Properties and genetic control of anthocyanin 5-O-glucosyltransferase in flowers of Petunia hybrida

Abstract
An anthocyanin 5-O-glucosyltransferase from flowers of Petunia hybrida was purified about 30-fold. Using uridine 5′-diphosphoglucose as glucose donor (Km 0.22 mM), the enzyme glucosylated the 3-(p-coumaroyl)-rutinoside derivatives of delphinidin and petunidin (Km 3 μM), isolated from pollen of Petunia. Delphinidin 3-rutinoside, cyanidin 3-rutinoside and delphinidin 3-glucoside did not serve as substrates. The glucosylation of petunidin 3-(p-coumaroyl)-rutinoside showed a pH-activity optimum at pH 8.3 and was neither stimulated by Mg2+ or Ca2+, nor inhibited by ethylenediaminetetraacetic acid. After separating the 5-O-glucosyltransferase from the anthocyanidin 3-O-glucosyltransferase by means of chromatofocusing, it was shown that both enzymes exhibit a high degree of positional specificity. The 5-O-glucosyltransferase activity was correlated with the gene An1, but not with the gene Gf.

This publication has 20 references indexed in Scilit: