The Content of Biologically Active Substances in Crocosmia × crocosmiiflora ‘Lucifer’ Tubers after Treatment with GA3

Abstract

This study was conducted to assess the influence of gibberellic acid (GA3) on the content of biologically active substances in Crocosmia × crocosmiiflora ‘Lucifer’ tubers. These tubers are a promising source of potential antioxidants, and their extracts can be used in pharmaceutical industry, as well as in cosmetics products and antifungal and antibacterial substances. Four groups of biologically active substances were determined from tubers: saponins, phenolic acid, flavonoids and carotenoids. The antioxidant activity of the extracts from tubers increased proportionally to the GA3 concentrations. GA3 at concentrations of 200, 400 and 600 mg dm−3 increased the content of medicagenic acid by 42.9–57.1% and the content of polygalic acid by 50% without affecting the content of medicagenic acid 3-O-triglucoside. The GA3 concentrations used in the experiment positively influenced the accumulation of caffeic acid, p-coumaric acid and gallic acid. The highest content of caffeic acid was noted in the tubers soaked in GA3 concentrated at 400 and 600 mg dm−3. GA3 at a concentration used in the study stimulated the accumulation of kaempferol by 15%, quercetin by 7–8.2%, quercetin 3-O-glucoside by 1.8% (when GA3 was applied at a concentration of 200 mg·dm−3) and by 4.1% and 3.6% (when GA3 was applied at concentrations of 400 and 600 mg·dm−3) and kaempferol 3-O-rhamnosylglucoside by 1.5–3.4%. The soaking of the tubers in GA3 increased the content of β-carotene by 7.9%, 5.2% and 7.9%, respectively, without affecting the content of crocin. For soaking of Crocosmia tubers, it is recommended to use GA3 at a concentration of 400–600 mg·dm−3.