Two glycosyltransferase genes belonging to UGT88 family were identified to have 6'-deoxychalcone 4'-glucosyltransferase activity in dahlia. 6'-Deoxychalcones (isoliquiritigenin and butein) are important pigments for yellow and orange to red flower color. 6'-Deoxychalcones are glucosylated at the 4'-position in vivo, but the genes encoding 6'-deoxychalcone 4'-glucosyltransferase have not yet been identified.
View Article and Find Full Text PDFPungent capsaicinoid is synthesized only in chili pepper (Capsicum spp.). The production of vanillylamine from vanillin is a unique reaction in the capsaicinoid biosynthesis pathway.
View Article and Find Full Text PDFBpCYP76AD15 is involved in betaxanthin biosynthesis in callus, but not in bracts, in bougainvillea. Bougainvillea (Bougainvillea peruviana) is a climbing tropical ornamental tree belonging to Nyctaginaceae. Pigments that are conferring colorful bracts in bougainvillea are betalains, and that conferring yellow color are betaxanthins.
View Article and Find Full Text PDFUnlabelled: Chili peppers are important as vegetables and ornamental crops, because of the variety of fruit shapes and colors. Understanding of flower and fruit development in is limited compared with closely related Solanaceae crops such as tomato. This study reports a novel malformed fruit mutant named (), which was isolated from an ethyl methanesulfonate-induced mutant population of chili pepper.
View Article and Find Full Text PDFThe seedless mutant tn-1 in chili pepper is caused by a mutation in CaCKI1 (CA12g21620), which encodes histidine kinase involving female gametophyte development. An amino acid insertion in the receiver domain of CaCKI1 may be the mutation responsible for tn-1. Seedlessness is a desirable trait in fruit crops because the removal of seeds is a troublesome step for consumers and processing industries.
View Article and Find Full Text PDFA novel gene belonging to the aldo-keto reductase 13 family is involved in isoliquiritigenin biosynthesis in dahlia. The yellow pigments of dahlia flowers are derived from 6'-deoxychalcones, which are synthesized via a two-step process, involving the conversion of 3-malonyl-CoA and 4-coumaloyl-CoA into isoliquiritigenin in the first step, and the subsequent generation of butein from isoliquiritigenin. The first step reaction is catalyzed by chalcone synthase (CHS) and aldo-keto reductase (AKR).
View Article and Find Full Text PDFCAP biosynthesis in the pericarp of chili pepper fruits occurs with an ambiguous boundary in the placental septum and pericarp. Capsaicinoid (CAP) is a pungent ingredient of chili pepper fruits. Generally, CAP biosynthesis is limited to the placental septum of fruits, but it has been reported that its biosynthesis occurs even in the pericarp of some extremely pungent varieties, resulting in a substantial increase in total content.
View Article and Find Full Text PDFBetalain is one of four major plant pigments and shares some features with anthocyanin; however, no plant has been found to biosynthesize both pigments. Previous studies have reported that anthocyanin biosynthesis in some plants is regulated by post-transcriptional gene-silencing (PTGS), but the importance of PTGS in betalain biosynthesis remains unclear. In this study, we report the occurrence of PTGS in betalain biosynthesis in bougainvillea (Bougainvillea peruviana) 'Thimma', which produces bracts of three different color on the same plant, namely pink, white, and pink-white.
View Article and Find Full Text PDFChrysanthemum stunt viroid (CSVd) was inoculated into two chrysanthemum () cultivars, the CSVd-susceptible cultivar Piato and the CSVd-resistant cultivar Mari Kazaguruma. For CSVd inoculation, grafting and -mediated inoculation were used. In grafting experiments, CSVd was detectable in Mari Kazaguruma after grafting onto infected Piato, but after removal of infected rootstocks, CSVd could not be detected in the uppermost leaves.
View Article and Find Full Text PDFis propagated by adventitious buds in horticulture, and periclinal chimeral cultivars are usually difficult to propagate. However, some periclinal chimeral cultivars can be propagated with adventitious buds, and the mechanism of which has been unknown. Striped flower cultivars "Kaname," "Concord," and "Monique" were used to investigate what causes flower color separation in adventitious shoot-derived plants by tissue culture.
View Article and Find Full Text PDFPost-transcriptional gene silencing (PTGS) of a chalcone synthase ( DvCHS2 ) occurred in the white part of bicolor petals and flavonoid-poor leaves; however, it did not in red petals and flavonoid-rich leaves. Petal color lability is a prominent feature of bicolor dahlia cultivars, and causes plants to produce not only original bicolor petals with colored bases and pure white tips, but also frequently single-colored petals without white tips. In this study, we analysed the molecular mechanisms that are associated with petal color lability using the red-white bicolor cultivar 'Yuino'.
View Article and Find Full Text PDFAgroinfiltration was tested as a method of inoculation of chrysanthemum plants with chrysanthemum stunt viroid (CSVd). Binary vectors harboring dimeric CSVd sequences in sense and antisense orientations were constructed, and Agrobacterium transfected with these binary vectors was infiltrated into chrysanthemum leaves. Northern blotting and reverse transcription polymerase chain reaction analysis showed that local infection was established within 7 days and systemic infection within 20 days.
