Figure 4.

Mechanical impedance enhances ethylene response in Arabidopsis roots. Real-time PCR analyses of the expression of ERF1 (A) and BACH (B) genes in horizontally or vertically grown roots. The copy number of ERF1 and BACH transcripts was calculated by normalizing against the number of copies of the EF1α transcript. Results are expressed as the mean ± se for the ratio of ERF1 or BACH to EF1α copy number (with the vertically grown root ratio assigned a value of 1) from three independent experiments. C, Expression of ASA1 and ASB1 genes during mechanical impedance. Four-day-old ASA1-GUS and ASB1-GUS transgenic seedlings were stained in a buffer containing 1 mm X-gluc for 18 h at 37°C in the dark. These are representative images of 30 seedlings stained in three separate runs. Bar = 100 μm.