title: How rapid is aphid-induced signal transfer between plants via common mycelial networks?
abstract: Arbuscular mycorrhizal (AM) fungi are important plant mutualists that can connect roots of neighboring plants to form common mycelial networks. A recent study demonstrated that these networks can act as conduits for aphid-induced signals between plants, activating chemical defenses in uninfested neighboring plants so that they become unattractive to aphids but attractive to their enemies (parasitoids). The benefit to the neighboring plants will increase if the signal speed is rapid, enabling them to respond before aphids attack. Here, we determine the speed of aphid-induced signal transfer between plants infested with aphids ("donor") and neighboring aphid-free plants that were either connected or unconnected to the donor via a common mycelial network. Induced changes in plant volatiles from neighbors connected to donors started within 24 h of aphid infestation of donors. This demonstrates a rapid signal, implying potential benefit to plants receiving the signal, and raises intriguing ecological and evolutionary questions.
authors.affiliation: Institute of Biological and Environmental Sciences; University of Aberdeen; Aberdeen, UK ; Rothamsted Research; Harpenden; UK ; James Hutton Institute; Craigiebuckler; Aberdeen, UK.
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Babikova
authors.affiliation: Institute of Biological and Environmental Sciences; University of Aberdeen; Aberdeen, UK.
authors.forename: David
authors.initials: D
authors.lastname: Johnson
authors.affiliation: Rothamsted Research; Harpenden; UK.
authors.forename: Toby
authors.initials: T
authors.lastname: Bruce
authors.affiliation: Rothamsted Research; Harpenden; UK.
authors.forename: John A
authors.initials: JA
authors.lastname: Pickett
authors.affiliation: James Hutton Institute; Craigiebuckler; Aberdeen, UK.
authors.forename: Lucy
authors.initials: L
authors.lastname: Gilbert
keywords: arbuscular mycorrhizal fungi; broad bean (Vicia faba); common mycelial network; induced plant defense; insect host location; inter-plant communication; pea aphid (Acyrthosiphon pisum); rhizosphere signaling; volatile organic compounds