Figure 6.

Expression level of BR biosynthetic genes in cyp51A2 mutants with and without exogenous BR (A) and membrane ion leakage (B) in cyp51A2 mutants. A, Expression level of BR biosynthetic genes, CPD and DWF4, in cyp51A2-3 mutants was changed as much as in wild type by the treatments with or without BR. Total RNAs were isolated from 7-d-old light-grown seedlings treated with or without epi-BL (0.5 μm) and a BR biosynthesis inhibitor, BRZ (1 μm), for 2 d. Total RNAs were subject to northern hybridization (CPD) and RT-PCR (DWF4). Actin-2 was used as a positive control. B, Membrane ion leakage was determined by measuring electrolytes leaked using 10-d-old wild-type (Ws-2), cyp51A2-2, and cyp51A2-3 mutant seedlings.