Amer J Bot 77:11931200, Giovannetti M, Mosse B (1980) An evaluation of techniques for measuring vesicular-arbuscular infection in roots. BMC Genomics 17:1015, Schoch CL, Seifert KA, Huhndorf S et al. from northwest Patagonia, Argentina. Evolutionary history of mycorrhizal symbioses and global host plant 2008). Smith and Read (2008a) argued that exposure of delicate hair root segments to sterilants, most commonly solutions of hypochlorite or hydrogen peroxide, will lead to a selective reduction [in the number of obtained ErMF isolates] as it has long been known that chemical sterilants, even when applied at low concentrations and for short durations, can kill internal as well as external fungal occupants of hair roots. Ericoid Mycorrhizal Fungi & Cranberry: Mutualisms with Potential [16], The ericoid mycorrhizal symbiosis is widespread. 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). Centraalbureau voor Schimmelcultures, Baarn, Garnica S, Schn MA, Abarenkov K et al. nov. (Aigialaceae, Pleosporales) as the dominant root mycobiont of the dominant Mediterranean seagrass Posidonia oceanica. (2013) Towards a unified paradigm for sequence-based identification of fungi. 3d in Vohnk et al. 2004. ErMF that inoculate cranberry vines are . The ericoid mycorrhiza is a mutualistic relationship formed between members of the plant family Ericaceae and several lineages of mycorrhizal fungi. Acta Hortic 346:230239, Grelet GA, Johnson D, Paterson E, Anderson IC, Alexander IJ (2009) Reciprocal carbon and nitrogen transfer between an ericaceous dwarf shrub and fungi isolated from Piceirhiza bicolorata ectomycorrhizas. Indeed, the true ErMF phylogenetically overlap with plant parasites and endophytes as well as free-living saprobes and Tedersoo et al. Folia Geobot 38:191200, Vohnk M, Albrechtov J, Vostka M (2005) The inoculation with Oidiodendron maius and Phialocephala fortinii alters phosphorus and nitrogen uptake, foliar C: N ratio and root biomass distribution in Rhododendron cv. While the first isolates of H. hepaticicola had been obtained from ericoid hair roots using the maceration method (i.e., incubation of a suspension of detached hair root cells), practically all following studies employed some modifications of the direct plating method (i.e., incubation of hair root segments; for details see Pearson and Read 1973b). Control vessels are inoculated with plugs without mycelium that also serve for double-checking sterility of the substrate. However, Obase et al. From the practical point of view, factors like easy assembly/setup, inoculation and access to the plants at harvest, the space occupied in the growth chamber and reusability/price typically influence the final decision. Vohnk, M. Ericoid mycorrhizal symbiosis: theoretical background and methods for its comprehensive investigation. So, it is necessary to establish the specificity of fungal . In general, lower limits serve for class/order/family assignment and higher for assignment at the genus/species level (for predicted threshold values for ITS and LSU of filamentous fungi see Vu et al. 2019) with new colonies still emerging from surface-sterilized root segments after a 1.5-year-long incubation (personal observation). Ann Bot 77:405411, McLean CB, Anthony J, Collins RA, Steinke E, Lawrie AC (1998) First synthesis of ericoid mycorrhizas in the Epacridaceae under axenic conditions. Can J Bot 82:12431263, Rep I (2011) Ectomycorrhizal inoculum and inoculation techniques. (2004) Ericaceae. PAC currently contains 21 characterized, morphologically indistinguishable but genetically isolated Phialocephala s. l. cryptic species and seven of them have scientific names (Stroheker et al. Indeed, the ErMF gene repertoire reveals a capacity for a dual saprotrophic and biotrophic lifestyle that may reflect an incomplete transition from saprotrophy to the mycorrhizal habit, or a versatile life strategy similar to fungal endophytes (Martino et al. New Phytol 164:183192, Vohnk M, Lukani S, Bahor E et al. The order Ericales is a worldwide group of closely related families, perhaps . Research on the diversity and identity of mycobionts associated with ericoid roots especially outside the already explored areas (see Fig. Detecting the colonization of ericoid mycorrhizal fungi in 2005; Nilsson et al. expressing GFP were obtained . (1995) and especially the AM colonization observed by Dighton and Coleman (1992) in Rhododendron maximum beaded roots (see Fig. Bars=20m. Trypan blue is a possible carcinogen and its excess solution should be collected and disposed of in accordance with corresponding regulations. Ericoid mycorrhizal fungal endophytes are a genetically diverse group, and they appear to be able to alleviate certain environmental stresses and so facilitate the establishment and survival of Ericaceae. Molina et al. [3] The geographic distribution of many of the fungi is uncertain, primarily because the identification of the fungal partners has not always been easy, especially prior to the application of DNA-based identification methods. At the same time, sampling from untreated and surface-sterilized inoculated roots, as well as the surrounding soil medium, would also provide an assessment of the vigor and survival of the fungal partner used (Hambleton and Sigler 2005). Resynthesis experiments are necessary to fulfill Kochs postulates. 