Age-Related Changes in Sensitivity of Tomato (Solanum lycopersicum L.) Leaves to Continuous Light

Abstract Tomato ( Solanum lycopersicum L.) belongs to the crops that are most sensitive continuous lighting (CL). We studied age-dependent changes in sensitivity of tomato leaves CL. The exposed CL from a lag-phase their growth exhibited pronounced chlorosis with loss 30% chlorophyll after 2 weeks. values maximum F v / m ) and actual (? II quantum yields PSII photochemical activity were decreased, photosynthesis rate was suppressed, relative electrolyte leakage enhanced. In contrast, less if they had passed early (lag-phase) under normal light conditions (16-h photoperiod) encountered as late log-phase. this case, content, rate, close levels control grown at 16-h photoperiod except for antioxidant enzymes—catalase, ascorbate peroxidase, guaiacol peroxidase—which more active. conclusion drawn age-related CL-sensitivity due difference activities enzymes. general, elder plants than younger ones.