Recovery of root meristem/growth activity in the absence of a functional QC.

(A–C) Expression analysis of QC markers in the wild-type, shr, and shr phb roots (5 DAG). (A) pWOX5:erGFP. (B) pPLT2:CFP. (C) pQC25:GUS. (D) Analysis of QC status in a shr phb root expressing pWOX5:SHR:nlsGFP, by confocal microscopy (upper panel) and Lugol staining (lower panel). Black arrowhead indicates the QC where SHR-nlsGFP is observed in the upper panel. Red arrowhead indicates the recovered columella stem cell layer where starch granules are absent. (E) The comparison of root length between shr-2 phb-6 and pWOX5:SHR:GFP;shr-2 phb-6. Root lengths were measured from seedlings 3–14 DAG. Scale bars: A–C, 25 μm; D, 20 μm. The error bars represent the standard error (n = 5–10 plants).