Figure 3.

Gibberellic acid (GA) and brassinosteroid (BR) biosynthetic gene expression levels and GA sensitivity assay. (a) Phenotypes of various rice seedlings grown for 7 days. (b) Shoot lengths. (c) Expression levels of GA and BR biosynthetic genes determined by reverse transcription-polymerase chain reaction (RT-PCR). (d) Shoot lengths of GA-treated seedlings. Rice seedlings were grown for 7 days in half-strength MS medium (a–c). Rice seeds were grown at various concentrations of GA₃ after pretreatment with the GA biosynthesis inhibitor paclobutrazol (PAC) (d). Different letters and asterisks indicate significant differences as determined by a post-hoc Tukey’s HSD test at p < 0.05. GenBank accession numbers are AB056519 (GA3ox2), AK101713 (GA2ox3), Os03g12660 (DWARF4), and Os03g13170 (UBQ5). Numbers in parentheses indicate the number of PCR cycles.