Search

BACKGROUND Wheat grain is recognized as a rich source of nutrients, including proteins, vitamins, minerals, fibers and antioxidants. In recent years, the focus of wheat breeding has been to increase the content of bioactive compounds to improve human health and prevent diseases. RESULTS: Five novel wheat mutant lines with variable seed color were developed using gamma irradiation of hexaploid wheat inbred line K4191 (purple seed color). The total anthocyanin contents of three mutant lines (L47, L167 and L925) were significantly higher than those of wild‐type lines, including K4191 and 'Keumkang' (white seed color). L925 showed the highest total anthocyanin content, and cyanidin‐3‐glucoside was presented as the most predominant anthocyanin. Compared with 'Keumkang', the expression of anthocyanin biosynthesis genes was significantly up‐regulated in purple seed mutant lines. The highest antioxidant activity was observed in L925 extracts. The expression of a few antioxidant‐related genes and total anthocyanin content were positively correlated with antioxidant capacity. These data suggest that anthocyanins and phenolic compounds in wheat grains contribute to the antioxidant potential. CONCLUSION: Purple grain color is associated with higher anthocyanin accumulation and antioxidant capacity in wheat. Wheat mutants developed in this study may serve as a valuable source of antioxidants. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this study, the flavonoid and isoflavone contents in four checks with seed coat colour altered from yellow to black were determined, and their antioxidant activity was measured. Three anthocyanins (delphinidin-3-O- β-D-glucoside, D3G; cyanidin-3-O- β-D-glucoside, C3G; and petunidin-3-O- β-D-glucoside, Pt3G) were detected in the four checks, while their controls (cvs. 'Danbaek' and 'Daepung') were not found. Among them, D-16 derived from cv. 'Danbaek' showed the highest anthocyanin contents. The isoflavone contents of all checks showed lower levels compared to their controls. Among six isoflavones, glycitein was only detected in DP-39. To analyse the radical scavenging activities among the four checks, we conducted DPPH, FRAP and UWLA assays. Significant differences in antioxidant activities were obtainable in the four checks, which contained significant differences in levels of anthocyanins and isoflavones. Based on these results, gamma irradiation may change the isoflavone and anthocyanin contents of soybean. Our four checks selected in this study may be useful for breeding soybean varieties to alter their nutritional values. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the mechanisms of adaptation and tolerance to ionizing radiation using chronic radiation in wheat. Materials and methods: We exposed wheat plants to chronic gamma irradiation (50 Gy) for 2, 4, and 6 weeks and measured various biological parameters. Results: Plant height was reduced by exposure to gamma irradiation; this effect increased with increasing exposure time. Photosynthetic pigment levels decreased with increasing exposure time, while anthocyanin levels significantly increased after exposure to gamma rays. The activities of antioxidant enzymes (superoxide dismutase [SOD], ascorbate peroxidase [APX], catalase [CAT], and peroxidase [POD]) and malondialdehyde (MDA) levels increased with increasing duration of exposure to gamma irradiation. Electron spin resonance (ESR) signals were strongly detected in wheat that was gamma-irradiated for two weeks and then gradually decreased with increasing exposure time. The expression of anthocyanin biosynthesis genes (flavanone 3-hydroxylase [ F3H], dihydroflavonol reductase [ DFR], anthocyanin reductase [ ANS], and UDPG-flavonoid glucosyl transferase [ UFGT]) and sugar contents increased after exposure to gamma rays. Conclusions: This suggests that exposure to ionizing radiation according to increase of exposure time has led to efficient induction of anthocyanin and antioxidant enzyme activities. This study indicates that reactive oxygen species (ROS) is eliminated by biosynthesis of anthocyanin and antioxidant enzymes. This study helps elucidate the biological effects of various durations of low-dose exposure to chronic gamma radiation in wheat plants. [ABSTRACT FROM AUTHOR]

Orchids with colorful leaves and flowers have significant ornamental value. Here, we used γ-irradiation-based mutagenesis to produce a Dendrobium bigibbum mutant that developed purple instead of the normal green leaves. RNA sequencing of the mutant plant identified 2513 differentially expressed genes, including 1870 up- and 706 downregulated genes. The purple leaf color of mutant leaves was associated with increased expression of genes that encoded key biosynthetic enzymes in the anthocyanin biosynthetic pathway. In addition, the mutant leaves also showed increased expression of several families of transcription factors including the MYB2 gene. Transient overexpression of D. biggibumMYB2 in Nicotiana benthamiana was associated with increased expression of endogenous anthocyanin biosynthesis genes. Interestingly, transient overexpression of orthologous MYB2 genes from other orchids did not upregulate expression of endogenous anthocyanin biosynthesis genes. Together, these results suggest that the purple coloration of D. biggibum leaves is at least associated with increased expression of the MYB2 gene, and the MYB2 orthologs from orchids likely function differently, regardless of their high level of similarity. [ABSTRACT FROM AUTHOR]

