Genetic and Biochemical Studies on the Conversion of Dihydroflavonols to Flavonols in Flowers of Petunia hybrida
نویسندگان
چکیده
Dioxygenase, Flavonoid Biosynthesis, Flavonols, Genetic Control, Petunia hybrida Soluble enzyme preparations from flower buds of Petunia hybrida catalyzed the conversion of dihydroflavonols to flavonols. Dihydrokaempferol and dihydroquercetin were readily converted to the respective flavonols, whereas dihydromyricetin was a poor substrate. The reaction required 2-oxoglutarate, ascorbate and Fe2+ as cofactors and had a pH optimum at about 6.5. In the presence of the dominant allele FI, high enzyme activity for flavonol formation was found, whereas in enzyme preparations from flower buds of recessive genotypes (fl/fl) only low enzyme activity could be observed. A substantial correlation was found between enzyme activity for flavonol formation and the flavonol content of buds and flowers during development.
منابع مشابه
Chalcone Synthase and Flavonol Accumulation in Stigmas and Anthers of Petunia hybrida.
Flavonol aglycones are required for pollen germination in petunia (Petunia hybrida L.). Mutant plants lacking chalcone synthase (CHS), which catalyzes the first committed step in flavonoid synthesis, do not accumulate flavonols and are self-sterile. The mutant pollen can be induced to germinate by supplementing it with kaempferol, a flavonol aglycone, either at the time of pollination or by add...
متن کاملDisequilibrium of Flavonol Synthase and Dihydroflavonol-4-Reductase Expression Associated Tightly to White vs. Red Color Flower Formation in Plants
Flower color is the main character throughout the plant kingdom. Though substantial information exists regarding the structural and regulatory genes involved in anthocyanin and flavonol biosynthesis, little is known that what make a diverse white vs. red color flower in natural species. Here, the contents of pigments in seven species from varied phylogenetic location in plants with red and whit...
متن کاملCommon Identity of UDP-Glucose: Anthocyanidin 3-O-Glucosyltransferase and UDP-Glucose: Flavonol 3-O-Glucosyltransferase in Flowers of Petunia hybrida
In an attempt to distinguish between the UDP-glucose: flavonol 3-O-glucosyltransferase (3G T ) and the UDP-glucose:anthocyanidin 3-O-glucosyltransferase in flower buds o f Petunia hybrida, several properties of these activities were determined. The 3-glucosylation o f anthocyanidin had a pH-activity optimum of 7.2, that o f flavonol pH 9.2 to 9.5. Anthocyanidin 3G T activity was lowered in the ...
متن کاملThe Effect of Chalcone Isomerase (Chi) Gene Silencing on Flavonoids Content in Petunia hybrida using RNAi Technology
have been bred with altered flower color using genetic engineering approaches. One of the most effective applications is the reduction of flower pigments by suppression of involved enzymes in their biosynthesis pathways. RNA interference (RNAi) has provided an effective tool for the knock down of genes involved in the production of flower pigments. In this study, a chi-RNAi construct was design...
متن کاملتأثیر سالیسیلیک اسید بر رشد و ویژگی های زینتی اطلسی ایرانی (Petunia hybrida) تحت شرایط تنش شوری
Application of salicylic acid (SA) as a phytohormone has been increased due to resistance to stresses such as salt stress. To evaluate the effects of SA on growth and ornamental characteristics of Persian petunia under salt stress, a factorial experiment, based on completely randomized design, was conducted with 3 levels of SA (0, 1 and 2 mM) and 3 levels of NaCl (0, 150 and 300 mM) with 4 rep...
متن کامل