Plant Physiol. Illumina
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Plant Physiology 64:1070-1073 (1979)
© 1979 American Society of Plant Biologists

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Web of Science (27)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Silvius, J. E.
Right arrow Articles by Snyder, F. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Silvius, J. E.
Right arrow Articles by Snyder, F. W.
Agricola
Right arrow Articles by Silvius, J. E.
Right arrow Articles by Snyder, F. W.
Articles

Comparative Enzymic Studies of Sucrose Metabolism in the Taproots and Fibrous Roots of Beta vulgaris L

John E. Silvius and Freeman W. Snyder

United States Department of Agriculture, Science and Education Administration, Agricultural Research, Light and Plant Growth Laboratory, Plant Physiology Institute, Beltsville, Maryland 20705

Comparative enzymic studies of sugar beet (Beta vulgaris L.) taproots and fibrous roots revealed differences in invertase (EC 3.2.1.26) and sucrose synthetase (EC 2.4.1.13) activity. Invertase activity of the two root forms differs with respect to specific activity, pH optimum, and enzyme solubility. Acid invertase (pH 4.5) in the taproot was restricted to the peripheral meristematic tissue which produces cells for both taproot and fibrous root growth. This finding supports the hypothesis that the enzyme regulates sucrose partitioning between the taproot and fibrous roots. A distinct alkaline invertase (pH 8.0) was detected in sucrose storage tissues of the taproot.

The Vmax of taproot sucrose synthetase (sucrose cleavage reaction) was highest in the presence of UDP. However, the fibrous root enzyme had the highest Vmax with ADP as substrate. Differential nucleoside diphosphate substrate affinities may provide for compartmentation and separate regulation of sucrose cleavage and resultant hexose utilization in adjoining taproot and fibrous root tissues.




This article has been cited by other articles:


Home page
 Proc. Natl. Acad. Sci. USAHome page
E. Baroja-Fernandez, F. J. Munoz, A. Zandueta-Criado, M. T. Moran-Zorzano, A. M. Viale, N. Alonso-Casajus, and J. Pozueta-Romero
Most of ADP{middle dot}glucose linked to starch biosynthesis occurs outside the chloroplast in source leaves
PNAS, August 31, 2004; 101(35): 13080 - 13085.
[Abstract] [Full Text] [PDF]

Home page
 Plant Cell PhysiolHome page
E. Baroja-Fernandez, F. J. Munoz, T. Saikusa, M. Rodriguez-Lopez, T. Akazawa, and J. Pozueta-Romero
Sucrose Synthase Catalyzes the de novo Production of ADPglucose Linked to Starch Biosynthesis in Heterotrophic Tissues of Plants
Plant Cell Physiol., May 15, 2003; 44(5): 500 - 509.
[Abstract] [Full Text] [PDF]

Home page
 Plant Cell PhysiolHome page
E. Baroja-Fernandez, F. J. Munoz, T. Akazawa, and J. Pozueta-Romero
Reappraisal of the Currently Prevailing Model of Starch Biosynthesis in Photosynthetic Tissues: A Proposal Involving the Cytosolic Production of ADP-Glucose by Sucrose Synthase and Occurrence of Cyclic Turnover of Starch in the Chloroplast
Plant Cell Physiol., December 1, 2001; 42(12): 1311 - 1320.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 1979 by the American Society of Plant Biologists