Ectomycorrhizae

An ectomycorrhiza (from Greek ἐκτός ektos, "outside", μύκης mykes, "fungus", and ῥίζα rhiza, "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont and the roots of various plant species. The mycobiont tends to be predominantly from the phyla Basidiomycota and Ascomycota, although a few are represented in the phylum Zygomycota. Ectomycorrhizas form between fungi and the roots of around 2% of plant species. These tend to be composed of woody plants, including species from the birch, dipterocarp, myrtle, beech, willow, pine and rose families.

Unlike other mycorrhizal relationships, such as arbuscular mycorrhiza and ericoid mycorrhiza, ectomycorrhizal fungi do not penetrate their host’s cell walls. Instead, they form an entirely intercellular interface, consisting of highly branched hyphae forming a latticework between epidermal and cortical root cells, known as the Hartig net.

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