What a Plant Knows

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I am enjoying What a Plant Knows.

The first week was very lightweight -- "Why study plants?"  He did make one really interesting set of points -- because plants cannot move under their own steam (my words, not his...), they are, of necessity, more complex than many animals.  They must cope, in place, with whatever happens around them.  Other plants, animals, predators (plants and animals!), infections of various kinds.  Weather and seasons.  Plants had to figure out how to reproduce without moving to find others of their kind, and without touching each other.

The second week we heard about what plants see (and what they do with that information).  Their perception of light goes over a broader part of the electro-magnetic spectrum than ours, and they have more different sorts of light receptors than we have.  They know a lot about their environment from their perception of light.  Are they shaded by other plants?  How long is the night, right now?  Is this a good time to flower?  Is it spring or fall?

This past week we heard about what plants can smell (and what they do with that information).  Plants learn a lot about their environments from their perception of volatile chemicals in the air (smell).  A ripening fruit gives off ethylene, which will induce the ripening of nearby fruit (from one fruit to fruit very nearby on the same tree, to the whole tree, to the whole orchard).  A leaf attacked by insects starts making chemicals to repel/kill insects, which are smelled by other leaves which also start making those chemicals.  A leaf with a viral or bacterial infection starts making chemicals to deal with those infections, which are smelled by other leaves which also make those chemicals.

We are learning that a plant not only can tell what's up with other plants via smell, but also with its own self.  It used to be thought that one part of a plant communicated with other parts of its self primarily via its vascular system (a very animal-centric view, I think), but now we are learning that a plant learns about what is going on with its self via smell.

The most interesting thing I've learned, I think, is that plants make salicylic acid as a defense against microbial infections.  It makes perfect sense that salicylic acid isn't just randomly made by plants.  It makes perfect sense that they make it because it is good for them in some way...........

The fascinating thing is that salicylic acid has been known since before ancient Greek times (Hipocrates describes using it) as something beneficial against human aches and fevers.

We call it aspirin..........................

I suppose it's hardly a surprise that a chemical that plants make for their own health might well have significant effects on our health, too.

We did evolve from the same organisms......  If something helped those long-ago critters stay healthy, it seems reasonable that it would help both plants and animals stay healthy now.........

How arrogantly shortsighted we are, to blithely poison this, that, and the other thing, assuring ourselves that what is poisonous to some kinds of plants is surely benign for animals (or that what is poisonous to insects can't possibly affect mammals).........................

I'm guessing we're going to be learning, more and more, that the interweaving of the web of life is much more complex, and much tighter, than we currently know.  I surely wish we'd be more judicious (and more cautious!) in our approach to changing things we know very little about............................... 

We seem to assume that we know everything -- so if we don't know there's a reason not to do something, it's ok to do it......

Sigh!

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