HY5 operates downstream of EIN3 to modulate ethylene-promoted hypocotyl growth.

(A) Morphological observations and (B) statistical analyses of hypocotyl length after 5 days of incubation in MS medium supplemented with or without 10 µM ACC. The data indicate the mean values plus SD from three independent experiments with approximately 30 seedlings. P-values (ACC treatment vs. non-treatment) were determined with a two-tailed Student's t-test assuming equal variances (*P<0.05).