Study of influence of ascorbic acid, reducing sugars and methyldopa on betalains content in Celosia cristata callus

Abstract

Aim. The aim of the present work is to investigate the influence of reducing sugars, ascorbic acid and methyl DOPA as one of the DOPA decarboxylase inhibitors on total amount and spectrum of betalains in the callus culture of cockscomb Celosia cristata L. (Amaranthaceae). Methods. Tissue culture methods, analytical high-performance liquid chromatography (HPLC), spectrophotometry. Results. Adding of some reducing sugars (1 % of glucose, arabinose or rhamnose) to the media does not increase the total betalains content. Ascorbic acid at a concentration of 5 mM also does not significantly affect the amount of betalains, but considerably inhibit the callus growth. Moreover, ascorbic acid causes significant decreasing of the dopamine content and the normalized concentration of the main betacyanin pigment of the callus – amaranthin. Investigations have begun to study the effects of DOPA-decarboxylase inhibitors on the content of betalains and dopamine. Increased level of betalains in the callus in the presence of all used concentrations of methylDOPA was aobserved. The necessity of use of ascorbic acid or another stabilizer of methylDOPA in order to prevent oxidation of this inhibitor has been established. Conclusions. The data obtained suggest that methylDOPA as well as, probably, other inhibitors of DOPA decarboxylase can influence on betalains level in callus culture, so their use may be a potential strategy for these pigments content increasing.
 Keywords: Celosia cristata L. betalains, dopamine, callus culture.