OPINION
WHEN STRESSED PLANTS MAKE SOUNDS TO COMMUNICATE For the first time in the world, researchers from Tel Aviv University recorded and analysed sounds clearly emitted by plants. The clicks, similar to the popping of popcorn, are emitted at a volume similar to that of human speech, but at high frequencies, beyond the range of hearing of the human ear. The sounds of plants are informative: they are emitted mainly when the plant is under stress, and they contain information about its state. The researchers recorded mainly tomato and tobacco plants, but also wheat, corn and cacti. This means that an idyllic field of flowers can be quite a noisy place, even if we cannot hear the sounds. The sounds that plants make when they are under stress vary, and each plant and each type of stress is associated with a specific identifiable sound. Although imperceptible to the human ear, the sounds emitted by plants can probably be heard by various animals, such as bats, mice, and insects. The study was conducted and led by researchers at Tel Aviv University. The work was published in the prestigious scientific journal Cell. It was known from previous studies that vibrations were recorded when vibrometers were attached to plants, but until now it had not been verified whether these vibrations were converted into airborne sound waves, that is, into sounds that can be recorded at a distance. This is a question that researchers have debated for many years.
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