Floral Scent in Wisteria: Chemical Composition, Emission Pattern, and Regulation

Volatile chemicals emitted from the flowers of chinese wisteria (Wisteria sinenesis) and japanese wisteria (W. floribunda) were collected using a dynamic headspace technique and identified using gas chromatography–mass spectrometry; 28 and 22 compounds were detected from chinese wisteria and japanese wisteria flowers, respectively. These chemicals can be classified into four major classes, including fatty acid derivatives, benzenoids/phenylpropanoids, terpenoids, and nitrogen-containing compounds. Two monoterpenes, (E)-β-ocimene and linalool, belonging to the class of terpenoids, were the most abundant compounds emitted from both species. Despite strong similarity, the floral volatile profiles of the two species displayed variations in both quality and quantity. Chinese wisteria was selected as a model for further study of volatile emission from different parts of flowers, emission dynamics, and regulation of floral scent production. Although floral volatiles were detected from all flower parts, petals emitted the most. The emission of floral volatiles displayed a diurnal pattern with the maximal emissions occurring during the daytime. This rhythmic pattern was determined to be light-dependent. Regulation of floral volatile emission by exogenous chemicals, including silver thiosulphate (an ethylene inhibitor), salicylic acid, and jasmonic acid, also was analyzed. Generally, jasmonic acid promoted the emission of floral volatiles. In contrast, neither silver thiosulphate nor salicylic acid showed a significant effect on floral volatile emission. The results presented in this article suggest that wisteria can serve as a useful system for exploring novel biochemistry of floral scent biosynthesis. They also build a foundation for the study of the biological/ecological significance of floral volatiles on the reproductive biology of wisteria species.

Download Full-text

Emission and Regulation of Volatile Chemicals from Globe Amaranth Flowers

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.136.1.16 ◽

2011 ◽

Vol 136 (1) ◽

pp. 16-22 ◽

Cited By ~ 4

Author(s):

Yifan Jiang ◽

Nan Zhao ◽

Fei Wang ◽

Feng Chen

Keyword(s):

Las Vegas ◽

Gas Chromatography Mass Spectrometry ◽

Floral Volatiles ◽

Emission Pattern ◽

Volatile Chemicals ◽

Volatile Emission ◽

Gomphrena Globosa ◽

Ethylene Inhibitor ◽

Floral Volatile

Volatile chemicals emitted from the flowers of globe amaranth (Gomphrena globosa) were collected using a dynamic headspace technique and analyzed using gas chromatography–mass spectrometry. Among the four globe amaranth cultivars analyzed, Fireworks was the highest producer of floral volatiles. The flowers of the other three cultivars, Las Vegas White, Las Vegas Pink, and Las Vegas Purple, emit less volatiles, both qualitatively and quantitatively, than ‘Fireworks’. ‘Fireworks’ was chosen for detailed characterization of regulation of floral volatile emission. A diurnal pattern of emission of floral volatiles was observed from the flowers of ‘Fireworks’. In addition, the emission pattern was not significantly affected by light, suggesting that the circadian clock plays a major role in the regulation of volatile emission. The emission of floral volatiles from ‘Fireworks’ flowers that were treated with several chemicals was also analyzed. The treatment with silver thiosulphate, an ethylene inhibitor, led to enhanced emission of total volatiles. In contrast, the treatments with salicylic acid and jasmonic acid led to enhanced emission of total floral volatiles at 4 h but reduced emission at 24 h after the treatment. Biochemical pathways leading to the production of the major floral volatiles of globe amaranth are proposed and partly validated by cluster analysis of floral volatiles emitted from ‘Fireworks’ flowers under various conditions. The implications of the results of this study to the understanding of the reproductive biology of globe amaranth and the breeding of novel globe amaranth cultivars are discussed.

Download Full-text

Molecular Cloning and Functional Characterization of CpMYC2 and CpBHLH13 Transcription Factors from Wintersweet (Chimonanthus praecox L.)

