Figure 8.

HPR multiple mutants show decreased F_v/F_m values after transfer to ambient air. Plants were grown in elevated CO₂ (0.15%) with a 10/14-h day/night cycle. After reaching growth stadium 5.1 (Boyes et al., 2001), plants were transferred to ambient air. F_v/F_m ratios were measured before transfer and 1, 2, and 3 weeks after transfer to normal air. Mean values ± sd (n = 5; five areas of interest each) are shown. Asterisks show significant alterations according to Student’s t test (P < 0.05 for the wild type [*], hpr1-1 [**], hpr1xhpr2 [***], and the corresponding line 1 week before transfer [⁺]).