Abstract
We previously reported comprehensive analysis of nitrogen-responsive gene expression in the shoots of rice and identified two MYB proteins (MYB-NR1 and MYB-NR2) as candidates for nitrogen-responsive transcription factors in rice. Here we show our recent progress in the analysis of nitrogen-responsive gene expression in rice. We found that a nitrogen-supply up-regulated 732 genes and down-regulated 190 genes in the roots of rice. Our analysis also revealed that MYB-NR1 and MYB-NR2 are induced by the nitrogen-supply in both shoots and roots. Further characterization of MYB-NR1 and MYB-NR2 indicated a strong expression of these genes in germinating seeds and leaf blades. By the use of maize protoplast transient assays, we also show nuclear localization of MYB-NR1 and MYB-NR2 fused to GFP. We are currently attempting to analyze transgenic rice plants overexpressing MYB-NR1 or MYB-NR2. This work was supported in parts by grants from the Program for promotion of Basic Research Activities for Innovative Biosciences (PROBRAIN).