Plants ◽

10.3390/plants9060785 ◽

2020 ◽

Vol 9 (6) ◽

pp. 785

Author(s):

Muhammad Zeshan Aslam ◽

Xiang Lin ◽

Xiang Li ◽

Nan Yang ◽

Longqing Chen

Keyword(s):

Arabidopsis Thaliana ◽

Transcription Factors ◽

Transgenic Plants ◽

Jasmonic Acid ◽

Volatile Compounds ◽

Floral Scent ◽

Functional Characterization ◽

High Expression ◽

Floral Volatile ◽

Chimonanthus Praecox

Wintersweet (Chimonanthus praecox L.) is an ornamental and economically significant shrub known for its unique flowering characteristics, especially the emission of abundant floral volatile organic compounds. Thus, an understanding of the molecular mechanism of the production of these compounds is necessary to create new breeds with high volatile production. In this study, two bHLH transcription factors (CpMYC2 and CpbHLH13) of Wintersweet H29 were functionally characterized to illustrate their possible role in the production of volatile compounds. The qRT-PCR results showed that the expression of CpMYC2 and CpbHLH13 increased from the flower budding to full bloom stage, indicating that these two genes may play an essential role in blooming and aroma production in wintersweet. Gas chromatography-mass spectroscopy (GC-MS) analysis revealed that the overexpression of CpMYC2 in arabidopsis (Arabidopsis thaliana) AtMYC2-2 mutant (Salk_083483) and tobacco (Nicotiana tabaccum) genotype Petit Havana SR1 significantly increased floral volatile monoterpene, especially linalool, while the overexpression of CpbHLH13 in Arabidopsis thaliana ecotype Columbia-0 (Col-0) and tobacco genotype SR1 increased floral sesquiterpene β-caryophyllene production in both types of transgenic plants respectively. High expression of terpene synthase (TPS) genes in transgenic A. thaliana along with high expression of CpMYC2 and CpbHLH13 in transgenic plants was also observed. The application of a combination of methyl jasmonic acid (MeJA) and gibberellic acid (GA3) showed an increment in linalool production in CpMYC2-overexpressing arabidopsis plants, and the high transcript level of TPS genes also suggested the involvement of CpMYC2 in the jasmonic acid (JA) signaling pathway. These results indicate that both the CpMYC2 and CpbHLH13 transcription factors of wintersweet are possibly involved in the positive regulation and biosynthesis of monoterpene (linalool) and sesquiterpene (β-caryophyllene) in transgenic plants. This study also indicates the potential application of wintersweet as a valuable genomic material for the genetic modification of floral scent in other flowering plants that produce less volatile compounds.

Download Full-text

Interspecific and Intersexual Differences in the Chemical Composition of Floral Scent inGlochidionSpecies (Phyllanthaceae) in South China

Journal of Chemistry ◽

10.1155/2015/865694 ◽

2015 ◽

Vol 2015 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

Daihong Huang ◽

Fuchen Shi ◽

Minwei Chai ◽

Ruili Li ◽

Houhun Li

Keyword(s):

South China ◽

Floral Scent ◽

Gas Chromatography Mass Spectrometry ◽

Floral Volatiles ◽

Qualitative And Quantitative ◽

Pollination Mutualism ◽

Obligate Pollination Mutualism ◽

Male Flowers ◽

Female Flowers ◽

Absorption Technique

Plants of theGlochidion(Phyllanthaceae) genus are pollinated exclusively by host-specificEpicephala(Gracillariidae) moths. Floral scent has been thought to play key role in the obligate pollination mutualism betweenGlochidionplants andEpicephalamoths, but few studies have been reported about chemical variation in floral volatiles ofGlochidionspecies in China. Floral volatiles of male and female flowers of fiveGlochidionspecies in south China were collected by dynamic headspace absorption technique and then were chemically analyzed by using gas chromatography-mass spectrometry. A total of 69 compounds were identified from floral scents of five investigated species.Glochidion hirsutumandG.zeylanicumshowed no qualitative differences in floral scent, whereas there were clear variations of floral scent among other species (G. eriocarpum,G.daltonii, andG. sphaerogynum) and also they distinctly differed from these two species. Male flowers emitted significantly more scent than female flowers.Glochidionplants exhibited qualitative and quantitative differences in floral scent between two sexes of flowers. The findings suggest that the volatile variation of floral scent amongGlochidionspecies reflects adaptations to specific pollinators. Sexual dimorphism in floral scent has evolved to signal alternative rewards provided by each sex toEpicephalamoths.

