Plant and Soil

, Volume 109, Issue 2, pp 181–188

Uptake of amino acids by plants from the soil: A comparative study with castor bean seedlings grown under natural and axenic soil conditions

  • Christian Schobert
  • Walter Köckenberger
  • Ewald Komor


Castor bean seedlings grown in different media (soil, quartz sand, or liquid culture) under natural or axenic conditions take up14C labelled proline when offered to the rooting medium at concentrations similar to those occuring in the soil. Most of the absorbed proline was transferred through the root into the xylem without metabolic conversion, though some conversion to glutamine and alamine occurred.

It is concluded that roots successfully compete with microorganisms for free amino acids in the soil for the following reasons: (a) The initial rate of appearance of radioactivity in the xylem sap was the same in plants grown in natural or in axenic soil, and (b) the specific activity of proline in the xylem sap was approximately the same in plants grown in natural conditions and in axenic soil (even somewhat higher under natural condition).

The role of soil microorganisms became evident however in long-term experiments (e.g. 5h), because the soil solution was much more rapidly depleted of labelled amino acids in natural soil than in axenic soil. Therefore after 20 hours roots grown in sterilized soil or quartz sand always contained more14C label than those grown in natural soil.

It is suggested that viable roots use free amino acids from the soil and that the main flux of carbon to the rhizosphere might be in the form of organic acids.

Key words

amino acid uptake Castor bean rhizosphere root pressure exudate soil amino acids xylem sap 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Aldag R W and Young J L 1970 D-amino acids in soils. I. Uptake and metabolism by seedling maize and ryegrass. Agron. J. 62, 184–188.Google Scholar
  2. Anraku Y 1980 Transport and utilization of amino acids by bacteria. pp. 9–34.In Microorganisms and Nitrogen Sources. Ed. J W Payne, Wiley, Chichester.Google Scholar
  3. Beevers L and Hageman R H 1983 Uptake and reduction of nitrate: Bacteria and higher plants. pp 351–375.In Inorganic Plant Nutrition. Eds. A Läuchli and R L Bieleski. Encycl. Plant Physiol. New Ser. 15A.Google Scholar
  4. Bowen G D 1969 Nutrient status effects on loss of amides and amino acids from pine roots. Plant and Soil 30, 139–142.Google Scholar
  5. Clarkson D T and Warner A J 1979 Relationship between root temperature and the transport of ammonium and nitrate by italian and perennial ryegrass (Lolium multiflorum andLolium perenne). Plant Physiol. 64, 557–561.Google Scholar
  6. Frenzel B 1960 Zur Åtiologie der Anreicherung von Aminosäuren und Amiden in Wurzelraum vonHelianthus annuus L. Planta, 55, 169–207.Google Scholar
  7. Führ F and Steffens W1972 Untersuchungen zum Stoffwechsel von D-Leucin in Pflanzen. I, Wurzelaufnahme aus Nährlösung und Boden und Verteilung inVicia faba L. Landwirtsch. Forschung 25, 3, 226–236.Google Scholar
  8. Fusseder A 1987 The longevity and activity of the primary root of maize. Plant and Soil 101, 257–265.Google Scholar
  9. Ivarson K C and Katznelson H 1960 Studies on the rhizosphere microflora of yellow birch seedlings. Plant and Soil 12, 30–40.Google Scholar
  10. Kowalenko C G 1978 Organic nitrogen, phosphorous and sulfur in soils. pp 95–136.In Soil Organic Matter. Ed. M Schnitzer. Elsevier, Amsterdam.Google Scholar
  11. Lin J K and Wang C H 1980 Determination of urinary amino acids by liquid chromatography with ‘Dabsyl Chloride’. Clin. Chem. 26, 5, 579–583.Google Scholar
  12. Mengel K 1984 Stickstoff. pp 286–304.In Ernährung und Stoffwechsel der Pflanze. Gustav Fischer Verlag, Stuttgart.Google Scholar
  13. Minchin F R and Baker D A 1973 The influence of calcium on potassium fluxes across the root Ricinus communis. Planta 113, 97–104.Google Scholar
  14. Monreal C M and McGill W B 1985 Centrifugal extraction and determination of free amino acids in soil solutions by TLC using tritiated 1-Fluoro-2,4-Dinitrobenzene. Soil Biol. Biochem. 17, 4, 533–539.Google Scholar
  15. Neadle D J and Pollit R J 1965 The formation of 1-Dimethyl-amino-naphtalene-5-sulphonamide during the preparation of 1-Dimethylaminonaphtalene-5-sulphonyl-amino acids. Biochem. J. 97, 607.Google Scholar
  16. Nickell L and Maretzki A 1969 Growth of suspension cultures of sugarcane cells in chemically defined media. Physiol. Plant. 22, 117–125.Google Scholar
  17. Rovira A D and McDougall B M 1967 Microbiological and biochemical aspects of the rhizosphere, pp 417–463.In Soil Biochemistry. Eds. A D McLaren and G H Peterson. Marcel Dekker, Inc., New York.Google Scholar
  18. Róźycki H and Strzelcsyk E 1985 Synthesis of free amino acids by bacteria isolated from soil, rhizosphere, and mycorhizosphere of pine (Pinus sylvestris L.). Zbl. Mikrobiol. 140, 41–53.Google Scholar
  19. Schjorring J K 1986 Nitrate and ammonium absorption by plants growing at a sufficient or insufficient level of phosphorous in nutrient solutions. pp 53–58.In Fundamental, Ecological and Agricultural Aspects of Nitrogen Metabolism in Higher Plants. Eds. H Lambers, J J Neeteson and I Stulen. Martinus Nijhoff Pub., Dordrecht.Google Scholar
  20. Schobert C and Komor E 1987 Amino acid uptake by Ricinus communis roots: characterization and physiological significance. Plant, Cell Environ 10, 493–500.Google Scholar
  21. Stevenson F J 1982 Organic forms of soil nitrogen. pp 67–122.In Nitrogen in Agricultural soils. Ed. F J Stevenson. American Society of Agronomy, Madison.Google Scholar
  22. Stewart C R and Beevers H 1967 Gluconeogenesis from amino acids in germinating Castor bean endosperm and its role in transport to the embryo. Plant Physiol. 42, 1587–1595.Google Scholar
  23. Whipps J M and Lynch J M 1986 The influence of the rhizosphere on crop productivity. pp 187–244.In Advances in Microbioal Ecology, 9. Ed. K C Marshall. Plenum Press, New York.Google Scholar
  24. Wright D E 1962 Amino acid uptake by plant roots. Arch. Biochem. Biophys. 97, 174–180.Google Scholar

Copyright information

© Kluwer Academic Publishers 1988

Authors and Affiliations

  • Christian Schobert
    • 1
  • Walter Köckenberger
    • 1
  • Ewald Komor
    • 1
  1. 1.Lehrstuhl für PflanzenphysiologieUniversität BayreuthBayreuthFRG

Personalised recommendations