Scent Emission Research Articles

Effect of Postharvest Temperature Management on Scent Emission from Cut Flowers of Tulip Cultivars

Tulip (Tulipa gesneriana L.) cultivars exhibit diverse floral scents, the emissions of which are generally influenced by temperature. To fully benefit from these scents and add value to cut tulips, it is necessary to evaluate the scent emission response to temperature. This study investigated the daily emission changes of 82 volatiles, including the main scent compounds, at different temperatures (13, 18, and 23°C), in the cut tulips from eight tulip cultivars with different scents. At 23 and 18°C, the total scent emissions of each cultivar increased with flower opening and subsequently decreased with visible senescence. Floral senescence progressed more rapidly at 23°C, and the decrease in total scent emission occurred most rapidly at 23°C. Scent emissions at 18°C tended to be lower than at 23°C. The vase life of the cut tulips was most prolonged at 13°C owing to the slow senescence; however, scent emissions remained low after the flower opening. These results indicate that improving both tulip scent emission and vase life under constant temperature conditions is difficult. It was observed that scent composition changed before and after flower opening, and with floral senescence. In contrast, temperature had little effect on scent composition. Cut tulips stored at a low temperature (10 or 15°C) over four and a half days and then transferred to room temperature (20°C) had a longer vase life than tulips maintained at room temperature, due to delayed senescence. In addition, scent emissions were low at low temperatures, but increased rapidly upon transfer to room temperature. Therefore, storage of cut tulips at low temperatures may lead to increased scent emissions upon transfer to room temperature. These findings imply that low-temperature storage of cut tulips before sale contributes to both vase life and a rich scent after sale. The results reported here demonstrate the improvement of cut tulip scent emissions by appropriate temperature management.

Effect of Pre- and Post-transport Preservative Treatments to Extend Vase Life on Scent Emission of Tulip Cut Flowers

Tulipa gesneriana L. ‘Sanne’, a tulip cut flower cultivar, has a fruity scent derived from monoterpenes based on linalool. Treatment with a commercial preservative containing plant growth regulators, such as ethephon, before transportation or with a preservative containing glucose after transportation extends the vase life of various tulip cut flowers. However, the effects of preservatives on floral scents are unknown. In this study, pre-transport ethephon treatment did not affect the scent emission and increased the vase life of Sanne. However, post-transport glucose treatment increased terpenoid emissions and caused stalk softening. The combination of pre- and post-transport treatments increased terpenoid emissions but did not cause stalk softening. Comparative analysis with previous sensory evaluation of the Sanne scent revealed that the duration of the noticeable scent under the combination treatment was estimated to be twice than that under the control treatment. In Sanne, the vase life and scents are expected to be improved by the pre- and post-transport treatment combination.

Histochemical and surface microstructural analyses of floral cuticles provide evidence for differential behaviors in scent volatiles emission in two tuberoses (Agave amica (Medik.) Theide and Govaerts) cultivars from Asparagaceae

Two popular cultivars of tuberose (Agave amica (Medik.) Theide and Govaerts syn. Polianthes tuberosa L.) from the family Asparagaceae, widely cultivated for floricultural purposes are ,'Calcutta Single' (CS) and 'Calcutta Double' (CD). It was evidenced that CS flowers emit intense scent volatiles as compared to CD flowers, while CD flowers retained higher contents of internal pool of scent volatiles than CS flowers. Such contrasting observations between the flowers of two cultivars suggest the role of possible barriers such as cuticles that prevent the emission of scent volatiles. The cuticular structure of both cultivars was studied using different histochemical approaches, including light and epi-fluorescence microscopies. Scanning electron microscopy (SEM) was used to understand the cuticular deposition in the cultivars. Our observations confirmed relatively higher cuticular thickness in CD flowers than in CS. SEM results showed the accumulation of wax crystalloids in CS flower and the formation of cuticular nanoridges in CD flowers over the surfaces of the tepals. In addition, accumulation of lipid droplets was also noticed on the tepal peels of the cultivars showing a denser deposition in CD. Our observations suggest that the presence of wax crystalloids in CS flowers enhances the emission of volatiles, while in CD flowers, the presence of thick cuticular nanoridges possibly deters the scent emission and accumulated as an internal pool in higher amounts. The stomatal behavior also indicates a proportional relationship between cuticular deposition and scent emission; low cuticular deposition corresponds to higher emission of floral volatiles emission and vice versa as observed in CS and CD flowers, respectively.

