Can Plants See Us or Feel Pain?

In the past century, plant research has greatly intensified. And a very old debate has begun to stir the curiosity of both botanists and garden enthusiasts: Can plants see us? 

Well, It may sound like science fiction. But inside the calm and green world of plants, there’s a super cool way they can sense things! It is debatable though, but is challenging our understanding of the vegetal world. 

In this article, we’ll deep dive into the fascinating world of plant perception, exploring their extraordinary sensory mechanisms and whether they can truly “see” us.

Who started the debate that plants can see or feel?

The debate about plant vision did not happen from a specific origin of thoughts. The initial issue of concern was, whether plants can perceive their environment or not. It has been ongoing for many years and does not have a single point of origin or a specific person who initiated it. Instead, it has evolved over time as scientists and researchers have made various discoveries related to plant perception and sensory mechanisms.

• Sir Jagadish Chandra Bose

One of the most groundbreaking moves on plant’s sensory mechanism was from Sir Jagadish Chandra Bose in the 19th century.

He developed sensitive instruments to measure the responses of plants to various stimuli, such as light, heat, and mechanical stimulation. His work contributed to the understanding of plant behavior and sensory mechanisms. But that was just the beginning only!

• Dr. Monica Gagliano and her team

  

Another significant research finding related to plant perception and communication came from a study conducted by Dr. Monica Gagliano and her team in 2010. Their research, published in the journal “Ecology Letters,” explored the phenomenon of plant communication through sound.

In this study, Dr. Gagliano and her colleagues exposed the young roots of corn plants to a continuous and gentle clicking sound. Surprisingly, the researchers observed that the corn seedlings leaned towards the source of the sound as if they were trying to “hear” it!

This phenomenon, referred to as “acoustic anemotropism,” raised intriguing questions about how plants might sense and respond to vibrations and sounds in their environment.

What is Acoustic Anemotropism?

Acoustic anemotropism” may sound like a complex term, but let’s break it down into simpler words:

• Acoustic: This word relates to sound, like what you hear when someone talks or when music plays.
• Anemotropism: It is a way of saying how something responds to the movement of air or wind.

So, when we put it all together, “acoustic anemotropism” means that plants can react or respond to sounds and the movement of air or wind.

Dr. Gagliano’s work sparked significant interest and debate within the scientific community. It suggests that plants could have a previously unrecognized sensory capacity related to sound perception. Actually, the research did not definitively prove that plants “hear” in the way animals do. However, it opened up a new avenue of exploration into the sensory abilities of plants and their potential for communication.

Since then, numerous studies and experiments have followed, further exploring the extent of plant perception and communication through various sensory mechanisms, such as light, gravity, touch, and chemical signaling.

How Can Plants See Us?

The debate about plants’ vision is not on whether plants have eyes or not. Plants definitely have no eyes or any other vision-based organ like animals possess. So, how are they able to see or sense us?

Well, there are two distinct ideas about how plant vision works. One hints at an eye-like mechanism in plants, termed ‘‘plant ocelli’’. And the other concept, which is more generalized, suggests photo-capturing materials in plant cells (proteins). 

What is the plant vision system?

Plants do not possess a vision system like animals with eyes, as we said earlier. Instead, they rely on a combination of sensory mechanisms to interact with their surroundings.

These mechanisms include-

•  Photoreceptor proteins for light perception
• Gravity-sensing cells for orientation
• Touch and mechanical sensitivity for responding to physical stimuli
•  Chemical sensing for detecting environmental cues

Light perception is primarily achieved through specialized proteins called photoreceptors in plants. These photoreceptors can sense light and its various characteristics, such as intensity, direction, and wavelength. Some of the key photoreceptors in plants include-

1. Phytochromes: Phytochromes gather or receive red and far-red light. These lights help plants to detect the presence of other plants, shadows, and changes in daylight hours. Phytochromes also play a significant role in regulating processes like flowering and germination.
2. Cryptochromes: Cryptochromes are involved in perceiving blue and ultraviolet (UV) light. They influence various plant responses, including growth, phototropism (bending towards light), and the regulation of circadian rhythms.
3. Phototropins: Phototropins are responsible for phototropism and other light-related growth responses. They primarily detect blue light and help plants grow towards light sources.
4. UVR8: This photoreceptor is specialized in sensing UV-B light, which can be harmful to plants. When activated, it triggers protective responses to shield the plant from excess UV-B radiation.

