Creating a two-dimensional pattern de novo during Arabidopsis trichome and root hair initiation.

During plant epidermal differentiation, root hairs and leaf hairs (trichomes) become specified in a regular pattern. Although the underlying mechanisms appear to be different in that the position of root hairs is determined by their position with respect to the underlying cortical cells and that of the trichomes appears to be generated de novo, a common set of genes was found to operate in both systems. A complex of transcription factors appears to be involved in creating the pattern and cell-cell movement of small transcription factors is postulated to mediate cell-cell communication. Copyright 2004 Elsevier Ltd.