Fragrant Flowers Research Articles

Identification and Characterization of CCD Gene Family in Rose (Rosa chinensis Jacq. ‘Old Blush’) and Gene Co-Expression Network in Biosynthesis of Flower Scent

Rose (Rosa sp.) is a widely used raw material for essential oil extraction and fragrance production. The carotenoid cleavage dioxygenases pathway is one of the main metabolic pathways for the degradation of carotenoids, which is located downstream of the terpenoids biosynthesis pathway and is closely related to the biosynthesis of volatile compounds. We performed a comprehensive genome-wide analysis of the rose CCD family genes (RcCCDs) in terms of phylogeny, sequence characterization, gene structure, gene duplication events, and transcriptome. Finally, 15 CCD family members were identified from the rose genome, and they were classified into three clades: nine for the CCD clade, four for the NCED clade, and two for the CCD-LIKE clade. The RcCCDs were distributed on chromosomes 1, 4, 5, 6, and 7, and were concentrated on both ends of the chromosomes. RcCCDs did not have paralogous genes or whole genome duplication events (WGD), eleven of them were single-copy genes, and their repetitive sequences were mainly dispersed and tandem. Ten RcCCDs were differentially expressed in the transcriptomes of different flowering stages. The expression of four of them increased and then decreased, which was the same process as the accumulation of volatile compounds, and it was speculated that these genes might be involved in the biosynthesis of volatile compounds. A total of fifteen modules were obtained by weighted gene co-expression network analysis of eighteen volatile compounds-related genes, of which six modules were a highly significant positive correlation with volatile compounds, and 20 hub genes in the modules were predicted. These hub genes all exercised their functions in the early flowering stage with strict temporal specificity. This study provided a theoretical basis for further exploring the biological functions of RcCCDs and hub genes regulating the synthesis and metabolism of volatile compounds in rose.

‘An aid to loveliness’: lavender, femininity and the affective economy of English beauty

By considering the cultural production, placement, promotion and personalization of a fragrant aromatic, this article attempts to compile a historical geography of lavender and loveliness. The purpose of this experimental exercise is threefold. First, to examine the emergence of modern affective economies based around fashioning the self, directed at women's physical appearance and delineating desirable new standards of femininity. Second, to interrogate how the mid twentieth century beauty industry formulated the new concept of facial skincare in which ideas of a healthy complexion was complexly encoded with an aesthetic of whiteness. Third, to understand how the exercise of researching and writing such a sensory history is a means to address the challenges which non-representational theory has raised for scholarship in historical geography. Empirically, the article focuses on the operations of the House of Yardley, one of London's oldest perfumeries and beauty companies, and its foremost perfumier-cosmetician of the modern era, W.A. Poucher. To explore how the scent of lavender was deployed in markets globally, promoting a selectively English version of loveliness, it travels to various points along the supply line between the fragrant flower and female face.

The Jasmine (Jasminum sambac) Genome Provides Insight into the Biosynthesis of Flower Fragrances and Jasmonates

Jasminum sambac (jasmine flower), 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 novogenome assembly of J. sambac with 550.12 Mb (scaffold N50 = 40.10 Mb) assembled into 13 pseudochromosomes. Terpene synthase (TPS) genes associated with flower fragrance are considerably amplified in the form of gene clusters through tandem duplications in the genome. Gene clusters within the salicylic acid/benzoic acid/theobromine (SABATH) and benzylalcohol O-acetyltransferase/anthocyanin O-hydroxycinnamoyltransferases/anthranilate N-hydroxycinnamoyl/benzoyltransferase/deacetylvindoline 4-O-acetyltransferase (BAHD) superfamilies were identified to be related to the biosynthesis of phenylpropanoid/benzenoid compounds. Several key genes involved in jasmonate biosynthesis were duplicated, causing an increase in copy numbers. In addition, multi-omics analyses identified various aromatic compounds and many genes involved in fragrance biosynthesis pathways. Furthermore, the roles of JsTPS3 in β-ocimene biosynthesis, as well as JsAOC1 and JsAOS in jasmonic acid biosynthesis, were functionally validated. The genome assembled in this study for J. sambac offers a basic genetic resource for studying floral scent and jasmonate biosynthesis, and provides a foundation for functional genomic research and variety improvements in Jasminum.

