Expression patterns of TIP isoforms in Arabidopsis roots. 8-day old roots from the indicated transgenic lines were excised, stained with propidium iodide for 2 min and visualised by CLSM. The images show representative results for each construct. The signals from YFP (green) and propidium iodide fluorescence (red) are merged. Top panels: single optical sections of the root tips, Middle panels: single optical sections of root differentiation zones. Bottom panels: maximal projection of 16 optical z sections (4 μm step-size) through mature root axes and young lateral roots. Scale bars: 100 μm.