1887

Abstract

Summary: Root surface colonization by Cd of tomato, pepper and cotton plants under normal growth conditions and soybean plants under normal and water-stress conditions was monitored by scanning electron microscopy and bacterial counts. Cd was capable of efficiently colonizing the elongation and root-hair zones of all four plant species tested. In these zones, the bacteria mainly colonized the root surface (tomato, soybean), root-hairs (pepper), or both (cotton), by single cells (tomato, soybean), micro-aggregates (pepper), or a combination of the two (cotton). All inoculated plants demonstrated (i) larger amounts of mucigel-like substance on the root surface than non-inoculated plants and (ii) fibrillar material which anchored the bacterial cells to the root surface and established connections between cells within bacterial aggregates. On non-water-stressed soybean plants, most Cd cells in the rhizosphere occurred as vibroid forms whereas those on water-stressed plants (wilting) were cyst-like. A lower rhizosphere bacterial population was observed on water-stressed plants. When water-stress conditions were eliminated, the bacterial cells reverted to the vibroid form and a concomitant increase in the bacterial population was observed. It is suggested that cyst-like formation is a natural response for Cd in the rhizosphere of water-stressed plants.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-137-1-187
1991-01-01
2021-08-02
Loading full text...

Full text loading...

/deliver/fulltext/micro/137/1/mic-137-1-187.html?itemId=/content/journal/micro/10.1099/00221287-137-1-187&mimeType=html&fmt=ahah

