Cymbidium sinense is a renowned ornamental orchid species appreciated for its captivating floral fragrance. To investigate the molecular mechanisms underlying floral scent formation, we performed an integrated analysis of transcriptomics and metabolomics across five developmental stages and three floral tissues. Metabolomic profiling revealed that (E)-β-ionone is the predominant volatile compound, with its levels fluctuating significantly during flower development and correlating with fragrance intensity. Notably, the sepals and petals were identified as the primary sources of floral scent, with their emission increasing as the flowers bloomed. Transcriptomic analysis revealed 1272 differentially expressed genes during the period of significant floral scent enhancement, with most genes, including CsCCD4, enriched in metabolic pathways and secondary metabolite biosynthesis. Weighted gene co-expression network analysis (WGCNA) identified CsCCD4 as a central hub gene, closely associated with (E)-β-ionone biosynthetic pathways. Functional validation through stable transformation in tobacco and transient expression in Phalaenopsis petals confirmed that CsCCD4 catalyzes (E)-β-ionone production, promoting floral fragrance accumulation. Additionally, yeast one-hybrid screening, dual luciferase, electrophoretic mobility shift, and protoplast assays showed that CsKHZ1, a zinc finger transcription factor, binds the CsCCD4 promoter and activates transcription, reported here for the first time. These findings suggest that the CsKHZ1-CsCCD4 module regulates (E)-β-ionone accumulation and enhances floral fragrance in C. sinense. This study provides a deeper understanding of the molecular networks governing floral scent formation and offers valuable genetic resources for future breeding programs aimed at enhancing fragrance traits in orchids. Moreover, the identification of key regulatory genes holds potential for biotechnological applications in the production of high-value volatiles.

Chinese orchids (Cymbidium spp.) are high-value ornamental plants, renowned for their elegant flowers, leaf variegation, and distinctive fragrance. However, their low transformation efficiency and prolonged regeneration periods have hindered the functional characterization of key genes in Cymbidium. To address these challenges, we developed a Tobacco rattle virus (TRV)-mediated virus-induced gene silencing (VIGS) system and a highly efficient Agrobacterium-mediated transient expression system using the Ruby reporter. These systems facilitate efficient transient gene silencing and overexpression in Cymbidium, enabling functional characterization of target genes. Phytoene desaturase (PDS), a visual marker commonly used for VIGS, and the Ruby reporter were selected to validate the system's efficiency. Infiltration with pTRV2-GFP confirmed that TRV can establish systemic infection and movement within Cymbidium plants. Furthermore, inoculation with pTRV2-CsPDS induced distinct photobleaching in leaves, and quantitative real-time polymerase chain reaction analysis confirmed the successful silencing of the endogenous PDS gene. We further optimized the VIGS conditions and identified the optimal parameters as an optical density at 600 nm (OD600) of 1.0 under a negative pressure of 0.06 MPa, followed by dark incubation at 25 degrees C for 24 h, which yielded the highest infiltration efficiency and plant survival rate. Using the Ruby reporter system, we also demonstrated efficient transient overexpression in Cymbidium petals and fleshy rhizomes. Additionally, we established that the optimal infiltration conditions for rhizomes were an Agrobacterium density of OD600 = 0.6 and a 10-min infiltration period. Collectively, the TRV-based VIGS system and the Ruby-based transient expression system offer reliable tools for comparative functional studies, enabling the dissection of molecular mechanisms that underlie key biological processes in Cymbidium.

