Figure 4.
Effect of excess irradiation on wild-type and FNR-expressing plants. Bleaching (A) and membrane damage (B) were analyzed in leaf discs from 6-week-old wild-type and transgenic plants exposed to 2,000 μmol quanta m−2 s−1 for 17 h at 28°C. The pFNR-1 and pFNR-3 plants employed contained 1.2- and 3.2-fold more reductase than their wild-type siblings. C, Light-dependent damage to PSII as estimated by the decrease in Fv/Fm. Leaf discs from wild-type (triangles) or pFNR-3 (circles) plants were irradiated with 700 μmol quanta m−2 s−1 at 8°C during the indicated times. White symbols correspond to discs kept in the dark at the same temperature. The transformant employed contained 4.5-fold more reductase than its wild-type sibling. Asterisks indicate significant differences between transgenic and wild-type plants by ANOVA (P < 0.05).