biologia plantarum

Biologia plantarum 45:563-568, 2002 | DOI: 10.1023/A:1022329210127

Seasonal Changes of Nitrogen Storage Compounds in a Rhizomatous Grass Calamagrostis epigeios

V. Gloser¹

¹ Department of Plant Physiology and Anatomy, Faculty of Science, Masaryk University, Brno, Czech Republic

The seasonal dynamics in content and distribution of N-rich compounds between overwintering organs of Calamagrostis epigeios were examined. Samples were taken both from plants grown in natural conditions and in containers with controlled nutrient supply. There were significant changes in content of nitrate, free amino acids and soluble protein in all investigated plant parts during the course of a year. Amino acids showed both the highest maximum and seasonal fluctuation among the all N compounds observed and, therefore, appear to have a central role in N storage. Their content rises in the autumn, remains stable during winter and declines quickly at the beginning of spring. The most abundant amino acids in the end of winter storage period - asparagine, arginine and glutamine - constituted about 90 % of N in fraction of free amino acids. The portion of N stored in soluble proteins, however, was considerably smaller compare to both amino acids and nitrate. The amount of N stored in rhizomes of C. epigeios was smaller than in roots and stubble base before the onset of spring re-growth. This indicates that roots and stubble base are particularly important for winter N storage in this species.

Keywords: free amino acids; nitrate; nitrogen mobilization; vegetative storage proteins

Subjects: amino acids, N storage compounds; Calamagrostis epigeios; seasonal changes, N storage compounds; storage proteins, nitrogen

Published: December 1, 2002  Show citation