This study comprehensively characterizes the PEBP gene family in Cymbidium sinense, an orchid with a prolonged vegetative phase that limits its industrial production. Genome-wide analysis identified six CsPEBPs, classified into FT-like, TFL1-like, and MFT-like subfamilies. Evolutionary, gene structure, and collinearity analyses revealed both conservation and lineage-specific diversification of these genes. CsFTL3, a distinctive FT-like member, displayed notably high expression during the bud undifferentiated stage, followed by a sharp downregulation upon floral initiation. Functional studies identified CsFTL3 as a key floral repressor. Heterologous overexpression in Arabidopsis delayed flowering time from 32.0 days (wild-type) to 63.0-75.3 days (transgenic) and increased rosette leaf number from 12.6 to 33.0-34.5, while its knockdown via virus-induced gene silencing (VIGS) in C. sinense accelerated floral bud development and upregulated flowering-promoter genes. Phylogenetically, CsFTL3 falls within the flowering repressor FT-I clade, and multiple sequence alignment identified critical amino acid substitutions (Y134S, W138L, Q140E) that likely underpin its functional divergence from typical flowering promoters. Furthermore, promoter analysis revealed an enrichment of light-, hormone-, and stress-responsive cis-elements, and its expression was modulated by gibberellin (GA), abscisic acid (ABA), and low-temperature treatments. Predicted protein-protein interaction and transcriptional regulatory networks provide preliminary insights into its complex regulation. We conclude that CsFTL3 acts as a crucial floral inhibitor, integrating environmental and endogenous cues to repress flowering. These findings offer fundamental insights into the molecular mechanisms of flowering in orchids and provide a valuable genetic resource for molecular breeding programs aimed at achieving precise flowering time control.

Low temperature is a key environmental cue governing floral transition and inflorescence development in nobile-type Dendrobium, and chilling treatments are routinely applied in horticultural practice to manipulate flowering time. Nevertheless, a robust genetic strategy for modulating flowering independent of temperature signals has yet to be established in this genus. To elucidate the molecular framework through which plants perceive and respond to chilling, we integrated cytological analyses with RNA sequencing (RNA-seq) to characterize transcriptional dynamics and chilling-responsive pathways under different low-temperature regimes. Continuous exposure to chilling markedly hastened floral induction, advancing flowering by nearly 1 month relative to plants maintained under standard growth conditions. Comparative transcriptomic analysis identified 13,708 differentially expressed genes (DEGs) between chilled and control plants. KEGG enrichment revealed strong overrepresentation of pathways related to photosynthesis and plant hormone signal transduction. Further analyses indicated that chilling triggered extensive reprogramming of hormone-related, cold-responsive, and floral-developmental genes. Specifically, low temperature reshaped hormonal homeostasis by elevating transcripts associated with CK and ABA catabolism, stimulating GA biosynthetic enzymes, and repressing JA biosynthesis. Concurrently, chilling suppressed FRI expression, while activating key cold-responsive genes, floral integrators, and meristem identity regulators, including LEA, FT, LFY,AP1, and CAL, collectively accelerated floral transition and organ initiation. These results not only offered actionable insights for horticultural control of flowering time, but also provided a valuable genetic resource for understanding chilling-induced flowering in nobile-type Dendrobium.

This work aims to explore and characterize the functional polysaccharide of Arundina graminifolia. The extraction process of the crude Arundina graminifolia polysaccharides (AGP) was optimized using response surface methodology (RSM). The maximum yield of AGP reached 10.2 % under the optimal conditions of extracting 84.7 min at 96.0 °C, and liquid-material ratio of 27.5 mL/g. Meanwhile, AGP-1, the purified polysaccharide, was obtained using DEAE-Cellulose52 and Sephadex G-200 chromatography, and its structure was analyzed and confirmed by multiple chromatographic and spectroscopic techniques. It was indicated that AGP-1 (Mw 494.3 kDa) was a glucomannan-based polysaccharide mainly consisted of mannose, glucose and galactose at a molar ratio of 10:7:1, and its structure skeleton contained glycosyl residues of Glcp-(1→, →4)-Manp-(1→, →4)-Glcp-(1→, →3,4)-Galp-(1→ and →4,6)-Galp-(1→. Distinct from the β-1,4 glycosidic linkage bonds of other glucomannans, AGP-1 was infrequently linked by α-1,4 glycosidic bonds between monosaccharides of mannose and glucose with a specific molar ratio of 3:2. Furthermore, it was found that AGP-1 exhibited strong DPPH, ABTS, and hydroxyl radicals scavenging abilities, along with excellent inhibition of α-glucosidase activity in vitro. Our finding indicated that AGP-1 possessed a potential as natural antioxidant and hypoglycemic product.

