Do you know what plant neuroscience is? To an uninitiated person, its description may seem surprising - this is a science that studies the communication system of plants, their sensory systems and "behavior". Neuroscientists claim that plants can hear, smell, communicate and almost see, as well as manipulate other plants and even animals. These unusual claims are based on experiments conducted in laboratories around the world, decades of work and publications in serious scientific journals. Recently, the founder of plant neurobiology, the Italian professor Stefano Mancuso, came to Moscow. He gave a lecture within the framework of the Philosophical Club at Winzavod and answered several of our questions.
Professor of the University of Florence Stefano Mancuso is the founder and popularizer of the field of plant neurobiology. The Italian newspaper La Repubblica and the American magazine The New Yorker have included his name on the list of leading scientists who are changing the world. In 2015, the team led by Mancuso received the EXPO Milano Award for Innovative Agribusiness Ideas for the Jellyfish Barge, a large floating house in the shape of a jellyfish, in which plants can grow without soil, fresh water and fertilizer, solely powered by solar energy. Mancuso is the author of several best-selling books, including Brilliant Green: Sensuality and Intelligence in the Plant World (2013) and The Plant Revolution: How Plants Invented Our Future (2017).
Mancuso begins his lectures by mentioning Noah's ark, where “each creature has a pair” - this concerned animals and birds, the professor recalls, but not plants. In general, he says, not enough attention has always been paid to plants, both by ancient scientists and philosophers, and in our time. Mancuso proposes to rethink the status of plants, abandoning the anthropocentric picture of the world, in order to expand the concepts of rationality and consciousness that, in his opinion, plants have, but which should be studied, abandoning the usual interpretations of these terms.
Stefano Mancuso.
Plants are capable of perceiving at least two dozen different environmental factors, including changes in gravity, light, chemical composition of air, water and soil. They also know how to "hear" some sounds and change their behavior depending on these factors. Mancuso argues that plants have a kind of intelligence, although not in the usual sense of the word. In some of the experiments he talks about, plants literally "predict the future." Their system of communication signals is a kind of alternative Internet, covering the entire planet.
Intelligence is the ability to solve problems, says Mancuso.
We are accustomed to thinking about large organisms to mean animals. For example, everyone knows that the largest animal on Earth is the blue whale. But in fact, a sequoia is a hundred times larger than a whale. If we evaluate the biomass of the planet, then plants occupy, according to various estimates, from 80 to 97 percent. If we look at the tree of life, Darwinian or any more modern, we see that plants are also much more ancient organisms than animals. Flowering plants, for example, predate mammals.
When we try to understand how the body works and how it responds to external influences, we usually pay attention to its organs. But the plant does not have paired or single organs like eyes or lungs. Therefore, in a certain sense, they are better protected - having lost both eyes, the animal loses the ability to see and adequately respond to the external environment, and in the plant all the "organs" are presented in the plural. It can lose up to 90 percent of its entire body and still survive. If plants, which can hardly move, had the same "weaknesses" as animals, then any caterpillar would pose a serious danger to them.
Promotional video:
Traffic
We are used to thinking that plants are motionless, but this is not entirely true. First, the plants, of course, grow. Interestingly, back in 1898, when cinema was just in its infancy, the German botanist Wilhelm Pfeifer conducted time-lapse serial footage recording plant growth, and these "films" still exist.
Secondly, plants are able to change their position in space and shape, and in some cases they do not even expend their own energy on this. For example, the buds of gymnosperms are designed in such a way that they open when it gets dry. This technology is used in the design of stadium roofs. The dandelion opens just as "economically". At the same time, he makes 15 different types of movement, but they all occur spontaneously.
