Vegetarians and vegans, this story may set your teeth on edge. How would you feel if you discovered that those plants you’re eating may be aware on some level that you’re eating them?
Have a bit of respect as you chomp on that celery stalk or spear that leafy green salad with your pointy fork. A new study says it has definitive evidence that at least one species of plant knows when it’s being attacked — and it can defend itself.
Researchers from the University of Missouri (MU) recorded the sounds of caterpillars feasting on plant leaves. To create their study’s baseline, they placed a caterpillar on a leaf of a plant called Arabidopsis, a small flowering plant that belongs to the mustard and cabbage family. They measured how the leaf moved as the caterpillar fed on it.
The next part is where this study becomes utterly fascinating. The researchers set up two groupings of plants. For one set, they played the caterpillar munching “sounds” — which were really vibrations — for several hours. The other set of plants “heard” nothing but silence.
When the team placed caterpillars on the leaves of both sets of plants, the set that had been “listening” to or feeling the caterpillar munching vibrations produced noticeably more mustard oils — a substance many caterpillars despise and won’t eat. See MU’s video report on this study here:
“We found that ‘feeding vibrations’ signal changes in the plant cells’ metabolism, creating more defensive chemicals that can repel attacks from caterpillars,” said Heidi Appel, an MU senior research scientist, in a press release.
“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,” said MU’s Prof. Rex Cocroft, who collaborated on this study. “This indicates that the plants are able to distinguish feeding vibrations from other common sources of environmental vibration.”
In other words, the plants knew they were under attack from an enemy, and they responded in a way clearly meant to drive that enemy away, using a home-grown sort of “pesticide.”
“Caterpillars react to this chemical defense by crawling away, so using vibrations to enhance plant defenses could be useful to agriculture,” Appel said. “This research also opens the window of plant 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.”
Obviously, no one’s going to stop eating vegetables because of this study, except perhaps for this confused young woman you might remember from the movie Notting Hill:
As for vegans and vegetarians, we can expect to hear more than a few guffaws from our meat eating friends about all this. Oh, how can we possibly continue to eat plants if they know we’re about to murder them? Yes, it’s all quite funny.
Should this little anti-veggie joke arise, perhaps we can use it as an opportunity to demonstrate that plant-based eaters are not as “hippie dippy” and charmingly odd as some would prefer to believe. You won’t catch many of us worrying about the well being of plants in the wake of this study.
There’s a monumental difference between understanding that a plant has a built-in defense mode and refusing to participate in the factory farming horrors our society imposes each day on intelligent, gentle, sentient creatures like cows, pigs, turkeys and chickens. Nearly everyone realizes this, of course, but don’t be surprised if a meat-eater tries to challenge your plant-based diet by citing this study, if only in jest.
No contest. I’ll keep eating the plants. I’ll also look forward to seeing future research into the potential for naturally induced insecticides. This study appears to validate that such a concept is worth a closer look.
Care2 readers, what do you think? Tell us in the comments below.
Photo credit: Thinkstock