COLUMBIA, Mo.— The idea that plants are in a vegetative state might need to be re-evaluated. Unbeknownst to many, over centuries of natural selection, plants have developed ways of communicating and some researchers argue that plants are intelligent, capable of learning and remembering.
Jack Schultz, director of the Life Sciences Center at the University of Missouri-Columbia, addressed misconceptions about plant communication at the Broadway Brewery on Tuesday, March 11. The informal lecture, The Thoughts of Plants, drew about 35 people. The lecture is a part of Science Cafe Columbia, a monthly get together where folks talk about science. Schultz studies chemical ecology, which strives to “…explain patterns seen in nature by their underlying mechanisms.”
While drinking beers and nibbling on appetizers, attendees listened as Schultz imparted quite a few facts about plants that most people would never know.
1) Plants emit volatiles, a type of chemical signal or odor, to communicate. “When you cut your lawn, what you smell is grass screaming in pain,” Schultz said.
2) Plants can tell the difference between the types of damage they sustain, whether it is a hornworm caterpillar chewing on their leaves or a virus infecting them. And the plant can tailor its response to the threat in the same way our immune system does.
3) When a plant is exposed to the volatiles a damaged plant releases, it prepares its own defenses in advance. Even the plant’s offspring will be better prepared as well to ward off the threat, Schultz explained. This occurs through epigenetics, or methylation of DNA. Methylation involves to addition of a methyl group (3 carbons and a hydrogen) to certain regions of DNA. The methyl group then acts like a light switch, turning certain genes on or off.
4) Plants growing together signal to one another through their network of roots. The entire population is connected. “Every plant is talking together,” Schultz said.
5) All of the biochemical signals present in humans are found in plants, they are just used differently. “Animals and plants are much more similar than you think,” Schultz said.
6) Plants have a language. They speak in chemicals. “We are learning to talk to plants by measuring their volatile emissions,” Schultz said.
7) Plants produce caffeine and nicotine to act as an insecticide and many of the spiced foods we eat are antimicrobial.
In general, plants are much more complicated than people think. “They respond in ways that make you think they are thinking about it,” Schultz quipped. And if you define intelligence as “it works well,” plants make intelligent movements, he said. “They bend to the light and that’s a behavior. It’s just slow.”
The comparatively slow responses of plants often means that plants are overlooked and under appreciated, but by no means are they static. Plants are actively working, responding and acting with purpose.
It just might be time to stop thinking about these plants as passive, or as part of the landscape.