“The topic of my thesis was the study of the movement of roots - how exactly they avoid obstacles. It seems like a simple process, but in reality it is incredibly complex. When I started doing this, science believed that the roots first "touch" the obstacles, and then change the direction of growth. I observed a completely opposite picture: firstly, the roots bend around obstacles in advance, not yet touching them, and secondly, they always choose the shortest and optimal path of growth, thus demonstrating a kind of "intelligence". This was the first sign for me that the plant is a much more complex organism than it seems. " - From Stefano Mancuso's answers to N + 1 questions
The seeds of some plants, for example Erodium achicutarium, seem to "dance" on the ground, looking for a place where the root can be launched, and this dance looks like a meaningful search, although the seed does not spend any of its own energy on it. Scientists are trying to apply similar mechanical characteristics of the shell structure and other structures of seeds when developing equipment for space programs.
Plants also have active types of movement. The well-known predatory Venus flytrap is capable of closing and digesting insects and even slugs. But less exotic processes, such as the opening of a flower, are also movement, even if we do not see it due to the fact that for us it happens very slowly.
There are also more unexpected types of plant movement. For example, young growing leguminous plants seem to "play" with each other, stretching shoots and leaves in all directions and constantly pushing them. Although the word "plays" here seems inappropriate, this is in its way the correct definition - just as small animals need play in order to learn how to interact with the world, so plants need to understand their position in the population and establish connections with each other. Such connections can be critical - if you plant a small sunflower among adults, sunflowers that have been growing together for a long time, it will most likely die, because it will not be able to fit into the system of their connections.
Hearing and Voice
Each top of the plant root is capable of receiving at least 20 different types of impact. The roots are sensitive to pathogens, chemicals, electrical impulses, oxygen and salt levels, light, temperature, and so on. Even Charles Darwin believed that the tips of the roots are a kind of "brain" of the plant.
In addition, the roots are also able to make sounds themselves. If you try to convey them in words, then they look like very quiet clicks, which, of course, the human ear does not hear. According to scientists, this may be due to the ability of the roots to echolocation - with the help of these sounds, they, like bats in the air, possibly determine the position relative to each other, as well as other obstacles in space.
“People have been trying to appeal to their crops with their voice and musical instruments for a long time. Even Prince Charles talks to plants to help them grow better. But plants are completely unable to distinguish between voices or music. But they are able to feel some frequencies of air vibrations. This phenomenon is called "phonotropism". The roots perceive frequencies in the region of 200 hertz and begin to grow towards this sound. These frequencies correspond to the noise of the water, and, probably, the roots thus tend to its source. That is, we can say that it is better for plants to play the bass guitar than the violin. " - From Stefano Mancuso's answers to N + 1 questions
Vision
Recently, scientists have become interested in another, completely unexpected ability of plants - they even began to talk about it as their ability to "see". Chilean botanists found this ability in the clinging vine Boquila trifoliolata. Liana is attached to different trees and mimics them with high precision. When it grows to a new tree, it begins to copy its leaves, and it turns out that in different parts of the same vine its leaves, firstly, turn out to be completely different, and secondly, they repeat the shape of the leaves of each of their "props".
Mimicking the leaves of Boquila trifoliolata liana turns out in different ways - sometimes very good, sometimes not very, but they are clearly trying to find their own approach to each tree. How do they recognize the shape of each next leaf they encounter? And how does this knowledge allow them to change the shape of their own leaves? In an experiment, one student substituted a liana with a plastic plant made in China whose leaf shape was completely unnatural. Liana also copied these leaves, and this is especially surprising, given that there was no question of any chemical or physiological analysis here.
The fact that plants supposedly have some kind of "eyes" was said back in 1905. Then the German botanist Gottlieb Haberlandt, one of the first scientists to propose a classification of plant tissues, said that plants supposedly can perceive images using the epidermis. The physiologist Francis Darwin, son of Charles, supported his research, but this topic was not further developed.