2weeks of incubation at room temperature in the dark. Nucleic Acids Res 41:D36D42, Boesenberg-Smith KA, Pessarakli MM, Wolk DM (2012) Assessment of DNA yield and purity: an overlooked detail of PCR troubleshooting. 2015) and genomes of the so far sequenced DSE fungi combine saprobic and pathogenic rather than mutualistic traits (Schlegel et al. 2016a). 3c in that paper). a New mycelium of the typical ErMF Hyaloscypha hepaticicola emerging from agar plugs after ca. 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. 2012; Edgar 2018). Ericoid mycorrhiza found to be associated with the members of family Ericaceae, which enables the plants to establish in inhospitable environments such as heathlands, bogs and evergreen forests. 2011, but see Vohnk et al. Both may lead to improved growth and/or nutrient uptake by the host plant. [4][5] This may allow some ericoid mycorrhizal fungi to act as saprotrophs. 22.2 in Grelet et al. Walker, J. F., L. Aldrich-Wolfe, A. Riffel, H. Barbare, N. B. Simpson, J. Trowbridge, and A. Jumpponen. 1520cm (Fig. are dissected from the margins of the actively growing colonies, placed on the surface of the sterile amended cultivation substrate in Magenta GA-7 vessels (see above), incubated in the dark at room temperature and the growth of new mycelium is periodically checked (Fig. and reference (updated when the respective manuscript gets published) should be provided. Healthy-looking hair roots are the very thinnest turgescent whitish/yellowish roots with characteristic anatomy (i.e., inflated rhizodermal cells, reduced cortex) andmorphology (i.e.,lacking root hairs, an important criterion distinguishing them from the majority of non-ericoid roots). Serial washing requires tap water running for several hours and considerable amounts of sterile water and laboratory equipment. 2009; Vohnk et al. Ann Bot 121:221227, Kron KA, Judd WS, Stevens PF et al. Physiol Plant 125:393404, Villarreal-Ruiz L, Anderson IC, Alexander IJ (2004) Interaction between an isolate from the Hymenoscyphus ericae aggregate and roots of Pinus and Vaccinium. in the following text; five subfamilies, see Kron et al. Small plugs (ca. (2013) The cultivable endophytic community of Norway spruce ectomycorrhizas from microhabitats lacking ericaceous hosts is dominated by ericoid mycorrhizal Meliniomyces variabilis. [3] Fungi ascribed to Rhizoscyphus ericae have been identified from Northern and Southern Hemisphere habitats, but these are not likely all the same species. and the rate of desiccation (e.g., see Tables 13 in Fal et al. J Mol Biol 215:403410, Baral H-O, Krieglsteiner L (2006) Hymenoscyphus subcarneus, a little known bryicolous discomycete found in the Bialowieza National Park. Mycorrhiza 23:199208, Obase K, Matsuda Y (2014) Culturable fungal endophytes in roots of Enkianthus campanulatus (Ericaceae). The decision as to whether the mycobiont in question is an ErMF or not should be based on a series of experiments under contrasting conditions, not a single resynthesis attempt (cf. Mycol Res 104:642644, Allen TR, Millar T, Berch SM, Berbee ML (2003) Culturing and direct DNA extraction find different fungi from the same ericoid mycorrhizal roots. Bars=20m. On the other hand, when some mycobiont is regularly isolated from ErM roots, repeatedly forms fine compact intracellular hyphal coils in the living rhizodermal cells of ericoid hosts and repeatedly enhances their growth and/or nutrient uptake, why not calling it, e.g., an ericoid root-associated beneficial mycobiont, until a reasonable proof of mutualism (that in fact does not need to be connected with the mycobiont carbon dependency on the phytobiont) is available? The plant mahatonga organic molecules such as sugars through photosynthesis and provides them to the fungus, while the fungus provides the plant with water and soil-derived mineral minerals such as phosphate. Experimental evidence of mutualism between liverwortsand ascomycete fungi. On the other hand, this can be a very complex task as, e.g., thick melanized superficial hyphae may change their diameter and color when colonizing intracellular spaces of the rhizodermal cells(cf. In a simplified way (and as generally accepted), this means that to be assigned as mycorrhizal, the fungus in question must originate from a corresponding host (cf. 1 in Vohnk and Albrechtov 2011 and Fig. 1975). Ericoid mycorrhiza - Wikiwand After surface sterilization, the applied sterilant(s) must be removed from the roots by consecutive washes in sterile water. 