Anthocyanins In Flowers Research Articles

Overexpression of CsANR Increased Flavan-3-ols and Decreased Anthocyanins in Transgenic Tobacco

Anthocyanins and flavan-3-ols are distributed widely in plants and synthesized by a common biosynthetic pathway. Anthocyanin reductase (ANR) represents branching-point enzyme of this pathway converting anthocyanidins to flavan-3-ols. Since tea contains highest amount of flavonoids, a cDNA encoding anthocyanin reductase from tea (CsANR) was overexpressed in transgenic tobacco to check the influence on anthocyanin and flavan-3-ols. The transgenic tobacco was confirmed by genomic PCR and expression of transgene was analyzed through semiquantitative PCR. Interestingly flowers of transgenic tobacco were light pink/white in color instead of dark pink in wild tobacco, documenting the decrease in anthocyanins content. Upon measurement, flower anthocyanin content was found to be lesser. While flavan-3-ols (epicatechin and epigallocatechin) contents were increased in leaf tissue of transgenic lines. The expressions of other endogenous flavonoid biosynthetic pathway genes in different floral parts (sepal, petal, stamen, and carpel) of CsANR overexpressing tobacco as well as wild tobacco were analyzed. The transcript levels of PAL and CHI genes were downregulated, while transcript levels of F3H, FLS, CHS, ANR1, and ANR2 genes were upregulated in all floral parts of CsANR transgenic plants compared to wild tobacco. The expressions of DFR and ANS genes were also spatially modulated in different floral parts due to overexpression of CsANR. Thus, CsANR overexpression increased flavan-3-ols and decreased anthocyanin content by modulating the expressions of various flavonoid biosynthetic pathway genes in flower of tobacco. These changes might be responsible for the observed pollen tube in the pollens of CsANR overexpressing transgenic tobacco when they were still in the anther before pollination.

Anthocyanin and carotenoid pigmentation in flowers of section Mina, subgenus Quamoclit, genus Ipomoea

Plants belong to the section Mina showed characteristic petal pigmentation among Ipomoea plants. For example, petals of Ipomoea hederifolia var. lutea display yellow color derived from carotenoids and those of Ipomoea quamoclit display red color derived from pelargonidin-based anthocyanins. In this study, the pigment composition and the expression patterns of genes for pigment biosynthesis in the petals of I. quamoclit and I. hederifolia var. lutea were analyzed to elucidate the crucial factors that determine petal color in section Mina. The petals of white-flowered I. quamoclit lack the ability to synthesize anthocyanins and carotenoids because of the suppression of anthocyanidin synthase (ANS) gene expression and transcriptional down-regulation of multiple carotenogenic genes, respectively. In petals of I. hederifolia var. lutea, the absence of dihydroflavonol 4-reductase (DFR) gene expression is responsible for the lack of anthocyanins. All F1 progeny obtained by interspecies crossing between I. quamoclit and I. hederifolia var. lutea had scarlet petal color produced by a combination of pelargonidin-based anthocyanins and carotenoids. The flavanone 3-hydroxylase gene, DFR, and ANS were expressed in the petals of the F1 progeny. The results suggest that in these section Mina species, the carotenoid-accumulating phenotype in petals is dominant, and that pelargonidin was produced in the F1 progeny by complementary expression of DFR from white-flowered I. quamoclit and ANS from I. hederifolia var. lutea.

Composition of anthocyanins in pomegranate flowers and their antioxidant activity

Anthocyanins in the flowers of pomegranate ( Punica granatum L.) were extracted and separated by reverse-phase high-performance liquid chromatography and Sephadex LH-20 chromatography. Two anthocyanins were identified to be pelargonidin 3,5-diglucoside and pelargonidin 3-glucoside by spectral methods, ultraviolet–visible spectroscopy, 1H nuclear magnetic resonance spectroscopy, mass spectroscopy and comparisons with the literature. These two anthocyanins were identified from pomegranate flowers for the first time. Furthermore, the antioxidant activities of purified anthocyanins were screened for their antioxidative potential using 2,2′-diphenyl-1-picryl hydrazyl (DPPH) and 3-ethyl-benzo-thiazoline-6-sulphonate (ABTS) systems. The purified anthocyanins showed strong radical scavenging activities. Pelargonidin 3-glucoside showed higher antioxidant activity (50% inhibition values of 19.56 μg/ml for DPPH and Trolox equivalents antioxidant activity of 2.39 μg/μg for ABTS) than pelargonidin 3,5-diglucoside.

