Differential expression of cytokinin signalling and related genes in root and shoot in response to the cytokinin status. (a) Changes in expression of cytokinin-related genes evaluated with Mapman . Genes associated with functions in cytokinin metabolism or signalling are listed on the left side, and a schematic drawing of cytokinin signal transduction is shown on the right side. Colour coding of the boxes in the middle shows changes of transcript abundance between the samples indicated at the top. Blue indicates an upregulation, red a downregulation. Grey boxes denote genes, which are detected in less than two out of four arrays of the higher expressed condition. Cytokinin-related genes which were never detected or not present on the microarray are not shown. The colour codes were generated using the Mapman software and aligned to a figure using standard image processing software. : None of the Arabidopsis histidine phosphotransmitter genes is present on the CATMA V2.3 microarray. (b) Interaction plots and significance of changes of transcript abundance of selected A-type ARR genes. The interaction plots show the relative fluorescence intensity (in log scale) of the spots on the array for the gene indicated on top of each graph in the cytokinin-deficient and cytokinin-treated samples for roots and shoots separately.