57 leaves. ISME J 1:97102, Duckett JG, Read DJ (1995) Ericoid mycorrhizas and rhizoid-ascomycete associations in liverworts share the same mycobiont: isolation of the partners and resynthesis of the associations in vitro. (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. 2016a); and modified Leonians agar (MLA, Malloch 1981) that seems to be the best medium for long term storage and subculturing of all fungal isolates I have so far tested, including the serendipitoid fungi. 4.2 in Brundrett et al. 2016a). Using damaged or moribund hair roots, thicker suberized roots that typically lack rhizodermis (see Fig. Unique and common traits in mycorrhizal symbioses - Nature Read, D. J., J. R. Leake, and J. Perez-Moreno. c A very common combination of the ErM colonization pattern (compact fine hyphal coils, asterisks) and the DSE microsclerotia in various stages of development (arrowheads). This applies not only to fruit-bodies, but indeed to any other form of fungal structure, such as sclerotia or ectomycorrhizas (Agerer et al. Nucleic Acids Res 22:46734680, Urcelay C (2002) Co-occurrence of three fungal root symbionts in Gaultheria poeppiggi DC in Central Argentina. roots and these morphologically correspond to the ErM hyphal coils (see Fig. The basidiomycetous ErMF comprise mycobionts from Serendipitaceae (Sebacinales, Vohnk et al. 1a), ericoid plants also thrive in soils with low organic content and their roots may penetrate deep into the mineral horizon (Fig. (2011) Ericaceous dwarf shrubs affect ectomycorrhizal fungal community of the invasive Pinus strobus and native Pinus sylvestris in a pot experiment. Fast-growing and sporulating mycelia are typically discarded as contaminants; they may produce submerged hyaline hyphae and grow unnoticed until contaminating most of the dish while others may immediately sporulate that typically leads to a loss of the whole dish. PLoS ONE 1:e59, Nilsson RH, Tedersoo L, Abarenkov K et al. Such a tremendous difference in growth may be mainly due to (1) substrate detoxification, (2) mineralization of the organically-bound nutrients in the rhizosphere, (3) phytohormone release, or (4) mycorrhizal transport of nutrients to the host plant by the ErMF, or a combination of these effects (see item 3 under Things to considerin the section "Resynthesis experiments"). Mycorrhiza 15:6164, Vierheilig H, Coughlan AP, Wyss U, Pich Y (1998) Ink and vinegar, a simple staining technique for arbuscular-mycorrhizal fungi. For explanation of basic mycorrhizal terminology, see Brundrett et al. 1995; Fujimura and Egger 2012) symbioses in the roots of ericoid plants, but ecophysiological significance of these observations remains unknown (also see the sectionRoot sample collection and handling and item 3 under Things to considerin the section "Microscopic observations and photo-documentation") and further research on this topic is needed and encouraged. item 3 under Things to considerin thesection "Root mycobiont isolation and maintenance of the obtained isolates"); available non-misleading alternatives include ericoid root associated fungus or simply ericoid root mycobiont. Can J Bot 77:15801594, Newell SY, Fell JW (1982) Surface sterilization and the active mycoflora of leaves of a seagrass. str., as ericoid plants, species etc. Ann Bot 38:401402, Brown W (1924b) Two mycological methods. a | The major morphological distinctions between ectomycorrhizas (ECM), mostly involving trees and shrubs, and endomycorrhizas, which include ericoid mycorrhizas (restricted to the Ericaceae),. From the physiological point of view, one must consider especially the material permeability for photosynthetically active radiation (PAR), sufficient space for the development of both the phytobiont and the mycobiont, unrestricted gas exchange (to prevent accumulation of CO2, volatile agents like ethylene, etc.) Therefore, deposition of ericoid root samples in a way that they are accessible for other scientists and suitable, e.g., for microscopy and DNA isolation, is encouraged (e.g., deposition in a public herbarium of washed ericoid roots in 3050% ethanol for microscopy and surface-sterilized+dried hair roots for DNA isolation), despite that it is not customary to do so. Ericoid Mycorrhizas BIOLOGY TEACH Plant Root 7:3348, Grunewaldt-Stcker G, von Alten H (2016) Is the root-colonizing endophyte Acremonium strictum an ericoid mycorrhizal fungus? . 