Figure 1. POR is critical for SCL-regulated chlorophyll biosynthesis in light.

(A) Phenotypes of WT (Col), MIR171c-OX, scl6 scl22 scl27, 35S::LUC-rSCL27, por-amiR, por-amiR/MIR171c-OX and por-amiR/scl6 scl22 scl27 plants grown under a 16 h/8 h light/dark cycle. Bars = 1 cm. (B) Chlorophyll content of the genotypes shown in (A). FW, fresh weight. ** indicates p values (Student's t-test) <0.01 compared with WT or between the indicated two genotypes. Error bars indicate the s.d. (n = 4). (C) PSII activity (Fv/Fm) of the leaves described in (A) treated with excess light (800 µmol m⁻² s⁻¹) for the indicated times and then incubated in the dark. Error bars indicate the s.d. (n = 18). (D) qPCR analysis of HEMAs, GUN4, GUN5, PORs and CAO transcript levels using total RNA extracted from the leaves of the genotypes shown in (A). The relative expression levels were normalized to that of ACTIN2, and the relative expression in WT plants was set as 1. Error bars represent the s.d. (n = 3). Two biological replicates were performed and provided similar results.