Fig. 2. cry1 and cry2 control GUS activity driven by a Lhcb1*2 gene promoter. One-day-old seedlings of the wild type and of the cry1, cry2, cry1 cry2, phyA phyB, phyA phyB cry1 and phyA phyB cry2 mutants, were exposed to continuous white light for 1, 2 or 3 days before harvest (A), or to orange light or white light for 3 days (B). GUS activity is expressed relative to the wild type, day 3 under white light. In dark controls GUS activities were below 0.01. Data are mean and s.e.m. of 6 (A) or 9 (B) replicates.