Search Results (64)

Background/Objectives: Flower color is a core ornamental trait in orchids (Orchidaceae), arising from the biosynthesis, accumulation, and spatial distribution of pigments under multilayered transcriptional regulation. Methods: We performed parallel RNA-seq transcriptomic and widely targeted metabolomic profiling of 15 samples representing five floral tissue/color categories from an F1 population of Cymbidium eburneum (‘Duzhan Chun’) × Cymbidium insigne (‘Meihua Lan’). Results: Across four prespecified pairwise comparisons, 4891 non-redundant differentially expressed genes (DEGs) and 383 non-redundant differentially accumulated metabolites (DAMs) were identified. WGCNA resolved 12 co-expression modules. Recalculation from archived files identified darkseagreen4 as the module most positively associated with red tissues (r = 0.888), lightgreen as the module most positively associated with yellow tissues (r = 0.916), and plum1 as the module most strongly associated with white tissues in the negative direction (r = −0.983). Genes meeting |MM| ≥ 0.80, |GS| ≥ 0.80, MM p < 0.01, and GS p < 0.01 were retained as color-associated candidates. Anthocyanin derivatives including Cyanidin-3-O-sambubioside-5-O-glucoside, Delphinidin-3-rutinoside, and Peonidin-3,5-O-di-β-glucoside were associated with red floral tissues. Conclusions: Integrated analyses consistently highlighted phenylpropanoid and flavonoid biosynthesis, whereas isoquinoline alkaloid enrichment remains hypothesis-generating. These associations nominate candidates but do not establish causal pigmentation regulators. Full article

Basic leucine zipper (bZIP) transcription factors are widely involved in plant development and stress responses. Cymbidium goeringii (Rchb.f.) Rchb.f. is a globally important ornamental orchid whose growth is frequently constrained by extreme heat, yet genome-wide information on its bZIP genes and their responses to heat treatment remains limited. In this study, 67 CgbZIP genes were identified from the C. goeringii genome; 63 were assigned to 10 subfamilies based on phylogenetic relationships, while four remained unclassified. RT-qPCR analysis showed that selected CgbZIP genes displayed different transcript-level responses under heat treatment. CgbZIP4 showed increased transcript abundance under heat treatment, whereas CgbZIP49, CgbZIP50, CgbZIP53, and CgbZIP2 showed reduced transcript abundance. CgbZIP25 displayed a fluctuating expression pattern during the 24 h treatment. Yeast two-hybrid assays supported a possible physical interaction between CgbZIP4 and CgbZIP25 in yeast. These results provide candidate CgbZIP genes for further functional studies of heat-stress responses in C. goeringii. Full article

This study explored the effects of one mineral fertilizer and two microbial inoculants and their combined applications on soil physicochemical properties, bacterial community structure, and plant growth of Cymbidium faberi under potted cultivation, aiming to provide theoretical and technical support for the sustainable cultivation of ornamental orchids. A single-factor randomized block experiment was designed with eight treatments: control (CK), mineral sulfosulfuric acid potassium (HF), Bacillus subtilis (KC), Trichoderma harzianum (HC), mineral sulfosulfuric acid potassium + Bacillus subtilis (HK), mineral sulfosulfuric acid potassium + Trichoderma harzianum (HH), Bacillus subtilis + Trichoderma harzianum (KH), and mineral sulfosulfuric acid potassium + Bacillus subtilis + Trichoderma harzianum (HKH). Plant growth traits, soil properties, and soil bacterial community characteristics were measured. The effects of inoculant agents on Cymbidium faberi growth, soil environment, and bacterial community, as well as their interaction relationships, were systematically analyzed. The combination of three inoculants significantly promoted plant height and leaf thickness in Cymbidium faberi. Compared with CK, the relative abundance of Pseudomonadota and Bacteroidota in HH treatment increased by 6.0% and 11.0%, respectively, while the relative abundance of Acidobacteriota and Verrucomicrobiota decreased by 6.0% and 12.0%, respectively. Venn diagram analysis revealed 146 ASVs shared among all treatments. KC, HC, and HF had more unique ASVs, whereas HK and HKH had the fewest. Principal component analysis (PCA) was used to visualize differences in bacterial community structure. Significant differences among treatments were confirmed using ANOSIM. Ecological network analysis indicated predominantly positive (cooperative) associations among bacterial taxa, with HKH showing the highest proportion of positive edges, suggesting stronger bacterial cooperation. Correlation analysis showed that Patesibacteria, Acidobacterita, and Planctomycetota were significantly negatively correlated with pH and TP, while Bacteroidota, Actinomycetota, and Methylomirabilota were significantly positively correlated with pH. The Mantel analysis revealed a significant positive correlation between bacterial community composition and richness and pH. Further analysis using the structural equation model revealed that soil nutrients and bacterial communities were the main factors affecting plant growth. This study clarifies the response rules of plant growth, soil physicochemical properties and rhizosphere bacterial communities to different mineral fertilizer and microbial inoculant combinations, and provides a practical basis for the rational screening of functional inoculants and the construction of healthy rhizosphere microecosystems in Cymbidium faberi pot cultivation. Full article

