Do plants “cry” when stressed?

Have you ever forgotten to water your plants? Then should probably know that plants emit sounds when they are thirsty or stressed.

Stress of plants usually manifests by changes in color such as leaves yellowing or browning, smelling, or shape alterations. Scientists from Tel-Aviv reported in the Cell journal that plants emit high-pitched airborne sounds, according to their physiological status. Tomato and Tobacco plants were subjected to different treatments like drought and cutting and were recorded with microphones. The results demonstrated that stressed plants emitted more sound than healthy ones, which can be perceived as cries or screams of distress.

Plants do not have vocal cords, lungs, or central nervous system. Therefore, they cannot feel pain and the current hypothesis to explain their noises is focused on their xylem which is responsible for water transport in the plant. Formation of air bubbles during drought or xylem incision may account for a popping sound from the plant. Although these sounds are likely inaudible to humans, surrounding animals may be able to hear and react to them.

According to the research team, this discovery might be of big ecological and evolutionary significance. The noises may provide information about stress for surrounding plants that can prepare to face the difficult conditions. Moreover, these scientists claim that people could use plant sound recordings in agricultural irrigation systems to distribute water more efficiently while monitoring the hydration status.