Volatile Compounds In Flowers Research Articles

Analysis of flower volatile compounds and odor classification of 17 tree peony cultivars

As one of the significant ornamental characteristics of tree peony, floral fragrance has garnered considerable attention. In this study, 65 cultivars of tree peony were classified into three groups based on their sensory evaluation scores: strong fragrance, medium fragrance, and no/light fragrance and 9 strong fragrance cultivars, 6 medium fragrance cultivars, and 2 light/no fragrance cultivars were selected for substance analysis. Using gas chromatography-mass spectrometry (GC–MS), 77 volatile organic compounds (VOCs) were identified and classified from 17 tree peony cultivars, they were terpenoids, benzenoids/phenylpropanoids, and fatty acid derivatives. Monoterpenoids were the main volatile compounds in the cultivars ‘Souvenir de Maxime Cornu’, ‘Okan’, ‘Chromatella’, ‘Yapianzi’, and ‘Liuli Guanzhu’, while benzenoids/phenylpropanoids were the main volatile compounds in ‘Shaonvqun’ and ‘Binglingzi’. Through the calculation of odor activity value (OAV), 17 cultivars were categorized into four distinct groups: flower-sweet scent, flower-rose scent, herb scent and mixed scent. This investigation presented the composition and classification of fragrant compounds of 17 tree peony cultivars and classified the odor profiles based on the contribution of flower volatiles to the overall olfactory experience, offering valuable materials for genetic enhancement of tree peony floral fragrance.

Differences in EAG Response and Behavioral Choices between Honey Bee and Bumble Bee to Tomato Flower Volatiles.

Bumble bees and honey bees are of vital importance for tomato pollination, although honey bees are less attracted to tomato flowers than bumble bees. Little is known about how tomato flower volatile compounds influence the foraging behaviors of honey bees and bumble bees. In this study, compounds of tomato flower volatiles were detected by gas chromatography-mass spectrometry. Electroantennography (EAG) and a dynamic two-choice olfactometer were used, respectively, to compare the differences of antennal and behavioral responses between Apis mellifera and Bombus terrestris towards selected volatile compounds. A total of 46 compounds were detected from the tomato flower volatiles. Of the 16 compounds tested, A. mellifera showed strong antennal responses to 3 compounds (1-nonanal, (+)-dihydrocarvone, and toluene) when compared with a mineral oil control, and B. terrestris showed 7 pronounced EAG responses (1,3-xylene, (+)-dihydrocarvone, toluene, piperitone, eucarvone, 1-nonanal, and β-ocimene). Additionally, 1-nonanal and (+)-dihydrocarvone elicited significant avoidance behavior of A. mellifera, but not of B. terrestris. In conclusion, bumble bees are more sensitive to the compounds of tomato flower volatiles compared to honey bees, and honey bees showed aversion to some compounds of tomato flower volatiles. The findings indicated that compounds of flower volatiles significantly influenced bee foraging preference for tomato.

Auxin-Responsive R2R3-MYB Transcription Factors HcMYB1 and HcMYB2 Activate Volatile Biosynthesis in Hedychium coronarium Flowers

Auxin, an important plant hormone, induces the biosynthesis of various secondary metabolites by modulating the expression of auxin-responsive genes. In the ornamental plant Hedychium coronarium, linalool and methyl benzoate are biosynthesized by the terpene synthase (TPS) HcTPS5 and the benzoic/salicylic acid methyltransferase (BSMT) HcBSMT2, respectively. However, the transcriptional regulation of this process remains unclear. Here, we identified and functionally characterized the R2R3-MYB transcription factors HcMYB1 and HcMYB2 in regulating the biosynthesis of these floral aroma compounds. HcMYB1 and HcMYB2 are specifically expressed in flowers, their expression is correlated with the emission of volatile compounds in flowers, and is induced by auxin. Moreover, HcMYB1 and HcMYB2 interact with the HcBSMT2 promoter region. HcMYB2 activates the expression of the linalool synthase gene HcTPS5. In flowers with HcMYB1 or HcMYB2 silenced, the levels of floral scent compounds were significantly reduced, and HcBSMT2 and HcTPS5 were downregulated compared with the wild type. Moreover, HcMYB1 form protein-protein interaction with key scent-related HcIAA4 protein to regulate floral aroma production. Taken together, these results indicate that HcMYB1 and HcMYB2 play crucial roles in regulating the formation of scent compounds in Hedychium coronarium (H. coronarium) flowers in response to auxin signaling.

