Phenolic compound production and biological activities from in vitro regenerated plants of gherkin (Cucumis anguria L.)

Background: The effect of polyamines (PAs) along with cytokinins (TDZ and BAP) and auxin (IBA) was induced by the multiple shoot regeneration from leaf explants of gherkin (Cucumis anguria L.). The polyphenolic content, antioxidant and antibacterial potential were studied from in vitro regenerated and in vivo plants. Results: Murashige and Skoog (MS) medium supplemented with 3% sucrose containing a combination of 3.0 mu M TDZ, 1.0 mu M IBA and 75 mu M spermidine induced maximum number of shoots (45 shoots per explant) was achieved. Regenerated shoots elongated in shoot elongation medium containing 1.5 mu M GA(3) and 50 mu M spermine. The well-developed shoots were transferred to root induction medium containing 1.0 mu M IBA and 50 mu M putrescine. Rooted plants were hardened and successfully established in soil with a 95% survival rate. Twenty-five phenolic compounds were identified by ultra-performance liquid chromatography (UPLC) analysis The individual polyphenolic compounds, total phenolic and flavonoid contents, antioxidant and antibacterial potential were significantly higher with in vitro regenerated plants than in vivo plants. Conclusions: Plant growth regulators (PGRs) and PAs had a significant effect on in vitro plant regeneration and also a biochemical accumulation of flavonols, hydroxybenzoic and hydroxycinnamic acid derivatives in C. anguria. Due to these metabolic variations, the antioxidant and antibacterial activities were increased with in vitro regenerated plants than in vivo plants. This is the first report describing the production of phenolic compounds and biological activities from in vitro and in vivo regenerated plants of C. anguria. (C) 2015 Pontificia Universidad Catolica de Valparaiso. Production and hosting by Elsevier B.V. All rights reserved.