FIGURE 13.
The decrease of γ-tocopherol in dark hypoxia is independent of CRR1. A, abundance of HPPD1 transcripts as determined by quantitative real time PCR. Independent cultures corresponding to CRR1 (black circles), crr1 (triangles apex up), and crr1-ΔCys (triangles apex down) were grown in TAP medium in the conditions indicated: dark hypoxia (white symbols) relative to dark (black symbols). Cells were collected after reaching a density of 2–6 × 106 cells/ml and analyzed for RNA abundance. Each symbol represents an independent experiment analyzed in technical triplicates. Tocopherol (B) and plastoquinone (C) content in Chlamydomonas crr1 and corresponding strains that have been complemented with full-length CRR1 (crr1(CRR1)) or with a truncated version of CRR1 lacking a cysteine-rich domain (crr1-ΔCys). Respective strains were either grown in the dark, normoxic (high) or hypoxic (low) as indicated. Data are the averages of three biological replicates ± S.D.