JoAnne Skelly: The science of plant intelligence
Associate Professor & Extension Educator Emerita
I’m reading an interesting book called “Brilliant Green – The Surprising History and Science of Plant Intelligence” by Stefan Mancuso (plant physiologist) and Alessandra Viola (science writer). It poses the questions: “Are plants intelligent? Can they communicate, solve problems, and navigate their surroundings? Or are they inert, incapable of independent or social behavior?” The foreword, written by Michael Pollan (The Botany of Desire, The Omnivore’s Dilemma), strongly suggests that plants are not the “mute, immobile furniture of our world,” rather “they are capable of directing their own success in the game of life.”
When studying plant physiology, systems and interactions, it is evident that plants are elegantly complex and evolved, even though their evolutionary path is distinctly different from ours. For example, a plant is divisible. It can lose one part while allowing the rest of the organism to survive. Plants breathe without lungs. They nourish themselves through photosynthesis without having a mouth or stomach. They remain upright without a skeleton. And, through chemical interactions they are able to make decisions without a brain. They have senses, but not in the way humans have senses. The authors propose there are 20 plant senses in all.
Plants sense light, both in quality, quantity and wavelength by way of chemical photoreceptors. Roots are able to identify mineral salts hidden in soil, almost as if they can “taste” them. Carnivorous plants differentiate between insects that are food sources and things that are not and “spit” out the ones that aren’t. Vine tendrils reach and seemingly search for things to cling to. This sense of touch is facilitated by “mechanosensitive channels” found throughout a plant. These channels also allow a plant to sense vibrations in the soil, similar to feeling the bass sound from a speaker. This “phonotropism” can influence where roots grow. Two of the many senses a plant has that we don’t are the abilities to measure soil humidity or to detect harmful chemical compounds in a soil.
Plants transmit messages within themselves and outside themselves using chemical signals. They warn off predators with chemicals that taste bad or are poisonous. Can plants communicate? It depends on how we look at communication. What I like about this book, is not only a new way of looking at plants, major players in mankind’s survival, but also the clear explanations of plant physiology and systems. Pollan reminds us “there is good science to back up its every claim.” The book concludes “plants are mediators between the sun and the animal world.”
JoAnne Skelly is associate professor and Extension educator, Emerita at University of Nevada Cooperative Extension. She can be reached at firstname.lastname@example.org.