Volatile compounds in flowers, samaras, leaves and stem bark of Ailanthus altissima (Mill.) Swingle, growing in Bulgaria

The aim of the present study was to determine the composition of essential oils (EOs) of different plant parts of A. altissima, growing in Bulgaria. Four samples (flowers, immature samaras, leaves, stem bark) of A. altissima were collected in the period June-July of the 2019 growing season, from Plovdiv, Bulgaria. The EOs were obtained by hydrodistillation with a Clevinger-type apparatus. Gas Chromatography/Mass Spectrometry analysis was applied to determine the volatile compounds. The yield (in fresh material) was 0.5 ml/kg (samaras), 0.27 ml/kg (flowers), 0.23 ml/kg (leaves), and 0.18 ml/kg (bark). There were identified 75 volatiles from the different plant parts. Oxygenated hydrocarbons (mainly fatty acids, their esters) were the best-represented group in samaras, leaves, bark (65.87%; 47.53%; 49.41% respectively). Oleic acid was the major constituent in the three EOs (samaras -34.26%; stem bark -30.21%; leaves -22.94%). In the flower EO, the dominant group was sesquiterpene hydrocarbons (46.48%) with main compounds β-caryophyllene (16.98%) and germacrene D (16.24%). The volatile components in Ailanthus altissima, growing in Bulgaria, have been determined for the first time. Differences in the composition of EOs were found.

Analysis of the Volatile Components in Flowers of <i>Paeonia lactiflora</i> Pall. and <i>Paeonia lactiflora</i> Pall. var. <i>Trichocarpa</i>

Paeonia lactiflora Pall. var. trichocarpa is a variety of Paeonia lactiflora Pall., and is currently the peony herb’s principal cultivar group. Here, we study the differences in aromatic components and flowers of different varieties between two groups of cultivars, providing a reference for applying natural fragrance substances of peonies, breeding fragrant flower types, and developing and using improved varieties. Headspace solid-phase microextraction (HS-SPME), gas chromatography-mass spectrometry (GC-MS), peak area normalization for each component relative to content, component library (NIST14/NIST14S) retrieval, and a literature review were used to analyze the volatile compounds in flowers of eight peony varieties, such as “Gaoganhong”, and ten comospore peony varieties, such as “Jinshanhong”. Results showed that the main volatile compound constituents in flowers of the two groups were terpenes and alcohols. Additionally, the content of eucalyptol, caryophyllene, α-Pinene, citronellol, and 3-Hexen-1-ol, acetate, (Z) was high. Peony cultivars contained linalool, (1R)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene, and 1,4-dimethoxybenzene, while comospore peony varieties contained 1,3,6-octatriene, 3,7-dimethyl-, (Z)-, phenylethyl alcohol, and geraniol. In this study, the differences between the volatile components of flowers of different peony varieties were clarified, laying a foundation for further molecular biology research into the floral fragrance of peonies and the cultivation of new varieties of aromatic peonies. At the same time, it also provides a theoretical basis for the development and application of peony flower by-products.

Comparative Analysis of Volatile Compounds in Flowers of Different Actinidia Species.

