<b>Production of pigments in <i>Alternanthera sessilis</i> calli mediated by plant growth regulators and light

Resumo

Among the compounds produced by plants, pigments such as betalains have received attention from both food and pharmaceuticals industries. The Alternanthera sessilis species produces these pigments, though in small quantities, and so it is necessary to increase production. Thus, many studies use elicitors that are capable of triggering physiological or morphological responses in plants. The objective was to establish callus production in A. sessilis grown under different combinations of growth regulators and light qualities and to assess whether these factors can increase betalain and flavonoid production. Leaf and internodal explants in MS medium with different growth regulators were used to obtain calli, which were subsequently transferred to a betacyanin induction medium remaining for 40 days under different light qualities (white, blue, red, and dark). The most suitable treatment for callus formation and subsequent betalain and flavonoid induction was to combine a medium containing 6.7 µmol L^-1 2,4-D and 9.0 µmol L^-1 BAP and blue light. Physical elicitation by light combined with appropriate concentration of growth regulators on calli can increase production of commercially important metabolites.