<p>Cells were dark adapted for 20 minutes and then the NPQ was induced by 100 s exposure to orange light (622 nm, 600 µmol m<sup>−2</sup> s<sup>−1</sup>; see white bar). <b>A</b>) Effect of ΔpH uncouplers nigericin and NH<sub>4</sub>Cl. The maximal efficiency of PSII photochemistry (F<sub>V</sub>/F<sub>M</sub>) in the presence of uncouplers was 0.75 for control, 0.62 for nigericin and 0.68 for NH<sub>4</sub>Cl. <b>B</b>) Effect of inhibitors of linear and cyclic electron transport DCMU, antimycin and rotenone. All data represent typical curves aligned to the same F<sub>o</sub> level.</p
