Figure 1.

Effect of Different Light Conditions during Growth of Wild-Type and Mutant Arabidopsis Plants.

(A) to (C) Each pot contained five seedlings. Control plants (A) (120 μE m⁻² s⁻¹); high light–grown plants (B) (1300 μE m⁻² s⁻¹); plants grown in limiting light conditions (C) (20 μE m⁻² s⁻¹). In low light, npq2 plants show a lower growth, consistent with sustained dissipation of excitation energy. In high light, npq2 plants appear to be highly resistant with respect to npq1 and npq4. npq1 plants, lacking zeaxanthin, appear to be more severely affected than npq4 plants, lacking PsbS.

(D) Fresh weight increase measured on populations of Arabidopsis wild-type and mutant genotypes growth for 3 weeks in different light conditions. During this treatment, the npq2 plant had been daily sprayed with 10 μM abscisic acid. Data are expressed as means ± sd, n = 15. Data sets with a significance level of P < 0.05 according to Student's t test are marked with an asterisk.