Talk is cheap: rediscovering sounds made by plants

• Published in: Trends in plant science 2024-06, Vol.29 (6), p.662-667
• Main Authors: Nardini, Andrea, Cochard, Hervé, Mayr, Stefan
• Format: Article
• Language: English
• Subjects: audible acoustic emissions; drought; Droughts; Plant Physiological Phenomena; plants; Plants - metabolism; Sound; Stress, Physiological; ultrasonic acoustic emissions
• ISSN: 1360-1385; 1878-4372; 1878-4372
• DOI: 10.1016/j.tplants.2023.11.023

Recent reports of airborne sound emissions by plants under drought stress have generated interest, leading to speculative ideas on plant–animal and plant–plant communication.Research on sound production by plants is more than 100 years old, with John Milburn demonstrating in 1966 that these sounds are mainly produced by xylem cavitation events and can be detected with dedicated instruments.Research from 1970 onward has shown that sounds can also be produced by other passive physical processes in plants, and also demonstrated that acoustic emissions can be used to monitor the water status of plants in the field.The hypothesis that sounds produced by plants are informative for insects feeding on stressed plants, or even for neighboring plants, is attractive but still purely speculative to date. A recent study and related commentaries have raised new interest in the phenomenon of ultrasonic sound production by plants exposed to stress, especially drought. While recent technological advancements have allowed the demonstration that these sounds can propagate in the air surrounding plants, we remind readers here that research on sound production by plants is more than 100 years old. The mechanisms and patterns of sound emission from plants subjected to different stress factors are also reasonably understood, thanks to the pioneering work of John Milburn and others. By contrast, experimental evidence for a role of these sounds in plant–animal or plant–plant communication remains lacking and, at present, these ideas remain highly speculative. A recent study and related commentaries have raised new interest in the phenomenon of ultrasonic sound production by plants exposed to stress, especially drought. While recent technological advancements have allowed the demonstration that these sounds can propagate in the air surrounding plants, we remind readers here that research on sound production by plants is more than 100 years old. The mechanisms and patterns of sound emission from plants subjected to different stress factors are also reasonably understood, thanks to the pioneering work of John Milburn and others. By contrast, experimental evidence for a role of these sounds in plant–animal or plant–plant communication remains lacking and, at present, these ideas remain highly speculative.