Plants feel pain too!

A team of scientists at Tel Aviv University have discovered that some plants emit a high frequency distress sound when they undergo environmental stress.

The researchers tested tomato plants and tobacco plants by depriving them of water and by cutting their stems and then recording their response with a microphone placed ten centimeters away. 

In both cases, they found the plants began to emit ultrasonic sounds between 20 and 100 kilohertz, which they believed could convey their distress to other plants and organisms in the immediate vicinity.

When a tomato plant’s stem was cut, the researchers found it emitted 25 ultrasonic distress sounds over the course of an hour, according to Live Science. 

Tobacco plants sent out 15 distress sounds when their stems were cut.

When the researchers deprived each plant of water, the tomato plants emitted even more distress sounds, 35 in one hour, while the tobacco plants made 11.

The plants also seemed to respond with different intensities of sound to different sources of stress.

The team observed that tobacco plants let out a louder sound when they were deprived of water than when they had their stems cut.

Plants that had no immediate environmental threat or damage, released less than one ultrasonic sounds per hour.

HOW DO PLANTS FEEL ‘PAIN’? 

• When a bug bites down on a plant leaf, the wound triggers the release of calcium.
• This sets off a chain reaction in the cells along the plant leaves and stem.
• It takes about one to two minutes for the response to reach every part of the plant.
• The calcium generates a hormonal response from the plant to protect its leaves.
• Some plants release noxious chemicals that makes it taste bad to other invading bugs.
• Others, such as grass, give off hormones that attract nearby parasitic wasp, which eat the attacking insects. 

‘These findings can alter the way we think about the plant kingdom, which has been considered to be almost silent until now,’ the group wrote in a paper summarizing their findings. (The paper was not peer reviewed.)

The researchers used the data they had gathered in a machine learning model to predict the different frequency of sound plants might emit under other conditions, such as during wind or intense rain.

The team believes that listening for different types of sound emitted by plants could help with precision agriculture and allow farmers to identify potential problems with the crops with less guess work.

Last year, another study found that some plants registered ‘pain’ after having their leaves plucked or even touched, which caused the release of a foul tasting chemical across their leaves, believed to ward off insects.

Video shows plants send out warning signals when attacked

https://www.dailymail.co.uk/sciencetech/article-7773333/Plants-emit-ultrasonic-scream-stems-cut-water-short-supply.html