An Update on the Function, Biosynthesis and Regulation of Floral Volatile Terpenoids

Floral volatile terpenoids (FVTs) belong to a group of volatile organic compounds (VOC) that play important roles in attracting pollinators, defending against pathogens and parasites and serving as signals associated with biotic and abiotic stress responses. Although research on FVTs has been increasing, a systematic generalization is lacking. Among flowering plants used mainly for ornamental purposes, a systematic study on the production of FVTs in flowers with characteristic aromas is still limited. This paper reviews the biological functions and biosynthesis of FVTs, which may contribute a foundational aspect for future research. We highlight regulatory mechanisms that control the production of FVTs in ornamental flowers and the intersection of biosynthetic pathways that produce flower fragrance and color. Additionally, we summarize the opportunities and challenges facing FVT research in the whole genome and -omics eras and the possible research directions that will provide a foundation for further innovation and utilization of flowering ornamental plants and their germplasm resources.

Creating Sim Flower Scent (Rhodomyrtus tomentosa) for Product Sim Fruit from Natural Materials in Vietnam

Aim and Objectives: The purpose of this study is to reproduce the scent of Sim (Rhodomyrtus tomentosa) flower from natural substances present in Vietnam to replace the scent extracted from Sim flower. Materials and Methods: All the materials for making the Sim flower fragrance and products from Sim fruit are natural sources in Vietnam. Fragrance assessment by olfactory, the aroma is diluted 20 times with an odorless diethyl phthalate (DEP) solvent, followed by a special scent paper and the smell of the nose to assess the scent. The fragrance of Sim flower was tested on Sim syrup product 0.2%, Sim jam 0.5%, Sim wine 0.3% by weight. Results: After the experiment, we have selected fragrance FW.1, FW.2 for Sim wine, FS.1 and FS.2 for Sim syrup, FJ.1 and FJ.2 for Sim jam. The main aroma of Sim flower is made up of Aldehyde anisic, Cinnamaldehyde, Cinnamon bark oil, Linalool, Linalyl acetate, Linalyl cinnamate, Linalyl formate, Linalyl butyrate. Aldehyde anisic and Linalool are the main constituents that determine the aroma of Sim flower. Conclusions: We have created the scent of Sim flower from natural materials in Vietnam for Sim wine FW.1, FW.2, for Sim syrup FS.1, FS.2, and Sim jam FJ.1, FJ.2. Sim flower FW.1, FW.2, FS.1, FS.2, FJ.1, and FJ.2 are added to Sim wine, Sim syrup, Sim jam to increase the value and appeal of the products made from Vietnam Sim fruit.

Perfume and Olfaction

This chapter explores the topic of olfaction and perfume in decadent culture by arguing that many decadent authors styled themselves as olfactifs—cultivated individuals with a refined sense of smell. They celebrated fragrance both in their personal lives and in their writings, where the odors of perfume, incense, and tobacco emerge as the dominant olfactory keynotes of decadence. The chapter opens with a discussion of smoking and notes its various olfactory meanings for both male and female decadent writers, before considering incense, perfume use, and fashion, including the positive and negative attitudes toward perfume wearing in the mid- to late Victorian era. The final section focuses on flower fragrance in an urban environment and examines poems by Arthur Symons and Laurence Binyon to tease out some of the complex relations between decadence, perfume, artifice, and nature prevalent at this time.

The jasmine (Jasminum sambac) genome and flower fragrances

Jasminum sambac, a world-renowned plant appreciated for its exceptional flower fragrance, is of cultural and economic importance. However, the genetic basis of its fragrance is largely unknown. Here, we present the first de novo genome of J. sambac with 550.12 Mb (scaffold N50 = 40.1 Mb) assembled into 13 pseudochromosomes. Terpene synthase genes associated with flower fragrance are significantly amplified in the form of gene clusters through tandem duplications in the genome. Eleven homolog genes within the SABATH super-family were identified as related to phenylpropanoid/benzenoid compounds. Several key genes regulating jasmonate biosynthesis were duplicated causing increased copy numbers. Furthermore, multi-omics analyses identified various aromatic compounds and the key genes involved in fragrance biosynthesis pathways. Our genome of J. sambac offers a basic genetic resource for studying floral scent biosynthesis and provides an essential foundation for functional genomic research and variety improvements in Jasminum.