Wild orchid populations are declining with intensified habitat fragmentation posing severe challenges to germplasm conservation. As an important ornamental Orchidaceae species, Cymbidium ensifolium has abundant germplasm resources and frequent natural and artificial hybridization. Long-term natural evolution and anthropogenic disturbance have led to complex genetic backgrounds and ambiguous phylogenetic relationships hindering accurate germplasm identification, elite resource excavation, and selective breeding. As a distinctive variety, Cymbidium ensifolium var. susin has great breeding potential. Clarifying its phenotypic and genetic characteristics is crucial for accelerating breeding progress. In this study, phenotypic determination, Hyper-seq reduced-representation genome sequencing, SNP/InDel genotyping, genetic diversity analysis, and core collection construction were used to evaluate the genetic diversity, population differentiation, and core germplasm screening of 13 Cymbidium ensifolium var. susin accessions. The results showed significant phenotypic differences and rich genetic variation among tested materials. Based on highly weighted floral traits, accessions were divided into three major phenotypic groups. At the molecular level, 963,239 SNP and 182,399 InDel loci were identified and mainly distributed in intergenic regions, followed by introns and exons. A phylogenetic tree was constructed from SNP loci combined with principal component and phenotypic clustering analyses. This study preliminarily clarified the genetic structure of pure-heart Cymbidium ensifolium var. susin, showing a distinct geographical pattern: “high consistency in Fujian and Guangdong; strong differentiation in Southwest China; and a transitional gradient in Central China”. Meanwhile, six core germplasm accessions were screened in this study, which provides a solid theoretical basis and material support for the conservation of pure-heart Cymbidium ensifolium var. susin accessions, variety improvement, hybrid parent selection, and molecular marker-assisted breeding. This is of great significance for promoting the innovation of Chinese orchid germplasm resources and the high-quality development of the industry. Full article

Vanilla planifolia, a high-value tropical orchid, is significantly impacted by viral pathogens that threaten its cultivation and productivity. This study employs metagenomic techniques to detect and characterize the viral communities associated with V. planifolia in South Florida. Using high-throughput RNA sequencing, the Cymbidium mosaic virus (CymMV) and Vanilla latent virus (VLV) were prevalent in the plant system, with CymMV being the dominant viral species. Phylogenetic analysis of the CymMV coat protein gene revealed notable genetic divergence in the Homestead isolate, forming a distinct clade from global reference strains, suggesting local adaptation or host-specific evolution. Viral distribution across the plant system revealed higher viral loads in stem tissue, consistent with their role in systemic transport, whereas leaves exhibited greater viral richness, likely due to increased environmental exposure. The low abundance of other viral species, including Garlic viruses and Senna severe yellow mosaic virus, suggests that V. planifolia may harbor a broader range of viral taxa than previously characterized, though these findings represent a preliminary survey of symptomatic plants rather than a comprehensive regional assessment. This study underscores the value of metagenomic approaches for uncovering both well-characterized and novel viruses in plant systems and highlights the need for expanded sampling and continuous viral surveillance to guide disease management strategies in economically important crops such as vanilla. Full article

