Figure 4

LUC reporter assay in hybrid aspen apices. The plasmid construct containing PttLHY2 promoter::luc⁺ was transformed into aspen cuttings using the Agrobacterium-mediated vacuum infiltration assay. The apices were supplemented with luciferin solution at one day after the transformation. The LUC activity was detected by a cooled CCD camera beginning about 5 h following addition of substrate to obtain dynamic, real-time expression. Gray and white boxes indicate subjective night and day, respectively. Luminescence values are means ± SE (biological replicates n = 5).