Do rice suspension-cultured cells treated with abscisic acid mimic developing seeds?
Starch synthesis is activated in the endosperm during seed development and also in rice suspension cells cultured with abscisic acid. In the anticipation that the mechanisms of starch synthesis are similar between the endosperm and the suspension cells cultured with abscisic acid, expression of genes involved in starch synthesis was evaluated in the suspension cells after abscisic acid treatment. However, it was found that the regulatory mechanism of starch synthesis in the suspension cells cultured with abscisic acid was different from that in developing seeds. Expression analyses of genes involved in oil bodies, which accumulate in the embryo and aleurone layer, and seed storage proteins, which accumulate mainly in the endosperm, showed that the former were activated in the suspension cells cultured with abscisic acid, but the latter were not. Master regulators for embryogenesis, OsVP1 (homologue of AtABI3) and OsLFL1 (homologue of AtFUS3 or AtLFL2), were expressed in the suspension cells at levels comparable to those in the embryo. From these results, it is suggested that interactions between regulators and abscisic acid control the synthesis of phytic acid and oil bodies in the cultured cells and embryo. We suggest that the system of suspension cells cultured with abscisic acid helps to reveal the mechanisms of phytic acid and oil body synthesis in embryo.
Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan, s0921207@gmail.com.
Koya
K
Matsuno
Tatsuhito
T
Fujimura
D000040:Abscisic Acid / Q000494:pharmacology*; D002478:Cells, Cultured; D016000:Cluster Analysis; D004305:Dose-Response Relationship, Drug; D056625:Endosperm / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D066292:Lipid Droplets / Q000378:metabolism; D012275:Oryza / Q000166:cytology*; D010833:Phytic Acid / Q000096:biosynthesis; D059828:Plant Cells / Q000187:drug effects* / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D013213:Starch / Q000096:biosynthesis; D013997:Time Factors
D010937:Plant Growth Regulators; D010940:Plant Proteins; D000040:Abscisic Acid; D010833:Phytic Acid; D013213:Starch