In contrast to humans, plants cannot feel pain. However, so-called mechanical stimulation—rain, wind and physical impact from humans and animals—contributes to the activation of a plant’s defence system at a biochemical level. This in turn triggers a stress hormone that, among other things, can lead to the strengthening of a plant’s immune system.
Click here for original story, Impact of water droplets on leaves quickly triggers stress responses in plants
Source: Phys.org