Can plants communicate?
Discover the secret signals plants send to each other on the wood wide web
Just as we have many different methods for staying in touch with friends, plants have their own ways of communicating with each other. The main purpose for this is to help each other out, warning nearby plants of approaching dangers, such as insects, infections or drought so that they can take appropriate action. One method they use to do this is to emit invisible volatile organic compounds (VOCs) into the air. Other plants can then detect these compounds and know to defend themselves, or signal for help.
Plants can warn each other about invasions of destructive insects, such as aphids
Another method is below ground and enlists the help of fungi. Beneath the mushrooms on the surface is a mass of thin threads called mycelium. These threads link the roots of different plants, allowing them to transfer compounds and communicate a specific message. The final way plants talk to each other is by secreting chemicals through their roots, which diffuse through the soil and are picked up by other plants, alerting them to danger. This complex plant communication network has been named the ‘wood wide web’ by biologists, but like our own version of the internet, it has a dark side. Some plants use mycelium to steal carbon from each other, while others use it as a method of attack, delivering toxic chemicals along the fungal threads to inhibit the growth of their competition.
The internet of plants
How do plants warn each other of impending dangers?
Herbivore attacks: Insects called aphids feed on the sap of many different plant species, which can destroy the plant in the process.
Infection: Plant diseases such as blight cause plant tissue to die and can spread rapidly between organisms.
Drought: A lack of moisture in the soil acts as a stressor for the plant, as it signifies that it may be in danger.
Warning signal: Plants under attack emit volatile organic compounds (VOCs) into the air, warning their neighbors of danger.
Defense response: Upon receiving the signal, the plants emit defense VOCs that repel aphids and attract aphid-hunting wasps.
Closed stoma: The chemicals warn the plant to close its stomata, small openings in its leaves, to prevent water escaping.
Chemical communication: The stressed plants secrete soluble chemicals from their roots, which are then absorbed by the roots of neighboring plants.
Pass it on: Plants can then relay the message to their own neighbours, helping to spread the warning far and wide.
Fungi network: Plants also transmit warning signals via the thin thread of fungi that connect their roots in the soil.