46weeks under the 21/16Cday/night regime). This simplified guide focuses on the traditional methodology used in the ErM research and includes basic advices on root sample collection and handling, microscopic observations and photo-documentation, root mycobiont isolation and maintenance of the obtained isolates, isolate identification, and resynthesis experiments. Is ericoid mycorrhiza in fact another example of controlled parasitism of a fungal partner by the host plant, similar to the type that occurs with orchids (Rice and Currah 2006)? (2016) Globally distributed root endophyte Phialocephala subalpina links pathogenic and saprophytic lifestyles. Antoine Sportes, Mathilde Hrich, Pierre Emmanuel Courty, Chew Jia Huey, Subash C. B. Gopinath, Ahmad Radi Wan Yaakub, Benjamin Feller, Martin Dank, Stephan Imhof, Alessandra Pepe, Manuela Giovannetti & Cristiana Sbrana, Candido Barreto de Novais, Cristiana Sbrana, Sergio Miana de Faria, Craig L. Carpenter, Merlin White & Marcelo D. Serpe, Mycorrhiza On the other hand, in contrast to the (direct) plating method, the maceration method does not select for fast growing fungi, provided that the individual detached rhizodermal cells are incubated separately and each cell is being colonized by a single mycobiont (which is not necessarily true for all ErM rhizodermal cells, see Selosse et al. Trypan blue is a possible carcinogen and its excess solution should be collected and disposed of in accordance with corresponding regulations. (Ericaceae) growing on decomposing wood: colonization patterns, identity, and in vitro symbiotic potential, Characteristics of root-cultivable endophytic fungi from Rhododendron ovatum Planch, Mycorrhiza: a natural resource assists plant growth under varied soil conditions, Mycorrhizal structures in mycoheterotrophic Thismia spp. Example: Ripe undamaged European blueberry (V. myrtillus) fruits are collected in nature when available, dried at room temperature for a few days and stored in a fridge at ca. Conversely, fungi that do form intracellular hyphal coils in the rhizodermis of ericoid species in vitro may not necessarily form mycorrhizae in nature (Monreal et al. Complex low-sugar media such as MLA are more suitable for long-term maintenance of the isolates, and it is advisable to keep every isolate on at least two different media, switching then during each sub-cultivation (e.g., PCA=>MLA=>PCA=>MLA, etc.). PLoS ONE 1:e59, Nilsson RH, Tedersoo L, Abarenkov K et al. For example, peat typically releases compounds phytotoxic to ericoid seedlings (Stribley et al. Ann Bot 121:221227, Kron KA, Judd WS, Stevens PF et al. 2015 and 2017, also see Selosse et al. A mycorrhiza is the symbiotic relationship between fungi and plants. Fig. Ericoid mycorrhiza plays two fundamental ecophysiological roles, i.e., detoxification of the soil environment and acquisition of essential nutrients (primarily nitrogen) (Leake and Read 1991; Read and Kerley 1999; Perotto et al. a Thick dark brown surface hyphae that, upon entering the rhizodermis, dramatically change their diameter and give rise to intracellular hyphal coils morphologically corresponding to ericoid mycorrhiza (asterisks). Both colonization patterns may be formed by the same mycobiont (cf. Indeed, the true ErMF phylogenetically overlap with plant parasites and endophytes as well as free-living saprobes and Tedersoo et al. At the same time, proper separation of ericoid roots from those of the surrounding vegetation is absolutely crucial to the success of all subsequent activities and, as such, should be approached with maximal caution and patience (cf. In nature, more than eighty percent of an-giosperms, and almost all gymnosperms are known to have myc-orrhizal associations. Ericoid mycorrhizal symbiosis: theoretical background and methods for PubMedGoogle Scholar. In addition, some lines of possible future research are indicated. New Phytol 174:864887, Selosse MA, Vohnk M, Chauvet E (2008) Out of the rivers: are some aquatic hyphomycetes plant endophytes? Vohnk et al. [15] Similarly, basidiomycetes from the order Hymenochaetales have also been implicated in ericoid mycorrhizal formation. It belongs to a guild of closely related root-symbiotic and saprobic (i.e., non-symbiotic) fungi that bears its name, i.e., the H. hepaticicola aggregate (=Hyaloscypha s. Mycorrhiza 30, 671695 (2020). At present, recognized ErM fungi include a narrow taxonomic range within the Ascomycota, and the Sebacinales, basal . Midgley et al. Using updated taxonomy is important, e.g., because the mycobionts genus/family assignment is often used for extrapolation of its lifestylewhile Pezizella (typified by P. sordida)belongs to Thelebolaceae, Hymenoscyphus (H. fructigenus), Rhizoscyphus (now monotypic withR. monotropae) and Scytalidium (S. lignicola)to Helotiaceae, andPezoloma (P. griseum) to Leotiaceae (MycoBank, https://www.mycobank.org, accessed 6 October2020), the actual placement of the prominent ErMF is in Hyaloscypha/Hyaloscyphaceae (Fehrer et al. [3] Ericoid mycorrhizal fungi establish loose hyphal networks around the outside of hair roots, from which they penetrate the walls of cortical cells to form intercellular coils that can densely pack individual plant cells. Short segments of surface-sterilized healthy-looking hair roots of Cassiope tetragona from a natural site in Longyearbyen (Svalbard) were plated on nutrient agar (MLA) and incubated for one month at 21C in the dark, yielding 16 fungal isolates (i.e., 64% success ratio; note no contaminating sporulating fungi). When sequences of all (or a large majority of) isolates are available, one can attempt to align them in order to produce FASTA files with reasonably aligned sequences that further serve as matrices for MOTU delimitation by software, e.g., TOPALi (Biomathematiscs & Statistics Scotland). 