Agrobacterium rhizogenes mediated transformation of Ficus carica L. for the efficient production of secondary metabolites

BACKGROUND Ficus carica L., an ancient source of food and medicines, is rich in valuable nutritional and secondary compounds with antioxidant, antimicrobial, and anticancer effects. The present study is the first attempt to examine hairy root (HR) induction of F. carica (Sabz and Siah) by inoculating the 3-week-old shoots and leaves with different strains of Agrobacterium rhizogenes and also to investigate methyl jasmonate (MeJA) elicitation of HRs to produce a fast and high-yield production method for secondary metabolites. RESULTS The maximum transformation rate (100%) was achieved by inoculating the shoots with Agrobacterium rhizogenes strain A7. Siah HRs elicited with 100 and 200 mu mol L-1 MeJA and Sabz HRs with 100 mu mol L-1 MeJA showed the highest total phenolic content. The highest flavonoid content was 3.935 mg QE g(-1) DW in Siah HRs treated with 200 mu mol L-1 MeJA and 2.762 mg QE g(-1) DW in Sabz HRs treated with 300 mu mol L-1 MeJA. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity and ferric reducing antioxidant power (FRAP) value of HRs were affected by MeJA treatments. Methyl jasmonate elicitation also significantly enhanced the content of six phenolic acids (gallic acid, caffeic acid, chlorogenic acid, coumaric acid, rosmarinic acid, and cinnamic acid) and three flavonoids (rutin, quercetin, and apigenin). Thymol, a monoterpene phenol, was the main HR compound detected in gas chromatography mass spectrometry (GC-MS) analysis of the essential oils. CONCLUSION Induction of HRs and elicitation of F. carica HRs by MeJA resulted in a significant increase in the production of important phenolic compounds and a significant increase in antioxidant capacity. (c) 2020 Society of Chemical Industry