Download Full-text

Circadian clock gene LATE ELONGATED HYPOCOTYL directly regulates the timing of floral scent emission in Petunia

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1422875112 ◽

2015 ◽

Vol 112 (31) ◽

pp. 9775-9780 ◽

Cited By ~ 46

Author(s):

Myles P. Fenske ◽

Kristen D. Hewett Hazelton ◽

Andrew K. Hempton ◽

Jae Sung Shim ◽

Breanne M. Yamamoto ◽

...

Keyword(s):

Circadian Clock ◽

Clock Gene ◽

Floral Scent ◽

Expression Patterns ◽

Constitutive Expression ◽

Regulatory Elements ◽

Circadian Clock Gene ◽

Volatile Emission ◽

Floral Volatile ◽

Volatile Production

Flowers present a complex display of signals to attract pollinators, including the emission of floral volatiles. Volatile emission is highly regulated, and many species restrict emissions to specific times of the day. This rhythmic emission of scent is regulated by the circadian clock; however, the mechanisms have remained unknown. In Petunia hybrida, volatile emissions are dominated by products of the floral volatile benzenoid/phenylpropanoid (FVBP) metabolic pathway. Here we demonstrate that the circadian clock gene P. hybrida LATE ELONGATED HYPOCOTYL (LHY; PhLHY) regulates the daily expression patterns of the FVBP pathway genes and floral volatile production. PhLHY expression peaks in the morning, antiphasic to the expression of P. hybrida GIGANTEA (PhGI), the master scent regulator ODORANT1 (ODO1), and many other evening-expressed FVBP genes. Overexpression phenotypes of PhLHY in Arabidopsis caused an arrhythmic clock phenotype, which resembles those of LHY overexpressors. In Petunia, constitutive expression of PhLHY depressed the expression levels of PhGI, ODO1, evening-expressed FVBP pathway genes, and FVBP emission in flowers. Additionally, in the Petunia lines in which PhLHY expression was reduced, the timing of peak expression of PhGI, ODO1, and the FVBP pathway genes advanced to the morning. Moreover, PhLHY protein binds to cis-regulatory elements called evening elements that exist in promoters of ODO1 and other FVBP genes. Thus, our results imply that PhLHY directly sets the timing of floral volatile emission by restricting the expression of ODO1 and other FVBP genes to the evening in Petunia.

Download Full-text

A Comparative Analysis of Floral Scent Compounds in Intraspecific Cultivars of Prunus mume with Different Corolla Colours

Molecules ◽

10.3390/molecules25010145 ◽

2019 ◽

Vol 25 (1) ◽

pp. 145 ◽

Cited By ~ 3

Author(s):

Tengxun Zhang ◽

Fei Bao ◽

Yongjuan Yang ◽

Ling Hu ◽

Anqi Ding ◽

...

Keyword(s):

Benzyl Alcohol ◽

Solid Phase ◽

Floral Scent ◽

Principal Component ◽

Hierarchical Cluster ◽

Floral Volatiles ◽

Benzyl Acetate ◽

Prunus Mume ◽

Benzyl Benzoate ◽

Floral Volatile

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.

Download Full-text

Composition and Emission Rhythm of Floral Scent Volatiles from Eight Lily Cut Flowers

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.137.6.376 ◽

2012 ◽

Vol 137 (6) ◽

pp. 376-382 ◽

Cited By ~ 27

Author(s):

Ying Kong ◽

Ming Sun ◽

Hui-tang Pan ◽

Qi-xiang Zhang

Keyword(s):