“This is what Felix Fedorovich Litvin, biophysicist and doctor of biological sciences, says on this topic. Plants, using phytochrome systems (phytochrome is a plant pigment in cells), are able to analyze their environment, focusing on the shadows and light falling on their own shoots. Leaves on trees, for example, grow in such a way that the top ones do not block the light from the bottom ones - this is called leaf mosaic. Moreover, when a gap is formed between the trees for some reason, the leaves quickly begin to grow in this lumen and occupy it all (as if "seeing" the space). Thus, the plant covers the maximum area for absorbing light, and at the same time darkens what is under it so that other plants cannot use solar energy here and outgrow themselves (the same distribution system, by the way,occurs in some corals due to their symbiosis with algae). One can imagine that the liana also reacts to the light and shadow from the leaves of foreign trees, and the shape of its leaf is determined by such "impressions". Therefore, sometimes she does worse, sometimes better - it depends on how clearly the shadows fall on her. - From Stefano Mancuso's answers to N + 1 questions
09:11 If Trees Could Talk
Do you know what plant neuroscience is? To an uninitiated person, its description may seem surprising - this is a science that studies the communication system of plants, their sensory systems and "behavior". Neuroscientists claim that plants can hear, smell, communicate and almost see, as well as manipulate other plants and even animals. These unusual claims are based on experiments conducted in laboratories around the world, decades of work and publications in serious scientific journals. Recently, the founder of plant neurobiology, the Italian professor Stefano Mancuso, came to Moscow. He gave a lecture within the framework of the Philosophical Club at Winzavod and answered several of our questions.
Professor of the University of Florence Stefano Mancuso is the founder and popularizer of the field of plant neurobiology. The Italian newspaper La Repubblica and the American magazine The New Yorker have included his name on the list of leading scientists who are changing the world. In 2015, the team led by Mancuso received the EXPO Milano Award for Innovative Agribusiness Ideas for the Jellyfish Barge, a large floating house in the shape of a jellyfish, in which plants can grow without soil, fresh water and fertilizer, solely powered by solar energy. Mancuso is the author of several best-selling books, including Brilliant Green: Sensuality and Intelligence in the Plant World (2013) and The Plant Revolution: How Plants Invented Our Future (2017).
Mancuso begins his lectures by mentioning Noah's ark, where “each creature has a pair” - this concerned animals and birds, the professor recalls, but not plants. In general, he says, not enough attention has always been paid to plants, both by ancient scientists and philosophers, and in our time. Mancuso proposes to rethink the status of plants, abandoning the anthropocentric picture of the world, in order to expand the concepts of rationality and consciousness that, in his opinion, plants have, but which should be studied, abandoning the usual interpretations of these terms.
Stefano Mancuso
Plants are capable of perceiving at least two dozen different environmental factors, including changes in gravity, light, chemical composition of air, water and soil. They also know how to "hear" some sounds and change their behavior depending on these factors. Mancuso argues that plants have a kind of intelligence, although not in the usual sense of the word. In some of the experiments he talks about, plants literally "predict the future." Their system of communication signals is a kind of alternative Internet, covering the entire planet.
Intelligence is the ability to solve problems, says Mancuso.
We are accustomed to thinking about large organisms to mean animals. For example, everyone knows that the largest animal on Earth is the blue whale. But in fact, a sequoia is a hundred times larger than a whale. If we evaluate the biomass of the planet, then plants occupy, according to various estimates, from 80 to 97 percent. If we look at the tree of life, Darwinian or any more modern, we see that plants are also much more ancient organisms than animals. Flowering plants, for example, predate mammals.
When we try to understand how the body works and how it responds to external influences, we usually pay attention to its organs. But the plant does not have paired or single organs like eyes or lungs. Therefore, in a certain sense, they are better protected - having lost both eyes, the animal loses the ability to see and adequately respond to the external environment, and in the plant all the "organs" are presented in the plural. It can lose up to 90 percent of its entire body and still survive. If plants, which can hardly move, had the same "weaknesses" as animals, then any caterpillar would pose a serious danger to them.
Traffic
We are used to thinking that plants are motionless, but this is not entirely true. First, the plants, of course, grow. Interestingly, back in 1898, when cinema was just in its infancy, the German botanist Wilhelm Pfeifer conducted time-lapse serial footage recording plant growth, and these "films" still exist.
