Plants Display Sentience and Social Behavior
Plants are sentient beings, capable of thought, communication and understanding kinship. Don’t believe me? Well, maybe some ongoing studies will convince you.
Biologist Susan Dudley studied a group of Pale Jewelweed (Impatiens pallida) plants. Her findings—published in the American Journal of Botany—show that these flowering plants use less energy to grow roots when they are surrounded by relatives (plants that share similar genes). However, when they are amongst plants that are unrelated, their roots will grow as fast as possible. This discovery shows that plants are capable of kin recognition; meaning they are able to tell the difference between related and unrelated plants, and adjust their social behavior accordingly.
“When I was in school, researchers assumed that some plants were better or worse than others at getting resources, but they were blind to the whole social situation. I went looking for it, and to my shock, found it. And we’ve found more of it since,” said Dudley.
Even though the idea of a plant social structure wasn’t widely accepted, further research into plant communication happened. A lot of the focus was on plant defensive actions, such as creating toxins or how to focus resources on their immune systems. This kind of behavior led to the conclusion that plants were, indeed, able to recognize themselves. The next step in these series of studies would be to find out if and how they might respond to relatives.
According to Plant Ecologist, Hans de Kroon, of the Radboud University in the Netherlands:
“We know that in the animal world, kin recognition and selection plays a very important role for family structure, altruistic behavior and those kinds of things. It’s so prominent in the animal literature. Once we start to discover that plants can recognize their kin, there’s a whole set of hypotheses we can apply to studying plants that nobody ever thought to.”
Another paper—based on further studies conducted by Dudley—revealed that American searocket plants (Cakile edentula) increased the speed of their root growth when planted amongst strangers (unrelated plants), but the speed would slow down if they were replanted with relatives. This would be the equivalent of animals of the same family or herd distributing food and water amongst themselves and keeping it away from strangers.
Susan Dudley was not the only one interested in these plant experiments, however. Biologists Harsh Bais and Meredith Biedrzycki from the University of Delaware also ran some tests, which involved the use of Thale Cress (Arabiodpsis thaliana) seeds. The seeds were isolated in separate pots, and each pot was exposed to root secretions from other Arabidopsis plants. The results confirmed Dudley’s previous findings: how the seeds reacted depended entirely on whether the root secretions came from genetically related or unrelated plants.
Even more research is currently underway to find out if the roots are the only source of such communication. In Dudley’s most recent study, the possibility of plants also communicating via chemical signals emitted by their leaves also came into play. A study from earlier this year, conducted by ecologist Richard Karban, adds to this possibility. Apparently, Sagebrush will boost its immune system when exposed to clippings of a related plant. Could these plants be sending alarms or warning signals to each other? Possibly, but more research is needed to confirm anything.
I find it absolutely fascinating that scientists are finally starting to consider plant sentience a serious possibility. The idea of plant communication is not entirely new, and has been an integral part of some spiritual practices. So, if plants are capable of communicating with each other, and understanding whether those around them are family or not, can they also feel pain? And if they can feel pain, do their relatives hear their screams when they are cooked or eaten? I think the idea of plant sentience may put a whole new perspective on things for some people. It would seem that if plants are capable of the same things as animals (realization and communication), that eating a carrot would be no different than eating a chicken leg, as both come from beings that display awareness. It certainly gives you something to think about.
By Heidi Marshall