Abstract
In higher plants, some of the genes involved in nitrogen metabolism, such as OsNADH-GOGAT1, are regulated by glutamine (Gln). This suggests that the occurrence of Gln-sensing and -signaling systems. To understand the molecular mechanism of Gln-sensing and -signaling systems, we have focused on ACT domain repeat proteins (ACRs) as a candidate of Gln sensor. Nine genes encoding ACR proteins (OsACR1-9) are found in rice genome. The transcripts of OsACR1 and OsACR5 to OsACR9 were detected. In leaf blades, the accumulation of OsACR9 transcript was maximal at the early stage of development. To analyze the profile of ACR9 protein in rice, an antibody specific to ACR9 was generated. Immunoblot analyses in various organs of rice showed that this protein was accumulated in both leaf blade and panicle during the life-span, with relatively a high accumulation in those organs at the early stage of development. Subcellular/cellular localization of ACR9 will be reported.
