Fig. 8.

Auxin flow and accumulation during PEG-induced water stress in the wild-type (WT) and lines overexpressing (35S:Pgb1) or down-regulating (Pgb1-RNAi) AtPgb1 grown for 48 h in the absence or presence of 40% PEG (–1.76M Pa). Numbers in brackets on the images indicate hours of treatment in PEG. (A) Confocal images of PIN1-GFP, and relative abundance of PIN1 transcripts during the imposition of water stress. Arrows indicate the basipetal flow of auxin; e, endodermis. Scale bars are 50 μm (larger panels) and 5 μm (smaller panels). (B) Expression of PIN4:GUS and relative abundance of PIN4 transcripts in roots. The relative expression values in (A) and (B) are normalized to the WT at 0 h (set at 1), and are means ±SE of three biological replicates. Scale bars in (B) are 50 μm. (C) Localization of DR5:GUS in roots of the different lines subjected to PEG-induced water stress. Scale bars are 50 μm.