Effects of Nitrogen Source and Concentration on the Free Amino Acid Composition of Developing Wheat Grains
- 1 January 1990
- journal article
- research article
- Published by CSIRO Publishing in Functional Plant Biology
- Vol. 17 (2), 199-206
- https://doi.org/10.1071/pp9900199
Abstract
Detached wheat heads (7 days post-anthesis) were grown in liquid culture containing nitrogen concentrations of 0.025% or 0.1% in the form of glutamine, ammonium nitrate or asparagine. With each form of the nitrogen, increasing the concentrations of nitrogen in the culture medium led to increases in the total nitrogen and the non-protein nitrogen in the grain. Protein contents (N × 5.7) were approximately 16% and 21% on a dry weight basis in the low and high treatments respectively for all nitrogen sources. Amino acids from the endosperm cavity, the ethanol-soluble extract of the grain, and the grain protein were analysed by HPLC techniques to define the site of transfer between amino acid forms. The results indicated that amino nitrogen from glutamine, ammonium nitrate, or asparagine enters the grain and is found in the endosperm cavity fluid mainly in the form of glutamine, alanine and, to a lesser extent, aspartate (including asparagine). These amino acids are then converted into the various other amino acids required for protein synthesis, as is demonstrated by the increases found in the others in the ethanol-soluble free amino acid fraction with different nitrogen regimes. These variations in the composition of the free amino acids occurred without altering the amino acid composition of the protein component of the grain.Keywords
This publication has 8 references indexed in Scilit:
- Amino Acid Composition Along the Transport Pathway during Grain Filling in WheatPlant Physiology, 1986
- The separation of o-phthalaldehyde derivatives of amino acids by reversed-phase chromatography on octylsilica columnsAnalytical Biochemistry, 1986
- The amino acid composition of wheat grain as a function of nitrogen contentJournal of Cereal Science, 1985
- Nitrogen redistribution during grain growth in wheat (Triticum aestivum L.)Planta, 1981
- The nitrate content and amino acid composition of the xylem fluid of spring wheat throughout the growing seasonJournal of the Science of Food and Agriculture, 1979
- Effect of Nitrogen Source on Grain Development in Detached Wheat Heads in Liquid CultureFunctional Plant Biology, 1978
- Influence of Nitrogen Source on Nitrogen Metabolism in Detached Wheat HeadsFunctional Plant Biology, 1978
- The growth of detached wheat heads in liquid culturePlant Science Letters, 1977