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Combining microtomy and confocal laser scanning microscopy for structural analyses of plant–fungus associations

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Abstract

The serious problem of extended tissue thickness in the analysis of plant–fungus associations was overcome using a new method that combines physical and optical sectioning of the resin-embedded sample by microtomy and confocal microscopy. Improved tissue infiltration of the fungal-specific, high molecular weight fluorescent probe wheat germ agglutinin conjugated to Alexa Fluor® 633 resulted in high fungus-specific fluorescence even in deeper tissue sections. If autofluorescence was insufficient, additional counterstaining with Calcofluor White M2R or propidium iodide was applied in order to visualise the host plant tissues. Alternatively, the non-specific fluorochrome acid fuchsine was used for rapid staining of both, the plant and the fungal cells. The intricate spatial arrangements of the plant and fungal cells were preserved by immobilization in the hydrophilic resin Unicryl™. Microtomy was used to section the resin-embedded roots or leaves until the desired plane was reached. The data sets generated by confocal laser scanning microscopy of the remaining resin stubs allowed the precise spatial reconstruction of complex structures in the plant–fungus associations of interest. This approach was successfully tested on tissues from ectomycorrhiza (Betula pendula), arbuscular mycorrhiza (Galium aparine; Polygala paniculata, Polygala rupestris), ericoid mycorrhiza (Calluna vulgaris), orchid mycorrhiza (Limodorum abortivum, Serapias parviflora) and on one leaf–fungus association (Zymoseptoria tritici on Triticum aestivum). The method provides an efficient visualisation protocol applicable with a wide range of plant–fungus symbioses.

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References

  • Alexander T, Meier R, Toth R, Weber HC (1988) Dynamics of arbuscule development and degeneration in mycorrhizas of Triticum aestivum L. and Avena sativa L. with references to Zea mays L. New Phytol 110:363–370

    Article  Google Scholar 

  • Alexander T, Toth R, Meier R, Weber HC (1989) Dynamics of arbuscule development and degeneration in onion, bean and tomato with reference to vesicular-arbuscular mycorrhizae with grasses. Can J Bot 67:2505–2513

    Google Scholar 

  • Blasius D, Feil W, Kottke I, Oberwinkler F (1986) Hartig net structure and formation in fully ensheathed ectomycorrhizas. Nord J Bot 6:837–842

    Article  Google Scholar 

  • Bonfante-Fasolo P, Faccio A, Perotto S, Schubert A (1990) Correlation between chitin distribution and cell wall morphology in the mycorrhizal fungus Glomus versiforme. Mycol Res 94:157–165

    Article  CAS  Google Scholar 

  • Brun A, Chalot M, Finlay RD, Söderström B (1995) Structure and function of the ectomycorrhizal association between Paxillus involutus (Batsch) Fr. and Betula pendula Roth. I. Dynamics of mycorrhiza formation. New Phytol 129:487–493

    Article  Google Scholar 

  • Diagne N, Escoute J, Lartaud M, Verdeil JL, Franche C, Kane A, Bogusz D, Diouf D, Duponnois R, Svistoonoff S (2011) Uvitex2B: a rapid and efficient stain for detection of arbuscular mycorrhizal fungi within plant roots. Mycorrhiza 21:315–321

    Article  PubMed  Google Scholar 

  • Dickson S (2004) The Arum–Paris continuum of mycorrhizal symbiosis. New Phytol 163:187–200

    Article  Google Scholar 

  • Dickson S, Kolesik P (1999) Visualisation of mycorrhizal fungal structures and quantification of their surface area and volume using laser scanning confocal microscopy. Mycorrhiza 9:205–213

    Article  Google Scholar 

  • Doehleman G, Wahl R, Vranes M, de Vries RP, Kämper J, Kahmann R (2007) Establishment of compatibility in the Ustilago maydis/maize pathosystem. J Plant Physiol 165:29–40

    Article  Google Scholar 

  • Domínguez LS, Sérsic A (2004) The southernmost myco-heterotrophic plant, Arachnitis uniflora: root morphology and anatomy. Mycologia 96:1143–1151

    Article  PubMed  Google Scholar 

  • Domínguez LS, Melville L, Sérsic A, Faccio A, Peterson RL (2009) The mycoheterotroph Arachnitis uniflora has a unique association with arbuscular mycorrhizal fungi. Botany 87:1198–1208

    Article  Google Scholar 

  • Fester T, Berg RH, Taylor CG (2008) An easy method using glutaraldehyde-introduced fluorescence for the microscopic analysis of plant biotrophic interactions. J Microsc 231:342–348

    Article  CAS  PubMed  Google Scholar 

  • Gallaud I. (1905). Etudes sur les mycorhizes endotrophes. Rev Gén Bot 17: 7–48, 66–83, 123–136, 223–239, 313–325, 425–433, 479–500.

