The precise mechanism by which plants pick up on these warning signs from their neighbors remains a mystery. Currently, a group of scientists from Japan is attempting to resolve this mystery.
Similar to people, plants communicate with one another as soon as they sense an impending threat or attack in their area. Since the 1980s, scientists have been aware of this occurrence, having discovered that at least 80 species will defend their own species in times of need. But how precisely plants pick up on these warning signs from their neighbors remained a mystery.
Now, a group of Japanese scientists has not only figured out this riddle but also captured plant communication on camera in an incredible movie. Yuri Aratani and Takuya Uemura, molecular biologists at Saitama University in Japan, showed how these plants react to threat in a study that was published in Nature Communications.
Set up created using engineered plants
In order to carry out the experiment, researchers ignited caterpillars on tomato plant leaves and an often used weed known as Arabidopsis thaliana. The compounds were pumped onto the recipient plant at a steady pace after being concentrated in a plastic container to better analyze their effects on the nearby plant.
Furthermore, the recipient Arabidopsis plant was genetically altered to have biosensors in its cells that fluoresced green in response to the presence of calcium ions.
How did unharmed plants react?
Clearly responding to messages from their injured neighbors, the unharmed plants in the video displayed calcium signaling across their extended leaves. By examining molecules in the air, the researchers were able to determine that substances Z-3-HAL and E-2-HAL caused calcium signals in Arabidopsis.
They discovered that the guard cells (producing stomata), mesophyll cells (inner leaf tissue), and epidermal cells (outermost layer) were the first to react to danger cues in Arabidopsis plants that had been genetically modified to contain fluorescence sensors in particular cells.
Check out the video below:
Guard cells and mesophyll cells were the first to produce calcium signals in response to Z-3-HAL. Furthermore, stomata serve as the plant’s “nostrils” since pre-treating plants with a phytohormone that closes stomata dramatically decreased calcium signaling.
“We have at last revealed the complex tale of when, where, and how plants react to aerial ‘warning signals’ from their endangered neighbors,” states Masatsugu Toyota, senior author of the research and molecular biologist at Saitama University in Japan.
“This ethereal communication network, hidden from our view, plays a pivotal role in safeguarding neighbouring plants from imminent threats in a timely manner.”
