Figure 2.

Dose–response effects of Heatin, picloram and N‐1‐naphthylphthalamic acid (NPA) on hypocotyl elongation, gravitropism and root length.

(a–c) Hypocotyl lengths and (d–f) agravitropy scores, of 8‐day‐old Col‐0 wild‐type (circles and squares) and pif4‐2 (triangles) seedlings in the presence of (a,d) Heatin, (b,e) picloram and (c,f) NPA at 22°C (dark square, triangles down markers, closed lines) or 27°C (circles and triangles up, light markers, dashed lines). (d,f) Dashed horizontal lines at 75% indicate complete agravitropy (random seedling orientation). (g) Image of representative seedlings grown on the indicated compounds (8.5 µm). Note the differences in hypocotyl lengths and gravitropism. Scale bar = 1 cm. (h) Root length of 8‐day‐old Col‐0 wild‐type (clear bars) and pif4‐2 (dashed bars) seedlings grown on mock (dimethyl sulphoxide solvent), Heatin, picloram or NPA (each 8.5 µm), at 22°C (blue bars) or 27°C (green bars). Letters indicate significance groups (Tukey HSD post‐hoc tests), where averages that do not share letters are significantly different from each other (P < 0.05). Values are averages of three replicates of 15–25 seedlings each. Error bars indicate SEM.