Secondly, plants are able to change their position in space and shape, and in some cases they do not even expend their own energy on this. For example, the buds of gymnosperms are designed in such a way that they open when it gets dry. This technology is used in the design of stadium roofs. The dandelion opens just as "economically". At the same time, he makes 15 different types of movement, but they all occur spontaneously.
“The topic of my thesis was the study of the movement of roots - how exactly they avoid obstacles. It seems like a simple process, but in reality it is incredibly complex. When I started doing this, science believed that the roots first "touch" the obstacles, and then change the direction of growth. I observed a completely opposite picture: firstly, the roots go around obstacles in advance, not yet touching them, and secondly, they always choose the shortest and optimal path of growth, thus demonstrating a kind of "intelligence". This was the first sign for me that the plant is a much more complex organism than it seems."
From Stefano Mancuso's answers to questions N + 1
The seeds of some plants, for example Erodium achicutarium, seem to "dance" on the ground, looking for a place where the root can be launched, and this dance looks like a meaningful search, although the seed does not spend any of its own energy on it. Scientists are trying to apply similar mechanical characteristics of the shell structure and other structures of seeds when developing equipment for space programs.
Plants also have active types of movement. The well-known predatory Venus flytrap is capable of closing and digesting insects and even slugs. But less exotic processes, such as the opening of a flower, are also movement, even if we do not see it due to the fact that for us it happens very slowly.
There are also more unexpected types of plant movement. For example, young growing leguminous plants seem to "play" with each other, stretching shoots and leaves in all directions and constantly pushing them. Although the word "plays" here seems inappropriate, this is in its way the correct definition - just as small animals need play in order to learn how to interact with the world, so plants need to understand their position in the population and establish connections with each other. Such connections can be critical - if you plant a small sunflower among adults, sunflowers that have been growing together for a long time, it will most likely die, because it will not be able to fit into the system of their connections.
"Hearing and Voice"
Each top of the plant root is capable of receiving at least 20 different types of impact. The roots are sensitive to pathogens, chemicals, electrical impulses, oxygen and salt levels, light, temperature, and so on. Even Charles Darwin believed that the tips of the roots are a kind of "brain" of the plant.
In addition, the roots are also able to make sounds themselves. If you try to convey them in words, then they look like very quiet clicks, which, of course, the human ear does not hear. According to scientists, this may be due to the ability of the roots to echolocation - with the help of these sounds, they, like bats in the air, possibly determine the position relative to each other, as well as other obstacles in space.
Since ancient times, people have tried to appeal to their crops with the help of voice and musical instruments. Even Prince Charles talks to plants to help them grow better. But plants are completely unable to distinguish between voices or music. But they are able to feel some frequencies of air vibrations. This phenomenon is called "phonotropism". The roots perceive frequencies in the region of 200 hertz and begin to grow towards this sound. These frequencies correspond to the noise of the water, and, probably, the roots thus tend to its source. That is, we can say that it is better for plants to play the bass guitar than the violin.
From Stefano Mancuso's answers to questions N + 1
"Vision"
Recently, scientists have become interested in another, completely unexpected ability of plants - they even began to talk about it as their ability to "see". Chilean botanists found this ability in the clinging vine Boquila trifoliolata. Liana is attached to different trees and mimics them with high precision. When it grows to a new tree, it begins to copy its leaves, and it turns out that in different parts of the same vine its leaves, firstly, turn out to be completely different, and secondly, they repeat the shape of the leaves of each of their "props".
Mimicking the leaves of Boquila trifoliolata liana turns out in different ways - sometimes very good, sometimes not very, but they are clearly trying to find their own approach to each tree. How do they recognize the shape of each next leaf they encounter? And how does this knowledge allow them to change the shape of their own leaves? In an experiment, one student substituted a liana with a plastic plant made in China whose leaf shape was completely unnatural. Liana also copied these leaves, and this is especially surprising, given that there was no question of any chemical or physiological analysis here.