Anthocyanins (a subclass of flavonoids) and flavonoids are crucial determinants of flower color and substances of pharmacological efficacy, respectively, in chrysanthemum. However, metabolic and transcriptomic profiling regarding flavonoid accumulation has not been performed simultaneously, thus the understanding of mechanisms gained has been limited. We performed HPLC-DAD-ESI-MS (high-performance liquid chromatography coupled with photodiode array detection and electrospray ionization mass spectrometry) and transcriptome analyses using "ARTI-Dark Chocolate" (AD), which is a chrysanthemum mutant cultivar producing dark-purple ray florets, and the parental cultivar "Noble Wine" for metabolic characterization and elucidation of the genetic mechanism determining flavonoid content. Among 26 phenolic compounds identified, three cyanidins and eight other flavonoids were detected only in AD. The total amounts of diverse flavonoids were 8.0 to 10.3 times higher in AD. Transcriptome analysis showed that genes in the flavonoid biosynthetic pathway were not up-regulated in AD at the early flower stage, implying that the transcriptional regulation of the pathway did not cause flavonoid accumulation. However, genes encoding post-translational regulation-related proteins, especially F-box genes in the mutated gene, were enriched among down-regulated genes in AD. From the combination of metabolic and transcriptomic data, we suggest that the suppression of post-translational regulation is a possible mechanism for flavonoid accumulation in AD. These results will contribute to research on the regulation and manipulation of flavonoid biosynthesis in chrysanthemum. [ABSTRACT FROM AUTHOR]

The flowers of chrysanthemum species are used as a herbal tea and in traditional medicine. In addition, members of the genus have been selected to develop horticultural cultivars of diverse floral colors and capitulum forms. In this research, we investigated the phytochemical composition of eight gamma-irradiation mutant cultivars of Chrysanthemum morifolium and their original cultivars. The mutant chrysanthemum cultivars were generated by treatment with various doses of 60Co gamma irradiation of stem cuttings of three commercial chrysanthemum cultivars as follows: 'ARTI-Dark Chocolate' (50Gy), 'ARTI-Purple Lady' (30 Gy), and 'ARTI-Yellow Star' (50 Gy) derived from 'Noble Wine'; 'ARTI-Red Star' (50 Gy) and 'ARTI-Rising Sun' (30 Gy) from 'Pinky'; 'ARTI-Purple' (40 Gy) and 'ARTI-Queen' (30 Gy) from 'Argus'; and 'ARTI-Rollypop' (70 Gy) from 'Plaisir d'amour'. Quantitative analysis of flavonoids, phenolic acids, anthocyanins, and carotenoids in the flowers of the 12 chrysanthemum cultivars was performed using high performance liquid chromatography-diode array detector-electrospray ionization mass spectrometry (HPLC-DAD-ESIMS). Essential oils from the flowers of these cultivars were analyzed by gas chromatography–mass spectrometry (GC-MS). The mutant cultivars, 'ARTI-Dark Chocolate', 'ARTI-Purple Lady', 'ARTI-Purple', and 'ARTI-Queen' showed higher total amounts of flavonoid and phenolic acid compared with those of the respective original cultivars. The mutant cultivars, 'ARTI-Dark Chocolate', 'ARTI-Purple Lady' and 'ARTI-Purple', which produce purple to pink petals, contained more than two-times higher amounts of anthocyanins compared with those of their original cultivars. Of the mutant cultivars, 'ARTI-Yellow Star' in which petal color was changed to yellow, showed the greatest accumulation of carotenoids. Ninety-nine volatile compounds were detected, of which hydrocarbons and terpenoids were abundant in all cultivars analyzed. This is the first report that demonstrated the phytochemical analysis of novel chrysanthemum cultivars derived from C. morifolium hydrid using HPLC-DAD-ESIMS and GC-MS. These findings suggest that the selected mutant chrysanthemum cultivars show potential as a functional source of phytochemicals associated with the abundance of health-beneficial components, as well as good source for horticulture and pigment industries. [ABSTRACT FROM AUTHOR]