2015) at different stages of development and that not every intracellular hyphal coil/loop in the rhizodermis of an ericoid hair root necessarily represents ericoid mycorrhiza (e.g., Fig. The isolation procedure should be sensitive enough to recover endophytic [i.e., living inside the investigated root] microorganisms, but at the same time be strong enough to eliminate epiphytes from the root surface (Hallmann et al. 2017). Where possible, this ontogenetic drift should be accounted for because the practice of quoting the results from a single harvest only may obscure changing relationships and unconsciously lead to erroneous conclusions, especially with regard to the frequently quoted percentage content of minerals (Stribley et al. (1996); for a brief introduction to working with microscopes, see Chap. (1990) exhibited a dense AM colonization in coarse roots (>1.5mm in diameter) while the hair roots were colonized in the manner typical for ericoid mycorrhiza. (2017) investigated Cassiope tetragona root samples that were not serially washed or surface-sterilized and reported that the detected mycobiont communities were dominated by fungal groups in the Basidiomycota traditionally classified as either saprotrophic or EcM symbionts, while only a minor part could be annotated as ErM-forming fungi. In: Varma A, Hock B (eds) Mycorrhizastructure, function, molecular biology and biotechnology, 2nd edn. Ericoid mycorrhiza is arguably the least investigated mycorrhizal type, particularly when related to the number of potential hosts and the ecosystems they inhabit. A mycorrhiza is a symbiotic relationship between a fungus and a green plant. (1996); for structural aspects of ericoid mycorrhiza, see Chap. Academic Press, London, pp 525572, Steinke E, Williams PG, Ashford AE (1996) The structure and fungal associates of mycorrhizas in Leucopogon parviflorus (Andr.) Eur J Soil Sci 54:735740, Chilvers GA, Douglass PA, Lapeyrie FF (1986) A paper-sandwich technique for rapid synthesis of ectomycorrhiza. In other words, the presence of the AM arbuscules or the EcM Hartig net in a corresponding healthy host is commonly interpreted as a proof of the AM or EcM status of the mycobiont in question, respectively. New Phytol 154:305326, Cairney JWG, Meharg AA (2003) Ericoid mycorrhiza: a partnership that exploits harsh edaphic conditions. 1.13 in Brundrett et al. What is Ericoid Mycorrhizae? - Definition from Maximum Yield A cooker or a water bath can be used in the absence of an autoclave; alternatively, roots can be left in 10% KOH at room temperature for 12days and then in the trypan blue-lactoglycerol or ink-vinegar solution overnight. This is, however, the reality of the naturally colonized ErM hair roots and we have to cope with it. Martin Vohnk. Despite that the presence of Trametes in Rhododendron roots is interesting (and that basidiomycetous soil saprobes may actually improve growth and fruiting of ericoid plants, see Vohnk et al. Mycologia 85:219230, Fal MA, Majada MP, Snchez Tams R (2002) Physical environment in non-ventilated culture vessels affects in vitro growth and morphogenesis of several cultivars of Dianthus caryophyllus L. In Vitro Cell Dev Biol-Plant 38:589594, Fehrer J, Rblov M, Bambasov V, Vohnk M (2019) The root-symbiotic Rhizoscyphus ericae aggregate and Hyaloscypha (Leotiomycetes) are congeneric: Phylogenetic and experimental evidence. ), root mycobionts can be effectively isolated with a help of a portable flow hood and an alcohol burner/lighter, provided that basic hygiene rules are maintained. While many ericoid species like European blueberry thrive on the forest floor and actually do not need much light, others like heather (C. vulgaris) or lingonberry (Vaccinium vitis-idaea) prosper in full sun (=heliophytes) and their light requirements in resynthesis experiments may be correspondingly higher. The 3D arrangements of intracellular hyphae can be explored using laser scanning confocal microscopy (see Figs. In: Schenck NC (ed) Methods and principles of mycorrhizal research. Shoots are dried and weighed and if conditions permit, their elemental composition is analyzed. 1986). When targeting specific ericoid root mycobionts, fungal competition can be to a certain degree reduced already at the sampling stage by focusing on specific host niches. The Mycorrhizal Network - microbewiki - Kenyon College