FIGURE 3.

Development of CB in the exodermis of WT plants and the mutant lines 1B-14436 (KO) and 3A-16329 (OE) as affected by Si supply (concentration are given in the legend of Figure 1). The root zone investigated was 4–6 cm behind the root tip. The CB formation was classified in four stages: I:0, II: 0–25, III: 25–50, IV: >50% of the length of the anticlinal cell wall with CB n = 4. Different capital and small letters indicate significant differences between Si treatments within a genotype and for genotypes within the same Si level, respectively; cumulative link mixed models with p < 0.05.