Stressed Plants Emit Sounds That Can Be Detected More Than a Meter Away (phys.org) 66
An anonymous reader quotes a report from Phys.Org: What does a stressed plant sound like? A bit like bubble-wrap being popped. Researchers in Israel report in the journal Cell on March 30 that tomato and tobacco plants that are stressed -- from dehydration or having their stems severed -- emit sounds that are comparable in volume to normal human conversation. The frequency of these noises is too high for our ears to detect, but they can probably be heard by insects, other mammals, and possibly other plants. "Even in a quiet field, there are actually sounds that we don't hear, and those sounds carry information," says senior author Lilach Hadany, an evolutionary biologist and theoretician at Tel Aviv University. "There are animals that can hear these sounds, so there is the possibility that a lot of acoustic interaction is occurring."
The researchers used microphones to record healthy and stressed tomato and tobacco plants, first in a soundproofed acoustic chamber and then in a noisier greenhouse environment. They stressed the plants via two methods: by not watering them for several days and by cutting their stems. After recording the plants, the researchers trained a machine-learning algorithm to differentiate between unstressed plants, thirsty plants, and cut plants. The team found that stressed plants emit more sounds than unstressed plants. The plant sounds resemble pops or clicks, and a single stressed plant emits around 30-50 of these clicks per hour at seemingly random intervals, but unstressed plants emit far fewer sounds. "When tomatoes are not stressed at all, they are very quiet," says Hadany.
Water-stressed plants began emitting noises before they were visibly dehydrated, and the frequency of sounds peaked after five days with no water before decreasing again as the plants dried up completely. The types of sound emitted differed with the cause of stress. The machine-learning algorithm was able to accurately differentiate between dehydration and stress from cutting and could also discern whether the sounds came from a tomato or tobacco plant. Although the study focused on tomato and tobacco plants because of their ease to grow and standardize in the laboratory, the research team also recorded a variety of other plant species. "We found that many plants -- corn, wheat, grape, and cactus plants, for example -- emit sounds when they are stressed," says Hadany. The researchers suggest that these noises "might be due to the formation and bursting of air bubbles in the plant's vascular system, a process called cavitation," reports Phys.Org. It's unclear if the plants are producing these sounds in order to communicate with other organisms.
The researchers used microphones to record healthy and stressed tomato and tobacco plants, first in a soundproofed acoustic chamber and then in a noisier greenhouse environment. They stressed the plants via two methods: by not watering them for several days and by cutting their stems. After recording the plants, the researchers trained a machine-learning algorithm to differentiate between unstressed plants, thirsty plants, and cut plants. The team found that stressed plants emit more sounds than unstressed plants. The plant sounds resemble pops or clicks, and a single stressed plant emits around 30-50 of these clicks per hour at seemingly random intervals, but unstressed plants emit far fewer sounds. "When tomatoes are not stressed at all, they are very quiet," says Hadany.
Water-stressed plants began emitting noises before they were visibly dehydrated, and the frequency of sounds peaked after five days with no water before decreasing again as the plants dried up completely. The types of sound emitted differed with the cause of stress. The machine-learning algorithm was able to accurately differentiate between dehydration and stress from cutting and could also discern whether the sounds came from a tomato or tobacco plant. Although the study focused on tomato and tobacco plants because of their ease to grow and standardize in the laboratory, the research team also recorded a variety of other plant species. "We found that many plants -- corn, wheat, grape, and cactus plants, for example -- emit sounds when they are stressed," says Hadany. The researchers suggest that these noises "might be due to the formation and bursting of air bubbles in the plant's vascular system, a process called cavitation," reports Phys.Org. It's unclear if the plants are producing these sounds in order to communicate with other organisms.
Physical objects make noises.... (Score:1)
It's interesting...but it's just a physical object. It's not "communication". Lots of things make noises when you change temperature, humidity, etc...
A house...made of wood...makes noises with environmental changes. Metal can make noise when it expands and contracts.
Re:Physical objects make noises.... (Score:5, Insightful)
Things like temperature and humidity can cause the release of pheromones - does that not make them a form of communication between organisms?
This paper doesn't prove audio communication - it just shows emission, not reception and reaction. But it does open up a possibility of communication. Communication doesn't require a "why", just that something is conveyed and something else reacts to it. Communication doesn't have to be some sort of high-bandwidth complex transmission with a grammar and elaborate conceptual structure. Things like "DANGER!" or "COME HERE!" are also communication.
Plant communication with other plants and other organisms via chemical means is already well established.
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Plant communication with other plants and other organisms via chemical means is already well established.
"This flower is emitting a smell! What does it mean?"
