Interaction between light quality and tocopherol antioxidant activity

Abstract

Notwithstanding, changing different light parameters the metabolism may be purposefully affected. The metabolism of tocopherol and its homologues in baby leaf lettuce depended on both the variety of lettuce and on light quality. Both the common trend of tocopherol homoloques contents in baby leaf lettuce and significant possitive effects of supplemental blue and green LEDs was in the order γ-T > α-T > δ-T > β-T. β-T was detected in very low (ng g-1, FW) concentrations or it was not detected at all. However in all treated species of green vegetables' α-T was observed in much higher contents than other homologues. Bigger positive effect of supplemental LED components was in the order: green 535 and 505 nm and blue 455 and 470 nm. Supplemental short-term (3 days) red-LED treatment before harvesting significantly effected the accumulation of tocopherols and it was in order α-T > β-T > γ-T > δ-T and it remained up to 7 days affer exposure. Notwithstanding `tocopherols did not directly participate in lighting reactions, it is clear that there is strong interaction between photoreceptor activation and antioxidant response. Thus, further investigations are needed for understanding the mechanism and interaction between antioxidants and light signal transduction pathways.