The fact that plants supposedly have some kind of "eyes" was said back in 1905. Then the German botanist Gottlieb Haberlandt, one of the first scientists to propose a classification of plant tissues, said that plants supposedly can perceive images using the epidermis. The physiologist Francis Darwin, son of Charles, supported his research, but this topic was not further developed.
This is what Felix Fedorovich Litvin, a biophysicist and doctor of biological sciences, says on this topic. Plants, using phytochrome systems (phytochrome is a plant pigment in cells), are able to analyze their environment, focusing on the shadows and light falling on their own shoots. Leaves on trees, for example, grow in such a way that the top ones do not block the light from the bottom ones - this is called leaf mosaic. Moreover, when a gap is formed between the trees for some reason, the leaves quickly begin to grow in this lumen and occupy it all (as if "seeing" the space). Thus, the plant covers the maximum area for absorbing light, and at the same time darkens what is under it so that other plants cannot use solar energy here and outgrow themselves (the same distribution system, by the way,occurs in some corals due to their symbiosis with algae). One can imagine that the liana also reacts to the light and shadow from the leaves of foreign trees, and the shape of its leaf is determined by such "impressions". Therefore, sometimes she does worse, sometimes better - it depends on how clearly the shadows fall on her.
Sense of space
One of the most effective experiments in analyzing the sense of space in organisms that are not animals was working with slime mold fungi, which not only know how to pass mazes, but also build optimal transport systems that completely imitate (only on a small scale, naturally) the road system in Tokyo, Italy, Holland or China. Sometimes the mushroom paved even more optimal paths between key points.
Plants also know how to choose the most optimal paths and suitable goals - for example, a cuscuta, a parasitic plant that needs to attach to someone, always between two plants that it has not even touched yet, will choose a tomato. It behaves as if it knows in advance what is growing around it and where.
Leguminous plants growing in the laboratory also seem to know in advance in which direction they grow in order to meet support. Whichever side you put a stick from their pot to which they need to catch on, they, at first twisting the shoot in all directions (in accelerated shooting, this can be seen especially well), quickly begin to grow purposefully towards the support. It is interesting that when two plants compete for support and one succeeds first, the second immediately "gives up" and begins to grow in the other direction. It turns out that the legume plant is aware of everything that is happening around.
“The behavior of plants must be distinguished from the behavior of animals - it is based on the principles of action of a differently organized living being. But they also have something in common. Look at plant competition, for example. You can take two identical pots, and plant two beans of the same type in one, and two beans of different types in the other, and care for them in exactly the same way. You will soon find two completely different pictures. In the first pot the plants will grow, and in the second they will be very small and underdeveloped. But if you look at their root system, you will see that in the second pot it is huge - because the plants have spent all their energy to capture the territory underground and fight each other. In the first pot, the roots will be ordinary, they do not compete with each other. Animals act in a similar way, displacing alien species,but use other methods for this.
Plants are in many ways much more sensitive organisms than animals, although this sounds paradoxical. Animals can run away if they sense danger, such as the appearance of smoke in the forest. Plants cannot escape, therefore, in order to better adapt to the environment and anticipate maximum trouble, they have developed a much more developed sensitivity that allows them to predict everything in advance. They have, one might say, almost all types of receptors. For example, scientists have not yet found thermoreceptors known to humans, but plants can respond to temperature. We just don't know how yet, but they are able to feel the slightest changes in temperature and change their physiology. -From Stefano Mancuso's Answers to N + 1 Questions
Taste and Smell
The roots of some plants are able to analyze the soil around them with high accuracy and, returning to the topic of labyrinths, they can not only bypass obstacles in advance, without touching them, but also grow towards useful substances and avoid harmful ones, again, not even having time to them touch. On the filming, it can be seen that some roots of the same plant behave "stupid" and grow in the wrong place, but the vast majority make their way in the optimal way.
