Differential expression between four different maize genotypes. Differentially expressed genes (DEGs) were identified on the basis of six pairwise comparisons between the four analyzed maize genotypes: B73 (B, purple), Mo17 (M, dark blue), B73xMo17 (BM, blue), and Mo17xB73 (MB, light blue) for each of the four primary root tissues: meristematic zone (A), elongation zone (B), stele (C), and cortex (D). The number of differentially expressed genes while controlling the FDR at 5% and with a cutoff of |log2(FC)| > 1 are displayed. For each pairwise comparison, two color-coded bars illustrate the genotype preference of the differentially expressed genes. Significant differences (α ≤ 5%) between the two bars per comparison are indicated by an asterisk.