Among the actinidia genus (Actinidia spp.) native to China, few species are grown commercially for their edible and healthy fruits. As they are dioecious plants, a lot of interest is paid to effective pollination and to insects as the most efficient pollinators. In this study we have concentrated on the composition of volatile compounds in male flowers of four different actinidia species (A. chinensis var. deliciosa, A. arguta, A. kolomikta and A. polygama) and on the diversity between male and female flower volatiles for the two most winter-hardy species (A. arguta and A. kolomikta) with growing commercial value. Analyses were provided using gas chromatography with mass spectrometry (GC-MS). In total, 120 compounds were found in 15 actinidia genotypes. However, the number of identified compounds varied between species. Different main compounds or groups of volatile compounds characterised flowers of every species. Smaller differences were observed between male and female flowers of the same species. Our results suggest that actinidia flowers could be attractive to pollinating insects.

Volatile compounds in flowers of Polianthes genus

Volatile compounds in flowers of <i>Polianthes</i> genus

Volatile compounds in perianth and corona of Narcissus Pseudonarcissus cultivars

Narcissus pseudonarcissus (daffodil) is a valuable plant for the cosmetic, pharmaceutical and therapeutical traits. The flower volatile compounds (FVCs) of ten Narcissus pseudonarcissus cultivars were analyzed by Headspace/Solid Phase Micro Extraction-Gas Chromatography Mass Spectrometry (HS/SPME- GC/MS). 69 and 73 FVCs were detected in perianth and corona of the ten cultivars. The compounds are largely comprised of monoterpenes, sesquiterpene, benzenoid compounds and other minor compounds classes. Monoterpenes were major component among the FVCs, with beta-ocimene and beta-myrcene as the two major compounds in most perianths and coronas. The composition and content of the FVCs of different cultivars are quite different from each other.

Characterization of volatiles in strawberry varieties ‘Elsanta’ and ‘Sonata’ and their effect on bumblebee flower visiting

The bumblebee Bombus terrestris is a general pollinator in Europe and also highly suitable as greenhouse pollinator of various agricultural and horticultural crops such as tomato, sweet pepper or strawberry. Here, we highlight the importance of volatile emissions for the attractiveness and pollination efficiency of strawberry varieties, starting from the unique observation that two related strawberry varieties are pollinated to a different extent when cultivated together. In a flight cage Fragaria × ananassa var. ‘Sonata’ was pollinated more frequently (>2 times) and with longer-duration visits (11.2 vs. 6.7 s) by B. terrestris as compared to var. ‘Elsanta.’ To investigate whether this visitation difference could be attributed to differential production of flower volatile compounds, we quantified and analyzed the floral emissions of both varieties. Samples of var. ‘Elsanta’ contained more green leaf volatiles such as E-2-hexenal (0.53 vs. 0 ng/3 flowers), Z-3-hexenol (2.26 vs. 0.20 ng/3 flowers) and Z-3-hexenyl acetate (2.15 vs. 0.46 ng/3 flowers) which are known to play a role in plant defense. In a third series of experiments, we determined olfactory responses of B. terrestris to some similar individual synthetic green leaf volatiles presented in a Y-tube olfactometer. B. terrestris workers responded in an aversive manner to these volatile compounds compared to purified air. Since the floral bouquet of var. ‘Elsanta’ contains more green leaf volatiles, bumblebees will exhibit a preference for var. ‘Sonata.’ Our observations suggest that the pollination preference for ‘Sonata’ is due to being ‘less repellent’ instead of ‘more attractive’ than ‘Elsanta,’ with variety-specific flower emissions lying at the basis.

Variation Patterns of the Volatile Compounds in Flowers of Chinese Native Citrus Species and Their Taxonomic Implications

