We’re sorry, something doesn't seem to be working properly.

Please try refreshing the page. If that doesn't work, please contact support so we can address the problem.

Skip to main content
Log in

Ultrastructure of infection-thread development during the infection of soybean by Rhizobium japonicum

  • Published:
Planta Aims and scope Submit manuscript

Abstract

The location and topography of infection sites in soybean (Glycine max (L.) Merr.) root hairs spot-inoculated with Rhizobium japonicum have been studied at the ultrastructural level. Infections commonly developed at sites created when the induced deformation of an emerging root hair caused a portion of the root-hair cell wall to press against an adjacent epidermal cell, entrapping rhizobia within the pocket between the two host cells. Infections were initiated by bacteria which became embedded in the mucigel in the enclosed groove. Infection-thread formation in soybean appears to involve degradation of mucigel material and localized disruption of the outer layer of the folded hair cell wall by one or more entrapped rhizobia. Rhizobia at the site of penetration are separated from the host cytoplasm by the host plasmalemma and by a layer of wall material that appears similar or identical to the normal inner layer of the hair cell wall. Proliferation of the bacteria results in an irregular, wall-bound sac near the site of penetration. Tubular infection threads, bounded by wall material of the same appearance as that surrounding the sac, emerge from the sac to carry rhizobia roughly single-file into the hair cell. Growing regions of the infection sac or thread are surrounded by host cytoplasm with high concentrations of organelles associated with synthesis and deposition of membrane and cell-wall material. The threads follow a highly irregular path toward the base of the hair cell. Threads commonly run along the base of the hair cell for some distance, and may branch and penetrate into subjacent cortical cells at several points in a manner analagous to the initial penetration of the root hair.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Bauer, W.D. (1981) Infection of legumes by rhizobia. Annu. Rev. Plant Physiol. 32, 407–449

    Google Scholar 

  • Berry, A.M., Torrey, J.G. (1983) Root hair deformation in the infection process of Alnus rubra. Can. J. Bot. 61, 2863–2876

    Google Scholar 

  • Bhuvaneswari, T.V., Bhagwat, A.A., Bauer, W.D. (1981) Transient susceptibility of root cells in four common legumes to nodulation by rhizobia. Plant Physiol. 68 1144–1149

    Google Scholar 

  • Bhuvaneswari, T.V., Turgeon, B.G., Bauer, W.D. (1980) Early events in the infection of soybean Glycine max (L.) Merr. by Rhizobium japonicum. I. Localization of infectible root cells. Plant Physiol. 66, 1027–1031

    Google Scholar 

  • Bieberdorf, F.W. (1938) The cytology and histology of root nodules of some leguminosae. J. Am. Soc. Agron. 30, 375–389

    Google Scholar 

  • Callaham, D.A., Torrey, J.G. (1981) The structural basis for infection of root hairs of Trifolium repens by Rhizobium. Can. J. Bot. 59, 1647–1664

    Google Scholar 

  • Calvert, H.E., Pence, M., Pierce, M., Malik, N.S.A., Bauer, W.D. (1984) Anatomical analysis of the development and distribution of Rhizobium infections in soybean roots. Can. J. Bot. (in press)

  • Chandler, M.R. (1978) Some observations of infection of Arachis hypogaea L. by Rhizobium. J. Exp. Bot. 29, 749–755

    Google Scholar 

  • Chandler, M.R., Date, R.A., Roughley, R.J. (1982) Infection and root-nodule development in Stylosanthes species by Rhizobium. J. Exp. Bot. 33, 47–57

    Google Scholar 

  • Dart, P.J. (1974) Development of root nodule symbiosis. The infection process. In: The biology of nitrogen fixation, pp. 381–429, Quispel, A., ed. North Holland, Amsterdam

    Google Scholar 

  • Dart, P.J. (1977) Infection and development of leguminous nodules. In: A treatise on dinitrogen fixation, pp. 367–372, Hardy, R.W.F., Silver, W.S., eds. Wiley, New York

    Google Scholar 

  • Fahraeus, G. (1957) The infection of clover root hairs by nodule bacteria studied by a simple glass slide technique. J. Gen. Microbiol. 16, 374–381

    Google Scholar 

  • Fahraeus, G., Ljunggren, H., (1967) The possible significance of pectic enzymes in root hair infection by nodule bacteria. Physiol. Plant. 12, 145–154

    Google Scholar 

  • Foster, R.C. (1981) The ultrastructure and histochemistry of the rhizosphere. New Phytol. 89, 263–273

    Google Scholar 

  • Haak, A. (1964) Über den Einfluss der Knöllchenbakterien auf die Wurzelhaare von Leguminosen und Nichtleguminosen. Zentralbl. Bakteriol. Parasitenkd. Infektionskr. Abt. 2 117, 343–361

