Advertisement

Conversion of Tryptophan, Indole-3-Pyruvic Acid, Indole-3-Lactic Acid and Indole to Indole-3-Acetic Acid by Azospirillum brasilense Sp7

  • Tami Bar
  • Yaacov Okon
Part of the NATO ASI Series book series (volume 37)

Abstract

The free-living nitrogen-fixing soil bacterium Azospirillum brasilense Sp7 produces indole-3-acetic acid (IAA) from tryptophan (Trp). Ammonia and oxygen are involved in the processes of IAA production and nitrogen fixation. Oxygen is required during the conversion of Trp to IAA via indole-3-acetamide (IAM). One ammonia molecule is released during the conversion of Trp to IAA. Under microaerophilic conditions, the cells were found to preferentially catalyze the enzymatic conversion of the tryptophan deaminated compound indole-3-pyruvic acid (IPyA) to IAA. Addition of ammonia caused a decrease in the conversion of Trp and IPyA but not indole-3-lactic acid (ILA) to IAA. Indole-3-pyruvic acid was found in the growth medium after addition of either Trp or ILA, indicating the function of an aminotransferase pathway for IAA synthesis from Trp. Three tryptophan-aminotransferases were observed on nondenaturing gels. No tryptophan-aminotransferase activity was observed upon addition of IPyA to the bacterial culture. Addition of 0.5 mM indole to the growth medium resulted in accumulation of IAA by an enzymatic process. Holotryptophanase activity was detected in cell-free extracts of A. brasilense Sp7 grown in a medium amended with indole. Addition of Trp to A. brasilense Sp7 culture as the sole N source partially inhibited nitrogenase activity. Study of the factors affecting both IAA production and nitrogen fixation is important for better understanding of the bacterial-plant association.

