Scientists Film Genetically-Altered Plants 'Talking' to Neighboring Plants With...

ScienceAlert reminds us that plants exude "a fine mist of airborne compounds that they use to communicate and protect themselves." And while they've been detected in over 80 plant species, now researchers have applied real-time imaging techniques "to reveal how plants receive and respond to these aerial alarms."

Yuri Aratani and Takuya Uemura, molecular biologists at Saitama University in Japan, and colleagues rigged up a pump to transfer compounds emitted by injured and insect-riddled plants onto their undamaged neighbors, and a fluorescence microscope to watch what happened. Caterpillars (Spodoptera litura) were set upon leaves cut from tomato plants and Arabidopsis thaliana, a common weed in the mustard family, and the researchers imaged the responses of a second, intact, insect-free Arabidopsis plant to those danger cues.

These plants weren't any ordinary weeds: they had been genetically altered so their cells contained a biosensor that fluoresced green when an influx of calcium ions was detected... [T]he team visualized how plants responded to being bathed in volatile compounds, which plants release within seconds of wounding. It wasn't a natural set-up; the compounds were concentrated in a plastic bottle and pumped onto the recipient plant at a constant rate, but this allowed the researchers to analyze what compounds were in the pungent mix...

[T]he undamaged plants received the messages of their injured neighbors loud and clear, responding with bursts of calcium signaling that rippled across their outstretched leaves... [G]uard cells generated calcium signals within a minute or so, after which mesophyll cells picked up the message... "We have finally unveiled the intricate story of when, where, and how plants respond to airborne 'warning messages' from their threatened neighbors," says Masatsugu Toyota, a molecular biologist at Saitama University in Japan and senior author of the study.