Introduction of Floral Scent Traits into Asiatic Hybrid Lilies (Unscented) by Crossbreeding with <i>Lilium cernuum</i> (Scented)

Although a strong floral scent is typical of hybrid lilies, Asiatic hybrid lilies (Lilium spp.) have only a weak scent. Therefore, developing new cultivars with pleasant floral scents is an important objective in Asiatic hybrid lily breeding programs. Among the wild species contributing to Asiatic hybrid lily establishment, L. cernuum has a characteristic scent that the nose can perceive. We crossed Asiatic hybrid lily cultivars twice with L. cernuum to introduce floral scent traits into Asiatic hybrid lilies, and scent emission in the F1 plants and their progeny lines was evaluated instrumentally. Flowers of L. cernuum emitted benzenoids/phenylpropanoids (mainly 2-phenylethanol and benzaldehyde), monoterpenes (predominantly linalool and linalool oxides), and a fatty acid (iso-valeric acid). Lilium cernuum gave off unpleasant odors mainly because of iso-valeric acid emission. The F1 flowers also emitted these three chemical classes. Among the lines derived from the crosses between Asiatic hybrid lily cultivars and the F1 plant, lines that emitted all three chemical classes and lines that released one or two of the three chemical classes were segregated, and some lines emitted benzenoids/phenylpropanoids or terpenoids without emitting fatty acids. We successfully selected elite breeding lines that predominantly emitted pleasant scents. Therefore, this study demonstrated the introduction of pleasant scent production capability into Asiatic hybrid lilies using interspecific hybridization with L. cernuum.

Phylogenetic Analyses of Some Key Genes Provide Information on Pollinator Attraction in Solanaceae.

Floral syndromes are known by the conserved morphological traits in flowers associated with pollinator attraction, such as corolla shape and color, aroma emission and composition, and rewards, especially the nectar volume and sugar concentration. Here, we employed a phylogenetic approach to investigate sequences of genes enrolled in the biosynthetic pathways responsible for some phenotypes that are attractive to pollinators in Solanaceae genomes. We included genes involved in visible color, UV-light response, scent emission, and nectar production to test the hypothesis that these essential genes have evolved by convergence under pollinator selection. Our results refuted this hypothesis as all four studied genes recovered the species' phylogenetic relationships, even though some sites were positively selected. We found differences in protein motifs among genera in Solanaceae that were not necessarily associated with the same floral syndrome. Although it has had a crucial role in plant diversification, the plant-pollinator interaction is complex and still needs further investigation, with genes evolving not only under the influence of pollinators, but by the sum of several evolutionary forces along the speciation process in Solanaceae.

Water Deficit, Nitrogen Availability, and Their Combination Differently Affect Floral Scent Emission in Three Brassicaceae Species

Floral scent plays a central role in plant-pollinator interactions, as flower visitors can discriminate between scent differences to recognize and forage on rewarding flowers. Changes in scent compositions might therefore lead to recognition mismatches between host plants and flower visitors. An understanding of the phenotypic plasticity of floral scent, especially in crop species, is becoming important because of climate change, e.g., increasing drought periods, and other anthropogenic influences, e.g., nitrogen (N) deposition. We have investigated the effects of the combination of progressive water deficits (dry-down) and N supplementation on floral scent emission in three Brassicaceae species (cultivated vs. wild). Individuals were randomly assigned to one of four treatments: (1) well-watered without N supplementation; (2) well-watered with N supplementation; (3) dry-down without N supplementation; (4) dry-down with N supplementation. We collected scent on day 0, 2, 7, and 14 after the commencement of the watering treatment. All samples were analyzed using gas chromatography coupled with mass spectrometry. We found that the highly cultivated Brassica napus had the lowest overall emission rate; its scent composition was affected by the interaction of watering treatment and N supplementation. Scent bouquets of the cultivated Sinapis alba also changed under these treatments. Scent bouquets of the common weed Sinapis arvensis were affected by watering treatment, but not by time and N supplementation. Furthermore, the influence of treatments on the emission rate of single compounds was highly compound-specific. Nonetheless, our study revealed that especially terpenes were negatively affected by drought-stress.