BACKGROUND:Orchids are well-known for their rich diversity of species as well as wide range habitats. Their floral structures are so unique in angiosperms that many of orchids are economically and culturally important in human society. Orchids pollination strategy and evolutionary trajectory are also fantastic human for centuries. Previously, OrchidBase was created not only for storage and management of orchid genomic and transcriptomic information including Apostasia shenzhenica, Dendrobium catenatum, Phalaenopsis equestris, and two species of Platanthera that belong to three different subfamilies of Orchidaceae, but explored orchid genetic sequences for their function. The OrchidBase offers an opportunity for the plant science community to compare orchid genomes and transcriptomes, and retrieve orchid sequences for further study. DESCRIPTION:Recently, three whole-genome sequences of the Epidendroideae species, Cymbidium sinense, C. ensifolium and C. goeringii, were sequenced de novo, assembled, and analyzed. In addition, the systemic transcriptomes of these three species have been established. We included these datasets to develop a new version of OrchidBase 6.0. Furthermore, four new analytical methods, namely regulation, updated transcriptome, advanced BLAST, and domain search, were developed for orchid genome analyses. CONCLUSION:OrchidBase 6.0 extended genetic information to that of eight orchid species and created new tools for an expanded community curation in response to the ever-increasing volume and complexity of data.

The Orchidaceae family, with its unparalleled species diversity among angiosperms, is integral to ornamental, medicinal, cultural, and ecological value. Multi-omics techniques have proven invaluable for the identification of candidate genes and the advancement of functional genomics research. Nevertheless, the application of these technologies in Orchidaceae remains severely limited due to the lack of effective platforms that can integrate and analyze multi-omics data, especially in understanding the mechanisms underlying key traits such as distinctive floral morphology. In this study, we present OrchidMD, the Orchid Multi-omics Database (www.orchidcomics.com), a resource platform that integrates data from five omics layers: genomics, transcriptomics, proteomics, metabolomics, and phenomics, encompassing a total of 213 species. OrchidMD is equipped with 18 specialized statistical and analytical tools, and features a user-friendly interface that facilitates efficient gene mining, multi-omics data exploration, and integrative interactive analysis. A case study on the comprehensive identification of the pan-ARF gene family across Orchidaceae species demonstrates the effectiveness and convenience of OrchidMD. Furthermore, experimental validation further shows that transgenic overexpression of CsiARF04 promotes the differentiation and budding of orchid rhizomes. In addition, another case study using gene editing in orchids, CRISPR Design was employed to predict the CsiPDS target site in Cymbidium sinense. Effective editing was subsequently achieved via Agrobacterium-mediated delivery of the CRISPR/Cas9 vector into leaves. These results underscore OrchidMD's formidable capacity to discern candidate genes associated with salient traits and elucidate their regulatory mechanisms. Thus, OrchidMD serves as a pivotal platform advancing multi-dimensional biological research and functional genomics in orchids.