2019). b H. hepaticicola mycelium covering most of the surface is ready to be mixed into the substrate (see the sectionResynthesis experiments). Acremonium strictum), a widespread soil-inhabiting and root-endophytic fungus, is sometimes isolated from ericoid roots and may form atypical [ericoid] mycorrhizae, i.e., loose intracellular hyphal complexes, in the rhizodermis of ericoid plants (Xiao and Berch 1996). Since it cannot completely eliminate, e.g., living extraradical hyphae/fungal spores firmly attached to the root surface (but without penetration inside the root), the combination of serial washing and isolation of mycobionts from hair root segments may lead to a selective increase in the number of obtained isolates, hence to an overestimation of the diversity of true ericoid root mycobionts. 2012a), followed by a multi-gene molecular identification of the mycobiont (Kolak and Vohnk 2018). Private and even university collections typically cannot ensure that the deposited cultures will be readily available for interested researchers also after twenty, thirty or more years. 2008) that often dominate cultivable spectra of ericoid root mycobionts. Mycorrhiza 12:8992, Usuki F, Narisawa K (2005) Formation of structures resembling ericoid mycorrhizas by the root endophytic fungus Heteroconium chaetospira within roots of Rhododendron obsutum var. This symbiosis represents an important adaptation to acidic and nutrient poor soils that species in the Ericaceae typically inhabit,[1] including boreal forests, bogs, and heathlands. 2002, also see Huang and Chen 2005). 2016). It is generally accepted that they are formed only when the respective associations are indeed functional, i.e., the bi-directional nutritional transfer does take place between the phytobiont and the mycobiont (cf. It is advisable to limit the amount of the nutrient agar involved, e.g., by harvesting aerial mycelium, cultivating the colony on the surface of a cellophane membrane or in liquid culture, etc. Springer Verlag, Berlin Heidelberg, pp 499520, Read DJ, Leake JR, Perez-Moreno J (2004) Mycorrhizal fungi as drivers of ecosystem processes in heathland and boreal forest biomes. 30years, one tends to conclude that most ErM studies did not go beyond this first stage. University of Toronto Press, Toronto, Martino E, Morin E, Grelet G-A et al. The definite tool for identification of the obtained ericoidisolates at the species level is a phylogenetic analysis that includes appropriate reference sequences. 2016a, cf. Representative sequence(s) of each delimited MOTU should be submitted to the INSD that includeintuitive instructions on how to do it. Ericoid mycorrhiza is a structurally well-defined endomycorrhizal type easily distinguishable from other types of mycorrhizae based on the fine compact intracellular hyphal coils formed in the rhizodermal cells of healthy ericoid hair roots (Read 1996, also see Figs. https://doi.org/10.1007/s00572-020-00989-1, DOI: https://doi.org/10.1007/s00572-020-00989-1. Newell and Fell 1982 and Vohnk et al. 2002) based on similarity of their genes, including the analysis of restriction fragment length polymorphism (RFLP) performed after PCR but prior to sequencing (laborious and less precise but saved resources when costs of sequencing were considerably higher). Note cells filled with hyphae changing their color (asterisks). Arbuscular mycorrhiza (AM), a symbiosis between plants and members of an ancient phylum of fungi, the Glomeromycota, improves the supply of water and nutrients, such as phosphate and nitrogen, to . Apparently, some means of surface treatment effective in avoiding contamination by casual surface dwelling mycobionts is necessary (cf. The possibility that Diapensiaceae and Enkianthoideae form the ErM symbiosis is intriguing and begs further investigation. Prolonged single-cell incubation could address this question better than plating of surface-sterilized root segments (see above). ), 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. Ericoid mycorrhizas represent a unique type of mycorrhizas confined to several families in the large angiosperm order Ericales. (2019) Large-scale generation and analysis of filamentous fungal DNA barcodes boosts coverage for kingdom fungi and reveals thresholds for fungal species and higher taxon delimitation. Washed pre-selected ericoid hair roots have to be cleared and their fungal colonization visualized