Table 1.

Physiological Parameters for the Wild Type, clpr2-1, and clpr2-1/R2:h Grown at 100 μmol·m−2·s−1 followed by a Shift to 1000 μmol·m−2·s−1 for Two or Four Light Cycles

Light IntensityParameterWild Typer2-1r2-1/R2:h
100 μE/m2sCa/Cb2.26 ± 0.0332.05 ± 0.078a2.18 ± 0.051b
Ca+b/Cx+c5.87 ± 0.2934.67 ± 0.484a5.73 ± 0.374
Fv/Fm0.84 ± 0.0030.66 ± 0.036a0.83 ± 0.002a
Thyl-Prot/Ca+b7.37.1ND
Thyl-Prot/Cx+c53.445.3ND
1000 μE/m2sCa/Cb12.22 ± 0.0792.28 ± 0.2162.50 ± 0.571
Ca+b/Cx+c15.78 ± 0.3913.76 ± 0.667a,c5.68 ± 1.161
Fv/Fm20.76 ± 0.014d0.66 ± 0.010a0.79 ± 0.014b,d
  • Measurements are means ± sd (n = 8). Student's t test probability for comparisons against the wild type (a and b) or against normal light conditions (c and d) are as follows: a and d, P < 0.001; b and c, 0.001 < P < 0.01. Ca, Cb, Ca+b, and Cx+c, concentration of chlorophylls a and/or b and xanthophylls + carotene; Fv/Fm, ratio of variable fluorescence versus maximum fluorescence of PSII; Thyl-Prot, thylakoid proteins. Light stress exposure: 1, four light cycles; 2, two light cycles. ND, not determined.