Yes, I have looked into it. And the scientific consensus clearly is that plants are not sentient. Heck, the very article you linked to says that any such claims are nothing more than "pseudoscience". Can we be 100% sure that there isn't some kind of consciousness on the level of cells? No. But we have no reason to assume there is as there is no evidence for it. We cannot change our behavior on the basis of what we do not know.
Besides, you are the one asserting plants can feel pain. That is your assertion, not mine. My primary assertion in this thread is that animals can feel pain. These are independent problems. We can conclude one way or another that plants have feelings or not, but that doesn't in the least affect the question whether animals have feelings. Kick a dog and you can easily observe that it expresses emotions. Whether or not plants have similar feelings is not really relevant, so I'm not sure why people keep bringing it up.
But let me ask you this. How do you think plants experience emotion without a central nervous system and a brain to interpret these signals? Clearly you think there is some alternative way in which this happens, a way completely different from how it works in animals and humans. What makes you think there is such a system?
It also appears to me you are trying to make a point which is, from what I understand, contrary to what Islam teaches. From what has been posted in this thread, it is clear that animal cruelty is not allowed in Islam. There isn't a similar rule that disallows 'vegetable cruelty'. Why do you think that is?
I do not have 'respect' for nature as such. I think nature and animals are by definition uncivilized and barbaric. There are no morals in nature. It is (ethically speaking) quite a vile place. As such I do not hold carnivores in very high regard, as they are merciless killers. Nevertheless, nature is a delicate balance and carnivores clearly serve a purpose in the grand scheme of things.
But we always need to keep in mind that unlike us humans, who are capable of reason, animals have no such abilities. They are therefore not truly capable of discerning right from wrong. I think it makes little sense to judge them, since they simply are what they are. I set higher standards for myself and fellow human beings.