A fungus that attacked other organisms 407 million years ago has been unearthed in a fossil collection, making it the oldest fungus of its kind ever discovered. The new plant pathogen was also named Potteromyces asteroxylicola in honor of Beatrix Potter, author of "The Tale of Peter Rabbit" and amateur mycologist.
While associating one's name with an ancient predatory fungus may not seem like the most laudable move, Porter's dedication to studying and documenting fungi has gained greater recognition in recent years. Porter made exquisite drawings of wild mushrooms and observed their structures under a microscope, but during the Victorian era women were largely excluded from professional science, so she remained an amateur.
It is now recognized that Porter's research on fungal growth was decades ahead of research in the field at the time. (Fortunately, her children’s books have diversified; the same can’t be said for “The Story of Peter Portobello…”
Christine Strullu-Derrien, lead author of the study and a scientific assistant at the British Museum of Natural History, said: "Naming this important species after Beatrix Potter seems like a perfect tribute to her outstanding work and commitment to piecing together the secrets of fungi."
Back to P. asteroxylicola. The fungus was discovered in fossil samples from the 407-million-year-old Rainy Limestone Sediment, an important geological site near Aberdeen, Scotland, which preserves incredible plant, bacterial and fungal life forms from the early Devonian period.
When Strullu-Derrien discovered the first P. asteroxylicola specimen in 2015, she noticed that its reproductive structures, the pycnidia, were unlike anything she had seen before. The specimen was found frozen while attacking an Asteroxylonmackiei plant. This plant is now extinct, but remains one of the earliest leafy plants in the fossil record. Upon closer inspection, it was discovered that not only did the fungus attack the plant, but the plant developed dome-shaped growth points as a result, indicating that it was still alive when the fungus attacked it.
But because of the differences between different fungi, a second specimen is needed. Fortunately, researchers found a specimen in the Rainey Stone collection at the National Museum of Scotland.
"New technologies such as confocal microscopy allow us to uncover more secrets from fossils held in museums such as the Natural History Museum," Strullu-Derrien said. "Technology and access to large fossil collections have helped speed up discoveries in the field - something we suspect Porter would be particularly excited about." But Derrien noted that the discoveries took 12 years.
Still, this appears to be just a blip in the timeline of the fungus, which began attacking plants some 407 million years ago. It's also a relevant discovery that helps scientists trace the line of evolution to this day.
"While other fungal parasites have been found in this area before, this is the first example of a fungal parasitism that is pathogenic in plants," says Strullu-Derrien. "What's more, Bot's yeast can provide a valuable basis for determining the evolution of different fungal phyla, such as the largest fungal phylum, Ascomycota."
The research was published in the journal Nature Communications.