    Google Scholar 

  • Gao L-L, Delp G, Smith SE (2001) Colonization patterns in a mycorrhiza-defective mutant tomato vary with different arbuscular-mycorrhizal fungi. New Phytol 151:477–491

    Article  Google Scholar 

  • Gutiérrez A, Morte A, Honrubia M (2003) Morphological characterization of the mycorrhiza formed by Helianthemum almeriense Pau with Terfezia claveryi Chatin and Picoa lefebvrei (Pat.) Maire. Mycorrhiza 13:299–307

    Article  PubMed  Google Scholar 

  • Haug I, Weiß M, Homeier J, Oberwinkler F, Kottke I (2005) Russulaceae and Thelephoraceae form ectomycorrhizas with members of the Nyctaginaceae (Caryophyllales) in the tropical mountain rain forest of southern Ecuador. New Phytol 165:923–936

    Article  CAS  PubMed  Google Scholar 

  • Imhof S (1999a) Anatomy and mycotrophy of the achlorophyllous Afrothismia winkleri (Engl.) Schltr. (Burmanniaceae). New Phytol 144:533–540

    Article  Google Scholar 

  • Imhof S (1999b) Subterranean structures and mycorrhiza of the achlorophyllous Burmannia tenella Benth. (Burmanniaceae). Can J Bot 77:637–643

    Google Scholar 

  • Imhof S (1999c) Root morphology, anatomy and mycotrophy of the achlorophyllous Voyria aphylla (Jacq.) Pers. (Gentianaceae). Mycorrhiza 9:33–39

    Article  Google Scholar 

  • Kormanik PP, McGraw AC (1982) Quantification of vesicular-arbuscular mycorrhizae in plant roots. In: Schenck NC (ed) Methods and principles of mycorrhizal research. The American Phytopathological Society, St. Paul, pp 37–45

    Google Scholar 

  • Lum MR, Li Y, LaRue TA, David-Schwartz R, Kapulnik Y, Hirsch AM (2002) Investigation of four classes of non-nodulating white sweetclover (Melilotus alba annua Desr.) mutants and their responses to arbuscular-mycorrhizal fungi. Integ and Comp Biol 42:295–303

    Article  Google Scholar 

  • Marcel S, Sawers R, Oakeley E, Angliker H, Paszkowski U (2010) Tissue-adapted invasion strategies of the rice blast Magnaporthe oryzae. Plant Cell 22:3177–3187

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • Massicotte HB, Melville LH, Molina R, Peterson RL (1993) Structure and histochemistry of mycorrhizae synthesized between Arbutus menziesii (Ericaceae) and two basidiomycetes, Pisolithus tinctorius (Pisolithaceae) and Piloderma bicolor (Corticiaceae). Mycorrhiza 3:1–11

    Article  Google Scholar 

  • Melville L, Dickson S, Farquhar ML, Smith SE, Peterson RL (1998) Visualization of mycorrhizal fungal structures in resin embedded tissues with xanthene dyes using laser scanning confocal microscopy. Can J Bot 76:174–178

    Google Scholar 

  • Merryweather JW, Fitter AH (1991) A modified method for elucidating the structure of the fungal partner in a vesicular-arbuscular mycorrhiza. Mycol Res 95:1435–1437

    Article  Google Scholar 

  • Monheit JE, Cowan DF, Moore DG (1984) Rapid detection of fungi in tissues using calcofluor white and fluorescence microscopy. Arch Pathol Lab Med 108:616–618

    CAS  PubMed  Google Scholar 

  • Ormsby A, Hodson E, Li Y, Basinger J, Kaminskyj S (2007) Quantitation of endorhizal fungi in high Arctic tundra ecosystems through space and time: the value of herbarium archives. Can J Bot 85:599–606

    Article  Google Scholar 

  • Peters C, Basinger JF, Kaminsky SGW (2011) Endorhizal fungi associated with vascular plants on Trueland Lowland, Devon Island, Nunavut, Canadian High Arctic. Arc Antarct Alp Res 43:73–81

    Article  Google Scholar 

  • Phillips JM, Hayman DS (1970) Improved procedures for clearing and staining parasitic and vesicular-arbuscular mycorrhizal fungi for rapid assessment of infection. Trans Br Mycol Soc 55:158–160

    Article  Google Scholar 

  • Rath M, Weber HC, Imhof S (2013) Morpho-anatomical and molecular characterization of the mycorrhizas of European Polygala species. Plant Biol 15:548–557

