Abstract
Azospirillum brasilense Cd localization in wheat roots was studied by light microscopy, by scanning, and by transmission electron microscopy.A. brasilense Cd cells were specifically identified immunocytochemically around and within root tissues.A. brasilense Cd cells found both outside and inside inoculated roots were intensively labeled with colloidal gold. In non-axenic cultures other bacterial strains or plant tissue were not labeled, thereby providing a non-interfering background. The roots of axenic grown wheat plants were colonized both externally and internally byA. brasilense Cd after inoculation, whereas non-axenic cultures were colonized by other bacterial strains as well.A. brasilense Cd cells were located on the root surface along the following zones: the root tip, the elongation, and the root-hair zone. However, bacteria were located within the cortex only in the latter two zones. In a number of observations, an electron dense material mediated the binding of bacterial cells to outer surfaces of epidermal cells, or between adjacent bacterial cells.A. brasilense Cd were found in root cortical intercellular spaces, but were not detected in either the endodermal layer or in the vascular system. This study proposes that in addition to root surface colonization,A. brasilense Cd forms intercellular associations within wheat roots.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bashan Y 1986a Enhancement of wheat roots colonization and plant development byAzospirillum brasilense Cd following temporary depression of the rhizosphere microflora. Appl. Environ. Microbiol. 51, 1067–1071.
Bashan Y 1986b Alginate beads as synthetic inoculant carriers for the slow release of bacteria that affect plant growth. Appl. Environ. Microbiol. 51, 1089–1098.
Bashan Y 1986c Migration of the rhizosphere bacteriaAzospirillum brasilense andPseudomonas fluorescens towards wheat roots in the soil. J. Gen. Microbiol. 132, 3407–3414.
Bashan Y 1986d Significance of timing and level of inoculation with rhizosphere bacteria on wheat plants. Soil Biol. Biochem. 18, 297–301.
Bashan Y and Levanony H 1985 An improved selection technique and medium for the isolation and enumeration ofAzospirillum brasilense. Can. J. Microbiol. 31, 947–952.
Bashan Y and Levanony H 1987 Horizontal and vertical movement ofAzospirillum brasilense Cd in the soil and along the rhizosphere of wheat and weeds in controlled and field environments. J. Gen. Microbiol. 133, 3473–3480.
Bashan Y and Levanony H 1988a Interaction betweenAzospirillum brasilense Cd and wheat root cells during early stages of root colonization.In Azospirillum IV: Genetics, Physiology, Ecology. Ed. W Klingmüller. pp 166–173. Springer-Verlag, Berlin, Heidelberg.
Bashan Y and Levanony H 1988b Migration, colonization and adsorption ofAzospirillum brasilense to wheat roots.In Lectins-biology, Biochemistry, Clinical Biochemistry. Eds. D Freed and T C Bøg-Hansen. Vol. 6, pp 69–84. Sigma Chemical Co. St. Louis Mo.
Bashan Y, Levanony H and Klein E 1986 Evidence for a weak active external adsorption ofAzospirillum brasilense Cd to wheat roots. J. Gen. Microbiol. 132, 3069–3073.
Berg R H, Vasil V and Vasil I K 1979 The biology of Azospirillum-sugarcane association. II. Ultrastructure. Protoplasma 101, 143–163.
De Mey J, Moermans M, Geuens G, Nuydens R and De Brabander M 1981 High resolution light and electron microscopic localization of tubulin with the IGS (immuno gold staining) method. Cell Biol. Int. Rep. 5, 889–899.
Döbereiner J and Day J M 1976 Associative symbioses in tropical grasses: Characterization of microorganisms and dinitrogen-fixing sites.In Proceedings of the 1st International Symposium on N2-fixation. Eds. W E Newton and C J Nyman. pp 518–538. Washington State University Press, Pullmann, WA.
Foster R C 1986 The ultrastructure of the rhizoplane and rhizosphere. Annu. Rev. Phytopathol. 24, 211–234.
Jain D K and Patriquin D G 1984 Root hair deformation, bacterial attachment, and plant growth in wheat-Azospirillum associations. Appl. Environ. Microbiol. 48, 1208–1213.
Jones W T, Macdonald P E, Jones S D and Pankhurst C E 1987 Peptidoglican-bound polysaccharide associated with resistance ofRhizobium loti strain NZP2037 toLotus pedunculatus root flavolan. J. Gen. Microbiol. 133, 2617–2629.
