Identification of floral scent in chrysanthemum cultivars and wild relatives by gas chromatography-mass spectrometry.
ABSTRACT: The objective of this study was to identify the major volatile compounds and their relative concentrations in flowers of different chrysanthemum cultivars and their wild relatives. The volatile organic components of fresh flowers were analyzed using a headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. In total, 193 volatile organic components were detected; the major scent components were monoterpenoids and oxygenated monoterpenoids, which accounted for 68.59%-99.93% of the total volatiles in all tested materials except for Chrysanthemum indicum collected from Huangshan, in which they accounted for only 37.45% of total volatiles. The major volatile compounds were camphor, ?-pinene, chrysanthenone, safranal, myrcene, eucalyptol, 2,4,5,6,7,7ab-hexahydro-1H-indene, verbenone, ?-phellandrene and camphene. In a hierarchical cluster analysis, 39 accessions of Chrysanthemum and its relatives formed six clusters based on their floral volatile compounds. In a principal component analysis, only spider type flowers were located closely on the score plot. The results of this study provide a basis for breeding chrysanthemum cultivars which desirable floral scents.
Project description:Prunus mume is the only fragrant flowering species of Prunus. According to the previous studies, benzyl acetate and eugenol dominate its floral scent. However, the diversity of its floral scents remains to be elucidated. In this work, the floral volatiles emitted from eight intraspecific cultivars of P. mume with white, pink and red flowers, were collected and analyzed using headspace solid-phase microextraction combined with gas chromatograms-mass spectrometry (HS-SPME-GC-MS). In total, 31 volatile compounds were identified, in which phenylpropanoids/benzenoids accounted for over 95% of the total emission amounts. Surprisingly, except for benzyl acetate and eugenol, several novel components, such as benzyl alcohol, cinnamyl acohol, cinnamy acetate, and benzyl benzoate were found in some cultivars. The composition of floral volatiles in cultivars with white flowers was similar, in which benzyl acetate was dominant, while within pink flowers, there were differences of floral volatile compositions. Principal component analysis (PCA) showed that the emissions of benzyl alcohol, cinnamyl alcohol, benzyl acetate, eugenol, cinnamyl acetate, and benzyl benzoate could make these intraspecific cultivars distinguishable from each other. Further, hierarchical cluster analysis indicated that cultivars with similar a category and amount of floral compounds were grouped together. Our findings lay a theoretical basis for fragrant plant breeding in P. mume.
Project description:<h4>Background and aims</h4>Studies of the effects of pollination on floral scent and bee visitation remain rare, particularly in agricultural crops. To fill this gap, the hypothesis that bee visitation to flowers decreases after pollination through reduced floral volatile emissions in highbush blueberries, Vaccinium corymbosum, was tested. Other sources of variation in floral emissions and the role of floral volatiles in bee attraction were also examined.<h4>Methods</h4>Pollinator visitation to blueberry flowers was manipulated by bagging all flowers within a bush (pollinator excluded) or leaving them unbagged (open pollinated), and then the effect on floral volatile emissions and future bee visitation were measured. Floral volatiles were also measured from different blueberry cultivars, times of the day and flower parts, and a study was conducted to test the attraction of bees to floral volatiles.<h4>Key results</h4>Open-pollinated blueberry flowers had 32 % lower volatile emissions than pollinator-excluded flowers. In particular, cinnamyl alcohol, a major component of the floral blend that is emitted exclusively from petals, was emitted in lower quantities from open-pollinated flowers. Although, no differences in cinnamyl alcohol emissions were detected among three blueberry cultivars or at different times of day, some components of the blueberry floral blend were emitted in higher amounts from certain cultivars and at mid-day. Field observations showed that more bees visited bushes with pollinator-excluded flowers. Also, more honey bees were caught in traps baited with a synthetic blueberry floral blend than in unbaited traps.<h4>Conclusions</h4>Greater volatile emissions may help guide bees to unpollinated flowers, and thus increase plant fitness and bee energetic return when foraging in blueberries. Furthermore, the variation in volatile emissions from blueberry flowers depending on pollination status, plant cultivar and time of day suggests an adaptive role of floral signals in increasing pollination of flowers.
Project description: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 <i>Chrysanthemum morifolium</i> and their original cultivars. The mutant chrysanthemum cultivars were generated by treatment with various doses of <sup>60</sup>Co 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 <i>C. morifolium</i> 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.