    Google Scholar 

  • Read DJ, Duckett JG, Francis R, Ligrone R, Russell A (2000) Symbiotic fungal associations in ‘lower’ land plants. Phil Trans R Soc Lond B 355:815–831

    Article  CAS  Google Scholar 

  • Robin JB, Arffa RC, Avni I, Rao NA (1986) Rapid visualization of three common fungi using fluorescein-conjugated lectins. Invest Ophthalmot Vis Sci 27:500–506

    CAS  Google Scholar 

  • Rounds CM, Lubeck E, Hepler PK, Winship LJ (2011) Propidium iodide competes with Ca2+ to label pectin in pollen tubes and Arabidopsis root hairs. Plant Physiol 157:175–187

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • Schelkle M, Ursic M, Farquhar M, Peterson RL (1996) The use of laser scanning confocal microscopy to characterize mycorrhizas of Pinus strobus L. and to localize associated bacteria. Mycorrhiza 6:431–440

    Article  Google Scholar 

  • Schmid E, Oberwinkler F (1993) Mycorrhiza-like interaction between the achlorophyllous gametophyte of Lycopodium clavatum L. and its fungal endophyte studied by light and electron microscopy. New Phytol 124:69–81

    Article  Google Scholar 

  • Sørensen CK, Justesen AF, Hovmøller MS (2012) 3-D imaging of temporal and spatial development of Puccinia striiformis haustoria in wheat. Mycologia 104:1381–1389

    Article  PubMed  Google Scholar 

  • Truernit E, Siemering KR, Hodge S, Grbic V, Haseloff J (2006) A map of KNAT gene expression in the Arabidopsis root. Plant Mol Biol 60:1–20

    Article  CAS  PubMed  Google Scholar 

  • Vierheilig H, Schweiger P, Brundrett M (2005) An overview of methods for the detection and observation of arbuscular mycorrhizal fungi in roots. Physiol Plant 125:393–404

    CAS  Google Scholar 

  • Zhang Q, Blaylock LA, Harrison MJ (2010) Two Medicago truncatula half-ABC transporters are essential for arbuscule development in arbuscular mycorrhizal symbiosis. Plant Cell 22:1483–1497

    Article  CAS  PubMed Central  PubMed  Google Scholar 

Download references

Acknowledgments

We thank all participants of the last 3 years of confocal microscopy courses who helped to test this method on various kinds of material, thus helping to improve the method to its present practicable stage; Florian Lemmer and Julian Walther for kindly providing the plant material of S. parviflora and L. abortivum; Friedemann Brauer (Dalhousie University, Halifax, Nova Scotia, Canada) and the anonymous referees for their valuable comments on the manuscript.

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Correspondence to Magnus Rath.

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Figure S3

a and b: Z extraction of the 3D projection in Fig. 2f and g. The high resolution of the initial data set (compare Fig. 2f) allows the analysis of complex structured arbuscules (ar) (S3 a) and their spatial arrangement inside the host plant cell (S3 b). Scale: 100 μm (JPEG 1.26 mb)

Figure S4

a–c: 3D Projection (AMIRA™) of the root fragment of Serapias parviflora (transverse view) with the host plant tissue displayed in grey and the fungus in orange. Tangential view on the initial plane (a) and, after rotation for 180°, last plane (b) of the scan through the root fragment. Although the scan reached 384 μm in depth (see radial view on the projection in c), the quality of the visualization remains high and allows to reconstruct even fine details like hyphae running along the epidermal surface (see arrowhead in b) or, if the fungal channel is displayed alone, hyphal coils forming a colonisation cluster inside the root cortex parenchyma (d). Scale: a, b, d=150 μm; c=384 μm (JPEG 3.33 mb)

Figure S5

3D projection (AMIRA™) of the root fragment of Polygala rupestris non-specifically stained with acid fuchsine. Fungal structures like degenerated arbuscules (da) and fungal hyphae (hy) are well distinguishable from host plant tissue cells. Scale: 100 μm (JPEG 1.08 mb)

Tomographic animation (AMIRA™) of the CLSM scan of a Polygala paniculata root in Fig. 2f (MPG 31821 kb)

Tomographic animation (AMIRA™) of the CLSM scan of a Triticum aestivum leaf infested by Zymoseptoria tritici (compare Fig. 2e) (MPG 71515 kb)

Table 1

Collecting data of the plant material used in this study (DOC 25.5 kb)

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Rath, M., Grolig, F., Haueisen, J. et al. Combining microtomy and confocal laser scanning microscopy for structural analyses of plant–fungus associations. Mycorrhiza 24, 293–300 (2014). https://doi.org/10.1007/s00572-013-0530-y

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  • DOI: https://doi.org/10.1007/s00572-013-0530-y

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