Stefano Marcuso, author of Brilliant Green, joined with Elizabeth Van Volkenburgh, an American plant biologist, Rainer Stahlberg, a German plant photobiologist, Eric D. Brenner, an American plant molecular biologist and František Baluška, a Slovak cell biologist to publish an article in 2006, Trends in Plant Science.

The authors contended that ‘the behaviour that plants exhibit is coordinated across the whole organism by some form of integrated signalling, communication and response system … [which] includes long-distance electrical signals, vesicle-mediated transport of auxin in specialised vascular tissues, and the production of chemicals known to be neuronal in animals’.

Michael Pollan, who wrote an article in the New Yorker in  Dec. 23, 2013, says for the longest time, even mentioning the idea that plants could be intelligent was a quick way to being labeled “a whacko.” But no more, which might be comforting to people who have long talked to their plants or played music for them.

The new research, he says, is in a field called plant neurobiology — which is something of a misnomer, because even scientists in the field don’t argue that plants have neurons or brains.

“They have analagous structures,” Pollan explains. “They have ways of taking all the sensory data they gather in their everyday lives … integrate it and then behave in an appropriate way in response. And they do this without brains, which, in a way, is what’s incredible about it, because we automatically assume you need a brain to process information.”

And we assume you need ears to hear. But researchers, says Pollan, have played a recording of a caterpillar munching on a leaf to plants — and the plants react. They begin to secrete defensive chemicals — even though the plant isn’t really threatened, Pollan says. “It is somehow hearing what is, to it, a terrifying sound of a caterpillar munching on its leaves.”

Pollan says plants have all the same senses as humans, and then some. In addition to hearing, taste, for example, they can sense gravity, the presence of water, or even feel that an obstruction is in the way of its roots, before coming into contact with it. Plant roots will shift direction, he says, to avoid obstacles.

So what about pain? Do plants feel? Pollan says they do respond to anesthetics. “You can put a plant out with a human anesthetic. … And not only that, plants produce their own compounds that are anesthetic to us.” But scientists are reluctant to go as far as to say they are responding to pain.

How plants sense and react is still somewhat unknown. They don’t have nerve cells like humans, but they do have a system for sending electrical signals and even produce neurotransmitters, like dopamine, serotonin and other chemicals the human brain uses to send signals.

“We don’t know why they have them, whether this was just conserved through evolution or if it performs some sort of information processing function. We don’t know. There’s a lot we don’t know,” Pollan says.

And chalk up another human-like ability — memory….

Pollan describes an experiment done by animal biologist Monica Gagliano. She presented research that suggests the mimosa pudica plant can learn from experience. And, Pollan says, merely suggesting a plant could learn was so controversial that her paper was rejected by 10 scientific journals before it was finally published.

Some of these plant neurobiologists believe that plants are conscious — not self-conscious, but conscious in the sense they know where they are in space … and react appropriately to their position in space.”  www.newyorker.com/magazine/2013/12/23/the-intelligent-plan