New Study Reveals How Trees Communicate and Defend Against Danger
In a scene that seems right out of “The Lord of the Rings,” researchers have discovered that real trees on Earth have the ability to communicate and warn each other of potential threats. The study, published in Nature Communications, explains how injured plants emit certain chemical compounds that can infiltrate a healthy plant’s tissues and activate defense mechanisms from within its cells.
Lead author of the study, Masatsugu Toyota, describes it as the first time researchers have been able to “visualize plant-to-plant communication.” The findings suggest that this mechanism could be used by scientists and farmers to fortify plants against future threats such as insect attacks or drought.
The idea of trees communicating with each other first emerged in the 1980s when ecologists observed how attacked trees produced chemicals that made their leaves unappetizing to insects. What surprised them even more was that healthy trees of the same species, located far away and with no root connections to the damaged trees, also activated the same defense mechanisms.
This led to the concept of plant eavesdropping, where trees send chemical signals to one another through the air. Over the years, scientists have observed this communication in more than 30 plant species. However, until now, they did not know which chemical compounds were important or how they were being sensed.
By manually triggering the emission of various green leafy volatiles in mustard and tomato plants, the research team discovered that only two compounds increased calcium ions in healthy plants’ cells, a sign of defense response activation. This finding indicated that the compounds were being absorbed into the plants’ inner tissues through stomata, which allow for gas exchange during photosynthesis.
With this new understanding, researchers hope to use these chemical signals to immunize plants against threats before they even occur. By exposing healthy plants to insect-ridden plants or the associated green leafy volatiles, farmers could boost their genetic defenses and reduce the need for pesticides. Additionally, plants could become more resilient during droughts by signaling them to retain more water.
While the study answered some long-standing questions, there is still much to explore. The researchers aim to identify the receptors in the plants that respond to specific chemical compounds and understand how plants produce specific responses based on the species of herbivores feeding on them.
André Kessler, a plant ecologist not involved in the study, describes plants’ ability to mount adaptive responses as a form of intelligence that raises questions about our understanding of the world. The study has opened up exciting possibilities for further research in plant communication and defense mechanisms, with the potential to benefit agriculture and conservation efforts in the future.