Plant Emotions?

I just watched this video from the BBC on plants.  It was very interesting.  It talked about several different things, all of which were fascinating to me.  But what really got me was the discussion of the "root-brain" hypothesis, first put forward by Charles and Francis Darwin. This is the idea that the roots of a plant function in similar ways to the brains of animals. Even down to structures that function in ways that are similar to synapses in the brain. Science has yet to take the next step to claim that plants "think", but it's clear that that idea is no longer absurd.

No surprise, it got me thinking about emotions.  When we think about emotions, if we ask, "what is an emotion?" the answer is obvious because we know about emotions experientially.  We've felt emotions, so it's not hard to identify them.  But if we try to define what an emotion is, it gets a bit harder.  An electrical impulse?  A chemical reaction? There are impulses and reactions all over the human body.  What is the evolutionary purpose of emotions?  Maybe emotions encourage bonding, which promotes group survival? What makes it an emotion, instead of a thought?  Where it's expressed?  Thoughts are expressed in the brain, emotions are expressed in the body.  Maybe.  I don't have clear answers.  But if there were clear answers to these questions, it might help answer some other questions.

There's plenty of evidence that other animals experience emotion.  What if plants do? What if they feel?  What if they mourn?  What if they experience joy?  It seems far-fetched, but if they may be able to think, I think it's reasonable to ask if they might also be able to feel.  Should I feel guilty for walking in the grass?  Oh gosh, I ate a salad for lunch! Are my potted plants depressed because they're isolated?  My daughter was out picking dandelions earlier!  

Obviously, if we can't eat vegetables, then we can't eat animals either.  And if we can't eat animals or vegetables, I think we might be in trouble.  So there must be different answers. At this point, it feels safe to say that it's premature to worry too much about it.  Science will make it all clear with time.  But I think it's incredibly interesting, and I hope I'm around when science gets it all figured out.