Anthocyanins of Wild Rhododendron simsii Planch. Flowers in Vietnam and Japan

Fourteen anthocyanins were detected in the flowers of R. simsii distributed in Vietnam and Japan. The anthocyanin constituents of R. simsii flowers seem to be more complex in the Japanese than Vietnamese population. The percentage of each flower anthocyanin was very low except for two major anthocyanins found in all Vietnamese and Japanese accessions. It was not possible to classify the Vietnamese and Japanese populations by flower anthocyanin constituents. The two major anthocyanins found in all accessions of R. simsii flowers in Vietnam and Japan were isolated and purified by column and high-performance liquid chromatography. Their structures were elucidated by 1H-NMR spectroscopic analyses and either acid or alkaline hydrolysis, and they were identified as cyanidin 3-galactoside and cyanidin 3-arabinoside. These two anthocyanins seem to be common to red-flowered evergreen azaleas, such as R. indicum, R. kaempferi, R. oldhamii, and R. scabrum.

Novel aspects of the flowers and floral pigmentation of two Cleome species (Cleomaceae), C. hassleriana and C. serrulata

Palely pigmented inflorescences of cultivated Cleome hassleriana Chodat (spider flower) have a unique two-toned appearance shown in the present study to be due to a loss of petal pigmentation within 24 h of anthesis, accompanied by an equally unique loss of petal mass. A similar loss occurs in deeply pigmented petals but is less evident to the eye because of the high initial content due to the presence, in the petal mesophyll, of globular anthocyanic vacuolar inclusions (AVIs). Inflorescences of the wild species, Cleome serrulata Pursh. (Rocky Mountain bee flower) are also two-toned because of the deeper pink colour of the unopened bud. No AVIs were seen. The pink colour of the bee flower petals is due to the same five acylated cyanidin glycosides as those previously isolated from mauve petals of spider flower. The structural pattern of the spider flower anthocyanins is shared with at least three genera of the Brassicaceae.

An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae

BackgroundThe control of plant anthocyanin accumulation is via transcriptional regulation of the genes encoding the biosynthetic enzymes. A key activator appears to be an R2R3 MYB transcription factor. In apple fruit, skin anthocyanin levels are controlled by a gene called MYBA or MYB1, while the gene determining fruit flesh and foliage anthocyanin has been termed MYB10. In order to further understand tissue-specific anthocyanin regulation we have isolated orthologous MYB genes from all the commercially important rosaceous species.ResultsWe use gene specific primers to show that the three MYB activators of apple anthocyanin (MYB10/MYB1/MYBA) are likely alleles of each other. MYB transcription factors, with high sequence identity to the apple gene were isolated from across the rosaceous family (e.g. apples, pears, plums, cherries, peaches, raspberries, rose, strawberry). Key identifying amino acid residues were found in both the DNA-binding and C-terminal domains of these MYBs. The expression of these MYB10 genes correlates with fruit and flower anthocyanin levels. Their function was tested in tobacco and strawberry. In tobacco, these MYBs were shown to induce the anthocyanin pathway when co-expressed with bHLHs, while over-expression of strawberry and apple genes in the crop of origin elevates anthocyanins.ConclusionsThis family-wide study of rosaceous R2R3 MYBs provides insight into the evolution of this plant trait. It has implications for the development of new coloured fruit and flowers, as well as aiding the understanding of temporal-spatial colour change.

