Adventitious roots formation for enhanced and sustainable production of antioxidants in Brassica oleracea var. acephala (Brassicaceae)

Brassica oleracea var. acephala is listed as the healthiest vegetable due to its high valued secondary metabolites content and antioxidant potential. This study was conducted to establish adventitious roots (ARs) culture as an alternative and feasible production of antioxidant secondary metabolites. ARs were induced from cotyledon explants in commercially available Murashige and Skoog (MS) plant nutrient media, gelled with 0.8% phyto-agar and supplemented with different concentration (0.1 ̶ 1.5 mg·L-1) of auxins (α-Naphthalene acetic acid; NAA, or Indole acetic acid; IAA, or Indole-3-butyric acid; IBA). AR formation responses in MS media at varying concentrations (0 ̶ 50 g·L-1) of sucrose and initial media pH (4, 5.0, 5.8, 7 & 8) were also studied. The bioprocessing of ARs were studied in liquid MS media containing NAA (1.5 mg·L-1) as growth regulator. The growth curve, important antioxidants (phenols & flavonoids), and free radical scavenging potential of ARs were studied for a period of 9-weeks. The ARs at stationary phase (7-week) attained highest accumulation of phenols and flavonoids, which ultimately showed the highest reactive species scavenging potential. This study provides the base for production of B. oleraceae var. acephala secondary metabolites on large scale to strengthen the bio-based economy of developing world.