Reduced seed set under water deficit is driven mainly by reduced flower numbers and not by changes in flower visitations and pollination

Abstract Water deficit can alter floral traits with cascading effects on flower‐visitor interactions and plant fitness. Water stress induction can diminish productivity, directly resulting in lower flower production and consequently seed set. Changes in floral traits, such as floral scent or reward amount, may in turn alter pollinator visitations and behaviour and consequently can reduce pollination services resulting in lower reproduction output. However, the relative contribution of this indirect in comparison to the direct effects to changes in seed set are not fully understood. We manipulated water availability using rain‐out shelters in a field experiment and measured effects on floral scent bouquet, morphology, phenology, flower‐visitor interactions, pollination and seed set. Plant individuals of Sinapis arvensis (Brassicaceae) were randomly assigned to one of three treatments: mean precipitation (=control), reduced mean precipitation or drought period treatment. Our results show that decreasing water availability lowers the number of flowers and seed set. This indicates a direct link between water stress and seed set, as seed mass increases with increasing flower number. The indirect link of water stress via floral traits, pollinator visits and pollination has weaker effects on seed set. However, floral traits remain relatively stable under decreased water availability, whereas plant growth and flower abundance decrease, potentially in order to allow investment in more resources in fewer flowers to maintain pollination success. Thus, plants are able to compensate for water stress and can maintain floral trait expression, such as a stable scent emission and bouquet, to retain pollinator attraction. These findings indicate that the direct link from water stress to seed set has a stronger impact on plants reproductive success than the indirect link through altered floral trait expression and pollinator visits in a generalist plant species. Read the free Plain Language Summary for this article on the Journal blog.

Floral scent emission is the highest at the second night of anthesis in Lonicera japonica (Caprifoliaceae)

AbstractFloral color change in diverse plants has been thought to be a visual signal reflecting changes in floral rewards, promoting pollinator foraging efficiency as well as plant reproductive success. It remains unclear whether olfactory signals co‐vary with floral color change. We investigated the production rhythms of floral scent and nectar associated with floral color change in Lonicera japonica. The flowers generally last 2–3 days. They are white on opening at night (N1) and become light yellow the following day (D1), yellow on the second night (N2), and golden on the second day of flowering (D2). Our measurements in the four stages indicated that nectar production decreased significantly from N1 and D1 to N2 and D2, tracking the floral color change. A total of 34 compounds were detected in floral scent and total scent emission was significantly higher in N2 than in the other three stages. The scent emission of three major compounds, Linalool, cis‐3‐Hexenyl tiglate, and Germacrene D was also significantly higher in N2, but the relative content of Linalool decreased gradually, cis‐3‐Hexenyl tiglate increased gradually, and the relative content of Germacrene D did not differ among the four measured stages. Greater scent emission by night than by day suggested a strong olfactory signal to attract nocturnal hawkmoths, the effective pollinators. However, floral scent rhythms in the four stages did not match the color change and nectar secretion, suggesting that floral color (visual) and scent (olfactory) in this species may play different roles in attracting or filtering various visitors.

Do onion (Allium cepa L.) floral scent emissions peak when pollinators are most active?

Do onion (Allium cepa L.) floral scent emissions peak when pollinators are most active?

The diurnal emission of floral scent in Oncidium hybrid orchid is controlled by CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) through the direct regulation on terpene synthase

BackgroundTo adapt the periodic fluctuation of environmental factors, plants are subtle to monitor the natural variation for the growth and development. The daily activities and physiological functions in coordination with the natural variation are regulated by circadian clock genes. The circadian emission of floral scents is one of the rhythmic physiological activities controlled by circadian clock genes. Here, we study the molecular mechanism of circadian emission pattern of ocimene and linalool compounds in Oncidium Sharry Baby (Onc. SB) orchid.ResultsGC-Mass analysis revealed that Onc. SB periodically emitted ocimene and linalool during 6 to 14 o’clock daily. Terpene synthase, one of the key gene in the terpenoid biosynthetic pathway is expressed in coordination with scent emission. The promoter structure of terpene synthase revealed a circadian binding sequence (CBS), 5’-AGATTTTT-3’ for CIRCADIAN CLOCK ASSOCIATED1 (CCA1) transcription factor. EMSA data confirms the binding affinity of CCA1. Transactivation assay further verified that TPS expression is regulated by CCA1. It suggests that the emission of floral scents is controlled by CCA1.ConclusionsThe work validates that the mechanism of circadian emission of floral scents in Onc. Sharry Baby is controlled by the oscillator gene, CCA1(CIRCADIAN CLOCK ASSOCIATED 1) under light condition. CCA1 transcription factor up-regulates terpene synthase (TPS) by binding on CBS motif, 5’-AGATTTTT-3’ of promoter region to affect the circadian emission of floral scents in Onc. SB.

