Fig. 1.

Arabidopsis root and root hairs. (A) Brightfield image of a root with root hairs. (B–D) Confocal images of a root hair-specific promoter::green fluorescent protein (GFP) line. (B) longitudinal section showing GFP in distinct root hair cell files; (C) cross-section showing root hair cell locations marked by GFP; (D) longitudinal section through an epidermal cell file showing GFP expression in two consecutive developmental stages: at the end of the determination phase (at the right) and in the root hair initiation phase (from the middle to the left). Scale bar: 200 μm (A), 50 μm (B), 20 μm (C, D).