Applied Microbiology and Biotechnology

, Volume 75, Issue 5, pp 1143–1150 | Cite as

Plant-growth-promoting compounds produced by two agronomically important strains of Azospirillum brasilense, and implications for inoculant formulation

  • D. Perrig
  • M. L. Boiero
  • O. A. Masciarelli
  • C. Penna
  • O. A. Ruiz
  • F. D. Cassán
  • M. V. LunaEmail author
Applied Microbial and Cell Physiology


We evaluated phytohormone and polyamine biosynthesis, siderophore production, and phosphate solubilization in two strains (Cd and Az39) of Azospirillum brasilense used for inoculant formulation in Argentina during the last 20 years. Siderophore production and phosphate solubilization were evaluated in a chemically defined medium, with negative results. Indole 3-acetic acid (IAA), gibberellic acid (GA3), and abscisic acid (ABA) production were analyzed by gas chromatography-mass spectrometry. Ethylene, polyamine, and zeatin (Z) biosynthesis were determined by gas chromatography-flame ionization detector and high performance liquid chromatography (HPLC-fluorescence and -UV), respectively. Phytohormones IAA, Z, GA3, ABA, ethylene, and growth regulators putrescine, spermine, spermidine, and cadaverine (CAD) were found in culture supernatant of both strains. IAA, Z, and GA3 were found in all two strains; however, their levels were significantly higher (p < 0.01) in Cd (10.8, 2.32, 0.66 μg ml−1). ABA biosynthesis was significantly higher (p < 0.01) in Az39 (0.077 μg ml−1). Ethylene and polyamine CAD were found in all two strains, with highest production in Cd cultured in NFb plus l-methionine (3.94 ng ml−1 h−1) and Az39 cultured in NFb plus l-lysine (36.55 ng ml−1 h−1). This is the first report on the evaluation of important bioactive molecules in strains of A. brasilense as potentially capable of direct plant growth promotion or agronomic yield increase. Az39 and Cd showed differential capability to produce the five major phytohormones and CAD in chemically defined medium. This fact has important technological implications for inoculant formulation as different concentrations of growth regulators are produced by different strains or culture conditions.


Azospirillum Abscisic acid Gibberellic acid Indole 3-acetic acid Ethylene Cadaverine Plant-growth-promoting rhizobacteria 



We are grateful to Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Secretaría de Ciencia y Técnica de la Universidad Nacional de Río Cuarto, and Nitragin Argentina SA for their support in this research.


