Symbiotic Fungi Genome Database
Two symbiotic fungal genomes are being sequenced under the US Department of Energy's Community Sequencing Program. These are the arbuscular mycorrhizal fungus Glomus intraradices and the ectomycorrhizal fungus Laccaria bicolor.
This site is hosted at New Mexico State University and was designed to provide easy access to sequence data from symbiotic fungi, in particular, G. intrararadices. The site currently includes a BLAST service for searching symbiotic fungal genome survey sequences and ESTs, plus a brief description of the AM and ECM fungal genome sequence projects. As data becomes available we will add links to Joint Genome Institute pages as well as provide access to early sequence data via our BLAST server.
Martin, F, Tuskan, G, DiFazio, S, Lammers, P, Newcombe, G, and Podila, G (2004) Symbiotic Sequencing for the Populus mesocosm. New Phytologist 161: 330-335Arbuscular Mycorrhizal (AM) Fungi
Some 150 described species of AM fungi colonize over 200,000 plant species including most major crop species. The AM fungi are unusual obligate symbionts with no known sexual cycle, although anastomosis between hyphae has been described. The AM symbiosis improves plant phosphorus and nitrogen nutrition resulting in a 5 to 20% increase in photosynthesis in normal soils. Evidence also suggest the symbiosis provides protection against pathogens and improves plant water relations. Glomus intraradices is a widespread AM fungus found in different ecosystems throughout the world, including temperate and tropical locations. It readily colonizes important species like maize, wheat, alfalfa, rice and key model plants such as Medicago truncatula, Lotus japonicum, and the poplar tree Populus tricocarpa. G. intraradices can be grown in vitro in dual culture with transformed carrot roots for the production of pure fungal tissue. Finally, spores are available in pure form in large quantities (Premier Tech, Quebec Canada), which is a resource for researchers worldwide. G. intraradices has a small genome of ~ 16 Mbp. Over 3,500 EST sequences and 580,000 bp of genome survey sequence data is currently available in the public databases.
Ectomycorrhizal (ECM) Fungi
The ECM fungi switch between saprobic and symbiotic lifestyles with perennial tree species. Laccaria bicolor is a member of the Tricholomataceae, a large order of ectomycorrhizal and saprobic basidiomycetes better known for producing mushroom fruiting bodies. L. bicolor grows as a heterokaryon composed of two different nuclei, each of a different mating type, but axenic haploid strains isolated from spores are available. This species is used in large-scale commercial inoculation programs in forest nurseries worldwide to enhance growth of tree seedlings. The genome size is thought to be 2-3 times the size of G. intraradices. EST sequencing projects have resulted in several thousand sequences in the public databases.