Figure 1.

Etiolated rpoTmp mutant plantlets exhibit a triple-response-like phenotype. (a) Images of etiolated rpoTmp mutant (two mutant alleles, rpoTmp-2 SALK_132842 and rpoTmp-3 SALK_086115) and WT plants (grown in the presence or in the absence of 20 µM ACC) were taken under a dissection microscope. Scale bar corresponds to 1 mm. (b) Top panel: median values of apical hook angle measurements are box-plotted for WT plants grown in the absence or in the presence of 20 µM ACC and for rpoTmp plants. The number of pooled individuals (N) that were measured in seven independent hook angle analyses corresponds to 304 for WT plants; N (measured in three independent analyses) corresponds to 130 for WT + ACC plants; N (measured in five independent analyses) corresponds to 211 for rpoTmp plants. Data are box-plotted using versions of the first and third quartiles [25] with median values (horizontal lines inside the boxes). The external horizontal lines show the largest and smallest observations that fall within a distance of 1.5 times the box size from the nearest hinge. Additional points are extreme value observations. The asterisks (*) indicate significant difference between two samples. Bottom panel: principal of angle determination. Magnified images of the hook from WT, rpoTmp and ACC-treated WT. The apical hook curvature was measured as the angle (blue line) that is formed by the two straight lines (red) passing through the hypocotyl and the cotyledon axes. Any hook angle larger than 180° (blue horizontal line) was considered as twisted. Images were analysed with the ImageJ program. (c) Median values of hypocotyl length measurements are box-plotted for WT plants grown in the absence or in the presence of 20 µM ACC and for rpoTmp plants. N (measured in two independent analyses) corresponded to 92 for WT plants, to 75 for ACC-treated WT plants, and to 98 for rpoTmp plants. Data are box-plotted as in figure 1b. (Online version in colour.)