Induction of hairy roots by Agrobacterium rhizogenes-mediated transformation of spine gourd (Momordica dioica Roxb. ex. willd) for the assessment of phenolic compounds and biological activities

An efficient protocol for hairy root induction of spine gourd (Momordica dioica) was established using Agrobacterium rhizogenes (KCTC 2703). This study evaluates the phenolic compound production, antioxidant and antimicrobial (antibacterial, antifungal and antiviral) activities of transgenic hairy root cultures in M. dioica . Hairy roots were induced from leaves, petiole, and internodal explants. Molecular analysis of PCR and gene sequencing using specific primers of rolC and aux1 revealed T-DNA integration in the hairy root clones and RT-PCR analysis confirmed the expression of hairy root inducible genes (rolC and aux1). The greatest biomass accumulation of hairy roots on MS liquid medium supplemented with 3% sucrose was observed at 22 days. Ultra-HPLC was used to compare the individual phenolic compound contents of transgenic and non-transgenic roots. Moreover, transgenic hairy roots efficiently produced several phenolic compounds, such as flavonols, hydroxycinnamic acid and hydroxybenzoic acid derivatives. The total phenolic, flavonoid contents and biological (antioxidant, antibacterial, antifungal and antiviral) activities were higher in hairy roots compared to non-transformed roots. These results demonstrate the greater potentiality of M. dioica hairy root cultures for the production of valuable phenolic compounds and for studies of their biological activity.