"It is a signal for pollinators to come and go, helping to propagate the species to the next generation."
"Astounding! How are you able to identify so much meaning from a single whiff?"
"Elementary school, my dear Watson."
In his next trick, Holmes identifies why ripe fruit also smells.
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> Plant communication with other plants and other organisms via chemical means is already well established.
"Communications Biology" - https://www.nature.com/commsbi... [nature.com]
"Plant Communication from Biosemiotic Perspective" - https://www.ncbi.nlm.nih.gov/p... [nih.gov]
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Some people can't help but anthropomorphize things. I'm sure someone will take this as advice to be nicer to plants. Put another way "stressed bubble wrap emits sounds that resemble plants at a lower frequency".
Oh the horror! (Score:5, Funny)
Re:Oh the horror! (Score:5, Funny)
Obviously! I've seen this phenomenon in rice for years. My Rice Krispies always snap, crackle, and pop when I drown them in milk.
Re: Oh the horror! (Score:2)
You have to kill them first.
I know a man's gotta eat, but c'mon... no reason to be unusually cruel about it. Us meay eaters have learned this years ago.
Re: Oh the horror! (Score:5, Funny)
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And there's always the one rice krispie that floats to the top, trying to escape. I have to push it under until it drowns.
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Anyone who started having an ethical dilemma about eating animals and plants would soon face starvation. See the Donner party for what can happen to ethics if you're hungry enough.
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Because getting a healthy mix of nutrients as a vegan was not already challenging enough.
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There is already a variant of veganism that addresses this; they espouse that as plants *may* be intelligent and feel pain, one should only eat the parts of plants that fall off naturally. This means only fruit, nuts, berries, and seeds that the plant naturally sheds, no eating any stems, fresh leaves, or roots.
Because getting a healthy mix of nutrients as a vegan was not already challenging enough.
If rationality was a concept for those adepts, I'd confront those fruit eaters to those anti-abortion adepts.
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Didn't the Jains come up with harm reduction to counter this very argument?
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Previous work (Score:2)
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Claiming that plants are conscious is popular because it is contrary to common experience, and also because vegetarians make people feel defensive and so they latch on to this sort of thing to go "see? You are just as evil as me! You can't escape it!!! hahahaha!"
It's crap. These sounds are being produced by natural chemical reactions, not by a nervous system with an intention to communicate. Like everything else in biology, the capacity to feel brings with it a metabolic cost, so organisms only pay tha
Re:Previous work (Score:5, Interesting)
Plants are actually rather reminiscent of corals (though the latter are animals). They're a thin smattering of life coating a dead skeleton. Xylem is dead. Heartwood is both dead and inactive. Phloem is just barely alive and does not reproduce. Bark is dead. The primary sites of growth, such as the cambium and cork cambium, are just a couple cells thick. Parenchyma in some places can "bulk up" the active living parts of a plant beyond that (most famously, leaves), but for the most part, plants are just a thin wrapper of life studded with energy- and water/mineral-gathering protrusions, atop a dead skeleton.
Communication is extremely important within plants (and yes, to a degree beyond them), in order to coordinate activities. This is primarily hormonal, and it works in clever regulatory balance between pairs of hormones. For example, auxin is created by top growth, esp. apically-dominant meristems. It discourages other top growth from other meristems (aka discourages lateral spreading, so the apically dominant meristem remains dominant) and encourages all root meristems to grow (acting as a measure of how much water the roots need to provide). Countering this are cytokinins, which are a 100% mirror - they're produced by roots, particularly dominant root meristems (such as taproots), which discourage growth from other root meristems, and promote all top growth (incl. axillary buds). So, for example, if you cut a bunch of branches off a tree, auxin production reduces, root growth declines, and top growth increases - countering your actions. And the inverse happens if you cut off a root.
There's lots of pairs like this. Another example would be ABA vs. gibberellins. Gibberellins are like shouting, "AAAH, LIFE IS SOOOO GOOD! BURN THAT STORED ENERGY AND SOAK IN THE SUN, DON'T WORRY ABOUT A THING!" While ABA is like shouting, "DOOOM!!! THE WORLD IS COMING TO AN END!!!! HUNKER DOWN! PREPARE FOR THE END TIMES!!!!"
With this sort of communication, different parts of plants, all for the most part functioning as independent organisms, coordinate their actions. Some even have rapid synaptic communication mechanisms. A famous example would be the Venus flytrap, which can actually "count" to a degree, requiring a certain pattern of stimulation to trigger its traps. This process works very similar to animal nerves' action potentials and in effect forms a (small) neural network.
