OsMYB4-Regulated Transcriptional Network of Rice

The OsMyb4 transcription factor of rice represents a more recent example of a regulatory gene used in various attempts to develop stress-tolerant crops by regulon engineering. Although OsMyb4 confers tolerance to low temperature and drought by affecting the biosynthesis of compatible osmolytes and the phenylpropanoid metabolic process, the exact composition and scope of the OsMyb4 network has not been established from the previous analysis of heterologous overexpression in Arabidopsis. Further characterization of the OsMyb4 regulon at the global scale will facilitate understanding of the intricate underpinnings of a pathway independent of the DREB/CBF network. To dissect the OsMyb4 network of rice in relation to chilling stress response mechanisms, we conducted a gene expression profiling using transgenic rice overexpressing the OsMyb4 cDNA. This experiment describes the analysis of the gene expression changes as a result of supra-optimal expression of transcription factor (OsMYB4) overexpressed as transgenic in the cv. Nipponbare. Control (WT) and transgenic (OsMYB4-OX) samples were labeled with Cy3 and Cy5, respectively. No dye-swap replicates was performed in this experiment. The microarray platform used in this study was the 45k oligonucleotide microarray (www.ricearray.org), which comes in pairs of slides A and B (each containing about 50% of the total number of features). The data described in this series includes all hybridizations with slide A and with slide B. Experiments were performed with two independent biological replicates (R1 and R2) for each transgenic line.