Plants are surrounded by volatile substances with which they can not only scare away some herbivores, but also warn plants living nearby of danger. Science has known about these mechanisms since the 1980s, but Japanese researchers have now been able to directly record what happens when a plant detects danger. It was easy to see that plants sent chemical messages, but we didn't know how they sensed the incoming messages.
Yuri Aratani and Takuga Uemura of Saitama University in Japan conducted an experiment in which volatiles released by a special odor absorber were transferred to a plant that was examined with fluorescent light under a microscope. The subject of the experiment was not an ordinary plant, but genetically modified goosegrass, in which the biosensing material emits a green light when it detects the appearance of calcium ions.
Cells preferentially use calcium ions as part of the messaging mechanism, not only in plants, but also in animals and humans. Japanese researchers described in their work last year that the mimosa plant, which closes its leaves when touched, is able to make instantaneous movements using the same mechanism.
During the new experiment, caterpillars feed on tomato leaves in a tank, and the gooseberries are supplied with air in the tank by a pump.
The researchers' video shows the plant reacting to the presence of caterpillars.
By analyzing the materials filtered into the air, it was found that the emergency signal for calcium in grasses was triggered by two volatile substances, Z-3HAL and E-2-HAL.
It also turns out that the reaction begins from the cells on the surface of the leaf, which are the so-called guard cells that form stomata. Stomata are the structures that control gas exchange in plants, so to speak, nostrils. It consists of two guard cells and opens or closes as needed. The distress signal detected here began to spread through the message within about a minute.
During the experiment, it was proven that if the stomata are closed using phytohormones, the plant reacts much slower to ominous odors.
We have long known that plants are able to communicate through the connections of fungi that live on their roots. the Nature CommunicationsPublished research mainly shows that plants try to recognize each other's distress signals in order to survive.