Project description:Melatonin is a pleiotropic molecule that regulates a variety of developmental processes. Floral volatiles are important features of flowers that facilitate flower-visitor interactions by attracting pollinators, structure flower-visitor communities, and play defensive roles against plant and flower antagonists. Aside from their role in plants, floral volatiles are an essential ingredient in cosmetics, perfumes, pharmaceuticals, and flavorings. Herein, integrated metabolomic and transcriptomic approaches were carried out to analyze the changes triggered by melatonin exposure during the <i>Hedychium coronarium</i> flower development stages. Quantitative analysis of the volatiles of <i>H</i>. <i>coronarium</i> flowers revealed that volatile organic compound emission was significantly enhanced after melatonin exposure during the half bloom (HS), full bloom (FB) and fade stage (FS). Under the melatonin treatment, the emission of volatile contents was highest during the full bloom stage of the flower. Variable importance in projection (VIP) analysis and partial least-squares discriminant analysis (PLS-DA) identified 15 volatile compounds with VIP > 1 that were prominently altered by the melatonin treatments. According to the transcriptome sequencing data of the HS, FB, and FS of the flowers, 1,372, 1,510, and 1,488 differentially expressed genes were identified between CK-HS and 100MT-HS, CK-FB and 100MT-FB, and CK-FS and 100MT-FS, respectively. Among the significant differentially expressed genes (DEGs), 76 were significantly upregulated and directly involved in the floral scent biosynthesis process. In addition, certain volatile organic compounds were substantially linked with various DEGs after combining the metabolome and transcriptome datasets. Moreover, some transcription factors, such as MYB and bHLH, were also significantly upregulated in the comparison, which might be related to the floral aroma mechanism. Our results suggested that melatonin increased floral aroma production in <i>H</i>. <i>coronarium</i> flowers by modifying the expression level of genes involved in the floral scent biosynthesis pathway. These findings serve as a foundation for future research into the molecular mechanisms underlying the dynamic changes in volatile contents induced by melatonin treatment in <i>H</i>. <i>coronarium</i>.
Project description:Volatiles from flowers at three blooming stages of nine citrus cultivars were analyzed by headspace-solid phase microextraction (HS-SPME)-GC-MS. Up to 110 volatiles were detected, with 42 tentatively identified from citrus flowers for the first time. Highest amounts of volatiles were present in fully opened flowers of most citrus, except for pomelos. All cultivars were characterized by a high percentage of either oxygenated monoterpenes or monoterpene hydrocarbons, and the presence of a high percentage of nitrogen containing compounds was also observed. Flower volatiles varied qualitatively and quantitatively among citrus types during blooming. Limonene was the most abundant flower volatile only in citrons; ?-citral and ?-citral ranked 2nd and 3rd only for Bergamot, and unopened flowers of Ponkan had a higher amount of linalool and ?-pinene while much lower amount of ?-terpinene and p-cymene than Satsuma. Taking the average of all cultivars, linalool and limonene were the top two volatiles for all blooming stages; ?-pinene ranked 3rd in unopened flowers, while indole ranked 3rd for half opened and fully opened flower volatiles. As flowers bloomed, methyl anthranilate increased while 2-hexenal and p-cymene decreased. In some cases, a volatile could be high in both unopened and fully opened flowers but low in half opened ones. Through multivariate analysis, the nine citrus cultivars were clustered into three groups, consistent with the three true citrus types. Furthermore, an influence of blooming stages on clustering was observed, especially with hybrids Satsuma and Huyou. Altogether, it was suggested that flower volatiles can be suitable markers for revealing the genetic relationships between citrus cultivars but the same blooming stage needs to be strictly controlled.
Project description:<h4>Background and aims</h4>Flowers emit a wide range of volatile compounds which can be critically important to interactions with pollinators or herbivores. Yet most studies of how the environment influences plant volatiles focus on leaf emissions, with little known about abiotic sources of variation in floral volatiles. Understanding phenotypic plasticity in floral volatile emissions has become increasingly important with globally increasing temperatures and changes in drought frequency and severity. Here quantitative relationships of floral volatile emissions to soil water content were analysed.<h4>Methods</h4>Plants of the sub-alpine herb Ipomopsis aggregata and hybrids with its closest congener were subjected to a progressive dry down, mimicking the range of soil moistures experienced in the field. Floral volatiles and leaf gas exchange were measured at four time points during the drought.<h4>Key results</h4>As the soil dried, floral volatile emissions increased overall and changed in composition, from more 1,3-octadiene and benzyl alcohol to higher representation of some terpenes. Emissions of individual compounds were not linearly related to volumetric water content in the soil. The dominant compound, the monoterpene ?-pinene, made up the highest percentage of the scent mixture when soil moisture was intermediate. In contrast, emission of the sesquiterpene (E,E)-?-farnesene accelerated as the drought became more intense. Changes in floral volatiles did not track the time course of changes in photosynthetic rate or stomatal conductance.<h4>Conclusions</h4>This study shows responses of specific floral volatile organic compounds to soil moisture. The non-linear responses furthermore suggest that extreme droughts may have impacts that are not predictable from milder droughts. Floral volatiles are likely to change seasonally with early summer droughts in the Rocky Mountains, as well as over years as snowmelt becomes progressively earlier. Changes in water availability may have impacts on plant-animal interactions that are mediated through non-linear changes in floral volatiles.