ДАГЕСТАНСКИЕ СОРТА ВИНОГРАДА ГОК ИЗЮМ И ХОЦА ЦИБИЛ НА КОЛЛЕКЦИИ В НИЖНЕМ ПРИДОНЬЕ

The results of observations and studies of the autochthonous Dagestan grapevine varieties Gok Izyum and Khotsa Tsibil, the control variety Riesling Reinskiy, are presented. The studies were carried out on the Don ampelographic collection named after Ya.I. Potapenko (Novocherkassk, Rostov region). Varieties were studied in grafted covering culture. The Gok Izyum variety in the conditions of Novocherkassk had an average ripening period, had 60% of fruitful shoots, an average bunch weight of 260 g, and a yield of 80 c/ha. Dry white wine from this variety was pale straw with a slight greenish tint. It had a bright aroma of field herbs, honey and fruits, which over time is transformed into noble tones of aging. Wine tasting score 8.5 points. Variety Khotsa Tsibil in the conditions of Novocherkassk had a medium-late ripening period, had 62% of fruit-bearing shoots, an average bunch weight of 235 g, a yield of 100 c/ha. Dry white wine from this variety had a pale straw color with a greenish tint, had a delicate aroma of flowers and fruits. The taste is delicate, elegant with a spicy bitterness. Has the potential to endure. Wine tasting score 8.5 points. The control variety Risling Rejnskij average ripening period, 66% of fruit-bearing shoots, an average bunch weight of 100 g, and a yield of 46 c/ha. Wine of pale straw color with a greenish tint, rich aroma with tones of field herbs and flowers, turning into taste. The taste is full, harmonious. Degustation score of wine 8.7 points. The studied varieties Gok Izyum and Khotsa Tsibil were superior in average bunch weight and yield to the control variety Risling Reinskiy, but not significantly inferior in quality of wine products (8.5 and 8.7 points, respectively), therefore, we believe that these studied varieties are promising for high-quality winemaking. Research in this direction will be continued.

Bebida alcohólica a base de aguaymanto (Physalis peruviana) y tomate de árbol (Solanum betaceum): Caracterización química y sensorial

Golden gooseberry (Physalis peruviana) and tree tomato (Solanum betaceum) have bioactive components, which open up the possibility of finding new ways to industrialize them. The objective of the study was to report the chemical and sensory characterization of a new alcoholic beverage produced by mixtures of Physalis peruviana and Solanum betaceum fruits, through fermentation with Saccharomyces cerevisiae (Ale) and Saccharomyces pastorianus (Lager). The physicochemical characterization of the beverages obtained was determined by basic parameters such as alcoholic degree, pH, density, total soluble solids, which were analyzed using: the AOAC "Official Methods of Analysis". Total carotenoids were analyzed according to: mg b-carotene eq/100g; the total phenolic compounds were determined under the Folin Ciocalteus protocol; the color characteristics (L*, a* and b*) using computer vision and Python data analysis. The sensory characterization was established with the help of 60 panelists, who evaluated 8 characteristics (flower aroma, nut aroma, wood aroma, astringency, body, flower odor, nut odor, and wood odor). Through a principal component analysis (PCA) and clustering analysis, it was shown that the fermented Ale-25AG-75BE and Ale-50AG-50BE, presented greater preference with 60 and 80%, being represented by Clusters 3 and 4. Finally, this study shows the feasibility of using mixtures of goldenberry and tree tomato to produce fermented alcoholic beverages, which could be inserted into the market as a new product.

