The micropropagation of watercress(Rorippa nasturtium-aquatic umL.)

Phytochemical and Biological Activity Studies on Nasturtium officinale (Watercress) Microshoot Cultures Grown in RITA® Temporary Immersion Systems

The main compounds in both extracts were gluconasturtiin, 4-methoxyglucobrassicin and rutoside, the amounts of which were, respectively, determined as 182.93, 58.86 and 23.24 mg/100 g dry weight (DW) in biomass extracts and 640.94, 23.47 and 7.20 mg/100 g DW in plant herb extracts. The antioxidant potential of all the studied extracts evaluated using CUPRAC (CUPric Reducing Antioxidant Activity), FRAP (Ferric Reducing Ability of Plasma), and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays was comparable. The anti-inflammatory activity of the extracts was tested based on the inhibition of 15-lipoxygenase, cyclooxygenase-1, cyclooxygenase-2 (COX-2), and phospholipase A₂. The results demonstrate significantly higher inhibition of COX-2 for in vitro cultured biomass compared with the herb extracts (75.4 and 41.1%, respectively). Moreover, all the studied extracts showed almost similar antibacterial and antifungal potential. Based on these findings, and due to the fact that the growth of in vitro microshoots is independent of environmental conditions and unaffected by environmental pollution, we propose that biomass that can be rapidly grown in RITA^® bioreactors can serve as an alternative source of bioactive compounds with valuable biological properties.

The Influence of Nasturtium officinale R. Br. Agar and Agitated Microshoot Culture Media on Glucosinolate and Phenolic Acid Production, and Antioxidant Activity

This paper presents an optimization of conditions for microshoot cultures of Nasturtium officinale R. Br. (watercress). Variants of the Murashige and Skoog (MS) medium containing different plant growth regulators (PGRs): cytokinins—BA (6-benzyladenine), 2iP (6-γ,γ-dimethylallylaminopurine), KIN (kinetin), Zea (zeatin), and auxins—IAA (3-indoleacetic acid), IBA (indole-3-butyric acid), 2,4-d (2,4-dichlorophenoxyacetic acid), IPA (indole-3-pyruvic acid), NAA (naphthalene-1-acetic acid), total 27 MS variants, were tested in agar and agitated cultures. Growth cycles were tested for 10, 20, or 30 days in the agar cultures, and 10 or 20 days in the agitated cultures. Glucosinolate and phenolic acid production, total phenolic content and antioxidant potential were evaluated. The total amounts of glucosinolates ranged from 100.23 to 194.77 mg/100 g dry weight of biomass (DW) in agar cultures, and from 78.09 to 182.80 mg/100 g DW in agitated cultures. The total phenolic acid content varied from 15.89 to 237.52 mg/100 g DW for the agar cultures, and from 70.80 to 236.74 mg/100 g DW for the agitated cultures. Extracts of the cultured biomass contained higher total amounts of phenolic acids, lower total amounts of glucosinolates, a higher total phenolic content and similar antioxidant potentials compared to plant material. The analyses performed confirmed for the first time the explicit influence on secondary metabolite production and on the antioxidant potential. The significance was statistically estimated in a complex manner.

A simple shoot multiplication procedure using internode explants, and its application for particle bombardment and Agrobacterium-mediated transformation in watercress

A shoot multiplication system derived from internode explants was investigated with the aim of improving genetic characteristics of watercress (Nasturtium officinale R. Br.). Internodes of ca. 1 cm excised from in vitro stock shoot culture were placed on half-strength Murashige and Skoog (MS) medium supplemented with 3 muM 2,4-dichlorophenoxyacetic acid as a pre-treatment. Laser scanning microscopy indicated clearly that the first sign of meristematic cell division could be seen after 1-2 days of pre-culture, and meristematic tissues multiplied along the vascular cambium of the internode segment during 7 days of culture. Multiple shoots could be obtained from more than 90% of the pre-treated explants when they were subsequently transferred to MS medium supplemented with 1 muM thidiazuron for 3 weeks. These findings indicate that pre-treatment of the internodes for 7 days promoted their capacity for organogenesis. Using this pre-treatment, frequent generation of transgenic watercress plants was achieved by adapting particle bombardment and Agrobacterium-mediated transformation techniques with a construct expressing a synthetic green florescent protein gene.