Additional file 1. Fig. S1. Expression analysis of the D3 gene in A OE-MIM528, OE-miR528 and B OE-D3 transgenic plants. Fig. S2. Sequence analysis of d3 mutants generated by CRISPR/Cas9. A The target sites and sanger sequence of d3-1 and d3-3 mutants. B Deduced amino acid sequence alignment of d3 mutants. Fig. S3. Phenotypes of plant height of different transgenic lines at the maturity stage. Bars, 10 cm. Fig. S4. Comparison of the contents of endogenous brassinolide (BL) (A), castasterone (CS) (B), 6-Deoxocastasterone (6-DS) (C), and 2′-epi-5-Deoxystrigol (D) in 31-day-old OE-miR528 and OE-MIM528 transgenic seedlings. Table S1. Primers used for vector construction and positive identification. Table S2. Primers used for qRT-PCR analysis.