Evidence for the recruitment of florivorous plant bugs as pollinators

Angiosperm flowers and their animal visitors have co-evolved for at least 140 Ma, and early flowers were likely used mainly as mating and feeding sites by several groups of insects, including beetles, flies, true bugs, and thrips. Earlier studies suggested that shifts from such neutral or antagonistic relationships toward mutualistic pollination interactions between flowers and insects occurred repeatedly during angiosperm evolution. However, the evolutionary mechanisms and adaptations, which accompanied shifts toward effective pollination, are barely understood, and evidence for such scenarios has been lacking. Here, we show that Syngonium hastiferum (Araceae), a Neotropical representative of an otherwise beetle-pollinated clade, is pollinated by plant bugs (Miridae; Heteroptera), which are florivores of Syngonium schottianum and other Araceae species. We found that S.hastiferum differs in several floral traits from its beetle-pollinated relatives. Scent emission and thermogenesis occur in the morning instead of the evening hours, and its pollen surface is spiny instead of smooth. Furthermore, the floral scent of S.hastiferum includes a previously unknown natural product, (Z)-3-isopropylpent-3-en-1-ol, which we show to have a function in specifically attracting the plant bug pollinators. This is the first known case of a specialized plant bug pollination system and provides clear evidence for the hypothesis that the adoption of antagonistic florivores as pollinators can drive flower diversification. VIDEO ABSTRACT.

Development of a flow‐cell coupled to dynamic SPME technique for automated measurement of fragrance emission from fabric

AbstractA novel automated flow‐cell coupled dynamic solid‐phase microextraction (SPME) method was developed to study the emission of volatile fragrance compounds from fabric samples in a microchamber. Calibration curves were developed with the liquid‐inner tube diffusion‐film‐emission (LIFE) vial technique to quantify the gas‐phase concentration of nine significant volatile fragrance compounds. The linearity range for the various volatile fragrance compounds ranged from 0.001 to 37.9 mg/m3. The limit of quantitation (LOQ) for each fragrance compound was determined as ~3.6–12.1 μg/m3. Using this method, we obtained comprehensive emission curves of target volatiles to quantify the volatile emission profiles of fabric samples. Compared with traditional chamber test method procedures, this work provides a novel and automated method to allow the online monitoring of the emission of various volatiles from multiple samples in one experiment. The repeatability and sensitivity of the method are comparable to or better than existing offline techniques.

High-energy-level metabolism and transport occur at the transition from closed to open flowers.

During the maturation phase of flower development, the onset of anthesis visibly marks the transition from buds to open flowers, during which petals stretch out, nectar secretion commences, and pollination occurs. Analysis of the metabolic changes occurring during this developmental transition has primarily focused on specific classes of metabolites, such as pigments and scent emission, and far less on the whole network of primary and secondary metabolites. To investigate the metabolic changes occurring at anthesis, we performed multi-platform metabolomics alongside RNA sequencing in individual florets harvested from the main inflorescence of Arabidopsis (Arabidopsis thaliana) ecotype Col-0. To trace metabolic fluxes at the level of the whole inflorescence and individual florets, we further integrated these studies with radiolabeled experiments. These extensive analyses revealed high-energy-level metabolism and transport of carbohydrates and amino acids, supporting intense metabolic rearrangements occurring at the time of this floral transition. These comprehensive data are discussed in the context of our current understanding of the metabolic shifts underlying flower opening. We envision that this analysis will facilitate the introgression of floral metabolic traits promoting pollination in crop species for which a comprehensive knowledge of flower metabolism is still limited.

Population-specific responses of floral volatiles to abiotic factors in changing environments.

Shifts in abiotic factors can affect many plant traits, including floral volatiles. This study examined the response of floral volatiles to water availability and whether phenotypic plasticity to water availability differs among populations. It also investigated genetic differentiation in floral volatiles, determined the effect of temperature on phenotypic plasticity to water availability, and assessed temporal variation in floral scent emission between day and evening, since pollinator visitation differs at those times. Rocky Mountain columbine plants (Aquilegia coerulea), started from seeds collected in three wild populations in Colorado, Utah, and Arizona, were grown under two water treatments in a greenhouse in Madison, Wisconsin, United States. One population was also grown under the two water treatments, at two temperatures. Air samples were collected from enclosed flowers using dynamic headspace methods and floral volatiles were identified and quantified by gas chromatography (GC) with mass spectrometry (MS). Emission of three floral volatiles increased in the wetter environment, indicating phenotypic plasticity. The response of six floral volatiles to water availability differed among populations, suggesting genetic differentiation in phenotypic plasticity. Five floral volatiles varied among populations, and emission of most floral volatiles was greater during the day. Phenotypic plasticity to water availability permits a quick response of floral volatiles in changing environments. The genetic differentiation in phenotypic plasticity suggests that phenotypic plasticity can evolve but complicates predictions of the effects of environmental changes on a plant and its pollinators.

