Abstract

If someone behind you tapped you on the shoulder, your first response would probably be to turn around. All living organisms respond to stimuli, and plants are no exception to this rule. Since they cannot turn around, though, how would they respond to light contact with neighboring plants? Are plants in touch with their neighbors? We searched for the answer to this question.

We applied a light touch to potato plants and measured changes in their trichomes (plant’s hair), biomass distribution, and the volatile compounds they released. We also analyzed changes in plant structure, physiology, and interactions with insects.

Our results showed that plants do respond to light touch by their neighboring plants. This affects their structure in a way that makes them shorter and stockier compared to the untouched plants. Curiously, insects do not find the smell of touched plants very attractive and prefer their untouched counterparts.