Having in hand a member of the elusive fungal group, the Swedish scientists and their collaborators have been able to study the group in more detail than ever before possible, using electron microscopy, DNA sequencing and in vitro growth studies to characterize it. The fungus they cultured is a slow-growing form that produces none of the typical aerial or aquatically dispersed spores most fungi typically reproduce with, suggesting it seldom if ever sees the light of day.
"By finding that it is slow growing and only produces spores in the soil, we can provide an explanation for why it has taken so long to be cultured," James said. The researchers also performed experiments aimed at understanding how the fungus, dubbed Archaeorhizomyces finlayi, interacts with the environment and with other organisms.
"We don't have any evidence that it's pathogenic; we don't have any evidence that it's mutualistic and doing anything beneficial for the plant," James said. "It's a little bit of a boring fungus." It may, however, help break down and recycle dead plants, a common---and extremely important---job for fungi. Hints of this role come from the observation that A. finlayi grows in the lab if provided with food in the form of glucose or cellulose (the main structural component of plant cell walls).
"Because it is so common in the soil, it must be very successful at what it does, and that role must be ecologically relevant," Rosling said.
Now that the researchers have ruled out some typical fungal roles---such as pathogen, benign endophyte, and member of a mycorrhizal association---they hope to find out through additional experiments ex
|Contact: Nancy Ross-Flanigan|
University of Michigan