NICOTINAMIDE INCREASES GLUTATHIONE AND ANTHOCYANIN IN TISSUE-CULTURE OF CATHARANTHUS-ROSEUS

Nicotinamide (NIC), at a concentration of 8.2 mM, increased the glutat hione content to 300% of the control in an anthocyanin accumulating Ca tharanthus roseus (periwinkle) tissue culture when harvested 10 days a fter NIC addition. One day after NIC addition, the content of oxidized glutathione (GSSG) increased to 169% of the control, but the contents of total glutathione (GSH(tot)) and reduced glutathione (GSH) were un changed. Longer NIC exposure resulted in increasing contents of GSH(to t) and GSH, as well as GSSG and a concomitant increase in anthocyanin accumulation. The glutathione biosynthesis inhibitor, buthioninesulfox imine (BSO), decreased glutathione levels in the tissue and offset the NIC-induced increase in glutathione content. BSO also decreased the N IC-induced anthocyanin accumulation in C. roseus tissue culture.