Nervous system
Previously, people believed that there were no electrical impulses in plants. However, experiments in recent years have refuted this hypothesis. Weak electrical impulses, similar to impulses in the nervous system, constantly occur in the plant organism. On high-speed video, the electrical impulses of the rice root system look like the most complex work of neurons in the brain.
Root movement can be very synchronized. They can all change the direction of movement at the same time, like fish in a school, copying the smallest changes in rhythm. It turns out that the roots exchange information and change their "behavior" depending on it.
Forest from "Avatar"
What's even more interesting (and even sci-fi) is that plants exchange similar impulses with each other. So, recent studies have shown that all trees in the forest, apparently, interact with each other and are in some kind of constant connection.
Using the example of a Canadian forest, it was demonstrated how trees transferred water and nutrients to their companion, who did not have enough resources. Mancuso jokingly calls these systems "Wood-wide web".
“Plants are peerless experts in networking. Here it is appropriate to cite the Internet as an example. I've written quite a lot about this in books, but I'll try to summarize the point in a nutshell: you can learn a lot from plants that we need to optimize our networks. This also includes the ability to "predict the future", which is based on the ability to receive information from other plants. The plant world is a network similar to the Internet or, say, the nervous system, but with completely different principles. And this system is unprecedented. Moreover, until recently, this aspect of plant life has not been studied at all. I like to cite the example of wikipedia, or the cryptocurrency system, which is as decentralized as plants, and therefore invincible in its own way.
If you cause stress in a plant, it will immediately transmit information about this to its neighbors, and they will all increase their resistance to certain stimuli. It is not constantly increased for them, because it would be too energetically unprofitable. They need to know exactly when to defend themselves against something. It can be used in agriculture. By stopping watering one plant, you can achieve greater resistance to loss of moisture in the rest, because it will inform them about the upcoming changes. And there is no need to use any special chemicals or other preparations, it is enough to use the plants' own tools. - From Stefano Mancuso's answers to N + 1 questions
Control over other kingdoms
In addition to the fact that representatives of other kingdoms can be dangerous to plants, they also need them. Everyone knows that insects are pollinators of many flowering species. In order to attract insects, plants sometimes go to amazing tricks. For example, some orchids are extremely successful in imitating female pollinators so that males try to mate with them and get a "horn" on their body, with which the orchid spreads its pollen. Interestingly, the males themselves sometimes like the plants more than the females, and the females remain unfertilized. As a result, parthenogenesis is common among these pollinators.
However, there are cases and more interesting mimicry - for example, myrmecophilia. This broad term implies close interaction with ants and is characteristic of a wide variety of living creatures. There are a lot of ants in nature, and some plants use their "services". To do this, says Mancuso in his lecture, some types of acacias, for example, provide ants with a home, food and drinks. At the same time, they produce much more nectar than necessary - Darwin would call this an impermissible waste. However, ants drinking nectar protect the plant from other insects and even from other plants - as soon as a twig grows closer, they immediately cut it off so that it does not interfere with the photosynthesis of acacia.
It turned out that such ants cannot be seduced with bread and even sugar - they just throw them off the leaves like garbage. It turned out that the acacia nectar contains a kind of "drug" with which it manipulates its lodgers. Moreover, it changes the level of the drug in the nectar depending on the circumstances, controlling the behavior of ants in different stages of life in different ways. Likewise, some other plants add caffeine to the nectar if they like their pollinators, and remove it altogether if the pollinators are not doing their job.
It turns out that plants, although they are practically immobile subjects without a nervous system and sensory organs familiar to humans, are capable of analyzing a lot of environmental parameters with high efficiency, as well as reacting to them, communicating with other individuals and even controlling other types of living organisms. Considering what was said at the beginning about the absolute domination of plant biomass on the planet, one involuntarily ponders who on Earth should actually be called the master (however, then you remember bacteria and viruses and give up trying to arrange a competition).
Anna Kaznadze