Background: Cymbidium kanran ‘Zhushalan’ is a famous traditional Chinese orchid with high ornamental and economic value. As its market expands, there is a need to improve its key horticultural traits and stress resistance. Unfortunately, these traits are difficult to breed using traditional methods, and an optimal regeneration and genetic transformation system for C. kanran has yet to be established. Methods: This study evaluated the factors affecting Agrobacterium-mediated genetic transformation and regeneration of C. kanran ‘Zhushalan’ using rhizomes obtained from seedlings as receptor material. Results: The highest regeneration frequency was achieved after pre-cultivating the rhizomes in the dark on ½ MS medium for 10 days. The genetic transformation system was optimized as follows: Agrobacterium strain, EHA105; optimal concentration of Agrobacterium solution, OD₆₀₀ = 0.6; 100 mg·L⁻¹ acetosyringone; an infection time of no more than 40 min; and co-culturing for one to three days. Positive strains were screened using meropenem (15 mg·L⁻¹) and hygromycin (50 mg·L⁻¹) and confirmed through PCR and qRT-PCR. A transformation rate of 11.67% was achieved. Conclusions: An efficient regeneration and genetic transformation system for C. kanran ‘Zhushalan’ has been established for developing transgenic technologies. Our findings will stimulate research on functional genes and molecular breeding related to C. kanran. Full article

Cymbidium eburneum Lindl. is a valuable ornamental orchid and breeding parent, but its genetic background remains unclear due to habitat destruction and germplasm mixing. This study developed specific SSR markers to evaluate the genetic diversity and structure of 96 C. eburneum Lindl. accessions from China and Vietnam. Transcriptome analysis identified 47,248 SSR loci. Sixteen polymorphic core primer pairs detected 150 alleles (mean Na = 9.375) with an average Polymorphism Information Content (PIC) of 0.444. Observed heterozygosity (Ho = 0.290) was noticeably lower than expected (He = 0.478), indicating heterozygote deficiency. UPGMA clustering identified eight groups strongly correlated with geography. Principal Coordinate Analysis (PCoA) revealed a clear geographical differentiation pattern, featuring the most genetically cohesive group from Guangxi and more differentiated geographically marginal populations from Hainan and Vietnam. STRUCTURE analysis (K = 2) indicated two main gene pools with signals of genetic admixture. Geographical isolation was suggested as a potential driver of genetic differentiation. The Guangxi population represents a genetically consistent major reservoir, while marginal populations harbor unique variations. These findings provide a scientific basis for germplasm identification, conservation, and parental selection in C. eburneum Lindl. breeding. Full article

Cymbidium goeringii, an important orchid species, holds significant aesthetic and commercial potential in horticulture. However, stem rot caused by Fusarium oxysporum has emerged as a major biological constraint hindering industry development. In this study, we isolated five endophytic fungal strains from C. goeringii roots—namely, DG3 (Bjerkandera), DG4 (Cylindrocarpon), CLG3 (Talaromyces), CLG6 (Clonostachys), and Z3 (Trichoderma)—and assessed their inhibitory efficacy against stem rot and their potential to promote growth in C. goeringii. In vitro assays indicated that all five fungal strains had the ability to fix nitrogen and produce indole-3-acetic acid, as well as the capability to produce protease and exert broad-spectrum antimicrobial effects. The five endophytic fungal strains exhibited stem rot-resistant effects, among which strain Z3 showed the best inhibitory effect against stem rot, with a control efficacy reaching 68.89%. Treatment of C. goeringii seedlings with these endophytic fungal fermentation broths for 100 d significantly promoted growth compared to the control. The fresh weight increased by 10.53% to 88.16%, and root activity was enhanced by 50% to 162.5%. Additionally, the plant height and the longest leaf length increased by up to 23.68% and 47.50%, respectively, compared to the control. Additionally, the total chlorophyll content was up to 25.34% higher than that of the control group, and the soluble protein content was up to 39.54% higher. The MDA content was reduced by up to 40.23% compared to the control group. These endophytes also regulated the activity of defense-related enzymes in C. goeringii, including delaying the decline in the activities of antioxidant enzymes such as superoxide dismutase, peroxidase, and catalase. These results highlight the potential of these five endophytic fungi as effective agents for managing stem rot in C. goeringii. Full article

