In the soil beneath our feet, plants and fungi are constantly trading. Fungal threads called hyphae reach out from plant roots, gathering water and nutrients from the dirt. In exchange, plants send back sugars made from sunlight. Scientists have known about this partnership, called mycorrhizae, for decades. But they had never been able to watch it happen in real time — until now.
Researchers at the Technical University of Munich in Germany have created a new way to see underground fungal networks in three dimensions without disturbing them. The method, published in the journal New Phytologist, lets scientists study the entire web of roots, fungal threads, and spores in their natural state for the very first time.
Before this breakthrough, researchers had to wash soil away from plant roots to study them. That cleaning process broke the delicate fungal threads and destroyed the connections between plants and fungi. "With our newly developed method, we have opened a 'black box' of plant research," said Mutez Ahmed, a professor who studies how roots interact with soil.
The new technique uses a powerful tool called synchrotron computed tomography. Scientists grow plants inside special baskets. When it's time to study them, the entire basket is lifted out with the plant and surrounding soil still intact. A machine then takes thousands of high-resolution pictures from different angles. Those pictures are combined into a 3D model showing everything in its exact original position.
Henri Braunmiller, who led the research, said the method could help fight one of the biggest challenges facing farming today. "The better we understand mycorrhizae and their connections to plant roots, the better we can make use of this symbiosis," he explained. "We can now see exactly which fungal networks work best at supplying plants with water and nutrients. In the long term, this could help us develop ways to make crops more resilient to drought and other consequences of climate change."
The researchers believe their findings can be applied to real farms, not just laboratories. If scientists can learn which underground networks work best, they might find ways to help crops survive longer without rain — a growing concern as temperatures rise around the world.