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Phytic Acid Suspension Induced by Phosphate Synthesis and Vacuolar Accumulation in Suspension-Cultured Cells of Catharanthus roseus Induced by High Concentration of Inorganic Phosphate and Cations.
- Source :
- Plant Physiology; Jul2005, Vol. 138 Issue 3, p1607-1614, 8p, 2 Black and White Photographs, 2 Diagrams, 2 Charts, 8 Graphs
- Publication Year :
- 2005
-
Abstract
- We have established a new system for studying phytic acid, myo-inositol hexakisphosphate (InsP<subscript>6</subscript>) synthesis in suspension-cultured cells of Catharanthus. InsP<subscript>6</subscript> and other intermediates of myo-inositol (Ins) phosphate metabolism were measured using an ion chromatography method. The detection limit for InsP<subscript>6</subscript> was less than 50 nM, which was sufficient to analyze Ins phosphates in living cells. Synthesis of Ins phosphates was induced by incubation in high inorganic phosphate medium. InsP<subscript>6</subscript> was mainly accumulated in vacuoles and was enhanced when cells were grown in high concentration of inorganic phosphates with the cations K<superscript>+</superscript> Ca<superscript>2+</superscript>, or Zn<superscript>2+</superscript>. However, there was a strong tendency for InsP<subscript>6</subscript> to accumulate in the vacuole in the presence of Ca<superscript>2+</superscript> and in nonvacuolar compartments when supplied with Zn<superscript>2+</superscript>, possibly due to precipitation of InsP<subscript>6</subscript> with Zn<superscript>2+</superscript> in the cytosol. A vesicle transport inhibitor, brefeldin A, stimulated InsP<subscript>6</subscript> accumulation. The amounts of both Ins(3)P<subscript>1</subscript> myo-inositol monophosphate synthase, a key enzyme for InsP<subscript>6</subscript> synthesis, and Ins(1,4,5)P<subscript>3</subscript> kinase were unrelated to the level of accumulation of InsP<subscript>6</subscript>. The mechanisms for InsP<subscript>6</subscript> synthesis and localization into vacuoles in plant cells are discussed. [ABSTRACT FROM AUTHOR]
- Subjects :
- PHYTIC acid
CATHARANTHUS roseus
PHOSPHATES
CATHARANTHUS
CATIONS
PLANT physiology
Subjects
Details
- Language :
- English
- ISSN :
- 00320889
- Volume :
- 138
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Plant Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 17788753
- Full Text :
- https://doi.org/10.1104/pp.105.060269