TaBZR2 is a positive regulator in the BR signaling pathway. A, Phenotypes of TaBZR2-overexpressing (OE5, OE9, and OE11), TaBZR2-RNAi (Ri3 and Ri7), and wild-type wheat plants grown in half-strength Hoagland’s liquid medium or medium containing 1 μm of BR. Scale bar = 2 cm. Root length of TaBZR2-overexpressing, TaBZR2-RNAi, and wild-type wheat plants grown on half-strength Hoagland’s medium that contained different concentrations of BR (0, 0.25, or 1 μm) in the light for 7 d. Each data point is the mean (±se) of three experiments (20 seedlings per experiment). The asterisks indicate significant differences between TaBZR2 transgenic (TaBZR2-overexpressing lines and TaBZR2-RNAi lines) and wild-type plants (Student’s t test, *P < 0.05). B, EMSA of TaBZR2 binding to the BRREs in the promoter of TaD2. Biotin-labeled BRRE probes (normal and mutated) were incubated with GST or GST-TaBZR2 protein. 100× competitor fragments were added to analyze the specificity of binding. C, The expression levels of BR biosynthetic genes in TaBZR2 transgenic (TaBZR2-overexpressing lines and TaBZR2-RNAi lines) and wild-type plants. The expression of β-actin was used as an internal control. Each data point is the mean (±se) of three experiments (10 seedlings per experiment). WT, wild type.