In this study, the volatile compounds in the flowers of nine Citrus species/varieties, seven of which are native to China, were analyzed using headspace-solid phase microextraction (HS-SPME) coupled with gas chromatography mass spectrometry (GC-MS). A total of 94 compounds were identified, including various terpenes, such as monoterpenes, sesquiterpenes, terpene alcohols and aldehydes, which together accounted for 80.4% to 92.4% of the total compounds analyzed. Limonene, linalool and γ-terpinene were the dominant terpenes. Different species/varieties were characterized by their volatile compounds. Papeda was characterized by a high level of β-ocimene, linalyl acetate, myrcene and neo-alloocimene; Citrophorum was characterized by a high level of limonene and caryophyllene, and Cephelocitrus by a high level of limonene, β-pinene and linolool. Sinocitrus had the highest amount of linolool. Sweet orange had the highest level of limonene, while sour orange was distinct from others with the highest level of γ-terpinene. The four basic types of the genus <i>Citrus</i> L., Papeda, Cephalocitrus, Citrophorum and Sinocitrus, can be clearly classified based on a cluster analysis of their volatile compounds. All of the presumed hybrid species, including Jinchengbeibei 447 (<i>C. sinensis</i> Osb.), Goutoucheng (<i>C. aurantium</i> L.), Ningmeng 4 (<i>C. limon</i> Burm.f.), and Changshanhuyou (<i>C. paradisi</i> cv. Changshanhuyou), were grouped closely together with a suggested parent species in the constructed dendrogram. Our study clearly demonstrates that Citrus flower volatile compounds and their variation patterns can be used for Citrus species identification and taxonomic study.

Characterization of volatile compounds in flowers from four groups of sweet osmanthus (Osmanthus fragrans) cultivars

Xin, H., Wu, B., Zhang, H., Wang, C., Li, J., Yang, B. and Li, S. 2013. Characterization of volatile compounds in flowers from four groups of sweet osmanthus ( Osmanthus fragrans ) cultivars. Can. J. Plant Sci. 93: 923–931. Headspace-solid-phase microextraction (HS-SPME) and gas chromatography-mass spectroscopy (GC-MS) were used to characterize the volatiles in flowers of four cultivar groups of sweet osmanthus (Osmanthus fragrans Lour.), including Thunbergii, Latifolius, Aurantiacus and Semperflorens Groups. A total of 72 volatiles were identified. Volatile compounds and their relative contents varied among the four groups or cultivars within each group. Briefly, β-ionone, cis-linalool oxide (furan), trans-linalool oxide (furan) and linalool were the most common volatiles in tested cultivars, while (E)-2-hexenal, (Z)-3-hexen-1-ol and hexanal were abundant in several cultivars. Principal component analysis showed that the Aurantiacus Group was rich in cis- and trans-linalool oxide (furan), whereas the Latifolius group had high levels of (E)-2-hexenal and (Z)-3-hexen-1-ol. Our results contribute to our understanding of the volatile composition and content in flowers from different osmanthus groups and will facilitate development of new osmanthus cultivars to meet requirements of the food and fragrance industries.

Flower Volatiles, Crop Varieties and Bee Responses

Pollination contributes to an estimated one third of global food production, through both the improvement of the yield and the quality of crops. Volatile compounds emitted by crop flowers mediate plant-pollinator interactions, but differences between crop varieties are still little explored. We investigated whether the visitation of crop flowers is determined by variety-specific flower volatiles using strawberry varieties (Fragaria x ananassa Duchesne) and how this affects the pollination services of the wild bee Osmia bicornis L. Flower volatile compounds of three strawberry varieties were measured via headspace collection. Gas chromatography showed that the three strawberry varieties produced the same volatile compounds but with quantitative differences of the total amount of volatiles and between distinct compounds. Electroantennographic recordings showed that inexperienced females of Osmia bicornis had higher antennal responses to all volatile compounds than to controls of air and paraffin oil, however responses differed between compounds. The variety Sonata was found to emit a total higher level of volatiles and also higher levels of most of the compounds that evoked antennal responses compared with the other varieties Honeoye and Darselect. Sonata also received more flower visits from Osmia bicornis females under field conditions, compared with Honeoye. Our results suggest that differences in the emission of flower volatile compounds among strawberry varieties mediate their attractiveness to females of Osmia bicornis. Since quality and quantity of marketable fruits depend on optimal pollination, a better understanding of the role of flower volatiles in crop production is required and should be considered more closely in crop-variety breeding.

