In 2013 David Johnson of the University of Aberdeen and his colleagues showed that broad beans also use fungal networks to pick up on impending threats – in this case, hungry aphids.
Johnson found that broad bean seedlings that were not themselves under attack by aphids, but were connected to those that were via fungal mycelia, activated their anti-aphid chemical defenses. Those without mycelia did not.
"Some form of signalling was going on between these plants about herbivory by aphids, and those signals were being transported through mycorrhizal mycelial networks," says Johnson.
But just like the human internet, the fungal internet has a dark side. Our internet undermines privacy and facilitates serious crime – and frequently, allows computer viruses to spread. In the same way, plants' fungal connections mean they are never truly alone, and that malevolent neighbours can harm them.
For one thing, some plants steal from each other using the internet. There are plants that don't have chlorophyll, so unlike most plants they cannot produce their own energy through photosynthesis. Some of these plants, such as the phantom orchid, get the carbon they need from nearby trees, via the mycelia of fungi that both are connected to.
Other orchids only steal when it suits them. These "mixotrophs" can carry out photosynthesis, but they also "steal" carbon from other plants using the fungal network that links them.
That might not sound too bad. However, plant cybercrime can be much more sinister than a bit of petty theft...
http://www.bbc.com/earth/story/20141111-plants-have-a-hidden-internet