View Article and Find Full Text PDFTobacco streak virus suppressed post-transcriptional gene silencing and caused a flower color change in black dahlias, which supported the role of cyanidin-based anthocyanins for black flower appearance. Black flower color of dahlia (Dahlia variabilis) has been attributed, in part, to the high accumulation of cyanidin-based anthocyanins that occurs when flavone synthesis is reduced because of post-transcriptional gene silencing (PTGS) of flavone synthase II (DvFNS). There are also purple-flowering plants that have emerged from a black cultivar 'Kokucho'.
View Article and Find Full Text PDFThe study was aimed to identify the factors that regulate the intensity of flower color in cyanic dahlia (Dahlia variabilis), using fifteen cultivars with different color intensities in their petals. The cultivars were classified into three groups based on their flavonoid composition: ivory white cultivars with flavones; purple and pink cultivars with flavones and anthocyanins; and red cultivars with flavones, anthocyanins, and chalcones. Among the purple, pink, and ivory white cultivars, an inverse relationship was detected between lightness, which was used as an indicator for color intensity and anthocyanin content.
View Article and Find Full Text PDFPlants in tropical regions experience temperature fluctuation only in non-extreme ambient temperatures. Thus, moderate changes in temperatures, which they never experience in their local environments, might be sufficient to manifest the locally hidden phenotype caused by natural mutation. To validate this hypothesis, temperature-treating experiments were performed on Capsicum accessions collected from tropical regions.
View Article and Find Full Text PDFThe corolla of Petunia 'Magic Samba' exhibits unstable anthocyanin expression depending on its phosphorus content. Phosphorus deficiency enhanced post-transcriptional gene silencing of chalcone synthase - A in the corolla. Petunia (Petunia hybrida) 'Magic Samba' has unstable red-white bicolored corollas that respond to nutrient deficiency.
View Article and Find Full Text PDFBlack color in flowers is a highly attractive trait in the floricultural industry, but its underlying mechanisms are largely unknown. This study was performed to identify the bases of the high accumulation of anthocyanidins in black cultivars and to determine whether the high accumulation of total anthocyanidins alone leads to the black appearance. Our approach was to compare black dahlia (Dahlia variabilis) cultivars with purple cultivars and a purple flowering mutant of a black cultivar, using pigment and molecular analyses.
View Article and Find Full Text PDFBackground: The origin of somaclonal variation has not been questioned previously, i.e., "pre-existing mutations" in explants and "newly induced mutations" arising from the tissue culture process have not been distinguished.
View Article and Find Full Text PDFDahlias (Dahlia variabilis) exhibit a wide range of flower colours because of accumulation of anthocyanin and other flavonoids in their ray florets. Two lateral mutants were used that spontaneously occurred in 'Michael J' (MJW) which has yellow ray florets with orange variegation. MJOr, a bud mutant producing completely orange ray florets, accumulates anthocyanins, flavones, and butein, and MJY, another mutant producing completely yellow ray florets, accumulates flavones and butein.
View Article and Find Full Text PDFGarden dahlias (Dahlia variabilis) are autoallooctoploids with redundant genes producing wide color variations in flowers. There are no pure white dahlia cultivars, despite its long breeding history. However, the white areas of bicolor flower petals appear to be pure white.
View Article and Find Full Text PDFTemperature is one of the most important environmental factors that influence plant growth and development. Recent studies imply that plants show various responses to non-extreme ambient temperatures. Previously, we have found that a pepper cultivar cv.
View Article and Find Full Text PDFThe variegated Saintpaulia cultivar Thamires (Saintpaulia sp.), which has pink petals with blue splotches, is generally maintained by leaf cuttings. In contrast, tissue culture-derived progeny of the cultivar showed not only a high percentage of mutants with solid-blue petals but also other solid-color variants, which have not been observed from leaf cuttings.
View Article and Find Full Text PDFJpn J Ophthalmol
October 2005
Purpose: To examine the immunohistochemical localization of L-arginine and L-citrulline and determine where and how nitric oxide (NO) is produced in the normal and streptozotocin (STZ)-induced diabetic rat retinas.
Methods: NO is produced when L-arginine is changed to L-citrulline by NO synthase (NOS). In normal and STZ-induced diabetic rats, using an immunohistochemical method, we examined the retinal distribution of L-arginine and L-citrulline after intracardiac perfusion.
Carbon monoxide (CO), an activator of soluble guanylate cyclase (SGC) and generated enzymatically by heme oxygenases (HO), is considered to function as an intra- and intercellular neuromodulator or neurotransmitter in the central and peripheral nervous systems. HO-2 is the constitutive isoform of HO and is more prevalent in nervous tissues than in the other peripheral tissues. Because previous studies have demonstrated different distributions of HO-2 in the retina depending on the species of animals, the aim of this study was to identify which cell types of the monkey retina express HO-2.
View Article and Find Full Text PDFThe effects of the beta1-selective adrenergic antagonist betaxolol on electroretinography (ERG) were studied in the isolated and arterially perfused cat eye. Betaxolol increased the perfusion flow rate, significantly at the administrations of more than 50 microM concentrations and induced a dose-related, reversible increase in the amplitudes of both the a-wave and b-wave of ERG. These results suggest that the calcium-channel blocking mechanism of betaxolol has a beneficial influence on ocular blood flow and retinal electrical activity in response to light.
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