I was wondering whether plants could feel pain, for example, does grass feel pain when you mow the lawn? Or do the plants and trees that grow vegetables and fruits feel pain when you harvest them?
The internet is very vague about it. There are several articles on the internet, but they just say that plants do not feel pain, they only send out a chemical substance. Others say that almost all multicellular organisms feel pain, because pain is defined as any signal of having impaired tissue.
I think that plants can't feel pain because they have no nerves or central nervous system. However I'm not sure whether this means that plants can't feel pain.
Since the question is clear when pain is defined as any signal of having impaired tissue, I think it would be more interesting in the case that pain is defined as actual discomfort, like humans and animals (maybe it should be restricted to Eumetazoa) feel it.