Keywords

Nitrogen Fixation Indole Derivative Azospirillum Brasilense Microaerophilic Condition Acetylene Reduction Activity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Badenoch-Jones J, Summons RE, Entsch B, Rolfe BG, Parker CW and Letham DS (1982) Mass spectrometric identification of indole compounds produced by Rhizobium strains. Biomed Mass Spectron 9: 429–437.CrossRefGoogle Scholar
  2. Bar T and Okon Y (1992) Induction of indole-3-acetic acid synthesis and possible toxicity of tryptophan in Azospirillum brasilense Sp7. Symbiosis 13: 191–198.Google Scholar
  3. Bar T and Okon Y (1993) Tryptophan conversion to indole-3-acetic acid via indole-3- acetamide in Azospirillum brasilense Sp7. Can J Microbiol 39: 81–86.CrossRefGoogle Scholar
  4. Behbahni-Nejad I, Dye JL and Suelter CH (1987) Tryptophanase from Escherichia coli B/It7- A. Method in Enzymol 142: 414–422.CrossRefGoogle Scholar
  5. Berman J., Gershoni JM and Zamir A (1985) Expression of nitrogen fixation genes in foreign hosts. J Biol Chem 260: 5240–5243.PubMedGoogle Scholar
  6. Bottini R, Fulchieri M, Pearce D and Pharis, RP (1989) Identification of gibberellins Al, A3 and iso-A3 in culture of Azospirillum lipoferum. Plant Physiol 89: 1–3.CrossRefGoogle Scholar
  7. Clark E, Manulis S, Ophir Y, Barasch I and Gafni Y (1993) Cloning and characterization of iaaM and iaaH from Erwinia herbicola pathovar ghysophilae. Phytopathol 83: 234–240.CrossRefGoogle Scholar
  8. Cohen JD and Bialek K (1984) The biosynthesis of indole-3-acetic acid in higher plants. In: The Biosynthesis and Metabolism of Plant Hormones, pp. 165–181, A. Crozier and JR Hillman (eds.). Cambridge University Press, Cambridge, Mass.Google Scholar
  9. Crozier A, Arruda P, Jasmin JM, Monterio AM and Sandberg G (1988) Analysis of indole-3- acetic acid and related indoles in culture medium from Azospirillum lipoferum and Azospirillum brasilense. Appl Environ Microbiol 54: 2833–2837.PubMedGoogle Scholar
  10. Dobereiner J and Pedrosa FO (1987) Nitrogen-fixing bacteria in nonleguminous crop plants. In: Brock Springer Series in Contemporary Biology, pp. 1–155, Sciencia Tech Publishers: Madison Wis. Springer Berlin.Google Scholar
  11. Dreyfus BL, Diem HG and Dommergues YR (1988) Future directions for biological nitrogen fixation research. Plant Soil 108: 191–199.CrossRefGoogle Scholar
  12. Ernstsen A, Sandberg G and Crozier A (1986) Effects of sodium diethyldithiocarbamate, solvent, temperature and plant extracts on the stability of indoles. Physiol Plant 68: 519–522.CrossRefGoogle Scholar
  13. Fallik E, Okon Y, Epstein E, Goldman A and Fischer M (1989) Identification and quantification of IAA and IB A in Azospirillum brasilense - inoculated maize roots. Soil Biol Biochem 21: 147–153.CrossRefGoogle Scholar
  14. Frankenberger WT Jr and Poth M (1987) Determination of substituted indole derivatives by ion suppression-reverse-phase high-performance liquid chromatography. Anal Biochem 165: 300–308.PubMedCrossRefGoogle Scholar
  15. Garcia-Rodriguez T, Gutierrez-Navarro AM, Garcia R and Perez Silva J (1982) Indole acetic acid production by Rhizobium: effect of 2-ketoglutaric acid. Soil Biol Biochem 14: 153–155.CrossRefGoogle Scholar
  16. Hartmann A and Burris RH (1987) Regulation of nitrogenase activity by oxygen in Azospirillum brasilense and Azospirillum lipoferum. J Bacterid 169: 944–948.Google Scholar
  17. Hartmann A, Fu H and Burris RH (1988) Influence of amino acids on nitrogen fixation ability and growth of Azospirillum spp. Appl Environ Microbiol 54: 87–93.PubMedGoogle Scholar
  18. Hartmann A, Singh M and Klingmuller W (1983) Isolation and characterization of Azospirillum mutants excreting high amounts of indoleacetic acid. Can J Microbiol 29: 916–923.CrossRefGoogle Scholar
  19. Hutcheson SW and Kosuge T (1985) Regulation of 3-indoleacetic acid production in Pseudomonas syringae pv. savastanoi. Purification and properties of tryptophan 2- monoxygenase. J Biol Chem 260: 6281–6287.PubMedGoogle Scholar
  20. Kaneshiro T, Slodki ME and Plattner RD (1983) Tryptophan catabolism to indolepyruvic and indoleacetic acids by Rhizobium japonicum L-259 mutants. Curr Microbiol 8: 301–306.CrossRefGoogle Scholar
  21. Kittell BL, Helinski DR and Ditta GS (1989) Aromatic aminotransferase activity and indoleacetic acid production in Rhizobium meliloti. J Bacteriol 171: 5458–5466.PubMedGoogle Scholar
  22. Loper JE and Schroth MN (1986) Influence of bacterial soufce of indole-3-acetic acid on root elongation of sugar beet. Phytopathology 76: 386–389.CrossRefGoogle Scholar
  23. Okon Y (1985) Azospirillum as a potential inoculant for agriculture. Trends Biotechnol 3:223–228.CrossRefGoogle Scholar
  24. Omay SH, Schmidt WA and Martin P (1992) Indoleacetic acid production by the rhizosphere bacterium Azospirillum brasilense Cd under in vitro conditions. Can J Microbiol 39: 187–192.CrossRefGoogle Scholar
  25. Paris CG and Magasanik B (1981) Tryptophan metabolism in Klebsiella aerogenes: regulation of the utilization of aromatic amino acid as source of nitrogen. J Bacteriol 145: 257–265.PubMedGoogle Scholar
  26. Perez-Galdona R, Corzo J, Leon-Barrios M and Gutierrez-Navarro AM (1989) Aromatic amino acid aminotransferases in Rhizobium leguminosarum biovar trifolii. Their role in indoleacetic acid synthesis. Soil Biol Biochem 21: 573–579.Google Scholar
  27. Ruckdaschel E. Kittell BL, Helinski DR and Klingmuller W (1988) Aromatic amino acid aminotransferases of Azospirillum lipoferum and their possible involvement in IAA biosynthesis. In: Azospirillum IV: Genetics, Physiology, Ecology, pp. 49–53, W Klingmuller (ed.) Springer Verlag, Berlin and Heidelberg.Google Scholar
  28. Sanchez-Alonso MPG, Varzquez-Cruz C, Martinez-Morales LU, Fluren-Martinez BE and Baca BE (1992) Enzymatic activities involved in auxin indoleacetic acid (IAA) biosynthesis and their relationship with plasmids harboured in Azospirillum strains. Rev Lat Amer Microbiol 33: 25–34.Google Scholar
  29. Sekine M, Watanabe K and Syono (1989) Molecular cloning of a gene for indole-3-acetamide hydrolase from Bradyrhizobium japonicum.. J Bacteriol 171: 1718–1724.PubMedGoogle Scholar
  30. Thomashow LS, Reeves S and Thomashow MF (1984) Crown gall oncogenesis: evidence that a T-DNA gene from the Agrobacterium Ti plasmid pTiA6 encodes an enzyme that catalyzes synthesis of indoleacetic acid. Proc Nat Acad Sci USA 81: 5071–5075.PubMedCrossRefGoogle Scholar
  31. Tien TM, Gaskins MH and Hubbell DH (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.PubMedGoogle Scholar
  32. Trinchant JC and Rigaud J (1974) Lactate dehydrogenase from Rhizobium. Purification and role in indole metabolism. Physiol Plant 32: 394–399.CrossRefGoogle Scholar
  33. Yamada T, Palm, CJ, Brooks B and Kosuge T. (1985) Nucleotide sequences of the Pseudomonas savastanoi indoleacetic acid genes show homology with Agrobacterium tumefaciens T-DNA. Proc Natl Acad Sci USA 82: 6522–6526.PubMedCrossRefGoogle Scholar
  34. Zimmer W, Roeben K and Bothe H (1988) An alternative explanation for plant growth promotion by bacteria of the genus Azospirillum. Planta 176: 333–342.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1995

Authors and Affiliations

  • Tami Bar
    • 1
  • Yaacov Okon
    • 1
  1. 1.Department of Plant Pathology & Microbiology Faculty of AgricultureThe Hebrew University of JerusalemRehovotIsrael

Personalised recommendations