  1. Aziz A, Martin-Tanguy J, Larher F (1997) Plasticity of polyamine metabolism associated with high osmotic stress in rape leaf discs and with ethylene treatment. Plant Growth Regul 21:153–163CrossRefGoogle Scholar
  2. Bashan Y, Holguin G (1997) Azospirillum–plant relationships: environmental and physiological advances. Can J Microbiol 43:103–121CrossRefGoogle Scholar
  3. Bashan Y, Holguín G (1998) Proposal for the division of plant growth-promoting rhizobacteria into two classifications: biocontrol-PGPB (plant growth promoting bacteria) and PGPB. Soil Biol Biochem 30:1225–1228Google Scholar
  4. Bashan Y, Levanony H (1990) Current status of Azospirillum inoculation technology: Azospirillum as a challenge for agriculture. Can J Microbiol 36:591–608CrossRefGoogle Scholar
  5. Bashan Y, Holguin G, de-Bashan L (2004) Azospirillum–plant relationships: physiological, molecular, agricultural, and environmental advances (1997–2003). Can J Microbiol 50:521–577CrossRefGoogle Scholar
  6. Bottini R, Fulchieri M, Pearce D, Pharis R (1989) Identification of gibberellins A1, A3, and Iso-A3 in cultures of A. lipoferum. Plant Physiol 90:45–47PubMedPubMedCentralGoogle Scholar
  7. Cassán F, Paz R, Maiale S, Masciarelli O, Vidal A, Luna V, Ruíz O (2005) Cadaverine production by Azospirillum brasilense az39. A new plant growth promotion mechanism. XV Annual Meeting Cordoba Biology Society, Argentina, p 10Google Scholar
  8. Crozier A, Arruda P, Jasmim JM, Monteiro AM, Sandberg G (1988) Analysis of indole-3-acetic acid and related indoles in culture medium from Azospirillum lipoferum and Azospirillum brasilense. Appl Environ Microbiol 54:2833–2837CrossRefGoogle Scholar
  9. Dobbelaere S, Croonenborghs A, Thys A, Vande Broek A, Vanderleyden J (1999) Phytostimulatory effect of Azospirillum brasilense wild type and mutant strains altered in IAA production on wheat. Plant Soil 212:155–164CrossRefGoogle Scholar
  10. Döbereiner J, Pedroza F (1987) Nitrogen-fixing bacteria in nonleguminous crop plants. Science Tech, Madison, WI, pp 1–155Google Scholar
  11. Döbereiner J, Marriel I, Nery M (1976) Ecological distribution of Spirillum lipoferum Beijerinck. Can J Microbiol 22:1464–1473CrossRefGoogle Scholar
  12. Hamana K, Matsuzaki S, Sakakibara M (1988) Completar. Int J Syst Bacteriol 38:89–98CrossRefGoogle Scholar
  13. Horemans S, Koninck K, Neuray J, Hermans R, Vlassak K (1986) Production of plant growth substances by Azospirillum sp. and other rhizophere bacteria. Symbiosis 2:341–346Google Scholar
  14. Janzen R, Rood S, Dormar J, McGill W (1992) Azospirillum brasilense produces gibberellins in pure culture and chemically-medium and in co-culture on straw. Soil Biol Biochem 24:1061–1064CrossRefGoogle Scholar
  15. Katznelson H, Bose B (1959) Metabolic activity and phosphate-dissolving capability of bacterial isolates from wheat roots, rhizosphere, and non-rhizosphere soil. Can J Microbiol 5:79–85CrossRefGoogle Scholar
  16. Kolb W, Martin P (1985) Response of plant roots to inoculation with Azospirillum brasilense and to application of indoleacetic acid. In: Klingmüller W (ed) Azospirillum III: genetics, physiology, ecology. Springer, Berlin, pp 215–221CrossRefGoogle Scholar
  17. Kovats E (1958) Gas chromatographische charakteriserung organischer verbindungen I. Retentions indices aliphatischer halogenide, alkohole, aldehyde und ketone. Helv Chim Acta 41:1915–1932CrossRefGoogle Scholar
  18. Niemi K, Häggman H, Sarjala T (2002) Effects of exogenous diamines on the interaction between ectomycorrhizal fungi and adventicius root formation in Scots pines in vitro. Tree Physiol 22:373–381CrossRefGoogle Scholar
  19. Okon Y, Labandera-González C (1994) Agronomic applications of Azospirillum: an evaluation of 20 years worlwide field inoculation. Soil Biol Biochem 26:1591–1601CrossRefGoogle Scholar
  20. Pan B, Bai Y, Leibovitch S, Smith D (1999) Plant-growth-promoting rhizobacteria and kinetin as ways to promote corn growth and yield in a short-growing-season area. Eur J Agron 11:179–186CrossRefGoogle Scholar
  21. Peck S, Kende H (1995) Sequential induction of the ethylene biosynthetic enzymes by indole-3-acetic acid in etiolated peas. Plant Mol Biol 28:298–301CrossRefGoogle Scholar
  22. Ribaudo C, Krumpholz E, Cassán F, Bottini R, Cantore M, Curá A (2006) Azospirillum sp. promotes root hair development in tomato plants through a mechanism that involves ethylene. J Plant Growth Regul 24:175–185CrossRefGoogle Scholar
  23. Saxena B, Modi M, Modi V (1986) Isolation and characterization of siderophores from Azospirillum lipoferum D-2. J Gen Microbiol 132:2219–2224Google Scholar
  24. Schwyn B, Neilands J (1987) Universal assay for detection and determination of siderophores. Anal Biochem 160:47–56CrossRefGoogle Scholar
  25. Seshadri S, Muthukumarasamy R, Lakshinarasimhan C, Ignacimuthu S (2000) Solubilization of inorganic phosphates by Azospirillum halopraeferans. Curr Sci 79:565–567Google Scholar
  26. Strzelczyk E, Kamper M, Li C (1994) Cytocinin-like-substances and ethylene production by Azospirillum in media with different carbon sources. Microbiol Res 149:55–60CrossRefGoogle Scholar
  27. Thuler D, Flosh E, Handro W, Barbosa M (2003) Plant growth regulators and amino acids released by Azospirillum sp. in chemically defined medium. Lett Appl Microbiol 37:174–178CrossRefGoogle Scholar
  28. Tiburcio AF, Altabella T, Borrell A, Masgrau C (1997) Polyamine metabolism and its regulation. Physiol Plant 100:664–674CrossRefGoogle Scholar
  29. Tien TM, Gaskins MH, 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 37:1016–1024CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • D. Perrig
    • 1
  • M. L. Boiero
    • 1
  • O. A. Masciarelli
    • 1
  • C. Penna
    • 2
  • O. A. Ruiz
    • 3
  • F. D. Cassán
    • 1
  • M. V. Luna
    • 1
    Email author
  1. 1.Laboratorio de Fisiología Vegetal, Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y NaturalesUniversidad Nacional de Río Cuarto, Campus UniversitarioRío Cuarto, CórdobaArgentina
  2. 2.Departamento de Investigación y DesarrolloNitragin Argentina SAPilar, Buenos AiresArgentina
  3. 3.Instituto de Investigaciones Biológicas—Instituto Tecnológico de ChascomúsBuenos AiresArgentina

Personalised recommendations