This study aims to identify and evaluate the phosphate-solubilizing ability of endophytic bacteria isolated from roots of Chinese Cymbidium and to assess their impact on phosphorus uptake and plant growth. Thirty strains of endophytic bacteria were isolated from six orchid varieties. Molecular identification based on 16S rRNA gene sequencing revealed that the most frequently isolated strains belonged to the genera Pseudomonas and Burkholderia. Among them, 10 bacterial strains exhibited the capacity to solubilize inorganic and organic phosphorus. Two strains, designated X1 (Paraburkholderia sp. Beta-32) and X13 (Rhizobium freirei PRF81 (X13), were identified as the most effective phosphate-solubilizing bacteria (PSB). Gluconic acid was the dominant organic acid secreted, driving inorganic phosphorus solubilization, while alkaline phosphatase activities facilitated organic phosphorus mineralization. Inoculation with phosphate-solubilizing bacteria (PSB) resulted in increased plant growth and phosphorus content in both leaves and roots as compared to the control plants. PSB treatments also increased available phosphorus content in soil, reduced total phosphorus content, and increased exopolysaccharide and alkaline phosphatase activities. Real-time q-PCR analysis showed that PSB inoculation significantly upregulated the expression of phosphorus transport-related genes, including PDR2, PHF1, PHR1, PHT1;9, and PHT4;4, thereby enhancing phosphorus absorption. Moreover, strains X1 and X13 not only exhibited strong phosphate-solubilizing capacity but also demonstrated stable colonization in both roots and root rhizosphere soil of orchids over extended periods. In conclusion, the endophytic PSB identified with phosphate-solubilizing abilities increased phosphorus availability and its uptake in Chinese Cymbidium, thereby promoting plant growth and development. This is the first attempt to characterize endophytic PSB from roots of Chinese Cymbidium orchids. These findings provide a basis for selection of PSB that are efficient in P uptake for application in microbial fertilizers for orchid cultivation.

Background: Research on orchids has experienced substantial growth since the early 20th century, reflecting their ecological and evolutionary significance. Methods: This paper provides a comprehensive bibliometric analysis of orchid-related literature published between 1902 and 2024, based on data retrieved from the Web of Science Core Collection™ (WoS). Results: The primary goal is to assess the global research landscape of orchids by identifying key authors, institutions, and journals, as well as major research themes in the field. A thorough analysis of publication trends, citation frequencies, and keyword co-occurrence networks was conducted to uncover significant research hotspots. The findings indicate that orchid research has evolved from foundational topics such as taxonomy and classification to more intricate subjects, including conservation strategies, orchid-pollinator dynamics, and the role of orchids in ecosystem functions. Additionally, biotechnology-related research is emerging as a dominant trend. This study also highlights that China has the highest publication output, while collaboration between the United States and Europe continues to grow. The co-word analysis of keywords suggests that future research is likely to continue to focus on orchid conservation, the impacts of climate change, pollination biology, and symbiotic relationships with mycorrhizal fungi. Conclusions: This review offers valuable insights for researchers and conservationists, helping to identify future research priorities and strategies for the preservation and sustainable use of orchids.

Lilies (Lilium spp.) are important scented cut flowers, with fragrance being one of their most crucial ornamental traits. However, there are few reports on the rapid and efficient detection of postharvest fragrance quality in cut lilies. This study evaluated the floral scents often cut lily cultivars at four stages of aging using HS-SPME-GC-MS and an electronic nose. A total of 51 volatile organic compounds (VOCs) were detected by HS-SPME-GC-MS. Monoterpenoids were the predominant compounds in the fragrances of 'White Present', 'Bai Xue Gong Zhu', 'Manissa', 'Sorbonne', 'Touchstone', 'Robina', and 'Yelloween', while benzenoids/phenylpropanoids were predominant in 'Cali', 'Roselily Isabella', and 'Wanxia'. The electronic nose sensors W1W, W2W, and W5S were more sensitive to the floral scents of these cut lily cultivars. Correlation analysis indicated good consistency between the GC-MS and E-nose detection results (r = 0.79, p < 0.01). PLS-DA and Random Forest analyses highlighted (E)-(1-ocimene, methyl benzoate, eucalyptol, and sensors W2S, W1S, W3S, and W2W as critical elements for differentiating fragrance quality at various stages of cut lilies. Furthermore, PLS regression analysis revealed a significant positive correlation between the W2W sensor and key VOCs, including (E)-(1-ocimene, alpha-terpinene, alpha-phellandrene, terpinolene, (1-myrcene, allo-ocimene, creosol, and cosmen. Additionally, W3S and W6S sensors showed strong positive correlations with methyl tiglate. These sensors can serve as potential markers for the corresponding compound concentrations, indicating that monitoring these sensor responses can rapidly detect the important fragrance compounds in cut lilies. The results provide a potential method for the efficient and rapid detection of postharvest floral scent quality in cut lilies. Utilizing the real-time detection advantage of the electronic nose can enhance the efficiency of postharvest fragrance quality detection in cut lilies by several orders of magnitude.

