In the “1KFG: Deep Sequencing of Ecologically-relevant Dikarya” project (CSP1974), we aim to sequence additional sampling of genomic diversity within keystone lineages of plant-interacting fungi and saprophytic fungi that are of special ecological importance for understanding terrestrial ecosystems. In addition, comparative genome analysis with saprotrophic, mycorrhizal and pathogenic fungi will provide new insights into the specific and conserved adaptations associated with each fungal lifestyle.
Leucangium carthusianum
We present the genome of Leucangium carthusianum (Tul. & C. Tul.) Paol., which is one of four genera of truffles in the Morchellaceae. Leucangium carthusianum was originally described from France where it is quite uncommon, but it also fruits in the Pacific Northwest USA in Douglas-fir forests (Trappe et al. 2010). Leucangium carthusianum is presumed to be ectomycorrhizal, since it is always found in association with Douglas-fir trees and because it cannot be isolated in pure culture. However, ectomycorrhizas of this species have still never been produced, nor found in the wild. In the Pacific Northwest, L. carthusianum is commercially harvested from native Douglas-fir forests. Fruiting bodies are produced underground and have a dark peridium, composed of isodiametric cells raised in warts overall or in patches. The gleba is solid, firm, whitish to yellowish gray, with grayish mottling of fertile pockets surrounded by whitish sterile, undifferentiated veins (see Figure). Ascopores are ellipsoid in form and are exceptionally large in size (60–90 mm). Benucci and Bonito (2016) report that L. carthusianum fruiting bodies harbor bacteria belonging to Pseudomonas and Janthinobacterium. Fresh collections of Leucangium carthusianum have a complex and distinctive aroma, reminiscent of pineapple.
As this species has never been successfully cultured, we generated a metagenome of L. carthusianum from fresh gleba tissue from a fruiting body that was collected in Oregon. The metagenome of L. carthusianum GMNB180 will be used to understand the evolution of truffle fruiting body formation in the Morchellaceae, to address the ectomycorrhizal and saprotrophic genomic capacity of L. carthusianum, and to better understand the potential function(s) of bacteria living within truffle fruiting bodies. Researchers who wish to publish analyses using data from unpublished CSP genomes are respectfully required to contact the PI and JGI to avoid potential conflicts on data use and coordinate other publications with the CSP master paper(s).
References
Trappe M, Trappe J, Bonito G (2010) Kalapuya brunnea gen. & sp. nov. and its relationship to the other sequestrate genera in Morchellaceae. Mycologia 101: (5) 1058-1065.
Benucci GMN, Bonito G. 2016. The truffle microbiome: Species and geography effects on bacteria associated with fruiting bodies of hypogeous Pezizales. FEMS Microbiology Letters. 72:4-8. doi: 10.1007/s00248-016-0755-3.