Abstract
Phytate is a major P-storage compound, which are synthesized during seed maturation and accumulated into vacuoles as a Ca/Mg-binding form. We have already succeeded to induce synthesis of phytate and accumulation into vacuoles in suspension-cultured Catharanthus and Arabidopsis cells by Pi supplement. We investigated the effects of metal ions on phytate synthesis. In the Catharanthus cells supplemented with both Pi and metals, phytate was accumulated much greater than in cells supplemented with Pi only. The protein amount of inositol monophosphate synthase, a key enzyme for phytate synthesis, was almost constant. In the cells supplemented with Ca, phytate was accumulated into vacuoles, while the cells supplemented with Zn, phytate was not accumulated into vacuoles. In this study, we examine about subcellular localization of phytate and Zn in Zn-supplied cells. Moreover, we are going to report about characteristic analyses of inositol phosphate kinases concerning with phytate synthesis.
