Summary
Spirodela oligorrhiza grown in sterile culture was able to use urea as sole source of nitrogen but only when the pH of the culture medium was below 4.3. Plants inoculated into urea media at pH 6.4 initially made little growth and became nitrogen-deficient in appearance and composition although they contained about 100 μgrams of urea per gram fresh weight of tissue. After a period the pH of the medium usually fell below 4.3 and growth commenced. Growth with other compounds, e.g. ammonium, nitrate or allantoin, as sources of nitrogen was not similarly affected by the pH of the culture medium.
Urease activity could always be detected in the tissues of Spirodela oligorrhiza growing on urea. Plants with little or no urease activity soon developed significant activity when inoculated into urea media at pH 4.0. When the pH of the medium was higher there was no increase in urease activity and no growth ensued. Plants growing on urea possessed an activity of about 50 milliunits per gram fresh weight of tissue, but if the pH of the medium fell to 3.5 or lower, the activity present rose to 10 times this level.
Urease activity also appeared, in the absence of supplied urea, as plants became increasingly nitrogen-deficient.
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References
Baker, J. E., and J. F. Thompson: Metabolism of urea and ornithine cycle intermediates by nitrogen-starved cells of Chlorella vulgaris. Plant Physiol. 37, 618–624 (1962).
Bieleski, R. L., and N. A. Turner: Separation and estimation of amino acids in crude plant extracts by thin-layer electrophoresis and chromatography. Analyt. Biochem. 17, 278–293 (1966).
Bollard, E. G.: Urease, urea and ureides in plants. Symp. Soc. exp. Biol. 13, 304–329 (1959).
—: A comparative study of the ability of organic nitrogenous compounds to serve as sole sources of nitrogen for the growth of plants. Plant and Soil 25, 153–166 (1966).
De Turk, W. E.: The adaptive formation of urease by washed suspensions of Pseudomonas aeruginosa. J. Bact. 70, 187–191 (1955).
Ferguson, A. R.: Responses of Spirodela oligorrhiza to changes in its nutrient environment. Dissertation M. Sc., University of Auckland, New Zealand (1966).
Hattori, A.: Studies on the metabolism of urea and other nitrogenous compounds in Chlorella ellipsoidea. I. Assimilation of urea and other nitrogenous compounds by nitrogen-starved cells. J. Biochem. 44, 253–273 (1957).
—: Studies on the metabolism of urea and other nitrogenous compounds in Chlorella ellipsoidea. II. Changes on levels of amino acids and amides during the assimilation of ammonia and urea by nitrogen-starved cells. J. Biochem. 45, 57–64 (1958).
Kleczkowski, K., U. Hiort u. H. Kating: Untersuchungen zum Stoffwechsel des Harnstoffs bei Mikroorganismen. IV. Adaptive Ureasebildung bei Micrococcus denitrificans Beij. Arch. Mikrobiol. 54, 177–183 (1966).
König, C., H. Kaltwasser u. H. G. Schlegel: Die Bildung von Urease nach Verbrauch der äußeren N-Quelle bei Hydrogenomonas H16. Arch. Mikrobiol. 53, 231–241 (1966).
Little, L. W. and R. A. Mah: Ammonia production in urea-grown cultures of Chlorella ellipsoidea. Bact. Proc. 34 (1967).
Magaña-Plaza, I., and J. Ruiz-Herrera: Mechanisms of regulation of urease biosynthesis in Proteus rettgeri. J. Bact. 93, 1294–1301 (1967).
Matsumoto, H., M. Kobayashi, and E. Takahashi: Studies on induced biosynthesis of urease in the leaf. I. Protein metabolism (in Japanese). J. Sci. Soil Manure (Japan) 37, 315–320 (1966a).
—, T. Yasuda, M. Kobayashi, and E. Takahashi: The inducible formation of urease in rice plants. Soil Sci. Plant Nutr. 12, 239–244 (1966b).
Mehta, S. L., M. S. Naik, and N. B. Das: Induced synthesis of urease in Azotobacter vinelandii. Indian J. Biochem. 4, 194–196 (1967).
Middelhoven, W. J.: The derepression of arginase and of ornithine transaminase in nitrogen-starved baker's yeast. Biochim. biophys. Acta (Amst.) 156, 400–443 (1968).
Mokronosov, A. T., Z. G. Ilinykh, and N. I. Shukolyukova: Assimilation of urea by potato plants. Fiziol. Rastenij (Soviet Plant Physiol.) 13, 707–713 (1966).
Trijbels, F., and G. D. Vogels: Allantoicase and ureidoglycolase in Pseudomonas and Penicillium species. Biochim. biophys. Acta (Amst.) 118, 387–395 (1966).
Valentine, R. C., R. Bojanowski, E. Gaudy, and R. S. Wolfe: Mechanism of the allantoin fermentation. J. biol. Chem. 237, 2271–2277 (1962).
Yemm, E. W., and E. C. Cocking: The determination of amino acids with ninhydrin. Analyst 80, 209–214 (1955).
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Bollard, E.G., Cook, A.R. & Turner, N.A. Urea as sole source of nitrogen for plant growth. Planta 83, 1–12 (1968). https://doi.org/10.1007/BF00385130
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DOI: https://doi.org/10.1007/BF00385130