Metabolic networking in Brunfelsia calycina petals after flower opening

Brunfelsia calycina flowers change colour from purple to white due to anthocyanin degradation, parallel to an increase in fragrance and petal size. Here it was tested whether the production of the fragrant benzenoids is dependent on induction of the shikimate pathway, or if they are formed from the anthocyanin degradation products. An extensive characterization of the events taking place in Brunfelsia flowers is presented. Anthocyanin characterization was performed using ultraperfomance liquid chromatography–quadrupole time of flight–tandem mass specrometry (UPLC-QTOF-MS/MS). Volatiles emitted were identified by headspace solid phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS). Accumulated proteins were identified by 2D gel electrophoresis. Transcription profiles were characterized by cross-species hybridization of Brunfelsia cDNAs to potato cDNA microarrays. Identification of accumulated metabolites was performed by UPLC-QTOF-MS non-targeted metabolite analysis. The results include characterization of the nine main anthocyanins in Brunfelsia flowers. In addition, 146 up-regulated genes, 19 volatiles, seven proteins, and 17 metabolites that increased during anthocyanin degradation were identified. A multilevel analysis suggests induction of the shikimate pathway. This pathway is the most probable source of the phenolic acids, which in turn are precursors of both the benzenoid and lignin production pathways. The knowledge obtained is valuable for future studies on degradation of anthocyanins, formation of volatiles, and the network of secondary metabolism in Brunfelsia and related species.

담배 형질전환체를 이용한 포도 UDP-glucose flavonoid glucosyl transferase (UFGT) 유전자의 기능 분석

페놀화합물인 안토시아닌은 과일, 꽃잎 등 식물 조직에서 청 혹은 적색을 나타내는 색소이다. 포도의 경우, 안토시아닌은 적포도 품종의 과피에만 축적되는데, 이것은 안토시아닌 생합성에 관여하는 효소 중에서 UDP-glucose: flavonoid 3-O-glucosyltransferase(UFGT)를 암호화하는 ufgt 유전자에 의해 조절된다고 보고된 바 있다. ufgt 유전자에 의해 안토시아닌의 축적 양상이 변하는지를 검증하기 위해, 포도로부터 ufgt cDNA를 분리한 다음, 각각 sense와 antisense 방향으로 발현하는 벡터를 제작하고, 이를 야생형 담배에 도입하였다. 담배 형질전환체를 선발하여 RT-PCR을 수행한 결과, 포도 ufgt 유전자가 sense 방향으로 들어간 snese 형질전환체에서는 야생형 담배에 비해 ufgt 전사체의 양이 증가하였고, antisense 방향으로 들어간 antisense 형질전환체에서는 전사체의 양이 도리어 감소하였다. 한편, 담배 형질전환체의 꽃을 분석한 결과, sense 형질전환체의 안토시아닌 함량은 야생형 담배에 비해 최고 44% 증가하였고, antisense 형질전환체에서는 최고 88% 감소하였다. 또한 sense 형질전환체의 꽃 색깔은 야생형 담배에 비해 더 진해졌다. 이러한 결과는 외부로부터 도입된 포도 ufgt 유전자의 발현으로 ufgt 전사체의 양이 증가하면 담배 내 안토시아닌의 함량이 높아지고 꽃 색깔이 진해진다는 것을 시사한다. Anthocyanin, a phenolic compound, is a pigment that shows blue or red color in the fruit, petal and other tissues. It is an important factor in grape berry skin pigment and accumulates only in the skin. This skin-specific accumulation of anthocyanin has been reported to be regulated by the ufgt gene which encodes UDP-glucose: flavonoid 3-O-glucosyltransferase that participates in the biosynthesis of anthocyanin. The ufgt gene is expressed only in berry skin, while the other genes involved in the biosynthetic pathway are expressed in both skin and flesh tissues. In order to determine whether anthocyanin accumulation is primarily regulated by compartment of UFGT, a ufgt cDNA clone was isolated from grape berry, its open reading frame was ligated in pBI121 vector in either a sense or an antisense orientation under the control of the CaMV35S promoter and the recombinant constructs were incorporated into tobacco plants. Several transgenic lines were selected and characterized to determine the level of expression of the grapevine ufgt transcript and endogenous homologs of tobacco. Compared to the wild-type, the amount of anthocyanins in sense transgenic plants increased by 44%, while the amount of anthocyanins in antisense transgenic plants decreased by 88%. In addition, the color of flowers became intense in the sense transgenic plants. These results suggest that over-expression or repression of the ufgt gene affected the accumulation of anthocyanin in flowers of tobacco.