In vitro seed germination and acclimatization of Encyclia cordigera (Kunth) Dressler

• 100% germination of E. cordigera was achieved in MS ½-strenght + 0,15 g L-1 Ac. • Efficient protocols for in vitro propagation and acclimatization of E. cordigera were established. Encyclia cordigera is a Mexican native orchid, of major ornamental importance due to its beautiful and fragrant flowers. The said characteristics also create a risk for the extinction of the species, thus, the urgent necessity to stablish propagation strategies to prevent its loss. The objective of this study was to establish a protocol for asymbiotic seed germination and acclimatization of E. cordigera . For asymbiotic germination, different concentrations (¼ and ½ and full-strength) of MS medium were evaluated, adding 0.15% of activated charcoal (AC). MS medium without AC was used as a control treatment. The germination percentage was evaluated after 16 weeks of culture. The treatments used for the germination stage were also used for the development of seedlings which lasted 20 weeks, then plant length, number of roots, root length, number of shoots, and number of leaves per shoot were measured. Finally, the plants obtained were acclimatized. The ½-strength MS + 0.15% AC resulted in 100% seed germination, while ¼-strength MS + 0.15% AC yielded longer seedlings (1.53 cm long). As for the number and length of roots, MS + 0.15% AC proved to be the best medium, with 2 roots and 2 cm respectively. No significant differences between culture media were found for the number of shoots and number of leaves per shoot. The plants obtained were transferred to an acclimatization process for eight weeks in the greenhouse, 209 plants (97% survival rate) were obtained during the acclimatization process. The presented protocols will contribute to the propagation and conservation of E. cordigera , an orchid species with ornamental and economic importance.

Genomic, metabonomic and transcriptomic analyses of sweet osmanthus varieties provide insights into floral aroma formation

Sweet osmanthus is an important ornamental evergreen tree or shrub, which has been widely used in the world's subtropical landscapes and the fragrance industry due to its deliciously fragrant flowers. In this study, whole-genome resequencing, RNA sequencing, and GC-MS analysis were used to compare 30 accessions of Osmanthus fragrans to gain insights into taxonomic classification and the diversity of volatile floral scents. A total of 13,466,389 high confidence SNPs were identified from the accessions with an average sequencing depth of 16.96 × . Phylogenetic analysis of the sequences of the 30 ancient or improved O. fragrans genotypes with diverse origins could be roughly divided into two differentiated sweet osmanthus populations, corresponding to the autumn-flowering and the four-seasons flowering characteristics. The odor activity values and orthogonal projections to latent structures-discriminant analysis of GC-MS metabolomics data indicated that linalool was one of the most important volatile organic compounds (VOCs) which can determine the scent diversity among different sweet osmanthus cultivars. Weighted gene co-expression network analysis (WGCNA) identified 23 distinct modules, four of which were highly associated with important floral VOCs. Based on WGCNA analysis, a critical enzyme gene OfHDR2.1 in the MEP pathway and its 12 co-expression transcription factors from the turquoise module were considered to play important roles in linalool synthesis among differently scented O. fragrans populations. Thus, our study provided new clues for the classification of O. fragrans cultivars and valuable genetic resources for future molecular breeding of O. fragrans accessions improved with respect to floral aroma.

Floral traits and reproductive biology of two Mediterranean species of Clematis, asynchronous and sympatric, are key food sources for pollinator survival

• We reveal the floral trends and reproductive biology of two Mediterranean Clematis species. • Volatile compounds were sampled using a SPME-HS followed by GC–MS. • 90% of the volatile compounds were monoterpenes in both species. • Pollen supply and nectar production are important for pollinators during critical periods. • Hedges plant formations play an essential role in the conservation of pollinators and act as a linking semi-natural environment and farmland. Clematis cirrhosa L. and C. flammula L. (Ranunculaceae) are perennial climbing species, that are sympatric and that bloom in two different seasons: winter and summer. Both have colourful flowers representing the two types of Clematis flowers present in the Western Mediterranean basin: bell-shaped and disc-shaped flowers, respectively. This morphological and positional diversity encourages the comparative analysis of their reproductive biology, as well as the profiles of their floral volatiles. Morphological floral traits and the shape of flowers are different and are highly correlated with the rainy season pollinator's availability. Both species exhibit facultative autogamy. Volatile compounds were extracted using a standardised solid-phase microextraction of headspace (SPME-HS) followed by gas chromatography and mass spectrometry (GC-–MS). The spectrum of flower scents highlights the importance of monoterpenes (93% in C. cirrhosa and 99% in C. flammula ) as the major components identified in both species. The study helps to explain the relationship between the floral shape, the pollination system, and the reproductive characteristics of Clematis . In addition, these two species act as food reservoirs for pollinators supplying pollen and nectar in critical periods of the year when resources are scarce. The two species play an important role in maintaining the populations of Apis mellifera, Bombus terrestris , and other seasonal pollinators.

