Figure 2.
Representative Seedlings Grown under Defined Light Conditions and Cluster Analysis of Their Light-Regulated Gene Expression.
(A) Wild-type Arabidopsis seedlings grown under different light conditions. WT, wild-type seedlings; W, white light; FR, far-red light; R, red light; B, blue light; 36D, white light–grown seedlings or leaves transferred to darkness for 36 hr; 36W, dark-grown seedlings transferred to white light for 36 hr. All light conditions were continuous illumination. All seedlings were 6 days old at the time of harvesting.
(B) Hierarchical cluster display of expression ratios from wild-type seedlings grown under different light qualities versus dark-grown siblings and seedlings or leaves before and after light/dark transitions. Only those ESTs that exhibited at least twofold differential change in at least one sample pair among the seven pairs tested were included for comparison. There are 4326 EST entries included in the cluster. WTL, leaves of 5-week-old white light–grown wild-type seedlings; vs, versus.
(C) and (D) Two subclusters of ESTs showed distinct patterns of regulation for selected light conditions. SOD, superoxide dismutase; ccr, cytokinin repressed; Cyt, cytochrome.