Acylated anthocyanins in inflorescence of spider flower ( Cleome hassleriana)

Five anthocyanins, cyanidin 3-(2′′-(6′′′-caffeoyl-β-glucopyranosyl)-6′′-( E- p-coumaroyl)-β-glucopyranoside)-5-β-glucopyranoside, cyanidin 3-(2′′-(6′′′- E-sinapoyl-β-glucopyranosyl)-6′′-( E- p-coumaroyl)-β-glucopyranoside)-5-β-glucopyranoside, cyanidin 3-(2′′-(6′′′-feroyl-β-glucopyranosyl)-6′′-( E- p-coumaroyl)-β-glucopyranoside)-5-β-glucopyranoside, pelargonidin 3-(2′′-(6′′′- E-sinapoyl-β-glucopyranosyl)-6′′-( E- p-coumaroyl)-β-glucopyranoside)-5-β-glucopyranoside, and pelargonidin 3-(2′′-(6′′′- E- p-coumaroyl-β-glucopyranosyl)-6′′-( E- p-coumaroyl)-β-glucopyranoside)-5-β-glucopyranoside, together with five known anthocyanins have been identified in flowers of Cleome hassleriana Queen line. One monoacylated and four diacylated cyanidin 3-sophoroside-5-glucosides were identified as the main anthocyanins in flowers with mauve colouration, while a homologous glycosidic pattern based on pelargonidin was found in the five main anthocyanins from flowers with pink colouration. The anthocyanins identified in C. hassleriana share the same glycosidic pattern as anthocyanins isolated from the genera Raphanus, Brassica and Iberis in the sister family Brassicaceae.

Red-purple flower due to delphinidin 3,5-diglucoside, a novel pigment for Cyclamen spp., generated by ion-beam irradiation

We previously bred fragrant cyclamen cultivars by interspecific hybridization between cultivars of Cyclamen persicum and the wild species Cyclamen purpurascens. One of these fragrant cultivars, Kaori-no-mai, blooms purple flowers containing malvidin 3,5-diglucoside as the major anthocyanin. Here, we irradiated etiolated petioles of Kaori-no-mai with a 320-MeV carbon-ion beam at 0–16 Gy to increase flower color variation by mutation. Some of the M2 plants derived from self-pollination of M1 plants irradiated at 2 Gy were flower-color mutants that retained desirable flower shape, flower size, and leaf color. One of the mutants bloomed novel red-purple flowers, the major anthocyanin of which was delphinidin 3,5-diglucoside. Loss of methylation activity at the anthocyanin 3′- and 5′-hydroxyl groups with little influence on anthocyanin concentration was attributed to the mutation. Because the major anthocyanins in flowers of Cyclamen spp. were previously restricted to malvidin, peonidin, and cyanidin types, the generation of a cyclamen containing mostly the delphinidin-type anthocyanin is an important breakthrough in cyclamen breeding. We expect this mutant to become not only a commercial cultivar itself, but also a valuable genetic resource for cyclamen breeding.

ANTHOCYANIN AND POTENTIAL THERAPEUTIC TRAITS IN CLITORIA, DESMODIUM, CORCHORUS, CATHARANTHUS AND HIBISCUS SPECIES

The USDA, ARS, Plant Genetic Resources Conservation Unit curates several important nutraceutical and medicinal plant species. Anthocyanins are responsible for flower, leaf and seed coat color in plants, and are antioxidants as well. However, little is known about anthocyanin content in Clitoria ternatea, Desmodium adscendens, Corchorus olitorius, Catharanthus roseus, Hibiscus sabdariffa and Acer saccharum. This study was conducted to identify anthocyanin indexes and additional health enhancing components in these species. An anthocyanin meter with an LED diode of 520 nm was used to measure the anthocyanin index of leaves and flowers from plants growing in the field during July, September and October 2006. We found anthocyanin indexes ranging from 4.1 to 52.4 for leaves and 0.8 to 26.8 for flowers in all five species. The highest leaf anthocyanin index average of 14.6 was found in D. adscendens (PI 316623) followed by sugar maple (A. saccharum) with a leaf anthocyanin average index of 13.0. Catharanthus roseus (PI 608581) also had the highest flower anthocyanin index average of 17.3. These data were recorded at or prior to 50% maturity. In addition, potential health uses for these species are discussed. Phytochemicals identified include but are not limited to an antimicrobial protein from C. ternatea, anthocyanin rich extracts from H. sabdariffa for potential use as a chemopreventive agent, and antitumor promoters in C. olitorius leaves. These anthocyanins and phytochemicals have potential value in the nutraceutical and medical industries. These variable anthocyanin indexes among these species will assist breeders and other scientists with valuable germplasm for development of anthocyanin enriched cultivars.

