Last week, I wrote an article about how subterranean insects use plants as telephonic devices to communicate with their above ground counterparts. I concluded that it is truly amazing to know that the basis behind some of the technologies we as humans pride ourselves on inventing today have existed in the plant world for millions of years. Well gang, the plants are at it again as a group of researchers at the Justus Liebig University and the Max Planck Institute have discovered a novel electric signal that plants use when wounded.

The electric signal discovered by the research team, known as the “system potential”, was discovered by inserting filamentary electrodes into the open stomata of plants to track any sort of ongoing electric signaling. While it has been known for years that both plants and animals use a form of electric signaling known as “active potential”, there is a crucial distinction between this type of signaling and the recently discovered “system potential”.

Hubert Felle, a member of the team from the Justus Liebig University, wrote of this difference, “Action potentials follow all-or-none characteristics: they are activated if a certain stimulus threshold is reached and then spread constantly. The “system potential”, however, can carry different information at the same time: The strength of the inducing stimulus (wound signal) can influence the amplitude of the systemic signal as well as the effect of different ions.”

The obvious benefit to this system is the fact that the intensity of a wound can be relayed to the rest of the plant in addition to the mere fact that a wound has occurred. Axel Mithofer of the Max Planck Institute goes as far as saying that this mechanism may as well be the most important signal transmission system to protect a plant from such dangers as insect herbivory.

While it is not yet known if this mechanism exists in all species of plants, the study did find that this novel “system potential” was detected in at least five of them including tobacco, maize, barley, and field bean. As I concluded last time, such feats on the part of the plant community are truly humbling as we consider their shocking similarity to many of our most advanced technologies.

Discussion Question: How do you think such a mechanism developed under the context of natural selection? (Hint: think of Axel Mithofer’s comments on insect herbivory)

Article Link: http://www.sciencedaily.com/releases/2009/03/090309105030.htm
Scientific Journal: http://www.plantphysiol.org/cgi/content/abstract/149/3/1593