Clustering of differentially expressed genes in the transcriptome of Jatropha inflorescence meristems treated with BA. N is the number of transcripts found in each cluster. Cluster I and II contain cytokinin-repressed or induced genes at all three time points, respectively; Cluster III, V and VII contain cytokinin-induced genes at T, T +4 H and T +22 H, respectively; Cluster IV, VI and VIII contain cytokinin-repressed genes at T, T +4 H and T +22 H, respectively. A number of differentially expressed genes were included in more than one cluster according to their expression profiles. The y-axis represents the normalized expression value. The expression value of each gene was Z-score (mean centered, with standard deviations as the unit, p <0.05). T: BA treatment for 2 hours, T +4 H: 4 hours post BA treatment, T +22 H: 22 hours post BA treatment.