Kavimandan S K, Subba Rao N S and Mohrir A V 1978 Isolation ofSpirillum lipoferum from the stems of wheat and nitrogen fixation in enrichment cultures. Curr. Sci. 47, 96–98.
Levanony H and Bashan Y 1989 Localization of specific antigens ofAzospirillum brasilense Cd in its exopolysaccharide by immuno-gold staining. Curr. Microbiol. 18, 145–149.
Levanony H, Bashan Y and Kahana Z E 1987 Enzyme-linked immunosorbent assay for specific identification and enumeration ofAzospirillum brasilense Cd in cereals roots. Appl. Environ. Microbiol. 53, 358–364.
Lynch J M 1982 The rhizosphere.In Experimental Microbial Ecology. Eds. R G Barns and J H Slater. pp 395–411. Blackwell Scientific Publications, Oxford.
Matthews S W, Schank S C, Aldrich H C and Smith R L 1983 Peroxidase-antiperoxidase labeling ofAzospirillum brasilense in field-grown pearl millet. Soil Biol. Biochem. 15, 699–703.
Okon Y and Hardy R W F 1983 Developments in basic and applied biological nitrogen fixation.In Plant Physiology—A treatise. Ed. F C Steward. 8. pp 5–54. Academic Press, New York.
Patriquin D G 1981 New developments in grass-bacteria association.In Advances in Agricultural Microbiology. Ed. N S Subba Rao. pp 139–190. Oxford and IBH Publishing Co., New Delhi.
Patriquin D G and Döbereiner J 1978 Light microscopy observations of tetrazolium-reducing bacteria in the endorhizosphere of maize and other grasses in Brazil. Can. J. Microbiol. 24, 734–742.
Patriquin D G, Döbereiner J and Jain D K 1983 Sites and processes of association between diazotrophs and grasses. Can. J. Microbiol. 29, 900–915.
Reinhold B and Hurek T 1988 Location of diazotrophs in the root interior with special attention to the Kallar grass association. Plant and Soil 110, 259–268.
Reinhold B, Hurek T, Niemann E-G and Fendrik I 1986 Close association of Azospirillum and diazotrophic rods with different root zones of Kallar grass. Appl. Environ. Microbiol. 52, 520–526.
Roth J 1983 Application of lectin-gold complexes for electron microscopic localization of glycoconjugates on thin sections. J. Histochem. Cytochem. 31, 987–999.
Roth J, Bendayan M and Orci L 1978 Ultrastructural localization of intercellular antigens by the use of Protein-A-gold complex. J. Histochem. Cytochem. 26, 1074–1081.
Schank S C, Smith R L, Weiser G C, Zuberer D A, Bouton J A, Quensberry K H, Tyler M E, Milam J R and Littell R C 1979 Fluorescent antibody technique to identifiedAzospirillum brasilense associated with roots of grasses. Soil Biol. Biochem. 11, 287–295.
Spurr A R 1969 A low-viscosity epoxy-resin embedding medium for electron microscopy. J. Ultrastruc. Res. 26, 31–43.
Suslow T V 1982 Role of root-colonizing bacteria in plant growth.In Phytopathogenic Prokaryotes. Eds. M S Mount and G H Lacy. 1, pp 187–223. Academic Press, New York.
Umali-Garcia M, Hubbell D H, Gaskins M H and Dazzo F B 1980 Association of Azospirillum with grass roots. Appl. Environ. Microbiol. 39, 219–226.
Van Laere O, De Wael L and De Mey J 1985 Immuno gold straining (IGS) and immuno gold silver staining (IGSS) for the identification of the plant pathogenic bacteriumErwinia amylovora (Burrill) Winslowet al. Histochemistry 83, 397–399.
Whallon J H, Acker G F and El-Khawas H 1985 Electron microscopy of young wheat roots inoculated with Azospirillum.In Azospirillum III: Genetics, Physiology, Ecology. Ed. W Klingmüller. pp 223–229. Springer-Verlag, Berlin, Heidelberg.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Levanony, H., Bashan, Y., Romano, B. et al. Ultrastructural localization and identification ofAzospirillum brasilense Cd on and within wheat root by immuno-gold labeling. Plant Soil 117, 207–218 (1989). https://doi.org/10.1007/BF02220714
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02220714