It sounds like the stuff of nightmares, right?
After all, plants don’t have vocal cords, how could they scream?
Yet, recent research on tobacco and tomato plants suggests that plants feel pain.
Apparently, they can emit high-frequency distress noises that could be the equivalent of human screams.
Do Plants Produce A “Scream” When In Pain?
A recent study, from Israel, published on Biorxiv.org suggests that “Plants emit informative airborne sounds under stress.“
It suggests plants stressed by drought or physical damage may emit ultrasonic sounds that you might be able to compare to a human scream.
Now, this doesn’t mean that plants feel pain in the way that human beings do.
What it means is that plants respond to certain stimuli and that healthy plants cry out to warn other plants with these stressed sounds to take action to preserve their own safety.
The researchers found these plant sounds by placing their microphones around four inches away from plants and then either withheld water or started to cut bits off of them.
The researchers tested tomato plants first and then they found that they and the tobacco plants emitted these “sounds” in the 20-150KHz range when they were stressed.
The plant species would squeal between 11 and 35 times an hour during the experiment depending on the conditions.
About Tomato And Tobacco Plants Screams
It’s only certain plants that can make these sounds and researchers aren’t even quite sure how they make them.
It may be due to a process known as cavitation in the xylem tubes of the plant (basically this is blowing bubbles of water through them very quickly – the exact same way that a submarine blows water through its body to create a water flow, and oddly, it’s the cavitation sound that allows an enemy submarine to track an opponent).
Does That Mean We Should Stop Cutting Tomato Plants? And What About Tobacco Plants?
No, while it may sound horrifying that your plants might “scream” when they are cut, there’s one definite difference between these plants and us.
Human beings and, indeed, all animals have a central nervous system. It is this system that allows us to feel pain.
When we come into contact with say a naked flame, our skin heats up to the point of burning and sends messages via the nervous system to our brains to say “hey! This is really not very nice and it might be a good idea to get away from this flame, right now!”
Plants don’t have this kind of system, in fact, as far as we can tell – plants don’t have any equivalent to a brain or nerves at all.
So, while they may be responding to a stimulus that we would think “that’s painful for the plant” – it’s not painful for the plant because it can’t feel pain.
Instead, the plant is making use of an evolutionary survival mechanism that may help to stimulate not just other similar plants but other creatures in the local vicinity and thus, create a response that causes the stimulus to stop.
And yes, that means you can continue to trim plants in your garden without fear that you’re hurting them.
And, of course, vegans can continue to munch on vegan food products and use their favorite vegan kitchen tools without any guilt. (We have some great reasons to go animal-free here too, if you need a little encouragement).
Final Thoughts On Screaming Plants
The researchers from Tel Aviv University have certainly discovered an interesting effect and the ultrasonic scream of plants as you cut stems or place them under drought conditions is fascinating but you don’t need to worry about eating your next meal, plants still don’t feel pain.