A novel genome sequence of Jasminum sambac helps uncover the molecular mechanism underlying the accumulation of jasmonates.

Jasminum sambac is a well-known plant for its attractive and exceptional fragrance, the flowers of which are used to produce scented tea. Jasmonate (JA), an important plant hormone was first identified in Jasminum species. Jasmine plants contain abundant JA naturally, of which the molecular mechanisms of synthesis and accumulation are not clearly understood. Here, we report a telomere-to-telomere consensus assembly of a double-petal J. sambac genome along with two haplotype-resolved genomes. We found that gain-and-loss, positive selection, and allelic specific expression of aromatic volatile-related genes contributed to the stronger flower fragrance in double-petal J. sambac compared with single- and multi-petal jasmines. Through comprehensive comparative genomic, transcriptomic, and metabolomic analyses of double-petal J. sambac, we revealed the genetic basis of the production of aromatic volatiles and salicylic acid (SA), and the accumulation of JA under non-stress conditions. We identified several key genes associated with JA biosynthesis, and their non-stress related activities lead to extraordinarily high concentrations of JA in tissues. High JA synthesis coupled with low degradation in J. sambac results in accumulation of high JA under typical environmental conditions, similar to the accumulation mechanism of SA. This study offers important insights into the biology of J. sambac, and provides valuable genomic resources for further utilization of natural products.

Epigenetic changes in the regulation of carotenoid metabolism during honeysuckle flower development

Flower development is one of the most vital pathways in plant development, during which the epigenetic regulation of gene expression is essential. DNA methylation, the most conserved epigenetic modification, participates in gene expression regulation and transposable element silencing. Honeysuckle (Lonicera japonica) is an important medicinal plant renowned for its colorful and fragrant flowers. Honeysuckle flowers change color from white to gold as a result of carotenoid accumulation during development. However, the role of DNA methylation in flower color changes is not well understood in L. japonica. Here, we performed whole-genome bisulfite sequencing and transcriptome sequencing during flowering development in honeysuckle. The results showed that a decrease in the levels of genome-wide average DNA methylation during flower development and changes in DNA methylation were associated with the expression of demethylase genes. Moreover, many genes involved in carotenoid biosynthesis and degradation, such as LjPSY1, LjPDS1, LjLCYE, and LjCCD4, have altered expression levels because of hypomethylation, indicating that DNA methylation plays an important role in flower color changes in honeysuckle. Taken together, our data provide epigenetic insights into flower development and color change in honeysuckles.

A long-flowering Hechtia (Bromeliaceae): Hechtia sanchezii, a new species from San Luis Potosí, Mexico

Background: Hechtia is known among Bromeliaceae by its unisexual, sexually dimorphic, mainly fragrant flowers and dioecy; delimitation of taxa particularly on those with lateral inflorescence, requires qualitative morphological evidence from both sexes, because dimensions of structures change during its growth.
 Hypotheses: Hechtia species are delimitated based on a combination of discrete morphological characters from both sexes, associated with narrow geographical distributions. If examination of populations of San Luis Potosí shows characters that place the taxon in the genus and distinguish it from other species in Hechtia, the taxon will be described as new.
 Taxon: Hechtioideae, Hechtia sp. nov.
 Study site and dates: Mexican State of San Luis Potosí and vicinities, 2015-2021.
 Methods: Live plants as well as herbarium material of the new taxon and the most morphological similar species, were analyzed, with examination of inflorescences and flowers of both sexes, fruits, and seeds. Geographical distribution was mapped and conservation status using IUCN criteria is reported for the new species.
 Results: Hechtia sanchezii has been confused with H. glomerata since both share lateral, glomerulate-like infructescences, but H. sanchezii shows red to ferruginous indumenta on floral bracts and sepals (vs. white), these red (vs. greenish or brownish), pink petals (vs. white), scentless (vs. fragrant) flowers, stamens with filaments of two lengths, three epipetalous, and three alternating with petals (vs. two lengths but all filaments epipetalous).
 Conclusions: Morphological and geographical evidence allow the recognition of H. sanchezii as a new species native from San Luis Potosí, Mexico.

