Figure 5.

ELF3 Acts Upstream of PIF7 in Shade-Induced Growth

(A) Relative expression of IAA29 and PIL1 in Col-0, elf3-1, elf3-1pif7-1 and pif7-1 seedlings at 20 h after transfer to constant conditions. The top panel represents the light treatment for the detection of shade-induced gene expression. Wild-type seedlings were grown under SD conditions for 5 days and transferred to continuous white light, after which the shade treatment was started or the seedlings were kept under continuous white light for 1 h. The white, black, and gray colors represent white light, darkness, and shade, respectively. The bottom panels represent the expression of IAA29 and PIL1. The error bars indicate the SEMs of three independent experiments. The asterisk indicates statistically significant differences between mean values according to Student's t test (*p < 0.05, **p < 0.01, ***p < 0.001).

(B) Relative expression of IAA29 and PIL1 in Col-0, elf3-1, elf3-1pif7-1, and pif7-1. The seedlings were grown under continuous white light (WLc) or transferred to continuous shade (Shadec) for 1 h. The error bars indicate the SEMs of three independent experiments. The asterisk indicates statistically significant differences between mean values according to Student's t test (*p < 0.05, **p < 0.01, ***p < 0.001).

(C) Hypocotyl phenotypes of Col-0, elf3-1, elf3-1pif7-1, and pif7-1 seedlings under SDs or end-of-day (EOD) shade treatment. The top panel represents the light treatment for the hypocotyl measurements of seedlings grown under SDs and EOD shade conditions. The seedlings were grown for 3 days under SD and either kept under SDs or treated for 2 h with shade at the end of each day for 4 days. The white, black, and gray colors represent white light, darkness and shade, respectively. The bottom panels represent the phenotypes of hypocotyl length. The data are presented as the means with SEMs; more than 20 seedlings were measured. The bars marked with different letters denote significant differences (p < 0.05), calculated by Student's t test. Scale bar, 2 mm.

(D) Hypocotyl length of Col-0, elf3-1, elf3-1pif7-1, and pif7-1 seedlings grown under WLc or Shadec conditions. The seedlings were germinated and grown for 5 days under continuous white light and either kept under white light or transferred to shade for 4 days. The data are presented as the means with SEMs; more than 20 seedlings were measured. The bars marked with different letters denote significant differences (p < 0.05), calculated by Student's t test. Scale bar, 2 mm.