xct-2 and ctr1-3 have similar phenotypes. A, Hypocotyl length of various genotypes (n = 35–40) grown on MS Suc medium in the presence or absence of 50 μm silver nitrate for 6 d under constant monochromatic blue light. B, Ethylene emission levels (n = 200–400) of various genotypes grown in the presence or absence of 3% Suc. Seedlings were grown under blue light for 3 to 4 d, capped, and allowed to accumulate ethylene over 24 h in blue light, then sent for ethylene detection. All error bars represent se. Asterisks denote significant differences from the wild type (WT) under the same condition based on Student’s t test (P < 0.05). All data presented are representative of at least three independent experiments.