Figure 3. Ectopic expression of WOX5 causes QC division and promotes root DSC differentiations in root tips. (A) ACL5::GFP expression patterns in the root apex. The scale bar represents 20 µm. (B-D) Differentiation status of root DSCs (yellow arrowhead) below the QC (red arrowhead) in 4-d-old seedlings as inferred from the lugol staining. Wild-type roots show typically 1 tier of root DS cells (A), ACL5::WOX5 lines show complete root DSC differentiation (C) or active cell divisions in the QC and root DSCs (B-C). The scale bar represents 20 µm. The green arrows indicate the ectopic cell division in the QC or stem cells. (E-F) The auxin gradient in the root apex which is shown by the auxin signaling reporter DR5rev::GFP. The auxin signaling gradient in ACL5::WOX5 lines (E-F) is not changed compared with the wild-type control (D). The scale bar represents 20 µm.