Fig. 2. The effect of hst on seedling morphology. (A) Three-day-old wild-type (left) and hst-1 (right) seedlings grown in the dark. (B) Seven-day-old wild-type (left) and hst-1 (right) seedlings grown in the light. (C-E) Anatomy of 3-day-old wild-type seedlings. (F-H) Anatomy of 3-day-old hst-1 seedlings. (C,F) Median longitudinal section of the shoot apex; the meristem is marked with an asterisk. (D,G) Cross-section of the hypocotyl. (E,H) Cross-section of the root. (I) Length of the hypocotyl and root in dark- and light-grown seedlings. Black, wild-type hypocotyl; white, wild-type root; white hatching on black, hst-1 hypocotyl; black hatching on white, hst-1 root. Scale bars: 50 µm.