Abstract
In bacteria, a PII protein plays a pivotal role in regulating nitrogen assimilation in response to intracellular concentrations of glutamine (nitrogen signal) and 2-oxoglutarate (carbon signal). A PII homolog(GLB1) was recently identified from Arabidopsis thaliana. Although any function of GLB1 is unknown, it would be involved in sensing of status for intracellular nitrogen and carbon. We isolated a cDNA for a PII-like protein, OsGLB1, from rice. The OsGLB1 encodes a 212 amino acid. The predicted peptide sequence for OsGLB1 showed 74.5% and 75% identity to the other PII-like proteins from Arabidopsis thaliana and Ricinus communis, respectively. It contained a chloroplast transit peptide. Southern blot analysis suggested that OsGLB1 is a single gene in rice genome. RT-PCR analysis showed that OsGLB1 mRNA was expressed in various organs of rice plants.