Plants also make extensive use of chemical communication with other plants, and indeed, with other species. Most plants are actually highly dependent on the services of other species. For example, more than 90% of plants are associated with mycorrhizal fungi, which are better at getting tightly-bound water and minerals than they are, and with whom they set up internal "trading posts" for exchange (with arbuscular mycorrhizal, the most common, the arbuscles look like tiny trees that the fungus builds within plant cells, and the plant cells rearrange their organelles to accommodate them). The same mycorrhizal network can intersect many different plants, and carbon sequestered by one plant can even end up in other plants.
A lot of communication is "call and response". For example, nitrogen-fixing plants emit flavinoids which let nitrogen-fixing bacteria know where they are, while the bacteria respond to them with NOD factors, sort of like a game of Marco-Polo, until the two find each other and the plant's roots grow a nodule around the bacteria (which they basically turn into a bacterial paradise, protecting and nurturing its offspring in exchange for nitrogen fixation services).
Certain types of plant chemical communication have been well known since the dawn of our species: the types that our noses can sense. For example, flowers don't emit aromas just for the fun of it; they're to communicate their presence to pollinators. Some plants also emit volatile compounds when damaged in order to attract predators of the prey that's damaging them. Some types of plants have even taken this to extremes: Cecropi
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Some plants also emit volatile compounds when damaged in order to attract predators of the prey that's damaging them
You seems to attribute some revenge intention to those plants.
Fact: Some plants emit volatile compounds when damaged
Assumption: in order to attract predators of the prey that's damaging them
This assumes that such plant can benefit from prey's predator in return. I think, it is more like some predators have adapted to identify the kind of emitted chemicals from damaged plants, that are sings of a suitable prey.
Re:Previous work (Score:4, Informative)
Purpose ("in order to") != Thought. A paramecium has cilia in order to move. That doesn't mean it's "thinking" about them.
The emission of those chemicals absolutely has purpose, even though they have absolutely nothing to do with thought.
And evolution does not simply apply to predators. Plants very much evolve in parallel with the things that eat them and the things that eat those things. It's not a one-way street. Look up, for example, "extrafloral nectar". Many plants have evolved "feeders" for predators that do nothing for the plant except attack predators that will kill the things that eat them. Plants use chemical attractants for predators, visual attractants, structural attractants, and here they're raising the (purely hypothetical) possibility to audio attractants as well. And this is using a very loose definition of "predators" too, which doesn't necessarily mean "macroscopic animals", or even animals at all.
As a general rule, emitted plant chemicals to attract predatory insects are not just "chemicals that happened to be in the plant and were let out by the feeding", but rather chemicals whose main or only purpose is as an attractant. Plants have evolved genes to make these chemicals and activate these genes in response to predation signals (such as jasmonates).
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**attract predators
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**attract predators
*** better than attracting aliens, I suppose
Re: Previous work (Score:2)
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This is closer to telling you that I can hear with a branch is stressed by pulling on it until it starts to break off. Or that a rope is stressed when it starts to pop before snapping.
Sounds like (Score:2)
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they ripped a page out of the reader digest experiment (which was proven false) and added AI to it.
And when they ripped that page, Reader's Digest (which is composed of plant material) literally screamed!
from 2019... (Score:3)
this has been confirmed from at least 2019....
why is this being recycled as a new discovery?
https://www.biorxiv.org/conten... [biorxiv.org]
Re:from 2019... (Score:5, Informative)
actually
https://www.biorxiv.org/conten... [biorxiv.org]
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I don't know what is going on. I remember hearing about this ages ago probably on Quirks and Quarks or Discovery Channel.
Just like so many other "brand new discoveries" of late, this particular one goes back quite a ways.
https://nph.onlinelibrary.wiley.com/doi/full/10.1111/j.1469-8137.2008.02521.x [wiley.com]
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This paper (Zweifel 2007) is cited in the work we are discussing (Khait 2023). It's reference 18. The difference is that in previous work, the piezoelectric sensor head was directly in contact with the internal part of the tree (removing bark locally). In the present work the sounds were recorded by regular microphones placed 1 metre away. The "more than one metre away" is even highlighted as the /. headline.
There is generally more than 1 scientist in the world working on a given topic, and all of them get
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why is this being recycled as a new discovery
The 2019 version is bioarxiv, a repository of unreviewed data (not considered a scientific publication). You can notice figure 3BCD (long term recordings) and figure 4 (correlation with transpiration rate) were not present in the first version. Either it took them 4 years to answer the criticism from the scientific publishing houses and make the additional experiments, or they did so because they wanted to keep part of the data secret while they worked on the patent submission, which is only mentioned in th
Not providing me a beer makes me emit sounds too (Score:4, Funny)
That sound can also be heard at least 5 meters from my couch.