First report of Phytophthora blight caused by Phytophthora nicotianae on Daphne odora in China.

The variegated leaves and fragrant flowers of Daphne odora var. marginata Mak. make it a popular garden plant. In May 2020, we found diseased D. odora plants in a greenhouse at the Ganzhou Vegetable and Flower Research Institute, in southeast China; 72% of 1800 plants had Phytophthora blight-like symptoms-shrunken stems, black withered branches, wilted and dropped leaves (Fig 1a), and rotted and dark green roots. The root and stem tissue surfaces were disinfected with 75% ethanol for 30s followed by 0.1% HgCl2 for 1min, rinsed thrice with sterile water, and cultured on potato-dextrose agar (PDA) medium at 25°C. Mycelia from the diseased tissue were subcultured on fresh PDA medium, providing three colonies. White colonies (~4.1mm) were formed after 10 days at 25°C (Fig 1b). Sporangia and chlamydospores were induced by placing actively growing mycelia on PDA medium at 25°C for ~30 days and then at 45°C for ~3 days. Sporangia were ovoid to spherical and 19.33 × 20.99µm in size (Fig 1c), whereas chlamydospores were spherical and 15.68 × 16.10µm in size (Fig 1d). All three colonies resembled Phytophthora spp. Genomic DNA was extracted from isolates using the Ezup Column Fungi Genomic DNA Purification Kit (Sangon Biotech [Shanghai] Co. Ltd.), and rDNA-ITS and β-tubulin were amplified and sequenced. BLAST analysis (GenBank) revealed that the ITS (Accession No. MZ676071) and β-tubulin (MZ748503) sequences of isolates shared the highest similarity (99-100%) with those of Phytophthora nicotianae (Duccio et al. 2015). A phylogenetic tree of the relationship between our isolate hjt3 and its close relatives within the P. nicotianae species was constructed using the MEGA X neighbor-joining method (Fig 2). The pathogen was identified as P. nicotianae based on morphological and molecular characteristics. Sequencing results of the three samples were consistent, all indicating P. nicotianae. A specimen (JXAU-H2020245) was deposited in the Herbarium of the College of Agronomy, Jiangxi Agricultural University. To confirm pathogenicity, 9-month-old healthy D. odora plants were used for stem and soil inoculation. Stems were cut ~5 cm from the soil with sterilized scalpels and inoculated with 0.8 cm diameter PDA plugs containing actively growing mycelia of isolate hjt3. The soil was sterilized and 0.8 cm PDA plugs containing actively growing mycelia were buried in the soil at ~5cm; the mycelia were in contact with the roots. Plants in both groups were treated equally; those inoculated with sterile PDA plugs served as controls. There were six plants in each group, with each experiment performed in triplicate. All plants were incubated in a greenhouse at 25-28°C. The stems shrank and began to rot rapidly after 7 days (Fig 3) and the branches turned black and withered within 2 weeks. After soil inoculation, the stems of the inoculated plants blackened and rotted in ~20 days (Fig 4) and the roots rotted and turned dark green (Fig 5). These symptoms rapidly spread to the branches. The control plants did not exhibit any symptoms. Reisolated colonies showed the same morphological traits as the isolates used for inoculation; no target colonies were isolated from the control plants. Phytophthora blight caused by P. nicotianae on D. odora has been reported in Italy (Garibaldi A, 2009) and Korea (Kwon et al. 2005). This is the first detection in China. Therefore, Phytophthora blight on D. odora caused by P. nicotianae should be monitored and controlled to promote the development of the D. odora industry.

Transcriptome analysis identifies key gene LiMYB305 involved in monoterpene biosynthesis in Lilium 'Siberia'.

