RRC ID 35741
Author Morita Y, Ishiguro K, Tanaka Y, Iida S, Hoshino A.
Title Spontaneous mutations of the UDP-glucose:flavonoid 3-O-glucosyltransferase gene confers pale- and dull-colored flowers in the Japanese and common morning glories.
Journal Planta
Abstract MAIN CONCLUSION:UDP-glucose:flavonoid 3- O -glucosyltransferase is essential for maintaining proper production quantity, acylation, and glucosylation of anthocyanin, and defects cause pale and dull flower pigmentation in morning glories. The Japanese (Ipomoea nil) and the common (I. purpurea) morning glory display bright blue and dark purple flowers, respectively. These flowers contain acylated and glucosylated anthocyanin pigments, and a number of flower color mutants have been isolated in I. nil. Of these, the duskish mutants of I. nil produce pale- and dull-colored flowers. We found that the Duskish gene encodes UDP-glucose:flavonoid 3-O-glucosyltransferase (3GT). The duskish-1 mutation is a frameshift mutation caused by a 4-bp insertion, and duskish-2 is an insertion of a DNA transposon, Tpn10, at 1.3 kb upstream of the 3GT start codon. In the duskish-2 mutant, excision of Tpn10 is responsible for restoration of the expression of the 3GT gene. The recombinant 3GT protein displays expected 3GT enzymatic activities to catalyze 3-O-glucosylation of anthocyanidins in vitro. Anthocyanin analysis of a duskish-2 mutant and its germinal revertant showing pale and normal pigmented flowers, respectively, revealed that the mutation caused around 80 % reduction of anthocyanin accumulation. We further characterized two I. purpurea mutants showing pale brownish-red flowers, and found that they carry the same frameshift mutation in the 3GT gene. Most of the flower anthocyanins in the mutants were previously found to be anthocyanidin 3-O-glucosides lacking several caffeic acid and glucose moieties that are attached to the anthocyanins in the wild-type plants. These results indicated that 3GT is essential not only for production, but also for proper acylation and glucosylation, of anthocyanin in the morning glories.
Volume 242(3)
Pages 575-87
Published 2015-9-1
DOI 10.1007/s00425-015-2321-5
PMID 26007684
MeSH Anthocyanins / metabolism Flowers / enzymology Flowers / metabolism* Gene Expression Regulation, Plant Glucosyltransferases / metabolism* Ipomoea / enzymology Ipomoea / metabolism* Mutation Uridine Diphosphate Glucose / metabolism*
IF 3.39
Times Cited 9
Morning Glory AK1 AK5 AK62 AK302 AK311 Q0073 Q0531 Q0853 Q0854 JMFF023O06