Cymbidium sinense is a significant traditional Chinese horticultural crop, valued both economically and ornamentally. The APETALA2/ethylene response factor (AP2/ERF) transcription factors play crucial roles in regulating growth, development, cell differentiation, and responses to both biotic and abiotic stresses in plants. However, the regulatory functions of AP2/ERF factors in C. sinense remain poorly understood. In the present study, 116 AP2/ERF genes were first identified from C.sinense genome. Based phylogenetic analysis, these genes were categorized into five groups: AP2, RAV, ERF, DREB, and Soloist. Within the ERF group, two subtypes were identified: ERF (containing six subtypes from ERF B1 to ERF B6) and DREB (containing six subtypes from DREB A1 to DREB A6), consistent with the classification in Arabidopsis. Significant variation was observed in gene exon-intron structures, though motifs and domain structures were highly conserved. Duplication events and collinearity analyses across five species were also conducted. Further investigations into potential cis-elements in promoter regions and expression profiles of 44 different samples, along with the analysis of 11,197 CsAP2/ERF target genes (functional annotation of 9,566), revealed diverse transcriptional regulatory patterns. GO enrichment and KEGG pathway analysis further elucidated these patterns. To validate transcriptome-based predictions, qRT-PCR analysis was performed on ten key CsAP2/ERF genes, showing high consistency with RNA-seq data. Moreover, a yeast one-hybrid (Y1H) assay confirmed that CsAP2_51 directly binds to the promoter of CsAG, a key gene involved in gynostemium development, providing experimental evidence for the regulatory role of CsAP2/ERF in floral morphogenesis. A regulatory model was proposed to illustrate the potential roles of CsAP2/ERF genes in floral patterning and flower color variation. Our findings deepen the understanding of CsAP2/ERF gene functions in C. sinense and provide a valuable foundation for future studies on the molecular mechanisms underlying its growth, development, and ornamental traits.

The SWEET (Sugar Will Eventually be Exported Transporters) protein family plays a key role in plant growth, adaptation, and stress responses by facilitating soluble sugar transport. However, their functions in Cymbidium remain poorly understood. This study identified 59 SWEET genes across four Cymbidium species, encoding conserved MtN3/saliva domains. Despite variations in exon-intron structures, gene motifs and domains were highly conserved. Phylogenetic analysis grouped 95 SWEET proteins from six species into four clades, with gene expansion driven by whole-genome, segmental, and tandem duplications. Cis-element analysis and expression profiling across 72 samples revealed diverse regulatory patterns. Notably, SWEET genes showed peak expression in floral development, leaf morph variations, and diurnal rhythms. qRT-PCR and transcription factor binding analysis further highlighted their regulatory roles in floral patterning, leaf variation, and metabolic rhythms. These findings provide a foundation for future studies on SWEET gene function and their potential molecular breeding value in orchids.