Mass Spectrometry ◽

Volatile Compounds ◽

Floral Scent ◽

Neutral Red ◽

Ethyl Benzoate ◽

Gas Chromatography Mass Spectrometry ◽

Floral Volatiles ◽

Cut Flowers ◽

Floral Scents ◽

Direct Thermal Desorption

Floral scents emitted from eight cultivars of cut lily flowers (Lilium) were analyzed. Floral volatiles were collected by headspace adsorption on sorbent tubes and analyzed by gas chromatography–mass spectrometry (GC/MS) using a direct thermal desorption. Fifty volatile compounds were identified. Nine compounds were detected in all lilies, whereas 20 compounds were detected in all scented lilies. The results revealed that non-scented lilies emitted trace amounts of volatile compounds, whereas scented lilies emitted high levels of volatile compounds. Monoterpenoids and benzenoids were the dominant compound classes of volatiles emitted from scented lilies. Myrcene, (E)-β-ocimene, linalool, methyl benzoate, and ethyl benzoate were the major compounds of the aroma of scented lilies; 1,8-cineole was also a major compound in the two scented oriental × trumpet hybrid lilies. Scent emissions occurred in a circadian rhythm with higher levels of volatiles emitted during the night. Lilium ‘Siberia’ was selected as a model to investigate the source of the emissions. GC/MS analysis of four flower parts and neutral red staining revealed that tepals were the source of floral scent.

Download Full-text

The Arabidopsis mediator complex subunit 8 regulates oxidative stress responses

The Plant Cell ◽

10.1093/plcell/koab079 ◽

2021 ◽

Cited By ~ 1

Author(s):

Huaming He ◽

Jordi Denecker ◽

Katrien Van Der Kelen ◽

Patrick Willems ◽

Robin Pottie ◽

...

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Salicylic Acid ◽

Jasmonic Acid ◽

Stress Responses ◽

Negative Regulator ◽

Mediator Complex ◽

Defense Gene Expression ◽

A Genome ◽

Oxidative Stress Responses

Abstract Signaling events triggered by hydrogen peroxide (H2O2) regulate plant growth and defense by orchestrating a genome-wide transcriptional reprogramming. However, the specific mechanisms that govern H2O2-dependent gene expression are still poorly understood. Here, we identify the Arabidopsis Mediator complex subunit MED8 as a regulator of H2O2 responses. The introduction of the med8 mutation in a constitutive oxidative stress genetic background (catalase-deficient, cat2) was associated with enhanced activation of the salicylic acid pathway and accelerated cell death. Interestingly, med8 seedlings were more tolerant to oxidative stress generated by the herbicide methyl viologen (MV) and exhibited transcriptional hyperactivation of defense signaling, in particular salicylic acid- and jasmonic acid-related pathways. The med8-triggered tolerance to MV was manipulated by the introduction of secondary mutations in salicylic acid and jasmonic acid pathways. In addition, analysis of the Mediator interactome revealed interactions with components involved in mRNA processing and microRNA biogenesis, hence expanding the role of Mediator beyond transcription. Notably, MED8 interacted with the transcriptional regulator NEGATIVE ON TATA-LESS, NOT2, to control the expression of H2O2-inducible genes and stress responses. Our work establishes MED8 as a component regulating oxidative stress responses and demonstrates that it acts as a negative regulator of H2O2-driven activation of defense gene expression.

Download Full-text

Hawkmoths evaluate scenting flowers with the tip of their proboscis

eLife ◽

10.7554/elife.15039 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 24

Author(s):

Alexander Haverkamp ◽

Felipe Yon ◽

Ian W Keesey ◽

Christine Mißbach ◽

Christopher Koenig ◽

...

Keyword(s):

Wind Tunnel ◽

Manduca Sexta ◽

Ecosystem Service ◽

Floral Scent ◽

Nicotiana Attenuata ◽

Floral Volatiles ◽

Pollen Transfer ◽

Olfactory Neurons ◽

Molecular Analyses ◽

Choice Tests

Pollination by insects is essential to many ecosystems. Previously, we have shown that floral scent is important to mediate pollen transfer between plants (<xref ref-type="bibr" rid="bib16">Kessler et al., 2015</xref>). Yet, the mechanisms by which pollinators evaluate volatiles of single flowers remained unclear. Here, Nicotiana attenuata plants, in which floral volatiles have been genetically silenced and its hawkmoth pollinator, Manduca sexta, were used in semi-natural tent and wind-tunnel assays to explore the function of floral scent. We found that floral scent functions to increase the fitness of individual flowers not only by increasing detectability but also by enhancing the pollinator's foraging efforts. Combining proboscis choice tests with neurophysiological, anatomical and molecular analyses we show that this effect is governed by newly discovered olfactory neurons on the tip of the moth's proboscis. With the tip of their tongue, pollinators assess the advertisement of individual flowers, an ability essential for maintaining this important ecosystem service.

