Fungus. Even the word itself feels like fungus. Slimy. Dirty. Sticky. In need of medicinal foot creams. That’s fungus in my book, and please don’t play the "but mushrooms are fungi!" card. Science be damned, I won’t believe you.
But it does appear we’ve all underestimated fungus and our beloved plants at the same time. Because new research published in Ecology Letters finds that fungus allows plants to communicate through underground networks.
Scientists discovered this by setting up a test with bean plants. Some plants were exposed to a common root fungus. Others were not. Then aphids—a natural plant predator—were unleashed upon some of the plants. In response, the plants acted as expected, releasing a variety of chemicals to attract wasps (the predators of aphids). What happened next was extraordinary, at least by our naive scope of science. From the Natural Environmental Research Council:
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 defence, so 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.
Dr David Johnson, of the University of Aberdeen, led the study. He says, 'We knew that plants produce volatile chemicals when attacked, and we knew they communicate danger to each other above ground. Now we know that they communicate danger through these underground fungal networks as well. Connected plants that weren’t infested by the aphids behaved as though they were. We don’t quite know the mechanism, but it’s likely to be a chemical signal.'
'Our understanding of ecological systems has not considered the fact that plants are interconnected in this way. It could have major implications for our understanding of how one organism affects another,' he adds.
He’s not exaggerating: Such symbiotic fungi colonize the roots of most plant systems, meaning this research could have impacts for the entire plant world (including those we eat, of course). But in an unforeseen downside to the news: James Cameron gets to be right about yet another thing.
[Hat tip: @ejacqui]