Figure 3.

ABCG37 and ABCG36 Localize to the Outer Polar Domain of Root Epidermal and Lateral Root Cap Cells.

Confocal images of root tips of 5-day-old seedlings carrying GFP–ABCG37 (pis1-1 carrying 35S:GFP–ABCG37) (Łangowski et al., 2010) and ABCG36–GFP (pen3-1 carrying PEN3:PEN3–GFP) (Stein et al., 2006). The upper panels show GFP signal and the lower panels show propidium iodide staining of endodermal (en), cortex (co), epidermal (ep), and lateral root cap (LRC) cell walls. Both GFP–ABCG37 (Łangowski et al., 2010; Růžička et al., 2010) and ABCG36–GFP (Strader and Bartel, 2009) accumulate on the outward face of epidermal and lateral root cap cells, a polar domain termed the ‘outer polar domain’ (Łangowski et al., 2010), implying that these transporters move IBA from the root into the rhizosphere.