Real-Time Visualization of Scent Accumulation Reveals the Frequency of Floral Scent Emissions.

Flowers emit a bouquet of volatiles to attract pollinators or to protect flowers from pathogen and herbivore attacks. Most floral volatiles are synthesized in the cytoplasm of petals and released into the headspace at a specific time of day. Various floral scent sampling methods coupled with gas chromatography-mass spectrometry have been used to measure the quality and quantity of floral volatiles. However, little is known about the emission patterns of floral scents. In most cases, it is still unclear whether floral scents emit continuously or discontinuously. Here we measured the frequency with which lily flowers emit scents using optical interferometry. By analyzing the refractive index difference between volatile organic compounds and ambient air, we were able to visualize the accumulation of the volatile vapors. The frequency of volatile emission was calculated from the unique footprint of temporal power spectrum maps. Based on these real-time measurements, we found that lily flowers emit the volatile compounds discontinuously, with pulses observed around every 10–50 min.

Extensive population-level sampling reveals clinal variation in (R)-(−)-linalool produced by the flowers of an endemic evening primrose, Oenothera harringtonii

The study of floral trait diversity has a long history due to its role in angiosperm diversification. While many studies have focused on visual traits including morphology and color, few have included floral scent despite its importance in pollination. Of the studies that have included floral scent, sampling has been limited and rarely explores variation at the population level. We studied geographic variation in the flowers of Oenothera harringtonii, a rare plant endemic to a vulnerable shortgrass prairie habitat, whose population structure and conservation status are well studied. The self-incompatible flowers of O. harringtonii open at dusk, produce nectar and a strong fragrance, and are pollinated by hawkmoths. We collected floral trait (morphology, scent chemistry and emission rates) data from 650 individuals from 19 wild populations to survey floral variation across the entire range of this species. Similarly, we collected floral data from 49 individuals grown in a greenhouse common garden, to assess whether variation observed in the field is consistent when environment factors (temperature, watering regime, soil) are standardized. We identified 35 floral volatiles representing 5 biosynthetic classes. Population differentiation was stronger for floral scent chemistry than floral morphology. (R)-(−)-linalool was the most important floral trait differentiating populations, exhibiting clinal variation across the distribution of O. harringtonii without any correlated shifts in floral morphology. Populations in the north and west produced (R)-(−)-linalool consistently, those in the east and south largely lacked it, and populations at the center of the distribution were polymorphic. Floral scent emissions in wild populations varied across four years but chemical composition was largely consistent over time. Similarly, volatile emission rates and chemical composition in greenhouse-grown plants were consistent with those of wild populations of origin. Our data set, which represents the most extensive population-level survey of floral scent to date, indicates that such sampling may be needed to capture potentially adaptive geographic variation in wild populations.

Effect of Temperature on Scent Emission from Carnation Cut Flowers

Temperature, an environmental factor affecting cut flowers' physiological state, is expected to affect scent emission. We investigated scent emission from carnation cut flowers of two scent types (Dianthus caryophyllus L.), exhibiting fruity (because of methyl benzoate) and spicy (because of eugenol) scents, at various temperatures (10°C, 15°C, 23°C, and 28°C). Cut flowers harvested on the day of flower opening were used for analysis. Scent emission was significantly higher at 23°C and 28°C than at 10°C and 15°C until 1 or 2 days but was significantly lower at 8 and 10 days postharvest. Methyl benzoate emissions decreased faster than eugenol emissions. Considering the lower limit of noticeable scent, as per previous sensory evaluations of carnations, scent lasted the longest at 10°C and 15°C. After ~5 days of pretreatment at 10°C, scent emission was slightly improved at 23°C than at 23°C. Such cut flower management at 10°C before sale may contribute to the persistence of scent at room temperature in consumers' homes after sale. Various factors, including the suppression of scent substrate consumption, regulation of scent emission from the cuticle, and influence on the expression of scent emission–related genes, may affect the retention of scent emission because of low temperature.