Flower anthocyanins of Calystegia in Japan

Flower anthocyanins of Calystegia in Japan

Three-way chemometric method study and UV-Vis absorbance for the study of simultaneous degradation of anthocyanins in flowers of the Hibiscus rosa-sinensys species

Ultraviolet-visible spectra of flower extracts of the Hibiscus rosa-sinensys L. var. regius maximus species have been measured between 240.02 and 747.97 nm at pH values ranging from 1.1 to 13.0. Deconvolution of these spectra using the Parallel Factor Analysis (PARAFAC) model permitted the study of anthocyanin systems without isolation and purification of the individual species. Seven species were identified: flavilium cation, carbinol, quinoidal base, and E and Z-chacone and their ionized forms. The concentration changes of flavilium cation, quinoidal basen, and E and Z ionized chalcones were determined as function of pH at the different wavelengths. The flavilium cation, quinoidal base, and ionized E-clacone are involved in tho stage kinetic processes, a fast one followed by a slower one. Ionized Z-chalcone obeys a simple first-order processes. The spectral profiles recovered by PARAFAC model are in excellent agreement with bands of experimental spectra reported in the literature for the individual species measured at specific pH values. These results complement those obtained using chemical and simple mathematical techniques and demonstrate how chemometric methods can resolve problems for complex systems.

Origin of the color of Cv. rhapsody in blue rose and some other so-called "blue" roses.

Flowers of the rose cultivar Rhapsody in Blue display unusual colors, changing as they age, from a vivid red-purple to a lighter and duller purple, which are based on tonalities corresponding to hue angles between 340 and 320 degrees in the CIELAB scale. Unexpectedly, the chemical basis of these colors is among the simplest, featuring cyanin (cyanidin 3,5-di-O-glucoside), the most frequent anthocyanin in flowers, as the sole pigment and quercetin kaempferol glycosides as copigments at a relatively low copigment/pigment ratio (about 3/1), which usually produces magenta or red shades in roses. This color shift to bluer shades is coupled with the progressive accumulation of cyanin into vacuolar anthocyanic inclusions (AVIs), the occurrence of which increases as the petals grow older. In addition to the normal lambda(max) of cyanin at approximately 545 nm, the transmission spectra of live petals and of epidermal cells exhibit a second lambda(max) in the 620-625 nm range, the relative importance increasing with the presence of AVIs. In petals of fully opened flowers, the only pigmented structures in the vacuoles of epidermal cells are AVIs; their intense and massive absorption in the 520-640 nm area produces a much darker and bluer color than measured for the vacuolar solution present at the very first opening stage. Cyanin is probably "trapped" into AVIs at higher concentrations than would be possible in a vacuolar solution and in quinonoidal form, appearing purple-blue because of additional absorption in the 580-630 nm area. Quite similar pigmentation features were found in very ancient rose cultivars (cv. L'Evêque or Bleu Magenta), also displaying this type of so-called "blue" color.

Recent Advances in Betalain Research.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Characterization of Anthocyanins in Flowers of Japanese Garden Iris, Iris ensata Thunb.

The flower colors of 15 cultivars and a line in Japanese garden iris, Iris ensata Thunb. were examined by CIELAB scatter diagram. The cultivars classified as anthocyanin types, malvidin 3RGac5G-petunidin 3RGac5G, malvidin 3RG5G-petunidin 3RG5G and peonidin 3RGac5G showed color distribution from purple to red-purple, while the cultivar and line in peonidin 3RG5G and peonidin 3RG5G-cyanidin 3RG5G types were purplish red to red. This indicates that cyanidin 3RG5G and peonidin 3RG5G are good anthocyanin source for the breeding of red flower color. The anthocyanins of 83 cultivars, 13 lines and 5 wild forms of I. ensata were analyzed by HPLC, and these plants were classified into 17 types of major anthocyanins. Among these, 7 new types, delphinidin 3RGac5G-delphinidin 3RG, delphinidin 3RG-petunidin 3RGac5G, petunidin 3G-delphinidin 3G, petunidin 3RGac, peonidin 3RG5G, cyanidin 3RG5G and malvidin 3RGac5G-peonidin 3RGac5G-petunidin 3RGac5G were detected, and a novel anthocyanin source of red flower, cyanidin 3RG5G was obtained for the first time.

