The Secret Chatter of Plants: When Stressed, They Speak Up!

Imagine walking through a garden, and the plants are gossiping about their day. Well, it turns out they might be! Researchers at Tel Aviv University have recorded and analyzed distinct sounds emitted by plants, particularly when they are under stress. The click-like sounds, similar to popcorn popping, are beyond the human hearing range but could very well be heard by animals such as bats, mice, and insects.

Settling an Age-Old Debate

Professors Lilach Hadany and Yossi Yovel, along with a team of researchers, set out to answer a question that has been debated for years: do the vibrations recorded by vibrometers attached to plants actually become airborne soundwaves? Their groundbreaking study, published in the prestigious scientific journal Cell, answers this question with a resounding "Yes!"

Listening to Plants in the Lab

To conduct the study, researchers placed various plants, including tomato and tobacco plants, in an acoustic box located in a quiet, isolated basement. Ultrasonic microphones were set up around 10cm from each plant to record sounds at frequencies between 20-250 kilohertz. The plants were subjected to different treatments, such as dehydration or stem cutting, to see if their condition affected the sounds they emitted.

Cracking the Code with AI

Using machine learning algorithms, the researchers analyzed the collected recordings and found that unstressed plants emitted less than one sound per hour on average, while stressed plants emitted dozens of sounds every hour. The algorithms successfully identified the plant and determined the type and level of stress from the recordings, even in a noisy greenhouse environment.

With this groundbreaking discovery, Prof. Hadany asserts, "We proved that plants do emit sounds! The world around us is full of plant sounds, and these sounds contain information – for example about water scarcity or injury." The researchers believe that humans can utilize this information with the right tools, such as sensors that tell growers when plants need watering.

What's Next?

Future research will explore intriguing questions such as the mechanism behind plant sounds, how animals like moths detect and react to these sounds, and if other plants can hear them. For now, just remember: your garden might be buzzing with conversation, even if you can't hear it.