Fig. 3.

In vivo redox changes of representative chloroplast enzymes during dark/light transitions in Arabidopsis WT and mutant plants. (A) In vivo redox state of Trxs f, FBPase, and PRK determined from leaves of 8-wk-old short-day grown plants at the end of the dark period (marked as “D”) and after 30 min of illumination at 125 μE m⁻²⋅s⁻¹ (“L”). (B) Band intensities were quantified (ScionImage), and the percentage of reduction is the ratio of the reduced form and the sum of reduced and oxidized forms. Each value is the mean of three independent experiments ± SE. Letters indicate significant differences between mutants by Student’s t test at a 95% CI. (C) In vivo redox state of 2-Cys Prxs. (D) Reduction level is the ratio between the sums of the half reduced (1SH) and fully reduced (2SH) forms and the sum of reduced and oxidized forms. Each value is the mean of at least three independent experiments ± SE. Letters indicate significant differences between mutants in darkness by Tukey test at a 99% CI (there are no significant differences in light). Statistical significance (*P < 0.05 and **P < 0.01) determined with the Student’s t test comparing dark and light values for each line. ns, nonspecific; Oxi, oxidized; red, reduced. 1SH and 2SH indicate reduction of one or the two cysteines, respectively, of 2-Cys Prxs.