Journal of Plant Process and Function

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In the present study, the effect of exogenous silver nitrate (Ag⁺) and copper sulfate (Cu²⁺) applications on production of artemisinin and phenolic compounds as well as oxidative stress in the shoot cultures of Artemisia annua was investigated. A significant decrease in the shoot biomass and the total chlorophyll was observed in the shoots exposed to increased Ag concentration. Additionally, a significant increase in the carotenoid content was evident in the shoots (1.5 fold). The shoots exposed to Cu exhibited a marked increment in the biomass (1.5 fold), the total chlorophyll (2.2 fold) and the carotenoid content (1.4 fold). Ag and Cu induced generation of H₂O₂, LOX activity and increased production of MDA via both enzymatic and non-enzymatic peroxidation of membrane lipids one week after elicitation. In this study, we found that Ag and Cu markedly induced GST activity at the concentrations as low as 100 µM Ag and 25 µM Cu. Furthermore, Ag and Cu elicited accumulation of phenolic compounds (maximum value: 6.5 mg/gfw) and phenylalanine ammonia-lyase activity (2.5 folds). Artemisinin content was increased in the shoot cultures supplemented only with 5 µM of CuSO₄ (0.65%). It was revealed that both Cu and Ag affected the phenolic compounds biosynthesis in the shoot cultures of Artemisia. However, artemisinin production was only affected by Cu.