Fig. 2.

PHYTOCHROME-INTERACTING FACTORS (PIF) proteins mediate FLOWERING LOCUS (FT) and TWIN SISTER of FT (TFS) expression in the low red/far-red (R/FR). a, b FT and TSF messenger RNA (mRNA) level using quantitative real-time PCR (RT-qPCR) after shift from high to low R/FR in Col-0 and pif4 pif5 pif7. Plants were de-etiolated for 5 days under long days (LDs) at 22 °C in high R/FR and samples were harvested at zeitgeber (ZT) 15–6 before 0 and 1, 2, 3, 5, and 7 days after transfer to low R/FR. Error bars represent 2× SEM. c, d FT and TSF mRNA levels of plants growing under LDs at 22 °C in high and low R/FR. Plants were grown for 5 days in high R/FR for complete de-etiolation. On day 6, plants were either shifted to low R/FR (FR+) or kept in high R/FR (FR−). Samples were harvested 10 days after sowing at ZT 15–16. Error bars represent standard deviation of three biological and three technical replicates, individual data points are indicated with black dots. e β-Glucuronidase (GUS) staining of pPIF4::GUS, pPIF5::GUS, and pPIF7::GUS transgenic seedlings 7 days after sowing. Plants were grown on soil for 5 days under LDs at 22 °C in high R/FR and either kept in the same condition of shifted to low R/FR on day 6. Samples were harvested after GUS staining at ZT 15–16. Scale bar corresponds to 1 mm