It turns out mushrooms aren’t just great to eat – they played an essential role in creating an atmosphere suitable for animal life, according to a new study. The earliest plants to dwell on land did not have well developed roots or vascular systems. Fungi, among the earliest colonizers of land, helped facilitate the transfer of phosphorus from rocky soil to primitive plants, which required the mineral to photosynthesize. “The results of including data on fungal interactions present a significant advance in our understanding of Earth’s early development,” said Benjamin Mills, co-author of a report on the research published in the journal Philosophical Transactions of the Royal Society B. “Our work clearly shows the importance of fungi in the creation of an oxygenated atmosphere.”
The recent research shines a light on a process that remains mysterious, even in modern times. “Photosynthesis by land plants is ultimately responsible for about half of the oxygen generation on Earth, and requires phosphorus, but we currently have a poor understanding of how the global supply of this nutrient to plants works,” said Mills. Without fungi helping them acquire their necessary phosphorus, the earliest land plants would not have been able to survive. The oldest fossil of a land-living organism is of a fungi species, one of many which moved on land and helped to break down the rocky mantle into soil, enabling plants with roots to more easily extract their minerals.
To test fungi’s symbiotic relationship with early plants, a research team at the University of Leeds incorporated computer modeling and laboratory experiments which involved ancient species of fungus that still endure today. The researchers observed the differing rates at which different species of fungi exchanged phosphorus and carbon, which indicated how quickly plants might have produced oxygen. “We used a computer model to simulate what might have happened to the climate throughout the Palaeozoic era if the different types of early plant-fungal symbioses were included in the global phosphorus and carbon cycles,” said Katie Field, study co-author and plant biologist. “We found the effect was potentially dramatic, with the differences in plant-fungal carbon-for-nutrient exchange greatly altering Earth’s climate through plant-powered drawdown of CO2 for photosynthesis, substantially changing the timing of the rise of oxygen in the atmosphere.”
Via Science Alert