Nitrogen metabolism of young barley plants as affected by NaCl-salinity and potassium
- 141 Downloads
In a solution culture experiment with 31 days old barley plants (var. Miura) the influence of NaCl-salinization (80 mM) and KCl addition (5 and 10 mM) on the uptake and turnover of labelled nitrogen (15NH415NO3) was studied. Labelled N was applied for 24 h at the end of a 20 days' salinization period. Salinization impaired growth and incorporation of labelled N into the protein fraction paralleled by accumulation of labelle dinorganic N. All salt effects were much more pronounced in the shoots than in the roots.
Potassium addition enhanced N uptake (total15N-content) and incorporation into protien, reduced the accumulation of inorganic N and improved the growth of salinized plants.
The presented data support the point of view that impairment of protein (enzyme) metabolism is an important aspect of salt stress which is probably induced by the disturbance of the K/Na balance of the tissues under saline conditions.
Key WordsBarley Chloride Growth Nitrogen metabolism Potassium Salinity Sodium
Unable to display preview. Download preview PDF.
- 1.Ben-Zioni, A., Itai, C. and Vaadia, Y. 1967 Water and salt stress, kinetin and protein synthesis in tobacco leaves. Plant Physiol.42, 361–365.Google Scholar
- 2.Conway, T. W. and Lipman, F. 1964 Characterization of a ribosome-linked guanosine triphosphatase in Escherichia coli extracts. Proc. Natl. Acad. Sci. U.S.52, 1462–1469.Google Scholar
- 3.Helal, H. M., Koch, K. and Mengel, K. 1975 Effect of salinity and potassium on the uptake of nitrogen and on nitrogen metabolism in young barley plants. Physiol. Plant.35, 310–313.Google Scholar
- 4.Huffaker, R. C. and Peterson, L. 1974 Protein turnover in plants and possible means of its regulation. Annu. Rev. Plant Physiol.25, 363–392.Google Scholar
- 5.Kahane, I. and Poljakoff-Mayber, A. 1968 Effect of substrate salinity on the ability for protein synthesis in pea roots. Plant Physiol.43, 1115–1119.Google Scholar
- 6.Kessler, B. and Snir, I. 1969 Salt effects on nucleic acids and protein metabolism in Citrus seedlings. Proc. 1st Int. Citrus Symp.1, 381–386.Google Scholar
- 7.Langdale, G. W., Thomas, J. R. and Littleton, T. G. 1973 Nitrogen metabolism of stargrass as affected by nitrogen and soil salinity. Agron. J.65, 468–470.Google Scholar
- 8.Lubin, M. 1963 Cell potassium and the regulation of protein synthesis.In The cellular functions of membrane transport (J. E. Hoffman, ed.), pp. 193–211. Prentice-Hall Inc., Englewood Cliffs, New Jersey.Google Scholar
- 9.Meier, G. and Müller, G. 1963 Zur emissionsspektroskopischen Isotopenanalyse des Stickstoffs mit photoelektrischer Registrierung. Isotopenpraxis1, 53–62.Google Scholar
- 10.Weimberg, R. 1975 Effect of growth in highly salinized media on the enzymes of the photosynthetic apparatus in Pea seedlings. Plant Physiol.56, 8–12.Google Scholar