Chrysanthemum morifolium Ramat is a perennial flowering plant widely cultivated for use in a tea infusion and as a popular beverage. To identify and evaluate the tea infusion made with a γ-irradiated mutant chrysanthemum cultivar with dark purple petals (cv. ARTI-Dark Chocolate), its phytochemical composition and antioxidant activity were tested and compared with those of the commercially available chrysanthemum cultivar with yellow petals (cv. Gamguk) by HPLC-DAD-ESIMS, as well as DPPH and ABTS radical scavenging assays. The purple chrysanthemum tea contained anthocyanins and linarin, which were not detected in the yellow chrysanthemum tea and the content of chlorogenic acid, acacetin-7-O-β-glucoside, and luteolin was higher compared with the yellow chrysanthemum tea. In contrast, the yellow chrysanthemum tea had higher luteolin-7-O-β-glucoside, 3,5-dicaffeoylquinic acid, apigenin-7-O-β-glucoside, and apigenin contents in comparison with the purple chrysanthemum tea. In addition, the content and antioxidant activity of the two chrysanthemum teas were investigated according to different water temperatures and infusing time. The yellow chrysanthemum tea did not show any significant differences according to infusing time and temperature, while the purple chrysanthemum tea was more influenced by the infusing time than water temperature, showing the highest total compound content in the infusing condition of 100 °C and 4 min. Moreover, the floral scent volatiles of the two chrysanthemum tea sources were analyzed using HS-SPME-GC-MS. In the DPPH radical scavenging assay, the purple chrysanthemum tea broadly showed greater antioxidant activity than did the yellow chrysanthemum tea, corresponding to the high content of anthocyanins known as the powerful antioxidant. Further, both chrysanthemum flower teas exhibited strong ABTS radical scavenging effects ranging from 76% to 61% under all infusing conditions. Therefore, the purple chrysanthemum cultivar, ARTI-Dark Chocolate, is worthy of breeding as a new tea cultivar. [ABSTRACT FROM AUTHOR]

Chrysanthemum is one of the most popular ornamental plants, whose petal colors are primarily determined by pigments including flavonoids/anthocyanins and carotenoids. To develop chrysanthemum cultivars with various petal colors, mutation breeding targeting alteration of pigmentation pattern has been performed. A radiation-induced mutant line, ‘ARTI-purple’, showed a flower color altered from the original bright pink to purple. In this study, we used suppression subtractive hybridization to analyze transcripts and characterize the differential gene expression of chrysanthemum petals between the mutant ‘ARTI-purple’ and its wild-type Chrysanthemum × morifolium cultivar ‘Argus’. One hundred and seventy-six genes were identified ( e- value ≤ 1e − 5) and classified based on sequence homology to genes with known or putative functions. The genes were categorized functionally by gene ontology analysis and their tentative pathways were confirmed using the TAIR database. The analyses revealed that these genes were related to carbohydrate metabolism, biosynthesis of secondary metabolites, and lipid metabolism. Six genes in a Kyoto encyclopedia of genes and genomes (KEGG) pathway which included the largest number of differentially expressed genes were selected for validation by quantitative PCR, and most of them showed higher expression levels compared with the wild-type. In addition, we isolated two novel clones (PC06E06 and PC08C09) having glutathione S -transferase (GST) family conserved domains and one clone (PC02G08) having a Multidrug and toxic compound extrusion (MATE) family conserved domain based on analysis using conserved domain database (CDD). The expressions of PC08C09 and PC02G08 were upregulated in ‘ARTI-purple’, which implies that anthocyanin accumulation pattern might be altered in mutant. In this study, we identified several differentially expressed genes between ‘Argus’ and ‘ARTI-purple’. The analysis suggested that several metabolic genes as well as glutathione S -transferases and MATEs might be involved in the control of flower pigmentation in chrysanthemum. [ABSTRACT FROM AUTHOR]

• Sucrose and plant hormones modulate the expression of genes in the anthocyanin pathway. • The expression of the genes was maximized at 18 h after treatment of 50 mM sucrose in chrysanthemum. • The expression of the genes was highly increased by treatment of sucrose with methyl jasmonate. • Pre-treatment of sucrose with methyl jasmonate increased the frequency of flower-color mutants induced by γ-irradiation. γ-rays have been used to develop many mutations in diverse ornamental plants, including chrysanthemum, of which most changes have been flower color. Flower color is determined by plant pigments, including anthocyanins, which are affected by mutation of genes in the anthocyanin biosynthesis pathway. Sucrose and plant hormones also crosstalk in complex signaling pathways and modulate anthocyanin biosynthesis. In this study, we determined the optimal sucrose and plant hormone treatments for expression of anthocyanin biosynthesis genes and compared the mutation frequency among sucrose, methyl jasmonate (MeJA), and/or γ-ray treatments in chrysanthemum. Anthocyanin biosynthesis genes were highly expressed with 50 mM sucrose treatment for 18 h. The highest expression levels of anthocyanin biosynthesis genes were observed under sucrose with MeJA treatment followed by MeJA treatment alone. Sucrose with abscisic acid (ABA) treatment, and ABA or GA 3 treatment alone, had no effect on expression of anthocyanin biosynthesis genes. Sucrose with MeJA pre-treatment followed by γ-irradiation resulted in the highest mutation frequency (14.5%) among all treatments and a 1.5-fold increase in mutation frequency compared with γ-ray treatment alone. The ratio of anthocyanin-related flower-color mutants with sucrose and/or MeJA pre-treatments followed by γ-irradiation was higher than that with γ-ray treatment alone. Sucrose and/or MeJA modulated the expression of anthocyanin biosynthesis genes and highly expressed genes may be affected more readily by γ-rays, thus resulting in an increased frequency of anthocyanin-related flower-color mutants in chrysanthemum. [ABSTRACT FROM AUTHOR]