Auxin responses are affected by salinity in Arabidopsis seedlings.

<p>(<b>A</b>) Four dpg WT seedlings were transferred from auxin-free medium onto ATS medium containing no auxin or 85 nM IAA in combination with increasing concentrations of NaCl. The total number of emerged lateral roots was counted 4 d after the transfer to new media. Data are mean values (±SE) of three independent experiments. Different letters indicate a significant difference at P≤0.05 (Tukey test). (<b>B</b>) Seven dpg <i>BA3pro:GUS</i> seedlings were incubated on 50 nM or 100 nM IAA in combination with increasing concentrations of NaCl for 4 h. GUS activity was revealed after incubation with X-Gluc at 37°C. GUS staining in representative root tip segment is shown. (<b>C</b>) Relative transcript level of GUS upon 100 nM IAA treatment in combination with NaCl as described in (B). The control value is arbitrarily set to 1 in each case. Data are mean values (±SE) of three independent experiments. Different letters indicate a significant difference at P≤0.05 (Tukey test). (<b>D</b>) Seven dpg <i>DR5pro:GUS</i> seedlings were incubated with 200 mM NaCl for 4 h and subjected to GUS staining. Images show different parts of seedlings: cotyledons (Cotyl), shoots, root tip and LR. The GUS signal detected in NaCl treatment relative to control is shown. The control value is arbitrarily set to 1 in each case. Data are mean values of three independent experiments.