New Study Shows Plants Talk to Each Other Through the Soil
A new study conducted by Dr. David Johnson at the University of Aberdeen found that plants actually communicate with one another through the soil. The study shows that when vegetables are infected with certain diseases, they alert other nearby plants to activate genes to ward off the disease when it heads their way. The key to this communication is a soil fungus that acts as a messenger.
Soil fungus and certain plants have a symbiotic relationship, according to the research team, who shared their findings with The Economist. The plants deliver food and the fungus delivers minerals. But now it turns out the fungal hyphae, which creates a network in the soil that connects the various plants, plays another essential role as a messenger.
In 2010, a team of Chinese researchers found that when a tomato plant became infected with a leaf blight, it was able to somehow alert nearby tomato plants, which then prepared their defense. Dr. David Johnson and his team sought to find out by which mechanism the plants were able to communicate this information with Broad Bean plants.
To prove that the plants were communicating through the soil, the team set up a series of “mesocosms” of five bean stalks each. Beans are often attacked by aphids. When this happens, they release a chemical that attracts wasps that then come around and annihilate the aphids.
“Five weeks after the experiment began, all the plants were covered by bags that allowed carbon dioxide, oxygen and water vapour in and out, but stopped the passage of larger molecules, of the sort a beanstalk might use for signalling. Then, four days from the end, one of the 40-micron meshes in each mesocosm was rotated to sever any hyphae that had penetrated it, and the central plant was then infested with aphids.”
You can read more about the experiment at The Economist, but the controls demonstrated that indeed the bean plants communicated to each other through the soil when it was found that one of them had been attacked by aphids!