Skip to main content
PMC home page
Plant Physiology logoLink to Plant Physiology
. 1991 Sep;97(1):322–329. doi: 10.1104/pp.97.1.322

Enzymes of Nitrogen Assimilation Undergo Seasonal Fluctuations in the Roots of the Persistent Weedy Perennial Cichorium intybus 1

Konrad A Sechley 1, Ann Oaks 1, J Derek Bewley 1
PMCID: PMC1081001  PMID: 16668389

Abstract

Chicory (Cichorium intybus), a deep rooted weed, grows in regions with temperate climates. Seasonal partitioning of compounds between the root and shoot results in fluctuations in the soluble carbohydrate, nitrate, amino acid, and protein pools within the roots. The activities of nitrate reductase (NR) (EC 1.6.6.1), glutamine synthetase (EC 6.3.1.2), NADH (EC 1.4.1.14), ferrodoxin glutamate synthase (EC 1.4.7.1), and glutamate dehydrogenase (GDH) (EC 1.4.1.2-4) vary throughout the year and coincide with seasonal alterations in nitrate, fructose, and sucrose. During the winter, NR, glutamine synthetase and ferrodoxin glutamate synthase activities increase in the root, while GDH displays the opposite trend with elevated activity in the summer months. All of these enzymes exhibit seasonal alterations in abundance as detected by Western blot analysis, increasing during the winter and, therefore, contributing to the seasonally dynamic protein pool. Extensive fluctuations in abundance and activity of these enzymes in the root occur during the spring and fall and coincide with shoot growth and senescence, respectively. Several observations indicate that posttranslational modifications of NR and GDH are taking place throughout the year; for example, NR is particularly unstable during the spring and fall, and seasonal GDH activity does not correlate with protein abundance.

Full text

PDF
322

Images in this article

324Figure 1
on p.324
325Figure 3
on p.325
326Figure 4
on p.326
327Figure 6
on p.327
328Figure 7
on p.328
328Figure 8
on p.328

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Dalling M. J., Tolbert N. E., Hageman R. H. Intracellular location of nitrate reductase and nitrite reductase. II. Wheat roots. Biochim Biophys Acta. 1972 Dec 14;283(3):513–519. doi: 10.1016/0005-2728(72)90267-8. [DOI] [PubMed] [Google Scholar]
  2. Hariharan I. K., Adams J. M. cDNA sequence for human bcr, the gene that translocates to the abl oncogene in chronic myeloid leukaemia. EMBO J. 1987 Jan;6(1):115–119. doi: 10.1002/j.1460-2075.1987.tb04727.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Hirel B., McNally S. F., Gadal P., Sumar N., Stewart G. R. Cytosolic glutamine synthetase in higher plants. A comparative immunological study. Eur J Biochem. 1984 Jan 2;138(1):63–66. doi: 10.1111/j.1432-1033.1984.tb07881.x. [DOI] [PubMed] [Google Scholar]
  4. Kamachi K., Yamaya T., Mae T., Ojima K. A Role for Glutamine Synthetase in the Remobilization of Leaf Nitrogen during Natural Senescence in Rice Leaves. Plant Physiol. 1991 Jun;96(2):411–417. doi: 10.1104/pp.96.2.411. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Long D. M., Oaks A. Stabilization of nitrate reductase in maize roots by chymostatin. Plant Physiol. 1990 Jul;93(3):846–850. doi: 10.1104/pp.93.3.846. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Mason H. S., Mullet J. E. Expression of two soybean vegetative storage protein genes during development and in response to water deficit, wounding, and jasmonic acid. Plant Cell. 1990 Jun;2(6):569–579. doi: 10.1105/tpc.2.6.569. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Miflin B. J. The location of nitrite reductase and other enzymes related to amino Acid biosynthesis in the plastids of root and leaves. Plant Physiol. 1974 Oct;54(4):550–555. doi: 10.1104/pp.54.4.550. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. O'Neal D., Joy K. W. Glutamine synthetase of pea leaves. I. Purification, stabilization, and pH optima. Arch Biochem Biophys. 1973 Nov;159(1):113–122. doi: 10.1016/0003-9861(73)90435-9. [DOI] [PubMed] [Google Scholar]
  9. Staswick P. E. Novel Regulation of Vegetative Storage Protein Genes. Plant Cell. 1990 Jan;2(1):1–6. doi: 10.1105/tpc.2.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Suzuki A., Vidal J., Gadal P. Glutamate synthase isoforms in rice: immunological studies of enzymes in green leaf, etiolated leaf, and root tissues. Plant Physiol. 1982 Sep;70(3):827–832. doi: 10.1104/pp.70.3.827. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Vézina L. P., Langlois J. R. Tissue and Cellular Distribution of Glutamine Synthetase in Roots of Pea (Pisum sativum) Seedlings. Plant Physiol. 1989 Jul;90(3):1129–1133. doi: 10.1104/pp.90.3.1129. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES