On March 17 on the Coast to Coast radio show, I heard Dr. Gerald Epling, a scientist, talk about his fascinating work with plants. He says that his experiments show that a plant can respond to something happening to another plant.
Also, a plant can respond to a human approaching the plant. One caller said that a tree branch tapped her on the shoulder ; it is an interesting topic. I stayed up too late listening to this and didn't get all the details.