Spectrophotometric Determination of Total Sulfite in White Wine Samples Using Crude Extracts from Flowers

A didactic spectrophotometric method for determining the sulfite content in white wine samples is proposed. It is based upon a discoloring reaction between flower anthocyanins and the sulfite in basic media. Students' results obtained from iodometric data agreed well with results obtained by the proposed procedure. The use of natural dyes attracted students' interest, enhancing the learning process.

Increased anthocyanin accumulation in aster flowers at elevated temperatures due to magnesium treatment.

Temperature is one of the main external factors affecting anthocyanin accumulation in plant tissues: low temperatures cause an increase and elevated temperatures cause a decrease in anthocyanin concentration. Several metals have been shown to increase the half-life time of anthocyanins, by forming complexes with them. We studied the combined effect of elevated temperatures and increased metal concentrations on the accumulation of anthocyanins in aster 'Sungal' flowers. It has been found that magnesium treatment of aster plants or detached flower buds, partially prevents colour fading at elevated temperatures. Anthocyanin concentration of aster 'Sungal' flowers grown at 29 degrees C/21 degrees C day/night, respectively, was about half that of flowers grown at 17 degrees C/9 degrees C. The activity of phenylalanine ammonia-lyase (PAL) and chalcone isomerase (CHI) decreased as the temperature increased. Treatment of both whole plants and detached flower buds grown at elevated temperatures in the presence of magnesium salts, increased flower anthocyanin concentration by up to 80%. Measurement of magnesium following these treatments revealed an increased level of the metal in the petals, suggesting a direct effect. Magnesium treatment does not seem to cause increased synthesis of anthocyanin through a stress-related reaction, since the activities of both PAL and CHI did not increase due to this treatment. The results of this study show that increasing magnesium levels in aster petals prevents the deleterious effect of elevated temperatures on anthocyanin accumulation, thus enhancing flower colour.

Genetic engineering of the anthocyanin biosynthetic pathway with flavonoid-3′,5′-hydroxylase: specific switching of the pathway in petunia

Flavonoid-3′,5′-hydroxylase (F3′5′H) is the key enzyme in the synthesis of 3′,5′-hydroxylated anthocyanins, which are generally required for the expression of blue or purple flower color. It has been predicted that the introduction of this enzyme into a plant species that lacks it would enable the production of blue or purple flowers by altering the anthocyanin composition. We present here the results of the genetic engineering of petunia flower color, pigmentation patterns and anthocyanin composition with sense or antisense constructs of the F3 ′ 5 ′ H gene under the control of the CaMV 35S promoter. When sense constructs were introduced into pink flower varieties that are deficient in the enzyme, transgenic plants showed flower color changes from pink to magenta along with changes in anthocyanin composition. Some transgenic plants showed novel pigmentation patterns, e.g. a star-shaped pattern. When sense constructs were introduced into blue flower petunia varieties, the flower color of the transgenic plants changed from deep blue to pale blue or even pale pink. Pigment composition analysis of the transgenic plants suggested that the F3 ′ 5 ′ H transgene not only created or inhibited the biosynthetic pathway to 3′,5′-hydroxylated anthocyanins but switched the pathway to 3′,5′-hydroxylated or 3′-hydroxylated anthocyanins.

A malonylated anthocyanin and flavonols in blue Meconopsis flowers

The structures of the major anthocyanin and two flavonols from the blue flowers of Meconopsis were identified by NMR spectroscopy as being cyanidin 3-O-[(6-O-malonyl-2-O-β-d-xy1opyranosyl)-β-d-glucopyranoside]-7-O-β-d-glucopyranoside, kaempferol 3-O-(6-O-β-d-glucopyranosyl)-β-d-glucopyranoside and kaempferol 3-O-(6-O-β-d-glucopyranosyl)-β-d-galactopyranoside respectively.