Fig. 4. Gradients of chlorophyll (Chl) fluorescence and FV/FM ratio upon illumination (A,B), or preillumination (C,D), of spinach leaves (from the adaxial or abaxial side), by using different colors of light: blue, red, and green, but also white, for (C,D). (A,B) Chl fluorescence was measured from different parts (cross-sections) of leaves, using an imaging fluorometer, and the fluorescence gradients were used as proxies for gradients of light inside the leaf (see the text). (C,D) Here, the leaves were treated with 1 mM lincomycin (an inhibitor of prokaryote-type protein synthesis), and preilluminated for 1 h; then, Chl fluorescence was measured with a fiber optic microprobe fluorometer. The gradients of FV/FM in control leaves (without lincomycin and light treatment) are also shown (see the black curves in C, D). The gradients of FV/FM were used to evaluate the photoinhibition effect of different colors of light (see the text). Figure modified from Vogelmann and Evans (2002) and Oguchi et al. (2011).
