IAA-induced hypocotyl elongation. The hypocotyl length was measured after 2 weeks of growth in the light. Data are mean ± SEM (n = 30). (A) Col-0 plants grown on LNM supplemented with a range of IAA concentrations (0.01 mg/liter, 0.1 mg/liter, 1 mg/liter, 2 mg/liter). (B) Effects of ethylene biosynthesis and action inhibitors on auxin-induced hypocotyl elongation (IAA, 1 mg/liter; Ag+, 100 μM; AVG, 2 μM; Co2+, 200 μM). ∗∗∗, P < 0.001 versus Col-0 grown on LNM.