Regulation of β-Glucan Synthetase Activity by Auxin in Pea Stem Tissue: II. Metabolic Requirements
Year: 1973
Type: article
Abstract: The 2- to 4-fold rise in particle-bound beta-glucan synthetase (uridine diphosphate-glucose: beta-1, 4-glucan glucosyltransferase) activity that can be induced by indoleacetic acid in pea stem tissue is not prevented by concentrations of actinomycin D or cycloheximide that inhibit growth and macromolecule synthesis. The rise is concluded to be a hormonally induced activation of previously existing, reversibly deactivated enzyme. The activation is not a direct allosteric effect of indoleacetic acid or sugars. It is blocked by inhibitors of energy metabolism, by 2-deoxyglucose, and by high osmolarity, but not by Ca(2+) at concentrations that inhibit auxin-induced elongation and prevent promotion of sugar uptake by indoleacetic acid, and not by alpha, alpha'-dipyridyl at concentrations that inhibit formation of hydroxyproline. Regulation of the system could be due either to an ATP-dependent activating reaction affecting this enzyme, or to changes in levels of a primer or a lipid cofactor.
Source: PLANT PHYSIOLOGY
DOI: 10.1104/pp.51.4.609
Author: Peter M. Ray
Institution: Stanford University
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2074993193