Lilium is a popular cut flower that is highly favored by consumers due to its snowy white color and strong fragrance, which originates from the release of monoterpenes. However, the underlying molecular mechanism of monoterpene synthesis remains poorly understood. In this study, the content of three main monoterpenes (linalool, ocimene, and myrcene) was examined in Lilium 'Siberia', and RNA sequencing of the 11 stages of flower development was conducted. The biosynthesis of the three monoterpenes increased with flower development, reaching their peak levels at the full flowering stage. Transcriptome data revealed 257,140 unigenes, with an average size of 794 bp, from which 43,934 differentially expressed genes were identified and enriched in the KEGG pathways partly involved in plant hormone signal transduction and monoterpenoid biosynthesis. Furthermore, the essential factor LiMYB305 was identified by WGCNA after the release of the flower fragrance. The transient silencing of LiMYB305 in petals using VIGS technology showed that the mRNA expression levels of LiLiS, LiOcS, and LiMyS were significantly downregulated and that the release of linalool, ocimene, and myrcene had decreased significantly. Y1H, LUC, and EMSA experiments revealed that LiMYB305 directly bound and activated the LiOcS promoter to increase the synthesis of monoterpenes. Taken together, these results provide insight into the molecular mechanism of monoterpene synthesis and provide valuable information to investigate the formation of the flower fragrance in Lilium.

Integrative analysis of transcriptomic and volatile compound profiles sheds new insights into the terpenoid biosynthesis in tree peony

Tree peony (Paeonia suffruticosa Andr.), a traditional Chinese ornamental plant, is famous for its large, colorful, and fragrant flowers. Studies on tree peony have mainly focused on the improvement of flower color and the regulation of the flowering stage, but the molecular mechanisms controlling the formation of floral fragrance has yet to be understood. In this study, the aromatic tree peony variety ‘High Noon’ was used to determine whether volatile compounds (volatiles) in flowers were synthesized at the balloon, initial opening, half opening, or full opening stages. Transcriptomic sequencing was conducted on petals and stamens collected at the balloon and full opening stages. The relative content of linalool peaked during the full opening stage of flowering, and linalool was the main component of flower fragrance. As flowering progressed, the relative content of monoterpenes gradually increased and the relative content of sesquiterpenes gradually decreased. Transcriptome data revealed 23695 differentially expressed genes (DEGs), 142 of which were related to terpene accumulation. Transcriptome analysis and correlation analysis between floral volatiles and gene expressions showed that, 1-deoxy-d-xylulose 5- phosphate synthase (DXS), 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR), acetyl-CoA acetyltransferase (AACT), geranyl pyrophosphate synthase (GPPS), and terpene synthase (TPS) may be major regulators controlling floral terpene biosynthesis in ‘High Noon’. And PsGPPS may regulate the expression of GPPS, and then participate in the synthesis of terpenes. This study provides a possible molecular mechanism for terpene formation in tree peony ‘High Noon’ flowers as well as a theoretical basis upon which to study tree peony flowers.

Standardization of callus induction in danthapala (Wrightia tinctoria R.Br.)

Wrightia tinctoria R.Br. (Family: Apocynaceae) commonly called “Indrajau” is distributed throughout the world and occurs abundantly in India. It is a deciduous tree with white fragrant flowers. The seeds and bark of this plant are used in Indian traditional medicine as anti-diarrheal, anti-dysenteric and also for the treatment of psoriasis. Callus induction is an important stage in micropropagation and was largely influenced by the medium, plant growth regulator, and explant.The present study was conducted at Onattukara Regional Agricultural Research Station, KAU, Kayamkulam to standardise the media for callus induction. The results revealed that callus induction from nodal segments started 20 days after inoculation and was high in MS medium containing BA 1 mg l-1 and 2,4-D 1.5 mg l-1. The callusing from the leaf started within 25 days after inoculation. It shows best in MS medium containing 1 mg l-1 NAA and 2 mg l-1 2,4-D.

Detection of Volatile Compounds of (Hyacinth Flowers Hyacinthus orientalis L.) from Turkey

Hyacinth (Hyacinthus orientalis L.) is one of the most beloved ornamental plants with fragrant flowers. As one of the important bulbous plants, hyacinth is used as a cut flower, potted flower, and garden flower. Due to their unique aroma, hyacinth flowers are used in perfumery especially in France whose perfume industry is well-known in the world. In this study, Headspace Solid Phase Micro Extraction (HS-SPME) GC/MS (Gas Chromatography/Mass Spectrometry) technique was used for the analysis of volatile compounds of flower samples. A total of 28 volatile compounds were identified in the fresh flowers of hyacinths. Phenylethyl alcohol, benzyl acetate, a-pinene, and furfural were the major aromas accounting for hyacinth fragrance.

