Figure 1.

Transcriptional regulation of GA metabolism genes by auxin. Six-day-old wild-type Col-0 Arabidopsis seedlings were treated with 50 μm NAA or mock treated for 24 h. mRNA levels of GA metabolism genes were determined by quantitative RT-PCR as described in “Materials and Methods” and normalized against transcript levels of EF1-α. Transcript level in the control sample for each gene was set to 1, and level in the treated sample was calculated relative to the corresponding control value. Error bars represent sd.