Analysis of Volatile Compounds in Flowers of &lt;i&gt;Akebia trifoliata&lt;/i&gt; by Headspace Solid-Phase Microextraction Coupled to Gas Chromatography-Mass Spectrometry

Objective: To analyse chemical constituents of the volatiles flowers of Akebia trifoliata. Method: The volatiles of bungei were extracted through Headspace solid-phase microextracti, and then the constituents were separated by GC and identified by MS. Result and Conclusion: 22 Compounds were identified. The principal chemical constituents of the volatiles flowers of Akebia trifoliata are α- Farnesene and Farnesene*(80.827%），Ocimene and Ocimene* （14.699%）、πPatchoulene and πPatchoulene*(1.200%) etc,respectively.

Volatile compound in cut and un-cut flowers of tetraploid Freesia hybrida

The flower volatile compounds (FVCs) of two tetraploid Freesia hybrida (pink-yellow and yellow) cultivars and their cut flowers were analysed by headspace solid-phase microextraction combined with gas chromatography–mass spectrometry. Twelve FVCs were identified in the pink-yellow cultivar, with linalool as the major compound; 30 FVCs were identified in the yellow cultivar, with linalool and terpineol as the two major compounds. The FVCs (>1%) of the two cut flower cultivars were very similar to that of the un-cut flowers, and no significant difference was observed.

Characterization of l-phenylalanine metabolism to acetophenone and 1-phenylethanol in the flowers of Camellia sinensis using stable isotope labeling

Acetophenone (AP) and 1-phenylethanol (1PE) are the two major endogenous volatile compounds in flowers of Camellia sinensis var. Yabukita. Until now no information has been available on the biosynthesis of AP and 1PE in plants. Here we propose that AP and 1PE are derived from L-phenylalanine (L-Phe), based on feeding experiments using stable isotope-labeled precursors L-[(2)H(8)]Phe and L-[(13)C(9)]Phe. The subacid conditions in the flowers result in more hydrogenation than dehydrogenation in the transformation between AP and 1PE. Due to the action of some enzyme(s) responsible for the formation of (R)-1PE from AP in the flowers, (R)-1PE is the dominant endogenous steroisomer of 1PE. The modification of 1PE into nonvolatile glycosidic forms is one of the reasons for why only a little 1PE is released from the flowers. The levels of AP, 1PE, and glycosides of 1PE increase during floral development, whereas the level of L-Phe decreases. These metabolites occur mostly in the anthers.

Volatile compounds of flowers and leaves of Sideritis italica (Miller) Greuter et Burdet (Lamiaceae), a plant used as mountain tea

Sideritis italica (Miller) Greuter et Burdet (Lamiaceae), widely used in ethnopharmacological medicine, occurs in Southern Italy and Sicily. The phytochemical composition of the essential oils of S. italica flowers and leaves, harvested in Piano Battaglia (Sicily), was analysed by GC and GC-MS. Of the 51 compounds, 43 in the oil from flowers and 29 in the oil from leaves were identified. Kaur-15-ene (20.0%) was recognised as the main constituent of the oil from flowers, together with β-cubebene (12.1%), β-pinene (8.5%), (Z)-nuciferol (6.5%), tricyclene (4.5%) and α-bisabolol (4.0%). In the oil from leaves, p-methoxyacetophenone (26.0%) prevailed, as did hexadecanoic acid (21.3%), followed by nonanal (4.8%), α-bisabolol (4.5%) and β-cubebene (4.7%).

Use of CLSA and SPME-Headspace Techniques Followed by GC-MS Analysis to Extract and Identify the Floral Odorants

Flowers of Ziziphus spina christi are known to be attractive for parasitoids and predators. In Y-tube olfactometer experiments, the dried flowers attracted significantly (p < 0.001) the female parasitoids Aphelinus abdominalis. The flower volatile compounds were analyzed to understand which compounds could be specifically responsible for this attractiveness. The volatile compounds of Ziziphus flowers were extracted by closed-loop-stripping-analysis (CLSA) and also by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis. The main chemical classes of the volatile compounds are aldehydes, monoterpene-alcohols, ketones and hydrocarbons. Flower extract and some specific compounds will be further tested for their responsiveness to predators and parasitoids in behavioural and electrophysiological experiments.