References

  1. Baldani V. L. D., Alvarez A. M. de B., Baldani J. I., Dobereiner J. 1986; Establishment of inoculated Azospirillum s in the rhizosphere and roots of field grown wheat and sorghum. Plant and Soil 90:35–46
    [Google Scholar]
  2. Bashan Y. 1986; Significance of timing and level of inoculation with rhizosphere bacteria on wheat plants. Soil Biology and Biochemistry 18:297–301
    [Google Scholar]
  3. Bashan Y., Levanony H. 1985; An improved selection technique and medium for the isolation and enumeration of Azospirillum brasilense . Canadian Journal of Microbiology 31:947–952
    [Google Scholar]
  4. Bashan Y., Levanony H. 1987; Horizontal and vertical movement of Azospirillum brasilense Cd in the soil and along the rhizosphere of wheat and weeds in controlled and field environments. Journal of General Microbiology 133:3473–3480
    [Google Scholar]
  5. Bashan Y., Levanony H. 1988a; Adsorption of the rhizosphere bacterium Azospirillum brasilense Cd to soil, sand and peat particles. Journal of General Microbiology 134:1811–1820
    [Google Scholar]
  6. Bashan Y., Levanony H. 1988b; Active attachment of Azospiril-lum brasilense Cd to quartz sand and to light textured soil by protein bridging. Journal of General Microbiology 134:2269–2279
    [Google Scholar]
  7. Bashan Y., Levanony H. 1988c; Migration, colonization and adsorption of Azospirillum brasilense to wheat roots. Lectins -Biology, Biochemistry, Clinical Biochemistry 669–84 Beg-Hansen T. C., Freed D. L. J. St Louis, Missouri: Sigma Chemical Co.;
    [Google Scholar]
  8. Bashan Y., Levanony H. 1989a; Wheat root tips as a vector for passive vertical transfer of Azospirillum brasilense Cd. Journal of General Microbiology 135:2899–2908
    [Google Scholar]
  9. Bashan Y., Levanony H. 1989b; Factors affecting adsorption of Azospirillum brasilense Cd to root hairs as compared with root surface of wheat. Canadian Journal of Microbiology 35:936–944
    [Google Scholar]
  10. Bashan Y., Levanony H. 1990; Current status of Azospirillum inoculation technology: Azospirillum as a challenge for agriculture. Canadian Journal of Microbiology 36:591–608
    [Google Scholar]
  11. Bashan Y, Levanony H., Klein E. 1986; Evidence for a weak active external adsorption of Azospirillum brasilense Cd to wheat roots. Journal of General Microbiology 132:3069–3073
    [Google Scholar]
  12. Bashan Y., Ream Y., Levanony H., Sade A. 1989a; Nonspecific responses in plant growth, yield, and root colonization of noncereal crop plants to inoculation with Azospirillum brasilense Cd. Canadian Journal of Botany 67:1317–1324
    [Google Scholar]
  13. Bashan Y., Singh M., Levanony H. 1989b; Contribution of Azospirillum brasilense Cd to growth of tomato seedlings is not through nitrogen fixation. Canadian Journal of Botany 67:2429–2434
    [Google Scholar]
  14. Bashan Y., Harrison S. K., Whitmoyer R. E. 1990; Enhanced growth of wheat and soybean plants inoculated with Azospirillum brasilense is not necessarily due to general enhancement of mineral uptake. Applied and Environmental Microbiology 56:769–775
    [Google Scholar]
  15. Bastarrachea F., Zamudio M., Rivas R. 1988; Non-encapsulat-ed mutants of Azospirillum brasilense and Azospirillum lipoferum . Canadian Journal of Microbiology 34:24–29
    [Google Scholar]
  16. Becking J. H. 1985; Pleomorphism in Azospirillum . Azospirillum III: Genetics, Physiology, Ecology243–262 Klingmiiller W. Berlin: Springer Verlag;
    [Google Scholar]
  17. Berg R. H., Vasil V., Vasil I. K. 1979; The biology of Azospirillum-sugarca.ne association. II. Ultrastructure. Protoplasma 101:143–163
    [Google Scholar]
  18. Berg R. H., Tyler M. E., Novick N. J., Vasil V., Vasil I. K. 1980; Biology of Azospirillum-sugarcane association: enhancement of nitrogenase activity. Applied and Environmental Microbiology 39:642–649
    [Google Scholar]
  19. Bleakley B. H., Gaskins M. H., Hubbell D. H., Zam S. G. 1988; Floe formation by Azospirillum lipoferum grown on poly-β-hydroxybutyrate. Applied and Environmental Microbiology 54:2986–2995
    [Google Scholar]
  20. Crossman S. M.., Hill W. A. 1987; Inoculation of sweet potato with Azospirillum . HortScience 22:420–422
    [Google Scholar]
  21. Eskew D. L., Focht D. D., Ting I. P. 1977; Nitrogen fixation, denitrification, and pleomorphic growth in a highly pigmented Spirillum lipoferum . Applied and Environmental Microbiology 34:582–585
    [Google Scholar]
  22. Jagnow G. 1982; Growth and survival of Azospirillum lipoferum in soil and rhizosphere as influenced by ecological stress conditions. Azospirillum: Genetics, Physiology, Ecology100–107 Klingmiiller W. Basel: Birkhauser Verlag;
    [Google Scholar]
  23. Kolb W., Martin P. 1985; Response of plant roots to inoculation with Azospirillum brasilense and to application of indole acetic acid. Azospirillum III: Genetics, Physiology, Ecology215–221 Klingmiiller W. Berlin: Springer-Verlag;
    [Google Scholar]
  24. Lamm R. B.., Neyra C. A. 1981; Characterization and cyst production of azospirilla isolated from selected grasses growing in New Jersey and New York. Canadian Journal of Microbiology 27:1320–1325
    [Google Scholar]
  25. Levanony H., Bashan Y. 1989; Enhancement of cell division in wheat root tips and growth of root elongation zone induced by Azospirillum brasilense Cd. Canadian Journal of Botany 67:2213–2216
    [Google Scholar]
  26. Levanony H., Bashan Y., Romano B., Klein E. 1989; Ultrastructural localization and identification of Azospirillum brasi-lense Cd on and within wheat roots by immuno-gold labelling. Plant and Soil 117:207–218
    [Google Scholar]
  27. Madi L., Kessel M., Sadovnik E., Henis Y. 1988; Electron microscopic studies of aggregation and pellicle formation in Azospirillum spp. Plant and Soil 109:115–121
    [Google Scholar]
  28. Mandimba G., Heulin T., Bally R., Guckert A., Balandreau J. 1986; Chemotaxis of free-living nitrogen-fixing bacteria towards maize mucilage. Plant and Soil 90:129–139
    [Google Scholar]
  29. Mano D. M. S.., Matos A. C., M. & Langenbach T. 1988; The effect of Dicofol on morphology, growth and nitrogenase activity of Azospirillum lipoferum . Azospirillum IV: Genetics, Physiology, Ecology159–165 Klingmiiller W. Berlin: Springer Verlag;
    [Google Scholar]
  30. Murray R. G. E.., Moyles D. 1987; Differentiation of the cell wall of Azospirillum brasilense . Canadian Journal of Microbiology 33:132–137
    [Google Scholar]
  31. Patriquin D. G., Dobereiner J., Jain D. K. 1983; Sites and processes of association between diazotrophs and grasses. Canadian Journal of Microbiology 29:900–915
    [Google Scholar]
  32. Plazinski J., Rolfe B. G. 1985; Interaction of Azospirillum and Rhizobium strains leading to inhibition of nodulation. Applied and Environmental Microbiology 49:990–993
    [Google Scholar]
  33. Sadasivan L., Neyra C. A. 1985; Flocculation in Azospirillum brasilense and Azospirillum lipoferum: exopolysaccharides and cyst formation. Journal of Bacteriology 163:716–723
    [Google Scholar]
  34. Sadasivan L., Neyra C. A. 1987; Cyst production and brown pigment formation in aging cultures of Azospirillum brasilense ATCG. 29145. Journal of Bacteriology 169:1670–1677
    [Google Scholar]
  35. Saha K. C., Sannigrahi S., Mandal L. N. 1985; Effect of inoculation of Azospirillum lipoferum on nitrogen fixation in rhizosphere soil, their association with roots, yield and nitrogen uptake by mustard (Brassica juncea). Plant and Soil 87:273–280
    [Google Scholar]
  36. Singh C. S.., Subba Rao N. S. 1979; Associative effect of Azospirillum brasilense with Rhizobium japonicum on nodulation and yield of soybean (Glycine max). Plant and Soil 53:387–392
    [Google Scholar]
  37. Smith R. L., Schank S. C., Milam J. R., Baltensperger A. A. 1984; Responses of Sorghum and Pennisetum species to the N2-fixing bacterium Azospirillum brasilense . Applied and Environmental Microbiology 47:1331–1336
    [Google Scholar]
  38. Tarrand J. J. Krieg, N. R., Dobereiner J. 1978; A taxonomic study of the Spirillum lipoferum group, with descriptions of a new genus, Azospirillum gen. nov., and two species, Azospirillum lipoferum (Beijerinck) comb. nov. and Azospirillum brasilense sp. nov. Canadian Journal of Microbiology 24:967–980
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-137-1-187
Loading
/content/journal/micro/10.1099/00221287-137-1-187
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error