Fig. 3. TTG, GL2 and CPC act in the subepidermal layer of scz mutants. (A) scz; (B) scz gl2; (C) scz ttg and (D) scz cpc. (Upper panels) Light micrographs of the beginning of the differentiation zone. scz gl2 and scz ttg form more root hairs than scz, while scz cpc form fewer root hairs. (Lower panels) Median longitudinal sections through the beginning of differentiation zone, showing that the number of subepidermal root hairs is altered in the double mutants when compared to scz single mutant. Bar, 50 µm.