Box plots of the relative mRNA levels of selected genes in individual seedlings. Relative mRNA levels were determined in six individual seedlings, each of wild-type (Col) and three AtCHR23 over-expressing lines, by quantitative RT-PCR using gene specific primers for eight different genes. Four of these genes (A) were characterized by high variability between the replicates of the over-expressing lines and four genes (B) did not show such variability. After normalization to the UBC reference gene, the expression value for each gene and each individual seedling was scaled relative to the lowest expression value (set to 1) for that gene in the line. In each box plot, the box area represents the lower and the upper percentiles, the horizontal line within the box indicates the median value and the horizontal dashes at the top and the bottom of the box show the minimum and maximum values observed. Asterisk indicate significantly different variances (Levene’s test) from the wild type at P < 0.05.