Diagram of Arabidopsis wild-type and SHR : GAL4–GR UAS : SHR–GFP shr2 mutant roots showing proliferative and formative division planes (adapted from ref. 52 ). SHR moves from the central tissues of the root into the adjacent cell layer. SHR expression and formative divisions occur in the inducible line upon treatment with dex. Yellow, QC (quiescent centre); orange, CEI (cortex–endodermal initial); red, CEID (cortex–endodermal initial daughter) and shr mutant layer; blue, cortex; purple, endodermis.
