Abstract
The aim of this study was to investigate the ability of Pantoea agglomerans, a plant growth-promoting bacterium, to colonize various regions and tissues of the wheat plant (Triticum aestivum L.) by using different inoculation methods and inoculum concentrations. In addition, the enzyme-linked immunosorbent assay (ELISA) and transmission electron microscopy (TEM) were used to determine: (a) the ability of the bacterial cells to grow and survive both on the surface and within internal tissue of the plant and (b) the response of the plant to bacterial infection. After inoculation, cells of the diazotrophic bacterial strain P. agglomerans were found to be located in roots, stems and leaves. Colony development of bacterial cells was only detected within intercellular spaces of the root and on the root surface. However, single bacterial cells were observed in leaves and stems on the surface of the epidermis, in the vicinity to stomatal cells, within intercellular spaces of the mesophyll and within xylem vessels. Inoculated bacterial cells were found to be able to enter host tissues, to multiply in the plant and to maintain a delicate relationship between endophyte and host. The density of bacterial settlement in the plant in all experiments was about 106 to 107 cells per mL root or shoot sap. Establishment was confirmed by a low coefficient of variation of ELISA means at these concentrations.
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Baldani V L D, Alvarez M A de B, Baldani J I and Döbereiner J 1986 Establishment of inoculated Azospirillum spp. in the rhizosphere and in roots of field grown wheat and sorghum. Plant and Soil 90, 35–46.
Bashan Y 1986 Significance of timing and level of inoculation with rhizosphere bacteria on wheat plants. Soil Biol. Biochem. 18, 297–301.
Bashan Y and Levanony H 1988 Migration, colonization and adsorption of Azospirillum brasilense to wheat roots. Lectins-Biology, Biochemistry, Clinical Biochemistry 6, 69–84.
Boddey R M and Döbereiner J 1988 Nitrogen fixation associated with grasses and cereals: Recent results and perspectives for future research. Plant and Soil 108, 53–65.
Döbereiner J 1988 Biotechnology: Recent advances in biological nitrogen fixation. VI Japan-Brazil symposium on science and technology in Sao Paulo, 145–160.
Döbereiner J, Day J M and Dart P J 1972 Nitrogenase activity and oxygen sensitivity of the Paspalum notatum-Azotobacter paspali association. J. Gen. Microbiol. 71, 103–116.
Ferreira M C B, Fernandes M S and Döbereiner J 1987 Role of Azospirillum brasilense nitrate reductase in nitrate assimilation by wheat plants. Biol. Fertil Soils 4, 47–53.
Hartmann A 1988 Ecophysiological aspect of growth and nitrogen fixation in Azospirillum spp. Plant and Soil 110, 225–238.
Hirte W F 1961 Glycerin-Pepton-Agar, ein vorteilhafter Nährboden für bodenbakteriologische Arbeiten. Zbl. Bakt. Abt. II 114, 141–146.
Klein J 1990 Molecular microbial ecology, Workshop European Environm. Research Organization, 28 April 28–1 May Braunschweig FRG.
Levanony H, Bashan Y, Romano B and Klein E 1989 Ultrastructural localization and identification of Azospirillum brasilense Cd on and within wheat root by immunogold labeling. Plant and Soil 117, 207–219.
Magalhaes L M S, Patriquin D and Döbereiner J 1979 Infection of field-grown maize with Azospirillum spp. Rev. Bras. Biol. 39, 587–596.
Martinez-Toleredo M V, Larubidea DE T, Moreiva J and Gonzalez-Lopez J 1988 Root exudates of Zea mays and production of auxins, gibberellins and cytokinins by Azotobacter chroococcum. Plant and Soil 110, 149–152.
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, Gracioli L A and Ruschel A P 1980 Nitrogenase activity of sugar cane propagated from stem cuttings in sterile vermiculite. Soil. Biol. Biochem. 12, 413–417.
Rennie R J, DeFreitas J R, Ruschel A Pand Vose P B 1982 Isolation and identification of N2-fixing bacteria associated with sugar cane (Saccharum sp.). Can. J. Microbiol. 28, 462–467.
Ruppel S, Wache H and Höflich G 1989 Wirkprinzipien zur Wachstumsstimulierung von Winterweizen durch N2-fixierende assoziative Rhizosphärenmikroorganismen. Forschungsbericht des FZB Müncheberg. FO 999.
Ruppel S and Wache H 1990 Isolation and selection of phytoeffective bacteria. Zentralbl. Mikrobiol. 145, 599–603.
Scholz C, Remus R and Zielke R, 1991 Development of DAS-ELISA for some selected bacteria from the rhizosphere. Zentralbl. Mikrobiol. 146, 197–207.
Scholz C and Ruppel S 1992 Nitrogenase- and phytohormone activities of Pantoea agglomerans in culture and their reflection in combination with wheat plants. Zentralbl. Mikrobiol. 147, 319–328.
Sitte P 1962 Einfache Verfahren zur stufenlosen Gewebe-Entwässerung für die elektr.-mikr. Präparation. Naturwissenschaften 49, 402.
Sprent J I and Faria S M 1988 Mechanism of infection of plants by nitrogen fixing organism. Plant and Soil 110, 157–165.
Spurr A R 1969 A low-viscosity epoxy resin embedding medium for electron microscopy. Ultrastructure Res. 26, 31–43.
Tien T M, Gaskins M H and Hubbell D H 1979 Plant growth substances produced by Azospirillum brasilense and their effect on the growth of pearl millet (Pennisetum americanum L.). Appl. Environ. Microbiol. 37, 1016–1024.
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Ruppel, S., Hecht-Buchholz, C., Remus, R. et al. Settlement of the diazotrophic, phytoeffective bacterial strain Pantoea agglomerans on and within winter wheat: An investigation using ELISA and transmission electron microscopy. Plant Soil 145, 261–273 (1992). https://doi.org/10.1007/BF00010355
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DOI: https://doi.org/10.1007/BF00010355