Fig. 1. ABA-responsive gene expression in Arabidopsis WT. The normalized abundance in ppm of each signature derived from the ABA-treated sample (y axis) was plotted on a logarithmic scale versus that derived from the untreated sample (x axis). The log scaling ends at 1 and signatures with abundance 0 are presented in the lower left corner. For each abundance (ppm) value, points are not placed on a line but allocated to a bar of a certain width that decreases with increasing abundance. Thus, data points are scattered in bi-dimensional space to better reflect density. This translates into a wide gap as seen at around 1 ppm because there were few signatures with both 1 or 2 ppm that would normally occupy a certain space either along the x- or y-axis. Up- or downregulated genes, as defined on the basis of a threefold ratio and/or a 0.0005% significance level, are shown in green. Genes unaffected by ABA are shown in red.