by suitable staining. Method Microbiol 23:75106, Peterson RL, Massicotte HB (2004) Exploring structural definitions of mycorrhizas, with emphasis on nutrient-exchange interfaces. Each delimited MOTU ideally represents a single species (at this point it is a good idea to get back to the isolates and check their phenotype diversity within individual MOTUs), and this may be checked by aligning all respective sequences to screen their heterogeneity, choosing the most divergent ones and compare these with publicly available sequences, e.g., using BLAST (Altschul et al. 2013) in UNITE is available for an unambiguous alphanumeric assignment of the respective MOTU. Even non-symbiotic fungi may stimulate ericoid plant growth and/or nutrient uptake, e.g., by detoxification of the substrate, mineralization of organic matter, release of phytohormones or their analogues, elevation of [CO2] in closed cultivation systems, etc. Hyaloscypha hepaticicola also forms a characteristic mutualistic symbiosis (mycothallus) with certain liverworts (Duckett and Read 1995; Kowal et al. Taxon 49:7984, Stroheker S, Queloz V, Sieber TN (2016) Spatial and temporal dynamics in the Phialocephala fortinii s. l. Acephala applanata species complex (PAC). Ericoid mycorrhizal symbiosis: theoretical background and methods for 2013). While developed heathlands typically comprise a thick layer of organic matter with ericoid roots confined to first ca. European blueberry (Vaccinium myrtillus) seedlings after ca. In addition, the recovery of the basidiomycetous strain from the Rhododendron roots was very low (only one isolate out of the 220 obtained) and BLAST searches in GenBank at NCBI (see below, accessed 7 January 2020) showed that its ITS nuc-rDNA sequence (EU888636) displays 100/100% coverage/similarity to several sequences of Trametes hirsuta, a known plant pathogen/wood decaying saprobe. 2016) coupled with experimental verification of their symbiotic status is encouraged. Scagel, C. F. 2005 Inoculation with ericoid mycorrhizal fungi alters fertilizer use of highbush blueberry cultivars. 1990; Dighton and Coleman 1992; Urcelay 2002) and EcM (e.g., Largent et al. (2012a) Novel root-fungus symbiosis in Ericaceae: sheathed ericoid mycorrhiza formed by a hitherto undescribed basidiomycete with affinities to Trechisporales. Some authors have reported the presence of AM (e.g., Gemma and Koske 1990; Koske et al. Mycorrhizal Plants Types & Function | What are Mycorrhiza? - Video Ad (3): The main advantage of the synthetic media/substrates like MMN is reproducibility. HortScience 40: 786-794. https://en.wikipedia.org/w/index.php?title=Ericoid_mycorrhiza&oldid=1123481611, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 24 November 2022, at 00:10. New Phytol 164:710, Vu D, Groenewald M, de Vries M et al. 1999; Villarreal-Ruiz et al. Ericoid mycorrhizae are terms that describe a mutualistic symbiosis relationship that formed approximately 140 million years ago between the Ericaceae plant family and certain fungi. The dishes are wrapped with an air permeable foil/tape and incubated in a growth chamber in the shade until the seeds start to geminate (usually after ca. 1420 in Massicotte et al. On the other hand, when controlled laboratory conditions are not available (longer field trips, unpopulated areas, etc. 2016). Since under natural conditions no plants grow without contacts with soil fungi and some non-mycorrhizal fungi may exhibit effectssimilar to ErMF, a proper selection of control treatments (see item 4 under Things to considerin the section "Resynthesis experiments") is necessary. To display the development of the extraradical mycelium (arrows), a sheet of sterile filter paper (asterisk) was removed from the surface of the substrate prior taking the photo (b). Ad (1): While the main advantage of tissue culture-derived rooted microcuttings is their genetic uniformity, the disadvantages include limited availability (typical Northern Hemisphere wild species like C. vulgaris, Erica carnea, and Vaccinium myrtillus are practically unavailable as tissue cultures) and price, sometimes also problems with rooting/root development. In contrast, the authors noted that the mycorrhizal infection rate of the strain was quite low in their in vitro resynthesis. Language links are at the top of the page across from the title. The rhizosphere soil is best removed with aid of a suitable sieve and tap water; even maximal tap flow is typically not enough and an adapter with a flexible rubber hose facilitating flow control always comes in handy, saving hours of inefficient labor (e.g., cleaning hair roots from soil particles using a small brush or tweezers).