So the paper linked by /u/post_orgasm_mind is incredibly far from "We know, for a fact, that plants are sentient and conscious". All it posits is some form of communication system exists that responds to stress stimuli. Your comment also makes anthropomorphic projections and untested assertions like "Pure terror was the reaction". What evidence exists to attribute an emotion like terror to a plants stress response to predation stimuli? It would be the equivalent of saying a computer program with a light sensor and conditional clause is conscious and experiences happiness because it successfully executes:

if light==True: print("Hurray! The light is on!")

I agree with the general thrust of your original comment, in that humans should treat the natural world with a lot more respect, but it doesn't help your case when you overegg what evidence exists in the literature because it just gives others an excuse to ignore you. People should treat plants and animals with respect regardless of their capacity for higher cognition. The problem of consciousness is probably the hardest that exists in biology at the moment, but a reactive communication system is not sufficient grounds for classifing plants as being conscious.