Essential Oil Constituents of Intact Plants and In Vitro Cultures of Tagetes patula L.

The occurrence of volatile compounds in flowers and roots of intact plants and in vitro hairy root cultures of Tagetes patula L. was investigated by GC and GC/MS. The flowers oil was dominated by mono- and sesquiterpenes. The main component was the sesquiterpene hydrocarbon β-caryophyllene (50.2%). However, the oils of normal roots and hairy root cultures were found to contain sulfur-containing thiophene structures. The following four compounds were identified: 5-(3-buten-1-ynyl)-2,2′-bithiophene (BBT), 5-(3-penten-1-ynyl)-2,2′-bithiophene (PBT), 2,2′:5′,2″- terthiophene (α-terthiophene) and 5-(4-acetoxy-1-butynyl)-2,2′-bithiophene (BBTOAc). The main components were BBT (47.0%) and α-terthiophene (19.8%) in the normal root oil and BBT (25.0%), α-terthiophene (14.3%) and BBTOAc (13.7%) in hairy root oil, respectively.

Sex and developmental stage of carob flowers affects composition of volatiles

SummaryThe aim of this work was to evaluate the volatiles composition in the scent emitted in vivo by the three types of carob tree (Ceratonia siliqua L.) flowers, during the different developmental stages. Additionally, an overview of some morphological aspects of carob flowers was also done. Carob trees may be male, female, hermaphrodite or exhibit polygamous inflorescences. The androecium of male flowers consists of a group of 5–7 stamens, inserted peripherically around the receptacle. The gynoecium of female flowers is apocarpous. Hermaphrodite flowers are a combination of male and female types. During the flower development six stages were identified. The volatile compounds of flowers were analysed by headspace solid-phase microextraction followed by capillary gas chromatography and mass spectrometry detection (HS-SPME-CGC/MSD). More than 25 compounds were identified, and flowers in stages III and IV showed higher abundances. In male and hermaphrodite flowers the total volatile compounds were more abundant in stage III, and in female flowers in stage IV. Linalool and trans linalool oxide were the dominant volatiles and there were remarkable differences in those compounds between different types of flowers and during the developmental stages. The results observed were discussed in terms of their possible implication on pollination efficiency.

Effect of Flower Color and Sampling Time on Volatile Emanation in Alfalfa Flowers

Flower volatile compounds of alfalfa (Medicago sativa L.) are involved in attractiveness to pollinating insects, and thus influence seed set. This study investigated differences in volatile emanation in this species by varying flower color of the sampled material or time of flower collection. Chemical determinations were made by gas chromatography and gas chromatography–mass spectrometry analyses. The first investigation examined volatile concentration in clones characterized by seven different color ratings. Significant variation among colors was found with a trend for greater emanation from dark‐ than from light‐colored flowers. This trend could bear an evolutionary significance to compensate for the possibly lower visibility of dark flowers in a stand. The second investigation analyzed volatiles from intact inflorescences and from florets and rachises taken separately. A substantial similarity of volatile amount and composition among the three kinds of samples was observed. The final investigation assessed the volatiles produced at different times of the day in each of the first three flowerings of the growing season, during which alfalfa pollination was expected to take place. Confirming previous evidence, temporal patterns of emanation were observed, with a sharp increase from the flowering in May to those in July and August and a strong time‐of‐day effect during the two summer flowerings (burst of volatiles around midday). The marked seasonal effect appeared somewhat related to temperature increase while the daily variation of emanation in summer paralleled that of solar radiation. There seems to be a coincidence between conditions for maximum volatile emanation and reported optima for insect foraging activity.