Plants have long been regarded as silent, passive entities, but groundbreaking research challenges this traditional view. A Japanese research team has made a breakthrough in plant communication, revealing that they can warn their neighbors of impending threats. This discovery, published in the prestigious journal Nature Communications, has profound implications for our understanding of plant life.
The study, led by molecular biologist Masatsugu Toyota from Saitama University, along with Dr. Yuri Aratani and postdoctoral researcher Takuya Uemura, observed and recorded how undamaged plants respond to volatile organic compounds (VOCs) released by their damaged neighbors. These VOCs are released when they face physical harm or threats from herbivores.
The experiment setup
The experimental setup involved an air pump connected to a container housing leaves and caterpillars and a space with Arabidopsis thaliana, a common weed in the mustard family. This plant was genetically engineered to emit green fluorescence when detecting calcium ions, a stress signal.
Using fluorescence microscopy, the researchers could monitor the undamaged plants receiving VOCs from the damaged leaves and the signals they released in response.
The implications of plant responses
When plants perceive danger signals from their neighbors, they engage in various defense responses. This inter-plant communication serves as a protective mechanism against environmental threats. For instance, when physically damaged, a plant releases VOCs to signal its distress, alerting nearby plants of potential danger and attracting predators of the pests that threaten them. In essence, they can seek help and recruit allies for survival.
Plants emitting distress calls
A study published in Cell on March 30, 2023, revealed that plants emit frequent “cries” under water scarcity or stress, producing up to 50 distinct sounds per hour. These ultrasonic sounds, ranging from 40 to 80 kHz, are imperceptible to the human ear.
Scientists from Tel Aviv University recorded these ultrasonic emissions from tomato and tobacco plants using specialized microphones. Subjected to various treatments, such as drought or stem-cutting, showed that their condition influenced the sound frequency.
The findings
- Under normal conditions, plants emitted less than one sound per hour.
- When dehydrated or injured, they could emit 30 to 50 sounds per hour, detectable up to 3 to 5 meters away.
- Tomato plants under drought emitted 35 sounds per hour, while tobacco plants emitted 11.
- After stem-cutting, tomatoes averaged 25 sounds per hour, and tobacco 15, compared to less than one sound per hour for unstressed plants.
The research team also tested various other plants, including wheat, corn, grapes, and cacti, all of which recorded emitting sounds. The exact mechanism of sound production and whether factors like UV radiation or extreme temperatures induce these sounds remain unclear.
Agricultural applications
This discovery has potential applications in agriculture, allowing farmers to water their crops or detect injuries timely, thus providing better care for their plants. It also suggests that they can hear the sounds of other plants and react accordingly, revolutionizing our perception of plant life.
Consciousness and cognition
A report by outerplaces.com on February 8, 2018, highlighted multiple experiments confirming plant consciousness. A study published in The American Naturalist on February 5, 2018, demonstrated that Venus flytraps selectively prey on insects, avoiding those beneficial for pollination. This selectivity suggests that the plant may recognize the importance of bees for its growth, hinting at a level of cognitive awareness.
Conclusion: A new era of plant perception
The research conducted by the Japanese team and the scientists from Tel Aviv University has opened a new chapter in our understanding of plant life. These studies indicate that plants are not only capable of communication but also possess a form of consciousness and cognition. As we continue to explore the depths of plant behavior, we may find that the green world around us is much more dynamic and interconnected than we ever imagined.
This knowledge enriches our appreciation of nature and promises to enhance agricultural practices for a more sustainable future.