First report of Fusarium solani (FSSC 6) associated with the root rot of Magnolia denudata in China.

Magnolia denudata (Lilytree or Yulan magnolia) is an important ornamental species of the genus Magnolia. It has considerable economical value because of its beautiful fragrant flowers and excellent tree structure (Wang et al. 2010). In Beijing, nurseries cultivate M. denudata as an ornamental plant and traditional medicine. In May 2020, patches of root rotted plants were observed in a field in Beijing, China, with an estimated incidence of approximately 31%. Early symptoms comprised leaves melanocratic shrunken, and the vascular tissue of roots turned brown. Progressively, the roots rotted and the whole plant died (Fig. 1 a-d). Infected roots tissue was surface disinfested and plated on potato dextrose agar (PDA) medium at 25±2 °C and incubated in the dark for 7 days. Pure cultures were obtained by hyphal tip excision (strain MFR1215.4). Fungal colonies were entire margins, and the aerial mycelium was copious, early white, and gradually developed into cream white. Colonies developed to 45.1 mm in 4 days at 25±2 °C on PDA media. On Spezieller Nährstoffarmer Agar (SNA) medium at 25±2 °C for 10 days. The morphological characteristics including macroconidia, microconidia, and chlamydospores were shown in Fig.1 (i-p). These morphological characteristics of the isolate corresponded to the description given for Fusarium solani sensu lato (Nelson et al. 1983, Summerell, 2003). Molecular identification was confirmed via amplification of translation elongation factor 1α (EF-1α), RNA polymerase I beta subunit gene (RPB1), and RNA polymerase II beta subunit gene (RPB2) regions using EF1/EF2, RPB1-Fa/G2R, RPB2-5f2/7cR, and RPB2-7cF/11aR primers (O'Donnell, 2010). Sequences were registered in GenBank. In the Fusarium-ID database, the EF-1α, RPB1, and RPB2 sequences showed 100% (677/677 bp), 99.8% (1568/1571 bp), and 100% (1457/1457 bp) identity with the F. solani species complex (FSSC). The same species-level identification was also found using Fusarium MLST. A best maximum likelihood tree was constructed using PhyloSuite v1.2.2 (Zhang et al. 2020), and the sequences of the MFR1215.4 isolation showed the same homology with FSSC 6. Pathogenicity tests were conducted on healthy one-year-old M. denudata potted seedlings. 200 ml spore suspension (1×106 spores/ml) was poured over the roots of twenty seedlings, and sterile distilled water was irrigated into twenty seedlings as controls in a greenhouse with 25/15°C day/night temperature and 80% relative humidity. The experiment was repeated three times. All inoculated seedlings showed similar symptoms to those in the field after 65 days, whereas the controls remained symptomless. The reisolating pathogens from symptomatic tissues were identical to the original isolates by morphology and EF-1α sequence identification. Based on morphological, molecular, and pathogenic characterization, the isolated pathogen was identified as FSSC 6. Fusarium species have been recorded in various places of the world and are known to be harmful to numerous plants (Trabelsi et al. 2017). It has been reported that FSSC has infected soybeans (Coleman, 2016, Nelson et al. 1989), oil palm (Hafizi et al. 2013), tobacco (Yang et al. 2020), resulting in sudden death syndrome, crown disease, and root rot. To our knowledge, this is the first report of FSSC-induced root rot in M. denudata in China. This research may contribute to the development of epidemiology and management strategies for root rot caused by FSSC on M. denudata.

More than Moths: Flower Visitors of a Night-Blooming Plant in South Florida Pine Rocklands, USA.

