There's sometimes confusion about what biologists mean when they talk about communication in plants. Despite the stories about plants doing better when you talk to them, we can be sure that there is no consciousness on the part of plants; nor, for that matter, on any organism that lacks a well developed nervous system. So what do biologists mean? Simply that chemicals traveling from one part of a plant to another part or from one plant to a different plant cause chemical reactions in the recipients. For example, within the body of many kinds of plants, chemicals produced at the end of a stem move down the stem and, reacting with chemicals in buds farther down the shoot, keep those buds dormant.
As for communication between plants, in at least some kinds, injury by
herbivorous animals causes the release of volatile chemicals into the air; the
chemicals cause nearby plants to crank up their production of toxic compounds that help
protect them from a similar attack. A sort of early warning system that says
"Enemies are in the neighborhood".
Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.