Pretreatment with High-Dose Gamma Irradiation on Seeds Enhances the Tolerance of Sweet Osmanthus Seedlings to Salinity Stress

The landscape application of sweet osmanthus (Osmanthus fragrans) with flower fragrance and high ornamental value is severely limited by salinity stress. Gamma irradiation applied to seeds enhanced their tolerance to salinity stress as reported in other plants. In this study, O. fragrans ‘Huangchuang Jingui’ seeds were pretreated with different doses of gamma irradiation, and tolerance of the seedlings germinated from the irradiated seeds to salinity stress and the changes of reactive oxygen species (ROS) production and ROS scavenging systems induced by gamma irradiation were observed. The results showed that seed pretreatment with different doses of gamma irradiation enhanced the tolerance of sweet osmanthus seedlings to salinity stress, and the positive effect induced by gamma irradiation was more remarkable with the increase of radiation dose (50–150 Gy). The pretreatment with high-dose irradiation decreased O2− production under salinity stress and mitigated the oxidative damage marked by a lower malondialdehyde (MDA) level, which could be related to the significant increase of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities in the seedlings germinated from the irradiated seeds compared to the corresponding control seedlings. In addition, the accumulation of proline in the irradiated seedlings may contribute to enhancing their tolerance to salt stress by the osmotic adjustment. The study demonstrated the importance of regulating plant ROS balance under salt stress and provided a potential approach to improve the tolerance of sweet osmanthus to salt stress.

Identification of Floral Fragrances and Analysis of Fragrance Patterns in Herbaceous Peony Cultivars

Thirty herbaceous peony (section Paeonia of the genus Paeonia) cultivars were divided into four groups (no fragrance, light fragrance, medium fragrance, or intense fragrance) based on their sensory evaluation scores. Using dynamic headspace sampling (DHS) and automatic thermal desorption–gas chromatography/mass spectrometry (ATD-GC/MS), 130 volatile organic components were detected in these 30 cultivars and a total of 72 compounds were identified as scent components. The main compounds were phenylethyl alcohol, β-caryophyllene, linalool, (R)-citronellol, and nerol. Selecting α-pinene as the standard, the volatile components of these cultivars were quantitatively analyzed. By combining the sensory evaluation scores and the results of quantitative analysis, we found that ‘Going Bananas’, ‘Cream Delight’, ‘Zhu Sha Pan’, ‘Qiao Ling’, ‘Duchess de Nemours’, and ‘Yang Fei Chu Yu’ displayed an intense fragrance and, thus, had relatively high commercial value for the flower fragrance industry. ‘Red Magic’, ‘Joker’, ‘Fairy Princess’, ‘Lovely Rose’, ‘Carina’, and ‘Etched Salmon’ were excluded from the hierarchical cluster of aromatic compounds and the analysis of fragrance patterns because of the low amount of fragrance they released and poor sensory evaluation results. Based on a cluster analysis, assessment of the major aromatic compounds, and the results of sensory evaluation, the remaining 24 cultivars were divided into five fragrance patterns for the first time: woody scent [cluster I (major fragrance β-caryophyllene)], fruity scent [cluster II (phenylethyl alcohol)], lily scent [cluster III (linalool)], rose scent {cluster IV [(R)-citronellol]}, and an orange blossom scent [cluster V (nerol)].

Using Mind Genomics® to Identify Essential Elements of a Flower Product

The IdeaMap® software suite and the concept of Mind Genomics® were used to analyze which features of a flower product are influential to consumer perception. By presenting online human subjects with combinations of elements that describe a flower product, a database was created to define how individuals perceive distinct components of an overall flower product. This study was conducted with two separate groups of participants, the first provided by a panelist fielding house and the second administered to an undergraduate introduction to plants and gardening class. The fielding house participants represented various demographic groups throughout the United States and the majority was 40 years of age and older. The undergraduate class participants consisted primarily of white, female students between the ages of 18 and 24 years. Each study participant was exposed to a permutation of flower-based elements derived from six categories: flower color, flower shape, consumer health and wellness, flower fragrance, flower purchase location, and flower use. The results of the two studies illustrated which elements of each flower category appealed to different demographics of the population and were used to identify segments of the population that possessed similar mindsets toward elements of interest and disinterest in regard to a flower product. In both the fielding house and student IdeaMap® studies, the highest and lowest interest values were for elements from the flower fragrance category, indicating that floral fragrance is an important aspect of flowers with respect to current and future consumer satisfaction. Three distinct segments were identified in each study with the segments being primarily concerned with elements involving olfaction, visual, and other attributes of a flower product.