Hairy Root Cultures as a Source of Polyphenolic Antioxidants: Flavonoids, Stilbenoids and Hydrolyzable Tannins

Due to their chemical properties and biological activity, antioxidants of plant origin have gained interest as valuable components of the human diet, potential food preservatives and additives, ingredients of cosmetics and factors implicated in tolerance mechanisms against environmental stress. Plant polyphenols are the most prominent and extensively studied, albeit not only group of, secondary plant (specialized) metabolites manifesting antioxidative activity. Because of their potential economic importance, the productive and renewable sources of the compounds are desirable. Over thirty years of research on hairy root cultures, as both producers of secondary plant metabolites and experimental systems to investigate plant biosynthetic pathways, brought about several spectacular achievements. The present review focuses on the Rhizobium rhizogenes-transformed roots that either may be efficient sources of plant-derived antioxidants or were used to elucidate some regulatory mechanisms responsible for the enhanced accumulation of antioxidants in plant tissues.

Automated summary

Plant-derived antioxidants have attracted significant attention due to their chemical properties and biological activity, and they are considered valuable components of the human diet, potential food preservatives and additives, ingredients of cosmetics, as well as factors involved in environmental stress tolerance mechanisms. Among these antioxidants, plant polyphenols are the most extensively studied secondary plant metabolites with antioxidative activity. Research on Rhizobium rhizogenes-transformed roots has yielded remarkable achievements in both the production of secondary plant metabolites and the investigation of plant biosynthetic pathways. This review focuses on exploring the potential of these transformed roots as efficient sources of plant-derived antioxidants and elucidating the regulatory mechanisms responsible for enhanced antioxidant accumulation in plant tissues.