Project description:<i>Prunus mume</i> is a traditional ornamental plant, which owed a unique floral scent. However, the diversity of the floral scent in <i>P. mume</i> cultivars with different aroma types was not identified. In this study, the floral scent of eight <i>P. mume</i> cultivars was studied using headspace solid-phase microextraction (HS-SPME) and organic solvent extraction (OSE), combined with gas chromatography-mass spectrometry (GC-MS). In total, 66 headspace volatiles and 74 endogenous extracts were putatively identified, of which phenylpropanoids/benzenoids were the main volatile organic compounds categories. As a result of GC-MS analysis, benzyl acetate (1.55-61.26%), eugenol (0.87-6.03%), benzaldehyde (5.34-46.46%), benzyl alcohol (5.13-57.13%), chavicol (0-5.46%), and cinnamyl alcohol (0-6.49%) were considered to be the main components in most varieties. However, the volatilization rate of these main components was different. Based on the variable importance in projection (VIP) values in the orthogonal partial least-squares discriminate analysis (OPLS-DA), differential components of four aroma types were identified as biomarkers, and 10 volatile and 12 endogenous biomarkers were screened out, respectively. The odor activity value (OAV) revealed that several biomarkers, including (<i>Z</i>)-2-hexen-1-ol, pentyl acetate, (<i>E</i>)-cinnamaldehyde, methyl salicylate, cinnamyl alcohol, and benzoyl cyanide, contributed greatly to the strong-scented, fresh-scented, sweet-scented, and light-scented types of <i>P. mume</i> cultivars. This study provided a theoretical basis for the floral scent evaluation and breeding of <i>P. mume</i> cultivars.
Project description:BACKGROUND:Previous reports have mainly focused on the volatiles in citrus fruits, and there have been few reports about the volatiles in citrus leaves and flowers. However, citrus leaves and flowers are also rich in volatile compounds with unique aromas. Here, to investigate the volatiles in citrus leaves and flowers, volatile profiling was performed on leaves from 62 germplasms and flowers from 25 germplasms. RESULTS:In total, 196 and 82 volatile compounds were identified from leaves of 62 citrus germplasms and flowers of 25 citrus germplasms, respectively. The dominant volatile terpenoids were more diverse in citrus leaves than in peels. A total of 34 volatile terpenoids were commonly detected in the leaves of at least 20 germplasms, among which 31 were overaccumulated in the leaves of wild or semiwild germplasms. This result was consistent with the high expression levels of five genes and one key gene of the mevalonate and 2-C-methyl-D-erythritol-4-phosphate (MEP) biosynthetic pathways, respectively, as well as the low expression levels of geranylgeranyl diphosphate synthase of the MEP pathway, relative to the levels in cultivars. Fully open flowers showed increased levels of four terpene alcohols and a decrease in sabinene content compared with balloon-stage flowers, especially in sweet orange. A monoterpene synthase gene was identified and functionally characterized as a sabinene synthase in vitro. CONCLUSIONS:Collectively, our results suggest that 31 important terpenoids are abundant in wild or semiwild citrus germplasms, possibly because of a negative effect of domestication on the volatiles in citrus leaves. The sweet smell of fully open flowers may be attributed to increased levels of four terpene alcohols. In addition, a sabinene synthase gene was identified by combined transcriptomic and metabolomic analyses.
Project description:Volatile composition is an important feature that determines flavor, which actively affects the overall evaluation of chrysanthemum tea. In this study, HS-GC-IMS (headspace-gas chromatography-ion mobility spectrometry) was performed to characterize the volatile profiles of different chrysanthemum tea subtypes. Forty-seven volatiles of diverse chemical nature were identified and quantified. Partial least squares discriminant analysis (PLS-DA) revealed that four chrysanthemum teas were distinct from each other based on their volatile compounds. Furthermore, this work provides reference methods for detecting novel volatile organic compounds in chrysanthemum tea plants and products.
Project description:Lily is a well-known ornamental plant with a diversity of fragrant types. Basic information on lily floral scent compounds has been obtained for only a few accessions, and little is known about Lilium aroma types, the terpene synthase genes that may play roles in the production of key volatiles, or the range of monoterpenes that these genes produce. In this study, 41 cultivars were analyzed for volatile emissions, and a total of 46 individual volatile compounds were identified, 16 for the first time in lilies. Lily accessions were classified into six groups according to the composition of major scent components: faint-scented, cool, fruity, musky, fruity-honey, and lily. Monoterpenes were one of the main groups of volatiles identified, and attention was focused on terpene synthase (TPS) genes, which encode enzymes that catalyze the last steps in monoterpene synthesis. Thirty-two candidate monoterpene synthase cDNAs were obtained from 66 lily cultivars, and 64 SNPs were identified. Two InDels were also shown to result from variable splicing, and sequence analysis suggested that different transcripts arose from the same gene. All identified nucleotide substitution sites were highly correlated with the amounts of myrcene emitted, and InDel site 230 was highly correlated with the emission of all major monoterpenoid components, especially (E)-?-ocimene. Heterologous expression of five cDNAs cloned from faint-scented and strong-scented lilies showed that their corresponding enzymes could convert geranyl diphosphate to (E)-?-ocimene, ?-pinene, and limonene. The findings from this study provide a major resource for the assessment of lily scent volatiles and will be helpful in breeding of improved volatile components.