ASSESSMENT OF THE ANTIOXIDANT POWER OF IN VITRO OBTAINED COLEUS FORSKOHLII BRIQ

In the present study, a simple protocol for in vitro rooting induction of the important medicinal plant Coleus forskohlii Briq with a high content of secondary metabolites with antioxidant activity was described. For the in vitro germination seeds of C. forskohlii were placed on MS medium supplemented with 0.4 mg L-1 gibberellic acid and 1.0 mg L-1 CaCl2. The obtained shoots were cultured on a half-strength 1/2 MS medium containing indole-3-butyric acid (IBA) or indole-3-acetic acid (IAA) at concentrations of 0.1 and 0.5 mg L-1. The maximum rooting of plants (95%) with mean values of 9.2 roots per explant, root length (5.1 cm) and root fresh weight (0.085 g) was obtained on half-strength MS medium with 0.1 mg L-1 IAA after three weeks of culture. The plants were successfully ex vitro adapted with 93.3% survival on the mixture substrate of soil, peat and sand (2:1:1 v/v/v). The antioxidant enzymes activities (superoxide dismutase, catalase, ascorbate peroxidase and guaiacol peroxidase) showed the highest values when IBA was used for C. forskohlii in vitro cultivation. Applied auxins influenced the level of secondary metabolites synthesis. Half strength MS culture medium supplemented with 0.5 mg L-1 IAA caused the highest total phenol and flavonoid content as well as the highest antioxidant activity level (radical scavenging activity and ferric reducing antioxidant power). The results indicate that organogenesis is a very complicated biological process involving up and downregulation of plant enzyme and non-enzyme antioxidant protection systems, which play an important role during the organogenesis of plants.

Automated summary

A simple protocol for in vitro rooting induction of Coleus forskohlii was described, which resulted in efficient root formation by adjusting the culture medium composition and concentrations of plant hormones IBA or IAA. The study found that different plant hormones have significant effects on antioxidant enzyme activity and secondary metabolite synthesis levels in plants.