TRANSFORMATION MEDIATED BY Agrobacterium rhizogenes AS APPROACH OF STIMULATING THE SYNTHESIS OF ANTIOXIDANT COMPOUNDS IN Artemisia absinthium L.

Abstract

Artemisia absinthium L. plants are known as producers of substances with antioxidant properties. Among others, phenols and flavonoids are found in these plants. The synthesis of these bioactive compounds can be activated by genetic transformation. This process can be carried out even without the transfer of specific genes involved in the synthesis of flavonoids. Thus, “hairy” roots, obtained after Agrobacterium rhizogenes – mediated transformation, can produce a variety of valuable substances. The aim of the study was to obtaine A. absinthium “hairy” roots with high phenolic content. Methods. “Hairy” roots of plants were obtained by co-cultivation leaves with suspension of A. rhizogenes with pCB124 vector. The presence of transferred genes was confirmed by PCR. The reactions with AlCl3 and Folin-Ciocalteu reagent were used to determine the total flavonoids and phenols content. The antioxidant activity of extracts was evaluated by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Results. PCR analysis detected the presence of bacterial rol genes and the absence of рСВ124 plasmid genes. Root lines differed in growth rate. “Hairy” roots were characterized by a higher phenolic content, particularly flavonoids (up to 4.784 ± 0.10 mg/g FW) compared to control (3.861±0.13 mg/g FW). Also, extracts from transgenic roots demonstrated higher antioxidant activity in the reaction with DPPH reagent (EC50 = 3.657 mg) when compared with extracts from control plants (EC50 = 6,716 mg). Conclusions. Transformation of A. absinthium mediated by A. rhizogenes can be applied for obtaining transgenic root lines with increased phenolic content and higher antioxidant activity.