Evaluation of the growth regulators, sugars and amino acid tryptophan effect on the rate of tryptophan decarboxylase enzyme on Catharanthus roseus (L.) G.Don. in tissue culture, cell suspension culture and field culture conditions

Catharanthus roseus The most important species from Apocyanaceae contains an important and special group of indole alkaloids with a great medicinal value, which are distributed in all organs of the plant. The presence of valuable alkaloids in all organs of the plant has led to the introduction of this species as very important medicinal plants and their properties to be studied. This study was performed to investigate the effect of growth regulatory treatments on the activity of tryptophan decarboxylase (TDC) which is a cytosolic enzyme and a key enzyme in the secondary metabolite biosynthesis The effects of some growth regulators such as KIN, BA, NAA and IAA in three concentrations (0.1, 0.5, 1.0 mg/L) as well as various sugar treatments like sucrose, fructose and glucose in 3 concentrations (2% , 4% , 6%) and also the amino acid tryptophan (at concentrations 100 and 200 mg/L, were investigated on TDC enzyme activity. The experimant was performed in three replications as a factorial in a completely randomized design in Karaj Seed and Plant Breeding Research Institute. in the applied IAA and NAA at concentrations of 0.1 and 0.5 mg/L respectively, increased the activity of TDC by about 10%. But cytokinins, KIN and BA at 1,0 mg/L had the greatest promotion effect of about 40%. Sugars such as Sucrose in concentrations 6%, fructose and glucose in 4% and amino acid tryptophan in concentration 100 mg/l had the maximal effects on the activity of TDC enzyme