ISSN:
1573-5036
Keywords:
amino acids
;
N fractions
;
nitrogen nutrition
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The influence of the source of inorganic nitrogen (KNO3, (NH4)2SO4 and NH4NO3) and its concentration (5, 10, 20 and 30 mM N) on total N incorporation, as well as on N distribution into different fractions (amminiacal, amino, amide and protein) and on free amino acid levels has been determined in grape vine explants cultured in vitro. Increasing concentrations of the nitrogen source resulted in increased total N content in tissues. This effect was small for KNO3, higher for (NH4)2SO4 and maximal for NH4NO3. In addition, nitrate promoted an increase in amino-N only, whereas ammonium increased both the ammoniacal-N and the amino-N fractions. Incorporation of N into amide-N and protein-N were not affected significantly by the N sources tested. The application of increasing quantities of N enhanced the accumulation of most free amino acids, especially arginine, alanine and proline, but to different extents, depending on both the N source and its concentration. The combination of ammonium and nitrate resulted in a higher accumulation of amino acids than that observed with either one of the two forms alone.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00012882
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