Acephala macrosclerotiorum EW76-UTF0540 v1.0
Acephala macrosclerotiorum
Mycorrhizas of Pinus sylvestris-Acephala macrosclerotiorum (© Babette Munzenberger).
Acephala macrosclerotiorum
Sclerotium of Acephala macrosclerotiorum breaking through the ectomycorrhizal mantle (© Babette Munzenberger).

Within the framework of the Mycorrhizal Genomics Initiative (MGI) and the 1000 Fungal Genomes (1KFG) project, we are aiming to explore the interaction of forest trees with communities of soil fungi, including ectomycorrhizal symbionts that dramatically affect tree growth, and saprotrophic soil fungi impacting carbon sequestration in forests. We are sequencing the genome of the most abundant fungal species harvested on studied long-term observatories to provide sufficient taxonomic coverage of fungal genomes to identify and analyze DNA and RNA samples sequenced from environmental samples.

Acephala macrosclerotiorum
The dark septate (DS) ascomycete Acephala macrosclerotiorum formed ectomycorrhizas on Pinus sylvestris (= mycorrhizal morphotype Pinirhiza sclerotia) (Münzenberger et al., 2009). This close relative of Phialocephala fortinii s.l. evolved the ability of establishing the ectomycorrhizal symbiosis very recently, probably within 1 to10 million years. DS fungi such as P. fortinii are thought to vary from mutualistic to neutral and parasitic, but their ecological functions are little understood. It is possible that the ectomycorrhizal A. macrosclerotiorum has retained a large set of genes required for saprotrophic nutrition. This is therefore a suitable model organism to study the evolution of mycorrhizal symbiosis from recent non-mycorrhizal ancestors. Other benefits of sequencing the genome of this species include its rapid growth in culture, rapid formation of ectomycorrhiza in aseptic synthesis trials, ongoing work on nutrition and host range of this fungus and its abundance in several forest ecosystems. Interestingly, A. macrosclerotiorum produces sclerotia breaking through the ectomycorrhizal mantle at maturity and then released into the soil.

The 'Metatranscriptomics of Forest Soil Ecosystems' and the 1KFG projects are large collaborative efforts aiming for master publication(s). As always, please contact the PI associated with unpublished MGI and 1KFG genomes for permission prior to the use of any data in publications. Contact for A. macrosclerotiorum: Francis Martin (INRA).

Münzenberger et al. (2009) The ectomycorrhizal morphotype Pinirhiza sclerotia is formed by Acephala macrosclerotiorum sp. nov., a close relative of Phialocephala fortinii. Mycorrhiza 19: 481-492.