These photoreceptors collectively form the plant’s “vision” system, allowing them to perceive and respond to light in various ways. While not equivalent to animal eyes or ocelli, these photoreceptors are essential for plant survival, as they help regulate growth, development, and other key processes based on their light environment.

Now, let’s have a brief idea of ‘Plant Ocelli’, which is not that much reclaimed now. But there is a huge prospect that this concept can be a thing in the future!

What is plant Ocelli?

Ocelli are small, simple eyes or light-sensing structures found in some animals. It helps them detect changes in light intensity and adjust their behavior based on light levels.

The term “plant ocelli” refers to a concept proposed by botanist Gottlieb Haberlandt in 1905. Haberlandt suggested that, plants might have specialized light-sensitive structures, somewhat analogous to the ocelli found in some animals.

Plant ocelli allows plants to monitor and respond to variations in light conditions. According to the theory, plant ocelli could help plants orient themselves toward light sources and make growth-related decisions based on light cues.

• Difference between animal Ocelli and Plant Ocelli

• Study Materials
• • Algal Ocelloids and Plant Ocelli– Dr. František Baluška, and Mr. Felipe Yamashita 
  • Vision in Plants via Plant-Specific Ocelli?- Dr.Frantisek Baluska, and Dr. Stefano Mancuso

The mystery behind the plant’s sensor mechanism

Let’s get back to our main question. While plants don’t have eyes or a nervous system like animals, how can they sense things?

Well, plants have various mechanisms that allow them to sense and respond to their environment. Here’s an overview of some of the ways plants perceive their surroundings:

These mechanisms include:

• Light Perception

Plants have photoreceptor proteins that enable them to sense different aspects of light, such as intensity, wavelength, and direction. This helps them optimize processes like photosynthesis and adjust their growth patterns to reach light sources.

• Gravity Sensing

Plants have specialized cells called statocytes that contain starch granules. These granules respond to gravity, helping plants grow their roots downward and stems upward.

• Touch and Mechanical Sensing

Plants can detect physical stimuli like wind, rain, and touch. They may respond by changing their growth patterns or activating protective responses.

• Chemical Sensing

Plants can detect chemicals in their environment, including nutrients, toxins, and signals from other plants. This helps them make decisions about nutrient uptake and defense mechanisms.

Read more about-

Light Perception: Phototropism of Plants

FAQ

1. Can plants see us?

Plants can not see us the way we see them. But they can sense the presence of us through their own sensing mechanism. If you stand near a plant or go away, most possibly the plant can sense it!

2. Can plants feel pain?

Plants lack any nervous system like us. So, it can be said that they do not experience pain as animals do. Although, they can respond to physical damage or stress. But it’s more of a mechanical response, not a sensation of pain. *There are some experiments that suggest that plants also feel pain, but these are not still recognized by science.

Study Materials

Do Plants Feel Pain?– Adam Hamilton, Justin McBrayer

The Role Of Electricity In Plant Movement– P.J. SIMONS

3. Can plants talk?

Yes, plants can talk to the other plants. Obviously, they don’t have any vocal organs. Rather, they communicate with each other through chemical signaling. For example, they release compounds into the air or soil to alert neighboring plants about threats like herbivores.

4. Do plants cry?

Plants do not cry in the way animals do. However, when they experience stress or damage, they may release fluids, like sap or resin, as a response. This is a protective mechanism rather than an expression of emotion.

5. How can I talk to my houseplants?

Talking to plants is a generalized philosophical concept. It is a popular idea that verbal interaction or soothing words can have a positive impact on plant growth and health, though not scientifically supported.

People who “talk to” their plants typically engage in a form of caregiving. It includes regular attention, watering, and overall care. Talking to plants may help create a nurturing environment and a sense of connection between the caretaker and the plant. 

This practice often reflects the idea that tending to plants with care and attention can promote their overall health. If you do so, it may also have psychological benefits for you. So, you can take care of your houseplants properly, and that’s how to talk to them!