Within the framework of the JGI CSP 'Metatranscriptomics of Forest Soil Ecosystems' project, we are aiming to explore the interaction of forest trees with communities of soil fungi, including ectomycorrhizal symbionts that dramatically affect bioenergy-relevant plant growth, and saprotrophic soil fungi impacting carbon sequestration in forests. We are sequencing the genome of the most abundant fungal species harvested on several long-term observatories to serve as the foundation for a reference database for metagenomics of fungi and for a comprehensive survey of the potential soil fungal metabolome.
Gymnopus androsaceus
Gymnopus androsaceus (a.k.a. Marasmius androsaceus) is a basidiomycete in the Omphalotaceae family. It is most frequently found in oligotrophic coniferous forests, where it specialises as a saprotrophic decomposer of fallen needles, particularly on Pinus hosts. The species is an important representative and potential model organism of the functional guild of litter decomposing basidiomycetes. By releasing large amounts of carbon from plant leaf litter, these fungi play a pivotal role in the carbon cycling of forest ecosystems. G. androcaseus is an efficient degrader of lignin, being able to almost fully decompose needle litter in pure culture. Litter substrates are bleached upon colonisation, suggesting white-rot mechanisms of decomposition. It regularly colonises litter by vegetative growth, using highly differentiated rhizomorphs (similar to those produced by Armillaria species, but much thinner), and appears later in succession than many spore colonising ascomycetes, but often earlier than other litter basidiomycetes, such as Mycena spp. A well-developed capacity to reallocated resources, such as nitrogen, throughout its dynamic mycelium, enables G. androsaceus to exploit this frequently limiting element particularly efficiently. A better knowledge of how nitrogen is immobilized in mycelial biomass is needed, in order to understand the mechanisms behind accumulation of organic nitrogen pools with slow turn-over rates. When fruiting, G. androsaceus produces clusters of tiny agaricoid sporocarps (English name: horsehair parachute), which shrivel when dry but rapidly unfolds when wetted.
The genome of Gymnopus luxurians was sequenced as a part of the large-scale multi-genome JGI CSP 'Saprotrophic Agaricomycotina Project (SAP)', which focuses on the diversity and evolution of decay mechanisms, organismal phylogenetic relationships, and developmental evolution.
As always, please contact the PI (Francis Martin, INRA) associated with unpublished genomes for permission prior to the use of any data in publications.
Genome Reference(s)
Barbi F, Kohler A, Barry K, Baskaran P, Daum C, Fauchery L, Ihrmark K, Kuo A, LaButti K, Lipzen A, Morin E, Grigoriev IV, Henrissat B, Lindahl BD, Martin F
Fungal ecological strategies reflected in gene transcription - a case study of two litter decomposers.
Environ Microbiol. 2020 Mar;22(3):1089-1103. doi: 10.1111/1462-2920.14873