<p><b>(A)</b> Representative picture of <i>HvpPIN1a</i>:<i>HvPIN1a-mVENUS</i> expression; transmitted light and mVENUS emission (A)), mVENUS emission only (A’)); six independent transgenic lines were examined which vary only in expression level but not in localisation or pattern; white box in A’) marks magnification in B); gray box in A’) marks magnification in D). <b>(B)</b> Magnification of the epidermal, cortical and endodermal cell layers depicted with white frame in A’). <b>(C)</b> Schematic illustration of HvPIN1a expression in the root meristem, high = dark gray, low = gray; red arrows indicate possible auxin flow created by localisation of PIN1 auxin transporters; En = endodermis, Co = cortex, Ep = epidermis, LRC = lateral root cap, RC = root cap. <b>(D)</b> Magnification of the stem cell niche depicted with gray frame in A’); transmitted light and mVENUS emission (D)), mVENUS emission only (D’)); white arrow heads mark apically localised PIN1, gray arrow heads mark basally localised PIN1; scale bars 100 μm in A), D); 50 μm in B).</p
