Open AccessHormonal Control of Lecithin Synthesis in Barley Aleurone Cells: Regulation of the CDP-Choline Pathway by Gibberellin
Author(s) -
Kenneth D. Johnson,
Hans Kende
Publication year - 1971
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.68.11.2674
Subject(s) - gibberellin , aleurone , biochemistry , phosphorylcholine , enzyme , chemistry , lecithin , choline , biology , botany
The enzymes of the cytidine diphosphate-choline pathway, which is involved in lecithin biosynthesis, are present in imbibed barley aleurone cells. The first enzyme, choline kinase (EC 2.7.1.32), is found in the soluble protein fraction. Its activity is not affected by prior treatment of aleurone layers with gibberellin. The second and third enzymes of the pathway, phosphorylcholine-cytidyl (EC 2.7.7.15) and phosphorylcholine-glyceride (EC 2.7.8.2) transferases, are associated with the particulate fractions. Their activities are greatly increased by gibberellin treatment during the lag phase (0-8 hr) of gibberellin-effected α-amylase synthesis. The hormonal effects are evident two hours after gibberellin treatment. Inhibitors that block gibberellin-effected α-amylase formation also inhibit the stimulation of these membrane-bound enzymes by the hormone.