Expert: Dana Krempels, Ph.D. - 5/18/2007

Question
Hi,
  I was wondering...do you think that plants can suffer when being cut or damaged? I found this article stating that they do because they physiologically react to aspirin:

http://www.sciencedaily.com/releases/1998/08/980806090010.htm

If they don't feel pain, then how can we explain that they can defend themselves, produce ethylene, communicate with other plants about a danger or even "move", like the leaves of a plant called "sensitive"? I wanted to have a scientific
advice on the question...thanks a lot !

Answer
Dear Jack,

As far as we know, a nervous system with a brain is a necessary prerequisite for feeling pain.  And as far as we know, only animals have that prerequisite.

Plants may be able to move and react to stimuli (those characteristics are what makes them alive), but it is highly unlikely that they are conscious of negative stimuli.  They react on a cellular level to being nibbled by herbivores, and though they do send chemical signals through their tissues that seem to be analogous to nerve transmission (though a lot slower!), there is no evidence to suggest that there is any central processing area that can process negative stimuli as "pain."

That isn't to say that plants don't react to negative stimuli (such as an insect nibbling on it).  They do.  And their reactions are a result of natural selection, with reactive plants probably surviving longer and leaving more offspring than those that didn't have the ability to react to negative environmental stimuli.

But so far there is no strong evidence to suggest that plants feel or perceive pain in any way similar to the way that animals do.

Hope that helps!

Dana