Green Intelligence

Scientists around the world continue to reveal that plants are much more than the primitive and passive entities that we once believed them to be.
Green Intelligence
6/27/2008
Updated:
7/27/2008

Scientists around the world continue to reveal that plants are much more than the primitive and passive entities that we once believed them to be. One such researcher—Ian Baldwin, from the Department of Molecular Ecology at the Max Planck Institute in Germany—asserts that plants are not only capable of emitting chemical substances to defend themselves against predatory insects, but can actually communicate among themselves through a complex vocabulary of nucleic acids.

Professor Baldwin, dubbed “the plant whisperer” by his colleagues, discovered that these forms of life are not only capable of communicating their injuries to botanical brethren, but they can even express how and where they are injured. This level of complex inter-botanical communication, studied more in depth in recent years, indicates that plants may have a kind of ‘green intelligence.’

Baldwin’s recent study might have never have arisen if it weren’t for Cleve Backster’s groundbreaking series of experiments that began in the 1960s. While some scoffed at Backster’s findings, he provided unequivocal proof for many that plants not only possess emotions, but advanced telepathic abilities as well.

The Backster Experiments

Since 1962, Backster had been teaching police and other law enforcement officials how to properly use polygraph (lie detector) equipment. His foray into cutting edge science began with a notion to connect one of his lie detectors to a classroom dracaena plant. After the electrodes were connected to its leaf, Backster watered his dracaena, and the polygraph immediately produced a graph signifying a positive emotion.  Intrigued by this, Backster decided to test the boundaries of what he was witnessing. As he tried to imagine what sort of threat might make the plant react, he considered burning its leaves.  The plant seemed to respond to his thought as the polygraph produced another pattern—one normally seen when a subject senses danger. This mind-blowing revelation prompted Backster, and other scientists around the world, to conduct further experiments to test the ‘awareness’ of plants.  Many of these experiments are detailed in ‘The Secret Life of Plants,’ by Peter Tompkins and Christopher Bird.

“When [Backster] and his collaborators, using other plants and other instruments in other locations all over the country, were able to make similar observations, the matter warranted further study.  More than twenty-five different varieties of plants and fruits were tested, including lettuce, onions, oranges and bananas.  The observations, each similar to the others, required a new view of life, with some explosive connotations for science,” from ‘The Secret Life of Plants.’

While Backster was able to detect that plants indeed had thought and communicated on levels higher than previously believed, Baldwin and others have been able to decipher some of the mechanisms behind these complex messages by isolating the chemical changes that take place.

Speaking Green

After reading about Backster’s plant experiments, an electronics engineer from Japan set out to craft a device that could give voice to a plant’s inner thoughts. He enlisted his wife—an avid gardener—to talk to a cactus and was able to get it to talk…so to speak.  The cactus (while attached to this electronic device) produced a varying hum with a noticeable emotional component, in response to what the woman was saying.

While plants don’t actually communicate in the same way as other organisms—they don’t make sounds or noticeable gestures—their ability to convey a clear message has proven effective, nevertheless.

After years of investigation, scientists discovered that through small ribonucleic acids (smRNA)—substances analogous to hormones—plants can fend off pests or other dangers, as well as ask for help and even communicate their turmoil to green companions. While science had understood smRNA’s to be active transmitters of genetic information between DNA and protein, Baldwin and his team discovered that these complex chemicals could regulate a plant’s developmental processes. Using a wild tobacco plant, Nicotiana attenuate, researchers found that these smRNAs revealed a sophisticated vocabulary to guard against predators.

After sequencing the whole smRNA vocabulary in tobacco plants, Baldwin’s team found about 110,000 “words” consisting of RNAs, each with a length of 15 to 30 letters. Using this “dictionary,” they showed in subsequent experiments that the smRNA transcription and therefore “word choice” changed after an insect attack; as a result, certain defense genes were regulated differently.

A Call to Arms

Plants don’t just communicate among themselves, when necessary they also call upon other organisms for help. For example, various species react to insect threats by releasing molecular messages that attract the attackers’ own predators. In addition, the plants close-by also receives messages that stimulate them to liberate, in the same way, the call for predators, forming as a group a genuine defense strategy.

In the plant world, insects aren’t the only threat; sometimes other plants can be the enemy. In 2007, researchers at McMaster University in Hamilton, Ontario discovered that plant species also get competitive for space. The study, published in the Royal Society journal ‘Biology Letters,’ was able to prove what gardeners have known for centuries: certain species don’t like to be near others.  Scientists studied a beach-loving weed known as the Great Lakes sea rocket and found that while it was happy to be near fellow sea rockets, it would try to crowd out foreign neighbors by growing a more extensive root system. As the sea rocket’s overgrown root system took all the surrounding soil nutrients and water, the intruders would soon die out.

While these findings can contribute to future agricultural endeavors—planting some species near crops merely for their ability to ward off predators—the marvelous and complex secret social interactions of plants help shape a new understanding of how we view our world. It prompts us to ask what other forms of communication exist. Without a brain how do plants think and react to stimuli? Without sensory organs how can they know and adapt to the world around them?