I recently came across this article via twitter. It summarizes some interesting research that was done by Professor Stanislaw Karpinski of the Warsaw University of Life Sciences about plants. Most of us learned in school that plants were non-thinking creatures with no nervous system. I've taught biology before and taught that. However, this research causes us to question that assumption.
Professor Karpinski and his team shone light at one leaf of a plant and looked to see what happened in the rest of the plant. Specifically, the parts of the plant being kept away from all light. What he found is that the entire plant reacts to a signal to one leaf. That means that the plant can transmit information throughout itself. That means a nervous system of some kind. Not like ours, of course -- we'd have recognized that sooner -- but a nervous system nonetheless.
In plants, it seems the role of the nervous system is played by bundle sheath cells. I always thought that bundle sheath cells were a rather boring structural and protective cell that surrounded the plant transport system (except in C4 plants, but that's a topic for another day), but apparently not. They send the chemical signals throughout the plant, starting a cascade of reactions.
Even more interesting, different signals get sent depending on the intensity and wavelength of the light (how bright and what color). A blue light sets off a different cascade than a white light. It seems that the purpose of these cascades is to activate different parts of the plant's immune system. The characteristics of the light are associated with different diseases, and the plant defends against the appropriate ones for the season and area with that light quality.
This means that the plant "remembers" different kinds of light. Is this decision making? Is it instinct? Could we say that a plant has "racial memory"? Where does memory lie in a plant?
While this research is very new, and obviously needs to be confirmed by other sources, it does call into question our assumptions about what intelligence is, and where it exists. I love finding out that the world is even more strange and mysterious than we thought it was. . . .
Me, too! And this is wonderful. Does this at all relate to research that shows that a tree under attack by certain insects will produce chemicals in response to that attack, and then its neighbors will, too, even before they end up being attacked by the insects? (I don't know if that question even made sense; perhaps I need more coffee.)
ReplyDeleteI think it's along the same vein, but the information transfer here is far more sophisticated than the simple chemical signal you're referring to. Also, this shows that different light yields different signals, as opposed to one general "defend yourself" signal. Very cool research . . .
ReplyDeleteIt is interesting to think of nervous systems, about which we mammals make such a big deal, as chemical cascades in a structured pathway. If the sheath cells indeed physically guide the chemical response, sure sounds like the behavior of a neuron to me (without the electronic potential bit, but maybe that's splitting hairs, or neurons).
ReplyDeleteIt is like a neuron. It uses chemical signals between cells instead of between synapses. Chemical signaling instead of electronic signaling . . . I just love this kind of research. And thanks for stopping by, twinsetelllen :-)
ReplyDeleteI had a professor at Michigan State back in the late 80s, Stan (Stanley K.) Ries, who was researching stuff like this, so the new research is fascinating!
ReplyDelete::*rummages*::
Rapid elicitation of second messengers by nanomolar doses of triacontanol and octacosanol
Stanley K. Ries and Violet F. Wert