    Google Scholar 

  • Higashi, S. (1966) Electron microscopic studies on the infection thread developing in the root hair of Trifolium repens L. infected with Rhizobium trifolii. J. Gen. Appl. Microbiol. 12, 147–156

    Google Scholar 

  • Higashi, S., Abe, M. (1980) Scanning electron microscopy of Rhizobium trifolii infection sites on root hairs of white clover. Appl. Environ. Microbiol. 40, 1094–1099

    Google Scholar 

  • Hubbell, D.H. (1981) Legume infection by Rhizobium: a conceptual approach. BioScience 31, 832–837

    Google Scholar 

  • Hubbel, D.H., Morales, V.M., Umali-Garcia, M. (1978) Pectolytic enzymes in Rhizobium. Appl Environ. Microbiol. 35, 210–213

    Google Scholar 

  • Ljunggren, H. (1969) Mechanism and pattern of Rhizobium invasion into leguminous root hairs. Physiol. Plant., Suppl. V

  • Martinez-Molina, E., Morales, V.M., Hubbell, D.H. (1979) Hydrolytic enzyme production by Rhizobium. Appl. Environ. Microbiol. 38, 1186–1188

    Google Scholar 

  • Munns, D.N. (1968) Enzymatic breakdown of pectin and acid-inhibition of the infection of Medicago roots by Rhizobium. Plant and Soil 60, 117–120

    Google Scholar 

  • Napoli, C.A., Hubbell, D.H. (1975) Ultrastructure of Rhizobium-induced infection threads in clover root hairs. Appl. Microbiol. 30, 1003–1009

    Google Scholar 

  • Newcomb, W. (1981) Nodule morphogenesis and differentiation. In: Biology of the Rhizobiaceae, pp. 247–297, Giles, K.L., Atherly, A.G., eds. Int. Rev. Cytol, Suppl. 13. Academic Press, New York London

    Google Scholar 

  • Newcomb, E.H., Bonnett, H.T. (1965) Cytoplasmic microtubule and wall microfibril orientation in root hairs of radish. J. Cell Biol. 27, 575–589

    Google Scholar 

  • Newcomb, W., McIntyre, L. (1981) Development of root nodules in mung bean (Vigna radiata): a reinvestigation of endocytosis. Can. J. Bot. 59, 2478–2499

    Google Scholar 

  • Nutman, P.S. (1956) The influence of the legume in root-nodule symbiosis. A comparative study of host determinants and functions. Biol. Rev. (Cambridge). 31, 109–151

    Google Scholar 

  • Pueppke, S.G. (1983) Rhizobium infection threads in root hairs of Glycine max (L.) Merr., Glycine soja Sieb. & Zucc., and Vigna unguiculata (L.) Walp. Can. J. Microbiol. 29, 69–76

    Google Scholar 

  • Robertson, J.G., Lyttleton, P., Bullivant, S., Grayston, G.F. (1978) Membranes in lupin root nodules. I. The role of golgi bodies in the biogenesis of infection threads and peribacteroid membranes. J. Cell Sci. 30, 129–149

    Google Scholar 

  • Sahlman, K., Fahraeus, G. (1963) An electron microscope study of root hair infection by Rhizobium. J. Gen. Microbiol. 33, 425–427

    Google Scholar 

  • Spurr, A.R. (1969) A low-viscosity epoxy resin embedding medium for electron microscopy. J. Ultrastruct. Res. 26, 31–43

    Google Scholar 

  • Stacey, G., Paau, A.S., Brill, W.J. (1980) Host recognition in the Rhizobium-soybean symbiosis. Plant Physiol. 66, 609–614

    Google Scholar 

  • Tsien, H.C., Dreyfus, B.L., Schmidt, E.L. (1983) Initial stages in the morphogenesis of nitrogen fixing stem nodules of Sesbania rostrata. J. Bacteriol. 156, 888–897

    Google Scholar 

  • Turgeon, B.G., Bauer, W.D. (1982) Early events in the infection of soybean Rhizobium japonicum. Time course and cytology of the initial infection process. Can. J. Bot. 60, 152–161

    Google Scholar 

  • Turgeon, B.G., Bauer, W.D. (1983) Spot inoculation of soybean roots with Rhizobium japonicum. Protoplasma 115, 122–128

    Google Scholar 

  • Verma, D.P.S., Long, S. (1983) The molecular biology of Rhizobium-legume symbiosis. Int. Rev. Cytol. 14, 211–245

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Turgeon, B.G., Bauer, W.D. Ultrastructure of infection-thread development during the infection of soybean by Rhizobium japonicum . Planta 163, 328–349 (1985). https://doi.org/10.1007/BF00395142

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00395142

Key words

Navigation