Histochemical analysis of pIAA26::GUS, pIAA27::GUS, and pIAA18::GUS expression in A. thaliana Shahdara leaves, petioles, and stems. (A) GUS expression in 7-wk-old leaves after staining overnight. (Scale bars, 2 mm.) (B) Petiole cross-sections. (Scale bars, 200 μm.) (C) Stem cross-sections. (Scale bars, 100 μm.)