Scientists have managed to film plants communicating with one another, capturing something usually invisible to the human eye. They discovered that plants use airborne chemical signals to warn neighbors of danger and to defend themselves from threats like insects.
When a plant is attacked by herbivores, it releases imperceptible compounds into the air. Nearby plants detect these signals and respond by activating their own defenses, such as producing chemicals that repel insects or by strengthening their cell walls.
Although scientists have known since the 1980s that plants release distress signals, the process of how other plants receive and respond to them remained unclear. To study this, researchers transferred these compounds from damaged plants to healthy ones and then used a fluorescence microscope to observe how the healthy plants reacted.
In one experiment, caterpillars were placed on the leaves of certain plants. Soon after, nearby untouched plants responded to the chemical warnings by preparing their defenses, showing that communication had taken place.
Plants also share information in other ways. Through underground networks of fungi called mycorrhizae, they can exchange nutrients and signals about soil conditions, creating a hidden web of communication beneath the earth.
This research reveals that plants are far from passive, they are constantly sensing, signaling, and adapting in order to survive in their ever-changing environments.