Enhancement phenolic content in callus of Taraxacum officinale plant by using phenylalanine precursors

Abstract

Dandelion (Taraxacum officinale) has been used in traditional medicine. It has been utilized as a source for bioactive compounds. Such as phenolic compounds. Thus, this study aimed to increase phenolic yield in callus cultures supplied with Phenylalanine (Phe.) as a precursor. Seeds of T. officinale were sterilized and cultured in vitro on Murashige and Skoog (MS) medium then used as a source of explants. Leaves and roots were cultured on MS medium supplemented with combinations (0.25, 0.5 or 0.75mg/L) of benzyl adenine purine (BAP) and (1, 2 or 3 mg/L) of indole acetic acid (IAA). The best fresh weight for callus formation was achieved at 0.75 mg/L BAP for leaves and 0.75 mg/L with 2 mg/L IAA for root. Quantitative analyses with spectrophotometer, the total phenols were expressed as Gallic acid standard curve showed phenolic content presence in leaves 15.38 mg and 14.89 mg in root of intact plant. The addition of different concentrations of Phe (0.3, 0.5, 0.7, 0.9, 1 or 1.5 mg/L) as a precursor to the medium led to increase the levels of phenolic content in leaves and roots callus tissue. Phe. at concentration 1.5mg/L enhanced production of phenols to 17.86 mg on leaves callus and 1mg/L concentration of Phe. Enhanced production of phenols to 16.50 mg on roots callus comparison with intact plant. In contrast, even the control treatment (0 mg/ L) concentration of (Phe.) was found to be stimulated phenolic yield in comparison with phenolic content in intact plant.