Mycorrhiza Symbiosis: It's not just for Ascomycetes anymore.

A mycorrhiza is the symbiotic bond between fungi and the roots of vascular plants. This important mutualistic relationship is found in over 90% of plant families. Without it they would be unable to absorb vital nutrients from the soil and their fungal partners would be left without  constant access to those tasty carbs that make life worth living.

Sheathed ericoid mycorriza on Vaccinum myrtillus

So basically: the plant absorbs light, photosynthesizes it, passes some sugars on to the fungus coating its root system; and in turn the fungus absorbs nutrients and minerals from the soil that the plant is unable to uptake on its own and exchanges them. Barter system!!

Anyway, as mentioned, while the vast majority of plants depend on this relationship only a very small portion of fungi are known to join in this inter-kingdom partnership, most notably those in the ascomycetes order Helotiales. But the world is going all wibbly because some basidiomycetes have taken a liking to blueberries.

A new study conducted by scientists from the Czech Republic and Norway have isolated a basidiomycete that forms a mycorrhizal sheath with the European blueberry(Vaccinium myrtillus) root system.

Novel Root-Fungus Symbiosis in Ericaceae: Sheathed Ericoid Mycorrhiza Formed by a Hitherto Undescribed Basidiomycete with Affinities to Trechisporales

In previous studies there have been tentative relationships between basidiomycetes and plants but until now the levels in studies have not been significant enough to differentiate between  true mycorrhizal cooperation, and saprotrophic or necrotrophic contamination.

Our intrepid heroes however managed to isolate this potentially new species (They are currently referring to it as "Sheathed ericoid mycorrhiza" from natural samples and synthesize it in vitro. In the lab they got it to form sheath clamps onto the root system, verifying that the fungus was indeed able to form symbiosis with the V. myrtillus. This demonstrates the first true evidence that a non-sedacinoid basidiomycete is capable of forming a mycorrhizal relationship with plants.

Unfortunately the team was unable to verify it into a new species as of yet. They were however able to isolate it into either the Trechisporales or Hymenochaetales orders. Both found in soils samples but until now unproven to be mycorrhizal fungi.

This type of study shows that even well studied areas, such as the mycorrhizal relationships between plants and fungi are continually turning up new and novel ways that adaptations can occur.



Photo and Study credit: Martin Vohník, Jesse J. Sadowsky, Petr Kohout, Zuzana Lhotáková, Rolf Nestby, and Miroslav Kolařík.