Accumulation of ascorbate in the leaves of Arabidopsis thaliana wildtype and vtc2 mutants under continuous light and short photoperiod conditions

摘要

The levels of vitamin C (ascorbic acid) in leaves is regulated by light but the mechanisms that regulate ascorbate accumulation are poorly understood. The effects of photoperiod duration on the ascorbic acid contents of Arabidopsis thaliana leaves were therefore compared in the wild-type and two mutants [vtc2 (EMS) and vtc2 (T-DNA)] that are impaired in the pathway of ascorbate biosynthesis. Under continuous light, the wild-type grown for 14 days accumulated nearly three times as much shoot biomass and ascorbate as the plants grown for 21 days under short day conditions. The vtc2 (EMS) and vtc2 (T-DNA) rosettes accumulated less ascorbate and less biomass under both growth conditions. There was a correlation between leaf ascorbate content and biomassaccumulation under short day growth conditions but not under continuous light.