Root inhibition assays showing different brassinosteroid (BR) responses in the wide-type, bri1-5 mutant and transgenic lines. (a) Phenotypes of the wide-type (WS2), bri1-5 mutant and three transgenic lines (Line 1, 6 and 9) were grown in half-strength MS medium supplemented with 1% sucrose (Mock), 100 and 500 nM 2,4-epibrassinolide (24-epiBL) for 10 days. The images were scanned by an Epson perfection V700 photo scanner (Epson, Nagano, Japan) and WinRHIZO Pro v.2009c software (Regent Instruments, Montreal, QC, Canada). Bar = 10 mm; and (b) Measurements of the total root length of the seedlings shown in (a). The data represents the mean ± SD of three independent experiments. The asterisks indicate significant differences compared to the bri1-5 mutant (**, p < 0.01 by the t-test).