Plants whose flowers open at night but remain open during the day also attract diurnal flower visitors, potentially boosting their pollination rates and providing resources that can support diverse arthropod communities. The rough-leaf velvetseed, Guettarda scabra (Rubiaceae), is an evergreen shrub that thrives only in the imperiled pine rockland habitat in south Florida. Its white, tubular, and fragrant flowers open during late afternoon, exhibiting traits strongly associated with the attraction of nocturnal hawkmoths (Sphingidae). Flowers of G. scabra remain open until the following morning, becoming available to a wider array of visitors, bringing into question the expectation that sphingophilous flowers are visited mainly by hawkmoths. To evaluate whether the flowers of G. scabra are mainly visited by nocturnal hawkmoths and understand the role of this plant in the pine rockland habitat, we characterized the arthropod fauna associated with its flowers during the morning, evening, and at night. We found that most flower visitors were diurnal insects of the orders Hymenoptera and Lepidoptera, although we observed other arthropod groups too. Visitation at night was dominated by two species of hawkmoths. Nectar was the main resource used by the arthropod community during this study. Legitimate visitation and nectar-robbing were the behaviors most frequently observed among the flower visitors. Our results suggest that flowers of the night-blooming G. scabra constitute an important food source for both diurnal and nocturnal arthropod fauna in the fire-dependent pine rocklands of southern Florida. Our study provides novel data to support efforts to conserve and protect pine rocklands and the plants and animals that inhabit them.

The genome of single-petal jasmine (Jasminum sambac) provides insights into heat stress tolerance and aroma compound biosynthesis.

Jasmine [Jasminum sambac (L.) Aiton] is a commercially important cultivated plant species known for its fragrant flowers used in the perfume industry, medicine and cosmetics. In the present study, we obtained a draft genome for the J. sambac cultivar 'Danbanmoli' (JSDB, a single-petal phenotype). We showed that the final genome of J. sambac was 520.80 Mb in size (contig N50 = 145.43 kb; scaffold N50 = 145.53 kb) and comprised 35,363 genes. Our analyses revealed that the J. sambac genome has undergone only an ancient whole-genome duplication (WGD) event. We estimated that the lineage that has given rise to J. sambac diverged from the lineage leading to Osmanthus fragrans and Olea europaea approximately 31.1 million years ago (Mya). On the basis of a combination of genomic and transcriptomic analyses, we identified 92 transcription factors (TFs) and 206 genes related to heat stress response. Base on a combination of genomic, transcriptomic and metabolomic analyses, a range of aroma compounds and genes involved in the benzenoid/phenylpropanoid and terpenoid biosynthesis pathways were identified. In the newly assembled J. sambac genome, we identified a total of 122 MYB, 122 bHLH and 69 WRKY genes. Our assembled J. sambac JSDB genome provides fundamental knowledge to study the molecular mechanism of heat stress tolerance, and improve jasmine flowers and dissect its fragrance.

Insights into the Cytochrome P450 Monooxygenase Superfamily in Osmanthus fragrans and the Role of OfCYP142 in Linalool Synthesis.

Osmanthus fragrans flowers have long been used as raw materials in food, tea, beverage, and perfume industries due to their attractive and strong fragrance. The P450 superfamily proteins have been reported to widely participate in the synthesis of plant floral volatile organic compounds (VOCs). To investigate the potential functions of P450 superfamily proteins in the fragrance synthesis of O. fragrans, we investigated the P450 superfamily genome wide. A total of 276 P450 genes were identified belonging to 40 families. The RNA-seq data suggested that many OfCYP genes were preferentially expressed in the flower or other organs, and some were also induced by multiple abiotic stresses. The expression patterns of seven flower-preferentially expressed OfCYPs during the five different flower aroma content stages were further explored using quantitative real-time PCR, showing that the CYP94C subfamily member OfCYP142 had the highest positive correlation with linalool synthesis gene OfTPS2. The transient expression of OfCYP142 in O. fragrans petals suggested that OfCYP142 can increase the content of linalool, an important VOC of the O. fragrans floral aroma, and a similar result was also obtained in flowers of OfCYP142 transgenic tobacco. Combined with RNA-seq data of the transiently transformed O. fragrans petals, we found that the biosynthesis pathway of secondary metabolites was significantly enriched, and many 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway genes were also upregulated. This evidence indicated that the OfCYP proteins may play critical roles in the flower development and abiotic response of O. fragrans, and that OfCYP142 can participate in linalool synthesis. This study provides valuable information about the functions of P450 genes and a valuable guide for studying further functions of OfCYPs in promoting fragrance biosynthesis of ornamental plants.