Extended Data Fig. 1: The GFP–tagged BR biosynthetic enzymes are functional and show similar expression patterns in multiple independent transgenic lines.

a, Rescue of the BR biosynthetic mutants by expression of the corresponding GFP–tagged enzymes under the control of their endogenous promoters. Two independent transgenic lines for each gene are compared with the wild type (Col-0) and the corresponding mutant. Six-day-old seedlings are shown. Scale bars, 1 cm. b, Consistent expression patterns of GFP–tagged BR biosynthetic enzymes under the control of their endogenous promoters in multiple independent transgenic lines. Root meristems of the 6-day-old seedlings from two independent transgenic lines for each GFP–tagged enzyme are shown. For seedlings expressing pCYP90D1:CYP90D1-GFP only the root elongation zone is shown, because the signal in the root apical meristem is extremely weak. Scale bars, 50 µm. c, Six-day-old pDWF4:DWF4-GFPdwf4 roots treated with mock (DMSO), brassinazole and brassinolide for 24 h. Scale bars, 50 µm. d, Expression patterns of the PROMOTER-NLS-GFP reporters for all BR biosynthetic genes. For each reporter line, 6-day-old root meristems and cross section are shown. Scale bars, 50 µm. e, Co-expression of NLS-GFP and NLS-mCHERRY reporters under the control of CPD and ROT3 promoters, respectively. Scale bar, 50 µm. Roots were stained with propidium iodide.