Source – Kew Magazine, Autumn 2013, p 18 – from feature written by Gail Vines
Researchers in the UK have shown for the first time that plants can communicate by sending signals along a network of underground fungi that link the roots of nearby plants. (Ecology letters, vol 16, p 835).
Mycorrhizal fungi can serve as channels for the transmission of ‘infochemicals’ which can act as an early warning system, alerting neighbours to herbivore attack so they can take defensive action.
Aphids find host plants by homing in on a cocktail of volatile organic compounds (VOCs) emitted by their leaves and when insects begin to feed, the plants respond by emitting very different VOCs that repel aphids while attracting aphid enemies like parasitic wasps.
Researchers – Lucy Gilbert at the James Hutton Institue in Aberdeen and David Johnson at the University of Aberdeen, together with PhD student Zdenka Babikova and biochemists at Rothamsted Research in Hertfordshire – showed that when broad bean plants were forewarned of approaching aphids, they switched their output of VOCs to defensive mode before any aphids reached them.
This worked when the plants were connected together underground by fungi around and between their roots. Only plants connected by underground fungi were able to respond in this way: cut off from the fungal network, the plants continued to give off aphid-attracting chemicals.
The Kew story states that implications could be far reaching – insect ecologists might need to take note of the activity of fungi in the soil and farmers could avoid ploughing and artificial fertilizers to encourage mycorrhizal fungi.
Note: did you know that fungi are more closely related to humans than they are to plants?
For further information click here for the Kew website.
Also, click here to see a video of the Kew Fungariam