Download Full-text

Chrysolina herbaceamodulates jasmonic acid,cis-(+)-12-oxophytodienoic acid, (3R,7S)-jasmonoyl-l-isoleucine, and salicylic acid of local and systemic leaves in the host plantMentha aquatica

Journal of Plant Interactions ◽

10.1080/17429145.2010.545282 ◽

2011 ◽

Vol 6 (2-3) ◽

pp. 99-101 ◽

Cited By ~ 7

Author(s):

Andrea Occhipinti ◽

Simon Atsbaha Zebelo ◽

Andrea Capuzzo ◽

Massimo Maffei ◽

Giorgio Gnavi

Keyword(s):

Salicylic Acid ◽

Jasmonic Acid

Download Full-text

Restoration of Defective Cross Talk in ssi2 Mutants: Role of Salicylic Acid, Jasmonic Acid, and Fatty Acids in SSI2-Mediated Signaling

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2003.16.11.1022 ◽

2003 ◽

Vol 16 (11) ◽

pp. 1022-1029 ◽

Cited By ~ 42

Author(s):

Pradeep Kachroo ◽

Aardra Kachroo ◽

Ludmila Lapchyk ◽

David Hildebrand ◽

Daniel F. Klessig

Keyword(s):

Cell Death ◽

Salicylic Acid ◽

Jasmonic Acid ◽

Cross Talk ◽

Pr Genes ◽

Exogenous Application ◽

Basal Level Expression ◽

Sa Signaling ◽

Spontaneous Cell Death

The Arabidopsis mutants ssi2 and fab2 are defective in stearoyl ACP desaturase, which causes altered salicylic acid (SA)- and jasmonic acid (JA)-mediated defense signaling. Both ssi2 and fab2 plants show spontaneous cell death, express PR genes constitutively, accumulate high levels of SA, and exhibit enhanced resistance to bacterial and oomycete pathogens. In contrast to constitutive activation of the SA pathway, ssi2 and fab2 plants are repressed in JA-mediated induction of the PDF1.2 gene, which suggests that the SSI2-mediated signaling pathway modulates cross talk between the SA and JA pathways. In this study, we have characterized two recessive nonallelic mutants in the ssi2 background, designated as rdc (restorer of defective cross talk) 2 and rdc8. Both ssi2 rdc mutants are suppressed in constitutive SA signaling, show basal level expression of PR-1 gene, and induce high levels of PDF1.2 in response to exogenous application of JA. Interestingly, while the rdc8 mutation completely abolishes spontaneous cell death in ssi2 rdc8 plants, the ssi2 rdc2 plants continue to show some albeit reduced cell death. Fatty acid (FA) analysis showed a reduction in 16:3 levels in ssi2 rdc8 plants, which suggests that this mutation may limit the flux of FAs into the pro-karyotic pathway of glycerolipid biosynthesis. Both rdc2 and rdc8 continue to accumulate high levels of 18:0, which suggests that 18:0 levels were responsible for neither constitutive SA signaling nor repression of JA-induced expression of the PDF1.2 gene in ssi2 plants. We also analyzed SA and JA responses of the fab2-derived shs1 mutant, which accumulates levels of 18:0 over 50% lower than those in the fab2 plants. Even though fab2 shs1 plants were morphologically bigger than fab2 plants, they expressed PR genes constitutively, showed HR-like cell death, and accumulated elevated levels of SA. However, unlike the ssi2 rdc plants, fab2 shs1 plants were unable to induce high levels of PDF1.2 expression in response to exogenous application of JA. Together, these results show that defective cross talk in ssi2 can be restored by second site mutations and is independent of morphological size of the plants, cell death, and elevated levels of 18:0.

Download Full-text