Scientists Identify Plants' Signaling Mechanism to Warn Danger

Scientists from the University of Aberdeen, the James Hutton Institute, and Rothamsted Research in the United Kingdom have discovered that plants use underground fungal networks to warn their neighbors of aphid attack. The study, published in Ecology Letters, is the first to reveal plants' ability to communicate underground in this way.

Scientists grew the bean plant (Vicia faba) in groups of five. They allowed three in each group to grow underground networks of mycelia – thread-like part of a fungus that grows from one set of roots to another. They kept the two remaining plants free of the fungal links. They then infested one of the plants in each group with aphids, triggering the release of a suite of chemicals designed to repel aphids but attract wasps, one of the aphid's predators.

Remarkably, plants which were not under attack themselves, but which were connected to the victim by the underground fungal network, also began to produce the defensive chemical response. Unconnected plants didn't mount a chemical defense, thus they have remained vulnerable to aphid attack. Previous research had shown that plants could communicate chemically through the air, but the researchers covered the plants with bags to rule out above-ground signaling.

See the James Hutton Institute's news release at http://www.hutton.ac.uk/news/plants-use-underground-networks-communicate-danger.