The Lateral Organ Boundaries Domain (LBD) gene family, encompassing plant-specific LOB domain proteins, plays essential roles in various aspects of plant growth and development, and has continuously diversified its functions across numerous species. However, studies on LBD genes in the Orchidaceae family remain limited. To our knowledge, this is the first systematic investigation of the LBD gene family in Cymbidium, a genus that exhibits remarkable species and trait diversity within the Orchidaceae. In this study, we identified 122 LBD genes within the genomes of four Cymbidium species, distributed on 20 chromosomes. These genes were classified into class I (109 members, including 16 in subclass Ic/d) and class II (13 members), with protein lengths ranging from 94—477 amino acids. Promoter sequences of CymLBD genes revealed various cis-elements significant for light, hormonal, biotic, and abiotic stress responses. Transcriptomic analysis revealed tissue- and stage-specific expression of CymLBD genes in Cymbidium, and RT-qPCR and yeast one-hybrid assays indicated that CsiLBD27 may regulate floral patterning by directly binding to the CsiSEP3 promoter and activating its transcription. Under ABA treatment, the genes CsiLBD13, CsiLBD19, and CsiLBD21 displayed tissue-specific expression changes, suggesting hormone-responsive regulation. In Cymbidium ensifolium, 16 CenLBD genes were differentially expressed, while in Cymbidium mannii, 9 CmaLBD gene expression exist obvious circadian rhythm. GO and KEGG enrichment of 1074 and 399 predicted target genes, respectively, indicating a diverse range of functions for LBDs. Collectively, this study provides the first comprehensive insight into the evolutionary dynamics, regulatory mechanisms, and functional roles of LBD genes in Cymbidium. These findings offer a valuable genetic resource for understanding floral and vegetative development in Orchidaceae and uncover potential novel functions of LBD genes.

Floral organ formation plays an essential role in Cymbidium sinense reproductive development and serves as a key determinant of their ornamental traits. During the domestication and natural evolution of C. sinense, numerous floral organ variant cultivars have emerged, among which many floral morphological variations arise from abnormal development of the gynostemium, a reproductive organ. These gynostemium variant (GV) cultivars not only exhibit enhanced commercial appeal but also provide a unique model for investigating floral morphogenesis and evolutionary diversification. In this study, we identified single nucleotide polymorphisms (SNPs) in the promoter region of CsSEP4 closely linked to GV through genome-wide association studies. Functional analyses of CsSEP4 revealed that it played a crucial role in the development of gynostemium. Yeast one-hybrid (Y1H) and dual-luciferase reporter assays indicated that the CsbZIP26 transcription factor binds to the CsSEP4 promoter and activates its expression in normal flowers, whereas the SNP mutations from ACGTG to ATGTG or ACGTA of the CsSEP4 promoter were detected in GV lines, which resulted in the inability of CsbZIP26 to bind and regulate the expression of CsSEP4. Furthermore, DNA affinity purification sequencing (DAP-seq) and Y1H experiments identified CsSPL18 as a direct downstream target of CsSEP4. Genetic evidence also demonstrated that CsSEP4 orchestrates gynostemium development by positively activating CsSPL18 expression. Collectively, our results revealed that the CsbZIP26-CsSEP4-CsSPL18 regulatory module governs the development of stamen gynostemium to regulate flower morphology in C. sinense. These findings provide insight into the molecular mechanisms underlying gynostemium development in orchids and establish a molecular framework for further elucidating orchid diversity and evolution.

Bamboo orchid (Arundina graminifolia), a fast-growing evergreen terrestrial orchid with year-round flowering capacity, exhibits limited germplasm resources for white floral variants despite its ornamental significance. This study investigates the molecular basis of natural white flower formation through comparative analysis of purple- and white-flowered variants across bud, post-bud, and blooming stages. Histological examination revealed anthocyanin accumulation restricted to two to three upper epidermal cell layers in purple petals, while white petals showed complete pigment absence. Transcriptome profiling coupled with RT-qPCR validation identified eleven differentially expressed structural genes in anthocyanin biosynthesis. Notably, AgDFR expression remained undetectable across all white-flower developmental stages. Sequence analysis demonstrated identical 3030 bp promoter regions of AgDFR between two variants, while white-flower AgDFR coding sequences contained over 107 bp insertion after the 330th nucleotide, causing premature translation termination. Molecular marker validation confirmed the presence of a diagnostic 472 bp fragment in all colored variants (13 purple/pink lines) and its absence in white phenotypes. This study establishes that insertional mutagenesis in AgDFR’s coding region underlies natural white flower in A. graminifolia. The developed molecular marker enables reliable differentiation of white-flowered variants from pigmented counterparts, providing valuable tools for germplasm management and breeding programs.

