Within the framework of the JGI Mycorrhizal Genomics Initiative, we are sequencing a phylogenetically and ecologically diverse suite of mycorrhizal fungi (Basidiomycota and Ascomycota), which include the major clades of symbiotic species associating with trees and woody shrubs. Analyses of these genomes is providing new insights into the diversity of mechanisms for the mycorrhizal symbiosis, including ericoid-, orchid- and ectomycorrhizal associations.
Rhizoscyphus ericae UMAH 7357
Rhizoscyphus ericae (D.J. Read) Zhuang & Korf is the archetypal ericoid mycorrhizal fungal species. It belongs to the phylum Ascomycota, class Leotiomycetes and order Helotiales. The sequenced strain UAMH7375 (=Read 101) was isolated in 1973 by V. Pearson and D.J. Read from hair roots of Calluna vulgaris (Scottish Heather) in Yorkshire, England. It is this very same strain that led to the formal first description of the species after production of ascomata in culture (Read 1974). This species is part of an aggregate of species referred to as the "Rhizoscyphus ericae aggregate" (Vrålstad et al. 2000), including both ectomycorrhizal and ericoid mycorrhizal species, including Cadophora finlandica and the two Meliniomyces species sequenced by JGI.
Rhizoscyphus ericae UAMH7357 was used as model in all initial in-vitro experimental research investigating the physiological and ecological behavior of ericoid mycorrhizal fungi. Hence the behavior of UAMH7375 laid the foundation to our current-day knowledge of the functioning of ericoid mycorrhiza. The fungus has been shown to significantly enhance the survival and growth of host plants, particularly in acid soils with poor mineral nutrient availability. The saprotrophic capabilities of R. ericae are highly developed with a wide range of extracellular catabolic enzymes involved. In the symbiotic state in vitro, these enzymatic capabilities have been shown to enhance nutrient acquisition by the fungus and transfer to host plant from a wide of range of structural and nutrient containing polymers, including protein, cellulose and lignin.
Rhizoscyphus ericae is readily isolated from most Northern Hemisphere Ericaceae plant species known to form ericoid mycorrhiza, including Vaccinium, VCalluna, VErica, and VRhododendron species accorss the whole of Europe and North America.
A large collaborative effort led by PI of this project, Francis Martin (INRA), aims for master publication(s) of the MGI data analysis. Researchers who wish to publish analyses using data from unpublished MGI genomes are respectfully required to contact the PI and JGI to avoid potential conflicts on data use and coordinate other publications with the MGI master paper(s).
- Read D. J. (1974). Pezizella ericae sp. Nov., the perfect state of a typical mycorrhizal endophyte of Ericaceae. Transactions of the British Mycological Society 63: 381.
- Vrålstad T, Fossheim T, Schumacher T (2000). Piceirhiza bicolorata the ectomycorrhizal expression of the Hymenoscyphus ericae aggregate? New Phytologist 145: 549-563.i