EFFECT OF GIBBERELLIC ACID ON TOTAL ANTIOXIDANT ACTIVITY DURING CHENOPODIUM RUBRUM L. ONTOGENESIS IN VITRO

Total antioxidant activity (TAA) represents the combined ability of diverse antioxidants present in a sample of plant material to scavenge free radicals. Chenopodium rubrum L. sel. 184 is a qualitatively short-day plant; as an early-flowering species, it is a suitable object for studying ontogenesis in vitro. We investigated the effect of GA3 (5 mg/l) on TAA during C rubrum ontogenesis under two different inductive photoperiodic regimes in vitro. Total antioxidant activity does not change in different phases of C. rubrum ontogenesis under the same photoperiodic treatment. Exposure to continuous irradiation caused an increase of TAA in both C. rubrum plants and collected matured seeds. Gibberellic acid stimulated stem elongation, but did not affect leaf development or the number of matured seeds per plant, regardless of photoperiodic treatment; it induced a decrease of TAA in C rubrum plants regardless of photoperiodic treatment or the phase of development, while it had no effect on TAA of matured seeds.