Green symphonies: a call for studies on acoustic communication in plants

Abstract

Sound and its use in communication have significantly contributed to shaping the ecology, evolution, behavior, and ultimately the success of many animal species. Yet, the ability to use sound is not a prerogative of animals. Plants may also use sound, but we have been unable to effectively research what the ecological and evolutionary implications might be in a plant's life. Why should plants emit and receive sound and is there information contained in those sounds? I hypothesize that it would be particularly advantageous for plants to learn about the surrounding environment using sound, as acoustic signals propagate rapidly and with minimal energetic or fitness costs. In fact, both emission and detection of sound may have adaptive value in plants by affecting responses in other organisms, plants, and animals alike. The systematic exploration of the functional, ecological, and evolutionary significance of sound in the life of plants is expected to prompt a reinterpretation of our understanding of these organisms and galvanize the emergence of novel concepts and perspectives on their communicative complexity.

Keywords: behavior; bioacoustics; communication; frequencies; plants signaling; sound..

Figure 1

A putative model of a mechanism underlying sound production in plants. Plant cells vibrate as a result of the active movement of organelles within the cell (i.e., cytoplasmic streaming; orange arrows in panel B). Cytoplasmic streaming is caused by the activity of motor protein myosins as they slide along actin filaments using the hydrolysis energy of adenosine triphosphate (panel C). As the nanomechanical motion generated within a cell reflects the unique metabolic status of that cell, this information is contained in the emitted vibrational wave. Vibrations from individual cells propagate through the medium as sound waves and reach neighboring cells; if the receiving cells are receptive to that particular frequency, they will also start vibrating proportionally to the intensity of the received signal and when all the cells are “in tune,” the signal is amplified (panel D). As the signal extends outside the leaf or root of the plant, it conveys information about that plant to neighboring plants or other organism (panel A).