A new study reveals that trees can communicate and warn each other of danger. "For the first time, researchers have been able to visualize plant-to-plant communication, "said Masatsugu, senior author of the study.
The idea of talking trees started to take root in the 1980s. Two scientists found that damaged trees began producing chemicals that made their leaves unappetizing and indigestible to discourage insects. The trees then sent chemical signals to one another through the air. Over the past four decades, scientists have observed this cell-to-cell communication in more than 30 plant species.
Past research shows plants communicate with their surroundings by releasing chemicals known as volatile (易挥发的)organic compounds. One class of these compounds are released when a plant is injured: green leafy volatiles. These are released by, as the name suggests, pretty much every green plant with leaves, and are produced when a plant experiences physical damage. An example of these compounds is the smell released from fresh-cut grass.
In the new study, Masatsugu and his colleagues manually damaged leaves and placed insects on tomato plants to trigger the release of various green leafy volatiles. After testing many of them, the team found it seemed to increase calcium ions(钙离子)inside cells. The calcium signaling is like a switch to turn on the defense responses from the plants.
With this new understanding, researchers say plants could be immunized against threats and stressors before they even happen. For instance, exposing healthy plants to insect-ridden plants or the associated green leafy volatiles could boost their genetic defenses, so farmers use less pesticides. The revelation could also help make plants more resilient(有复原力的)during a drought, signaling the plants to conserve more water.
