We can’t hear it, but scientists are finding that in the apparently silent world of plants, a whole lot of communication is going on.
The roots of most land plants are colonised by mycorrhizal fungi that provide mineral nutrients in exchange for carbon. Mycorrhizal mycelia can also act as a conduit for signaling between plants, acting as an early warning system for herbivore attack. Insect herbivory causes systemic changes in the production of plant volatiles, particularly methyl salicylate, making bean plants, Vicia faba, repellent to aphids but attractive to aphid enemies such as parasitoids. We demonstrate that these effects can also occur in aphid-free plants but only when they are connected to aphid-infested plants via a common mycorrhizal mycelial network.
This underground messaging system allows neighbouring plants to invoke herbivore defences before attack. Our findings demonstrate that common mycorrhizal mycelial networks can determine the outcome of multitrophic interactions by communicating information on herbivore attack between plants, thereby influencing the behaviour of both herbivores and their natural enemies.
Sending a signal via fungi
LESS mysterious, but of great significance, is the discovery by UK researchers from several universities of an Avatar-like signaling network broadcast through mycorrhizae.
These fungi form a symbiotic relationship with plant roots. In exchange for compounds the plant makes during photosynthesis, mycorrhizae transports nutrients and moisture through its vast networks of hyphae to the host plant. The UK research shows the fungal networks also form an underground communications network.
The researchers used plots of broad beans, with each plant covered with a bag so it wasn’t possible for the beans to communicate with chemicals released into the air.
Some plots were connected through mycorrhizal networks; in others, the fungi weren’t allowed to grow.
When aphids were introduced to one of the mycorrhizae-connected bean plants, the levels of defensive chemicals in bean plants on the same fungal network quickly rose.
In the unconnected beans, introducing aphids to a plant provoked no response in other plants.
John Pickett of Rothamsted Research told the BBC one possible use for this knowledge would be to include particularly aphid-prone sacrificial plants in a crop. When aphids attacked, the fungal signaling system could raise the natural defences of more economically valuable plants.
It could prove a robust method of switching on plant defences when needed — without demanding the plant produce defensive chemicals all the time.
Ref: Underground signals carried through common mycelial networks warn neighbouring plants of aphid attack
See also: The Secrets Life of Plants by Peter Tompkins & Christopher Bird The Field by Lyn McTaggart
Dr. Phil Callahan entitled: “Antennas of Nature: Biological Form & Earth Magnetics.” Dr. Callahan has a lifetime of experience with the FDA, with multiple university positions and PhDs. His voice on waveforms and biology is unquestionably the best in the world. His books “Tuning in to Nature” and “Nature’s Silent Music” circle the world, and tell the story of birds and insects as exquisite magnetic antennae.