Scanning electron micrograph of the Arabidopsis root. The epidermis is specified in the embryo and maintained in the post embryonic seedling after germination. The ring of epidermal initials gives rise to epidermal cells situated inside cap cells in wild type roots. Transverse section of the Arabidopsis root. The epidermis is orange.
Hair cells are pale orange and non-hair cells are in dark orange.
ERH3 may therefore be required for the organisation of positional information in the cell wall. This positional information is perceived by cells that express a set of transcription factors which then directly specify cell fate. We are presently defining the function of these genes during embryo development. Once cells have been specified, tip growth is initiated. The analysis of these mutations in combinations is leading to hypothetical genetic pathways required for the growth of the root hair.