EXPERIMENTAL AND GENETIC-ANALYSIS OF ROOT DEVELOPMENT IN ARABIDOPSIS-THALIANA

The cellular organisation of the Arabidopsis thaliana root is remarkab ly regular. A fate map of the primary root and root meristem that pred icts the developmental destinies of cells within the embryonic root pr imordium has been constructed. Nevertheless, laser ablation experiment s demonstrate that root meristem cells develop according to position a nd not according to lineage. Mutational analysis has identified genes required for cell specification in the radial as well as in the apical -basal dimension. The corresponding gene functions appear to be necess ary during embryogenesis for the formation of a correctly patterned pr imary root.