There are nearly 30,000 species of orchids globally, of which over 1,700 species are found in China. Orchids share a profound and intimate connection with Chinese society. With the rapid development of science and technology, China's orchid industry has flourished with many scientific and technological achievements. Here, we summarize the developmental history, current situation, latest research achievements, and industrialization technology of the orchid industry in China, and present a discussion and outlook on the future development direction of orchid research in China. This review unveils new prospects for the high-quality advancement of China's orchid industry.

The Chinese orchids symbolise nobility and gentility in China, and the variation of leaf color makes Cymbidium sinense more diversified and valuable. However, its color variations especially at the protein level still remain largely unexplored. In this study, the proteomics and phosphoproteomics of Cymbidium sinense leaf color variation mutants were studied. A total of 1059 differentially abundant proteins (DAPs) and 1127 differentially abundant phosphorylation sites belonging to 644 phosphoproteins (DAPPs) were identified in the yellow section of leaf variegation mutant of Cymbidium sinense (MY) compared with the green section (MG). Moreover, 349 coexpressing proteins were found in both omics' datasets, while only 26 proteins showed the same expression patterns in the two omics. The interaction network analysis of kinases and phosphatases showed that DAPs and DAPPs in photosynthesis, response to hormones, pigment metabolic process, phosphorylation, glucose metabolic process, and dephosphorylation might contribute to leaf color variation. The abundance of 28 Hsps and 28 phosphorylation sites belonging to 10 Hsps showed significant differences between MG and MY. CsHsp70 was selected to explore the function in Cymbidium sinense leaf variegation. The results showed CsHsp70 is essential for maintaining photosynthetic pigment content and the 399S phosphorylation site is crucial to the function of CsHsp70. Collectively, our findings construct a comprehensive coverage of protein and protein phosphorylation in leaf variegation of C. sinense, providing valuable insights into its formation mechanisms.

Lilies are economically significant crops, and their fragrance is a crucial trait for cut flowers. Different lily varieties exhibit a rich diversity of fragrance profiles. To identify chemical markers associated with sensory attributes, this study screened 36 popular cut lily varieties with varying fragrances. Sensory analysis and HS-SPME-GC-MS were used to evaluate their fragrance characteristics. The aroma intensity evaluation showed that OT and O varieties had stronger fragrances, while LA and L varieties had lower fragrance intensities. LO, L, and LA varieties were preferred by evaluators over O, OA, and OT varieties. However, there was no significant correlation between aroma intensity and hedonic tone. A total of 73 VOCs were detected. Methyl benzoate, (3-myrcene, (E)-(3-ocimene, allo-ocimene, ethyl benzoate, and (Z)-caryophyllene were present in the fragrances of most varieties. PCA and HCA analyses indicated that the relative emission of volatile organic compounds (VOCs) could effectively distinguish the fragrance characteristics of LO, O, and OT varieties, while the proportion of VOCs emissions could differentiate LA, LO, and OT varieties. PLS regression and jackknife analyses identified that the relative emission and proportion of terpinolene, eugenol, and (E)-isoeugenol were positively correlated with aroma intensity. Linalool (proportion) and cyclopentene, 3-isopropenyl-5,5-dimethyl- were positively correlated with hedonic tone, while methyl salicylate (proportion) was negatively correlated with hedonic tone. These findings provide potential chemical markers for the efficient evaluation of cut lily fragrances and offer references for selecting raw materials for lily fragrance oils and hydrosols.

