Abstract
It is known that plants grown under high light conditions have larger amount of xanthophyll cycle pigments compared to those of the plants grown under low light conditions. However, little is known about the regulation mechanism of biosynthesis of xanthophylls in green leaves. In recent years, many photosynthesis related genes have been reported to be regulated by chloroplast redox signals. In this study, we examined the regulatory effect of redox-state of the photosynthetic electron transport chain on the xanthophyll biosynthesis.
The photoautotrophically cultured tobacco cells grown under high light conditions did not exhibit an increase in xanthophyll cycle pigments pool size when DCMU was added to the culture medium. In contrast, lowering the CO2 concentration in the atmosphere of culture flasks induced an increase in the xanthophyll cycle pool under low light condition. Our results suggest that chloroplast-derived redox signaling regulate the xanthophyll biosynthesis.
