It is very interesting and I am really fascinated of how complex organisms are!!
The researcher I quoted agrees on that plants are communicating. I agree with him on that this doesn’t imply that plants are sentient, thinking beings, that are able to feel subjective pain.
You can e.g. create robots that are communicating. I think the trees communication is much more complex. But a more complex design, doesn't imply that they are sentient.
The researcher answers the question “Do plants communicate with each other?”:
At a basic level, yes. But I guess it centers around how you define communication. There is no doubt that plants respond to cues from other plants. For example, if a maple tree is attacked by bugs, it releases a pheromone into the air that is picked up by the neighboring trees. This induces the receiving trees to start making chemicals that will help it fight off the impending bug attack. So on the face of it, this is definitely communication.