The seasonal flowering Chinese Cymbidium produce an axillary floral meristem and require a dormancy period during cold conditions for flower development. However, the bud activation mechanism remains elusive. This study evaluates the multi-omics across six stages of flower development, along with functional analysis of core genes to decipher the innate mechanism of floral bud initiation and outgrowth in the Chinese orchid Cymbidium sinense. Transcriptome and proteome analyses identified 10 modules with essential roles in floral bud dormancy and activation. Gene clusters in the early stages of flower development were mainly related to flowering time regulation and meristem determination, while the late stages were correlated with hormone signaling pathways. The metabolome identified 69 potential hormones in which gibberellin (GA) and abscisic acid (ABA) were the main regulatory hubs, and GA4 and GA53 exhibited a reciprocal loop. Extraneous GA application caused rapid elongation of flower buds and promoted the expression of flower development genes. Contrarily, exogenous ABA application extended the dormancy process and ABA inhibitors induced dormancy release. Moreover, CsAPETALA1 (CsAP1) was identified as the potential target of ABA for floral bud activation. Transformation of CsAP1 in Arabidopsis and its transient overexpression in C. sinense protoplasts not only affected flowering time and floral organ morphogenesis in Arabidopsis but also orchestrated the expression of flowering and hormone regulatory genes. The presence of ABA response elements in the CsAP1 promoter, rapid downregulation of CsAP1 after exogenous ABA application, and the activation of the floral bud after ABA inhibitor treatment suggest that ABA can control bud outgrowth through CsAP1.

Aglaonema commutatum is a famous species in the Aglaonema genus, which has important ornamental and economic value. However, its chloroplast genome information and phylogenetic relationships among popular green cultivars of Aglaonema in southern China have not been reported. Herein, chloroplast genomes of one variety of A. commutatum and seven green cultivars of Aglaonema, namely, A. commutatum ‘San Remo’, ‘Kai Sa’, ‘Pattaya Beauty’, ‘Sapphire’, ‘Silver Queen’, ‘Snow White’, ‘White Gem’, and ‘White Horse Prince’, were sequenced and assembled for comparative analysis and phylogeny. These eight genomes possessed a typical quadripartite structure that consisted of a LSC region (90,799–91,486 bp), an SSC region (20,508–21,137 bp) and a pair of IR regions (26,661–26,750 bp). Each genome contained 112 different genes, comprising 79 protein-coding genes, 29 tRNA genes and 4 rRNA genes. The gene orders, GC contents, codon usage frequency, and IR/SC boundaries were highly conserved among these eight genomes. Long repeats, SSRs, SNPs and indels were analyzed among these eight genomes. Comparative analysis of 15 Aglaonema chloroplast genomes identified 7 highly variable regions, including trnH-GUG-exon1-psbA, trnS-GCU-trnG-UCC-exon1, trnY-GUA-trnE-UUC, psbC-trnS-UGA, trnF-GAA-ndhJ, ccsA-ndhD, and rps15-ycf1-D2. Reconstruction of the phylogenetic trees based on chloroplast genomes, strongly supported that Aglaonema was a sister to Anchomanes, and that the Aglaonema genus was classified into two sister clades including clade I and clade II, which corresponded to two sections, Aglaonema and Chamaecaulon, respectively. One variety and five cultivars, including A. commutatum ‘San Remo’, ‘Kai Sa’, ‘Pattaya Beauty’, ‘Silver Queen’, ‘Snow White’, and ‘White Horse Prince’, were classified into clade I; and the rest of the two cultivars, including ‘Sapphire’ and ‘White Gem’, were classified into clade II. Positive selection was observed in 34 protein-coding genes at the level of the amino acid sites among 77 chloroplast genomes of the Araceae family. Based on the highly variable regions and SSRs, 4 DNA markers were developed to differentiate the clade I and clade II in Aglaonema. In conclusion, this study provided chloroplast genomic resources for Aglaonema, which were useful for its classification and phylogeny.