Figure 3.

Contribution of PAR1 and HFR1 to the control of PSY expression and carotenoid biosynthesis. A, Levels of PAR1 transcripts quantified by qPCR analysis of RNA samples from wild-type seedlings grown for 7 d under W and then treated for the indicated times with W+FR. B, Levels of HFR1 transcripts in the samples described in A. Values in A and B are represented relative to those before the simulated shade treatment (0 h). Average and sd values of n = 3 independent samples are shown. C, Carotenoid levels (white bars) and PSY transcript abundance (gray bars) in plants producing the fusion proteins GFP-ΔN_HFR1 and PAR1-GFP and in wild-type controls (WT) grown under W for 7 d. Values are shown relative to those in wild-type samples (the mean carotenoid amount was 112.84 µg g⁻¹ fresh weight) and correspond to means and sd of n = 3 independent samples. Asterisks mark statistically significant differences (P < 0.05) relative to wild-type plants.