Only problem is that nobody is listening to that sound anymore.
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She left ya, huh?
Re: Not providing me a beer makes me emit sounds t (Score:5, Funny)
I believe his mom just does not go down to the basement anymore because if the smell. ;-)
We can hear it... (Score:1)
... but we don't care. :)
Dead wood (Score:2)
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The paper did not make any experiment that relates to communication and does not discuss the question. They focus on "airborne sound emission" not on the effects of sounds on other plants. Their introduction even cites other words which are titled with "communication", and they summarize that in more careful words to avoid touching the "communication" issue.
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So the press ruins science reporting again. Abstract, methodology, and carefully worded conclusions be damned?
The biggest reason for science denialism is the press. They have to turn every mildly worded, carefully circumspect finding into click bait.
It is not the biggest reason for science skepticism. The largest source of that is science itself because it is baked into the method. The press also assiduously avoids mentioning this, speaking generally in absolutes: "Science has found x," "Scientists have pro
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Shoot, burning wet wood (obviously alive) can cause it to scream and actually toss/pop fire ember bullets at the fire tender (creation of and use of tools)!
OMG! (Score:3)
Now I can't even eat tomatoes?
Re:OMG! (Score:5, Funny)
Of course you can. Just know that with every bite it screams in pain.
You monster.
This is why I eat meat, it's already dead.
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Physics Is Biology (Score:2)
Just wait until they start listening to the mushrooms. The mycelial network is the true underpinning of all reality. I learned this from the science advisors on Star Trek. Engage the Spore Drive!
Compare front-page of Ars and /. (Score:2)
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Voices Carry (Score:2)
The burning wood is popping at me, the boiling water on the fire is angry, and the lobster in the pot is screaming it's head off. Now you're telling me that the tomatoes are getting in on the act?
Geez, you can't eat anything anymore....
I need a smoke. Oh wait.
Tomatoes scream when sliced ... (Score:2)
I ate a lot of Romaine lettuce (Score:2)
And it's been making some intermittent gurgling sounds from inside me.
What's old is new again! (Score:2)
From 2019:
https://www.smithsonianmag.com... [smithsonianmag.com]
paper: https://www.biorxiv.org/conten... [biorxiv.org]
And I specifically remember reading this finding from Slashdot.
Raold Dahl - The Sound Machine (Score:2)
Yup, Dahl did scifi too.
Deep Thoughts (Score:2)
“If trees could scream, would we be so cavalier about cutting them down?
We might, if they screamed all the time, for no good reason.”
Jack Handy
Not only sound (Score:2)
There is some scientific evidence to suggest that when giraffes start browsing on a tree, it can trigger a response in nearby trees that causes them to release chemicals into the air as a defense mechanism. This process is known as "volatile organic compound signaling" or "VOC signaling."
These chemicals, called volatile organic compounds, can be detected by other trees in the vicinity, which then respond by producing their own bitter-tasting chemicals to deter the giraffes from eating their leaves. This pro
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Sounds useful (Score:2)
Even if it was known before, the AI angle could actually make this useful in greenhouses or other commercial plant environments - you could optimally water plants on demand as they "ask" for water rather than on a specific schedule. I'm sure growers have guessed approximate schedules for watering, but this would allow an exact optimal feeding time regardless of temperature or other environmental conditions, or plant type since it sounds like the same technology can easily be applied to any plant. Make a n
Plants are sentient? (Score:2)
It's unclear if the plants are producing these sounds in order to communicate with other organisms.
That statement is both inane and provocative, as it asks if plants are sentient. Certainly plants are alive based on most accepted definitions of life. However, plants don't have brains. Perhaps plants can "communicate" with other organisms, but "in order to" implies intent which implies sentience. Currently computer systems can "communicate" with each other, but communication doesn't require intent or sentience, although some of us silly humans have defined sentience into existence for computer systems
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Communication doesn't require sentience, just a transfer of information.
In this case, I don't believe the plants create the sounds to communicate (sentient or not) because the only possible response to a plant announcing that it is in trouble is to draw predators. It's not like a nearby plant is going to water it.
Caring carrots (Score:2)
Vegetarian: Someone too insensitive to hear a carrot scream.
"That's not funny anymore!"
Run a crystal, it will become clear to you. (Score:2)
Crowley had it (Score:1)
Let's get ChatGPT to translate it (Score:2)
Drying wood... (Score:2)
...pops and crackles too. Drying anything that's under stress (such as the twisting forces on plant stems) can make it squeak.
Well, at least now it's measured. Water your tomatoes. ;)