Professor Peter Nick at Germany's Karlsruhe Institute of Technology has uncovered a survival trick that plants have been hiding for over a century. When crops get too hot, too dry, or planted in salty soil, their cells send out tiny finger-like projections that work like an emergency alarm system, activating protection programs to limit damage.
Inside every plant cell are chloroplasts, which Nick describes as tiny solar power stations. These green structures absorb sunlight and pull carbon dioxide from the air to make sugar, the fuel plants need to grow. Without chloroplasts, plants could not survive, and without plants, other living things would lose a major food source while the atmosphere would have far less oxygen.
When heat or drought strikes, this delicate energy system gets disrupted and harmful substances start building up. The cell must act fast to survive. That's where the finger-like projections, called stromules, come in. The researchers discovered that stromules serve as an internal alarm system, sending signals to the cell's control center that switch certain genes on or off and trigger protective responses.
This discovery ends a long mystery in plant science. Gottlieb Haberlandt, a plant physiologist in Berlin, first described these structures more than 130 years ago, but they were largely forgotten until U.S. researchers rediscovered them in the 1990s. Scientists originally thought stromules connected different chloroplasts to share materials. The new study shows their real purpose is communication, not transport.
The findings could matter enormously as climate change makes extreme weather more common. Nick's team has already identified molecular factors that can speed up how quickly stromules form and make them work more efficiently. In the future, this could help scientists find wild plants that handle heat and drought especially well and transfer those traits to crops.
"Maybe these properties can be transferred to crops in the future to better protect them against heat, drought, or saline soils," Nick said. The research was published in the journal Plant Physiology.