The Similarity of Floral Scent Composition in Two Breynia Species Pollinated by the Same Host-Specific Epicephala Moth

Floral scent has been thought to play a critical role in the obligate pollination–seed consumption mutualism between Breynia (Phyllanthaceae) species and Epicephala moths. The two closely related Breynia species, B. fruticosa and B. Rostrata are jointly pollinated by the same moth species (E. lativalvaris and E. mirivalvata), which has led to an obligate pollination mutualism of ‘two-to-two’ species specificity. However, empirical data on host floral volatiles as chemical cues maintaining the plant−moth specificity are missing. In the present study, 27 volatile compounds were identified from floral scents of the two Breynia species. A total of 25 compounds were shared jointly by the two species, and only one compound, β-humulene, was species specific and exclusively produced by B. fruticosa. The two Breynia species clearly showed no interspecific floral scent profiles within both sexes, especially in male flowers. Male and female flowers of floral scent from these plants exhibited major qualitative differences, and male flowers produced more scent than female flowers. For male flowers of B. fruticosa, there was significant temporal variation in the volatile chemical profiles and total floral scent emission before and after pollination. Interestingly, β-phenylethyl butyrate and phenylethyl alcohol were present in maximal amounts during pollination, but they rapidly reduced in concentration after pollination. The findings suggest that the similar floral scent profiles of the two Breynia species reflect adaptations to the same pollinator, Epicephala, for their pollination. Sexually dimorphic floral scent between male and female flowers has been selected to provoke pollinator’s active pollination behavior on host flowers. Temporal changes in floral scent of male flowers before and after pollination may have evolved to limit the overexploitation of the ovaries by seed predators, Epicephala moths. We speculate that the two most abundant compounds in the male flowers, β-phenylethyl butyrate and phenylethyl alcohol, may be two signal compounds to attract Epicephala in a species-specific manner.

Extensive pollinator sharing does not promote character displacement in two orchid congeners.

Pollinator sharing between close relatives can be costly and can promote pollination niche partitioning and floral divergence. This should be reflected by a higher species divergence in sympatry than in allopatry. We tested this hypothesis in two orchid congeners with overlapping distributions and flowering times. We characterized floral traits and pollination niches and quantified pollen limitation in 15 pure and mixed populations, and we measured phenotypic selection on floral traits and performed controlled crosses in one mixed site. Most floral traits differed between species, yet pollinator sharing was extensive. Only the timing of scent emission diverged more in mixed sites than in pure sites, and this was not mirrored by the timing of pollinator visitation. We did not detect divergent selection on floral traits. Seed production was pollen limited in most populations but not more severely in mixed sites than in pure sites. Interspecific crosses produced the same or a higher proportion of viable seeds than intraspecific crosses. The two orchid species attract the same pollinator species despite showing divergent floral traits. However, this does not promote character displacement, implying a low cost of pollinator sharing. Our results highlight the importance of characterizing both traits and ecological niches in character displacement studies.

Diffusion of volatile organics and water in the epicuticular waxes of petunia petal epidermal cells.

Plant cuticles are a mixture of crystalline and amorphous waxes that restrict the exchange of molecules between the plant and the atmosphere. The multicomponent nature of cuticular waxes complicates the study of the relationship between the physical and transport properties. Here, a model cuticle based on the epicuticular waxes of Petunia hybrida flower petals was formulated to test the effect of wax composition on diffusion of water and volatile organic compounds (VOCs). The model cuticle was composed of an n-tetracosane (C24 H50 ), 1-docosanol (C22 H45 OH), and 3-methylbutyl dodecanoate (C17 H34 O2 ), reflecting the relative chain length, functional groups, molecular arrangements, and crystallinity of the natural waxes. Molecular dynamics simulations were performed to obtain diffusion coefficients for compounds moving through waxes of varying composition. Simulated VOC diffusivities of the model system were found to highly correlate with in vitro measurements in isolated petunia cuticles. VOC diffusivity increased up to 30-fold in completely amorphous waxes, indicating a significant effect of crystallinity on cuticular permeability. The crystallinity of the waxes was highly dependent on the elongation of the lattice length and decrease in gap width between crystalline unit cells. Diffusion of water and higher molecular weight VOCs were significantly affected by alterations in crystalline spacing and lengths, whereas the low molecular weight VOCs were less affected. Comparison of measured diffusion coefficients from atomistic simulations and emissions from petunia flowers indicates that the role of the plant cuticle in the VOC emission network is attributed to the differential control on mass transfer of individual VOCs by controlling the composition, amount, and dynamics of scent emission.