Figure 7.

Expression of DGL1. A, Expression of DGL1 in various organs of wild-type rice. Total RNA was isolated from leaf blade (LB), leaf sheath (LS), stem (ST), root (RT), young flower before heading (FL), shoot apex (SA), and entire young seedlings (SH). Five micrograms of total RNA were loaded in each lane. The gel was stained with ethidium bromide (EtBr) as a control. B, Expression of DGL1 in GA- and BR-related mutants. Total RNAs were extracted from 1-month-old seedlings of the mutants and the RNAs were analyzed as in A. oskao-3, Severe-GA-deficient dwarf mutant; gid2-1, severe-GA-insensitive dwarf mutant; slr1-11, constitutive-GA-response slender mutant; brd1-1, severe-BR-deficient dwarf mutant; dgl1-3, severe allele of dgl1. C, DGL1 expression in the GA-deficient mutant oskao-3 after GA₃ treatment. The experiments were performed as in A. The expression of OsGA20ox2/SD1 was also examined as a control for the GA₃ treatment. The down-regulation of OsGA20ox2/SD1 indicates the functioning of the negative feedback regulation of GA signaling.