before it was attacked by caterpillars, it reacted with more defense than if it hadn't heard the feeding vibrations. A silent playback device served as a control."
Does this mean that any noise will cause plants to defend themselves?
Cocroft and Appel did more experiments using chewing vibrations, insect "songs" and wind vibrations, according to Ag Web. Again, mustard oil levels were checked, but in addition, anthocyanins (what gives flowers and red wine their hue) were checked.
Anthocyanins also increased when the Arabidopsis plants heard chewing vibrations.
How do the plants distinguish between the various types of vibrations? Science isn't sure.
It could be cell proteins called mechanoreceptors that are embedded in the membranes, according to Ag Web. The movement detecting proteins may detect the movement of vibrations.
"There are maybe 400,000 species of plants, and what are the chances that we just happened to pick the one species that has this ability to detect vibration," asked Cocroft, according to Ag Web. "The ability for plants to pick up sound is pretty clear, but the advance from this study is unique."
"Rather than playing plants a sound that is foreign to their natural environment, we approached it from a plant perspective," Cocroft continued. "What everyday sounds would be relevant? This wasn't Beethoven's 5th; this was a chewing herbivore capable of doing a lot of damage to the plant."
Cocroft and Appel plan to continue their research and study the "perception and detection" of the plants, according to Ag Web.
