Expression analysis of VYL. A, qRT-PCR analysis showing that VYL expression peaks in the L4 section of wild-type plants with fully emerged third leaves. The VYL gene was normalized using a Ubiquitin gene as an internal control. Error bars represent sd of three independent experiments. Asterisk indicates statistical significance at P < 0.05 by Student’s t test. B, Histochemical staining shows that the pVYL::GUS reporter gene is ubiquitously expressed in young buds, young roots, stems, leaves, leaf shoots, and panicles. C, qRT-PCR analysis showing that VYL is expressed in different tissues of the wild-type plants at the heading stage and was normalized using a Ubiquitin gene as an internal control (n = 3). D, qRT-PCR analysis of the VYL gene during greening of etiolated seedlings. After growing in darkness for 10 d, etiolated wild-type rice seedlings were illuminated for 3, 6, 9, 12, 15, 18, 21, or 24 h. The relative VYL RNA levels increased along with the increased illumination time and peaked at 6 h after illumination started. After that, VYL expression decreased. Seedlings grown under continuous light or darkness were used as controls. The VYL gene was normalized using a Ubiquitin gene as an internal control. Data are means ± sd (n = 3).