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. 2016 Dec 14;7:13692. doi: 10.1038/ncomms13692

Figure 3. TOC1 suppresses thermomorphogenesis and warm-temperature activation of PIF4 target genes.

Figure 3

(a,b) Hypocotyl length of seedlings grown under the continuous white light at 20 °C for 4 days followed by the indicated time of warm temperature (29 °C) treatment (a) or 12 h-warm-temperature treatment (b) and then grown at 20 °C till hypocotyl measurement on the seventh day. Error bars in a–e indicate s.d. (n=10 plants). *P<0.05 (Student's t-test). Numbers in b indicate ratios of hypocotyl lengths (29 °C/20 °C). (c–e) Hypocotyl lengths of wild-type (WT), TOC1-OX, PRR5-OX and ztl-105 seedlings grown under the continuous white light at 20 °C for 7 days or 20 °C for 4 days followed by 29 °C for 3 days. *P<0.05 (Student's t-test); NS, not significant (P≥0.05); numbers in e indicate ratio of hypocotyl lengths (29 °C/20 °C). (f,g) qRT–PCR analysis of YUC8 (f) and PIF4 (g) expression in WT and TOC1-OX seedlings grown at 20 °C for 5 days then incubated at 20 °C or 29 °C for 4 h. Gene expression levels were normalized to PP2A and presented as values relative to that of wild type at 20 °C. Error bars in f–i indicate s.d. (n=3). *P<0.05 (Student's t-test); NS, not significant (P≥0.05); numbers in g indicate ratio of PIF4 expression levels (29 °C/20 °C). (h,i) qRT–PCR analysis of the expression levels of PIF4 and its target genes YUC8 and IAA29 in WT and PRR5-OX seedlings grown at 20 °C for 5 days then incubated at 20 °C or 29 °C for 4 h. *P<0.05 (Student's t-test); NS, not significant (P≥0.05); numbers in i indicate ratio of PIF4 expression levels (29 °C/20 °C). (j) TOC1 ChIP assays showing TOC1 binds to the promoters of PIF4 target genes. Five-day-old TOC1p::TOC1-YFP seedlings were used for ChIP assay. Enrichment of DNA was calculated as the ratio between TOC1p::TOC1-YFP and WT control, normalized to that of the PP2A coding region as an internal reference. Error bars indicate s.d. (n=3). *P<0.05 (Student's t-test). (k) Hypocotyl lengths of TOC1-OX;elf3-1 seedlings grown under continuous white light at 20 °C for 7 days or 20 °C for 4 days followed by 29 °C for 3 days. Error bars indicate s.d. (n=10 plants). *P<0.05 (Student's t-test); numbers indicate ratio of hypocotyl lengths (29 °C/20 °C). (l) qRT–PCR analysis of YUC8 expression in seedlings grown at 20 °C for 5 days then incubated at 20 °C or 29 °C for 4 h. *P<0.05 (Student's t-test); NS, not significant (P≥0.05); numbers indicate ratio of YUC8 expression (29 °C/20 °C).