EFFECTS OF HIGH AMMONIUM CONCENTRATIONS ON GROWTH AND ANTHOCYANIN FORMATION IN GRAPE (VITIS-VINIFERA L) CELL-SUSPENSION CULTURED IN A PRODUCTION MEDIUM

Cultivating Vitis vinifera cell suspensions in a production medium which is characterized by high sucrose and low nitrate concentrations (132 mM and 6.25 mM respectively) repressed growth but enhanced the intracellular accumulation of anthocyanins, especially peonidin 3-glucoside. Increasing the ammonium concentration of the production medium from 2 to 8-16 mM increased growth and decreased the accumulation of anthocyanins and peonidin 3-glucoside specifically. Instead, peonidin 3-p-coumaroyl-glucoside accumulated. At 24 mM ammonium concentration, growth was inhibited and accumulation of peonidin 3-p-coumaroylglucoside was significant (p < 0.05) and represented 42% of total anthocyanins after 12 days of culture compared with 19% in the production medium with 2 mM ammonium.