Structure of the acyl-glucose-dependent anthocyanin 5-O-glucosyltransferase gene in carnations and its disruption by transposable elements in some varieties.

The pink, red and crimson petal colors of carnations (Dianthus caryophyllus) are produced by anthocyanins. The anthocyanins, pelargonidin and cyanidin can be modified by two glucoses at the 3 and 5 positions, and by a single malic acid. Petal color variation can result from failure of such modification, for example, the lack of a glucose at the 5 position is responsible for the color variants of some commercial varieties.

Kaempferol glycosides in the flowers of carnation and their contribution to the creamy white flower color.

Three flavonol glycosides were isolated from the flowers of carnation cultivars 'White Wink' and 'Honey Moon'. They were identified from their UV, MS, 1H and 13C NMR spectra as kaempferol 3-O-neohesperidoside, kaempferol 3-O-sophoroside and kaempferol 3-O-glucosyl-(1 --> 2)-[rhamnosyl-(1 --> 6)-glucoside]. Referring to previous reports, flavonols occurring in carnation flowers are characterized as kaempferol 3-O-glucosides with additional sugars binding at the 2 and/or 6-positions of the glucose.

A novel glucosylation reaction on anthocyanins catalyzed by acyl-glucose-dependent glucosyltransferase in the petals of carnation and delphinium.

Glucosylation of anthocyanin in carnations (Dianthus caryophyllus) and delphiniums (Delphinium grandiflorum) involves novel sugar donors, aromatic acyl-glucoses, in a reaction catalyzed by the enzymes acyl-glucose-dependent anthocyanin 5(7)-O-glucosyltransferase (AA5GT and AA7GT). The AA5GT enzyme was purified from carnation petals, and cDNAs encoding carnation Dc AA5GT and the delphinium homolog Dg AA7GT were isolated. Recombinant Dc AA5GT and Dg AA7GT proteins showed AA5GT and AA7GT activities in vitro.

Detection of 1-O-malylglucose: pelargonidin 3-O-glucose-6''-O-malyltransferase activity in carnation (Dianthus caryophyllus).

Carnations have anthocyanins acylated with malate. Although anthocyanin acyltransferases have been reported in several plant species, anthocyanin malyltransferase (AMalT) activity in carnation has not been identified. Here, an acyl donor substance of AMalT, 1-O-beta-D-malylglucose, was extracted and partially purified from the petals of carnation.