We now know that even plants respond to touch! Scientists are still studying the implications of this finding, but it certainly says a lot about the power of touch. The plants responded, registered for up to half an hour afterwards, to having a leaf moved or being sprayed. When asked about how it felt, the test plant, an Arabidopsis said "I feel... "
Nah, just kidding.
Scientists did say plants’ stress response seems to be similar to an immune response in animals and that the response deserves further study. They have discovered the more the plant is touched, the greater the chance it's flowering will be delayed.
http://www.sciencewa.net.au/topics/environment-a-conservation/item/4265-plants-respond-to-the-human-touch