PROPERTIES AND GENETIC-CONTROL OF UDP-L-RHAMNOSE - ANTHOCYANIDIN 3-O-GLUCOSIDE, 6''-O-RHAMNOSYL-TRANSFERASE FROM PETALS OF RED CAMPION, SILENE-DIOICA

In petals of Silene dioica plants the presence of a glycosyltransferase has been demonstrated, which catalyses the transfer of the rhamnosyl moiety of UDP-l-rhamnose to the glucose of cyanidin 3-O-glucoside. This enzyme can also use pelargonidin 3-O-glucoside as a substrate. The enzyme activity is controlled by a single dominant gene N; no rhamnosyltransferase activity is found in petals of n/n plants. The rhamnosyltransferase exhibits an optimum of pH 8.1 and is stimulated by the divalent metal ions Mg, Mn and Co. The biosynthetic pathway for the synthesis of cyanidin 3-rhamnosylglucoside-5-glucoside in petals of S. dioica is discussed. © 1979.