Background: Cymbidium goeringii, one of China’s traditional and valuable orchids, possesses significant ornamental and economic value. However, it is relatively sensitive to low temperature and other abiotic stresses, which severely restrict its application in landscaping and industrial development. WRKY transcription factors play important roles in plant responses to abiotic stresses, yet related research in C. goeringii remains limited. Methods: In this study, based on transcriptome data of C. goeringii under four different stresses, we identified and cloned the WRKY transcription factor gene CgWRKY53. Through bioinformatics analysis, quantitative real-time PCR, and heterologous transformation in Arabidopsis thaliana, we systematically investigated its structural characteristics, expression patterns, and function under cold stress. Results: The full-length CDS of CgWRKY53 is 1080 bp, encoding a protein of 359 amino acids with a molecular weight of 39.95 kDa. Group III subfamily of the WRKY family, possessing the conserved WRKYGQK domain and a C2HC-type zinc finger motif. CgWRKY53 is expressed in roots, pseudobulbs, leaves, and flowers of C. goeringii, with the highest expression observed in flowers. Under cold, heat, waterlogging, and ABA treatments, CgWRKY53 displayed significant changes in expression, with the most pronounced response occurring under cold stress, where its expression was significantly upregulated. Homozygous transgenic A. thaliana lines overexpressing CgWRKY53 exhibited dwarfed stature, with smaller and deformed leaves and notably shorter roots compared to wild-type plants. The overexpression lines also showed cold-sensitive phenotypes under low-temperature stress, and the expression of several cold-responsive genes was suppressed, suggesting that CgWRKY53 may act as a negative regulator in the response to cold stress. Conclusions: These results identify CgWRKY53 as a negative regulator of cold stress response in C. goeringii. This study provides important genetic resources and theoretical foundations for molecular breeding of stress-resistant orchids. Full article

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. Full article

This study introduces an optimized and selective extraction methodology using dichloromethane/methanol (DCM/MeOH, 95:5, v/v) in combination with accelerated solvent extraction (ASE) for the targeted stilbenoid and phenanthrene derivatives from five orchid species: Cattleya nobilior (root), Cymbidium defoliatum (root and bulb), Dendrobium phalaenopsis (stem), Encyclia linearifolioides (leaf), and Phalaenopsis aphrodite (root). Sequential extraction was performed with hexane, followed by DCM/MeOH (95:5 and 1:1, v/v) under controlled temperatures (70 °C for hexane, 100 °C for DCM/MeOH), using three static cycles per stage. Chemical profiling by high-performance liquid chromatography with a diode-array-detector and tandem mass spectrometry (HPLC-DAD-MS/MS) enabled the identification of twenty specialized metabolites—seven stilbenoids and thirteen phenanthrenes—several reported here for the first time, including crepidatuol B, dendrosinen D, and coeloginanthridin. The analytical method showed excellent separation of structurally related phenolic compounds, demonstrating the efficiency of the extraction protocol and the selectivity of the solvent system. Many of the identification metabolites are known for cytotoxic, antioxidant, anti-inflammatory, and metabolic regulatory properties, while newly detected compounds remain unexplored and present promising candidates for future biological evaluation. The broad distribution of these metabolites across the studied orchids enhances the current understanding of their phytochemical diversity and suggests chemotaxonomic relevance within the Orchidaceae family. Importantly, the extraction strategy requires minimal plant material, offering ecological advantages when working with rare or endangered species. Overall, this environmentally conscious extraction approach provides a robust platform for metabolic discovery and supports future research in natural products chemistry, plant ecology, drug discovery, structure–activity relationships studies and biotechnological applications. Full article

Cymbidium sinense is a highly valued ornamental orchid renowned for its strong floral fragrance. In this study, dihydro-β-ionone was identified as a major volatile compound in C. sinense ‘Qi Hei’. Its emission increased progressively during flower development and was predominantly released from the sepals and petals. Transcriptome analysis of flowers at three developmental stages led to the identification of four double-bond reductase genes, designated CsDBR1–CsDBR4. Spatiotemporal expression profiling demonstrated that transcript levels of CsDBRs were highest in sepals and petals, showing a significant positive correlation with dihydro-β-ionone accumulation (p < 0.05). Heterologous expression in Escherichia coli and subsequent in vitro enzymatic assays confirmed that recombinant CsDBR1, CsDBR2, and CsDBR4 proteins catalyze the conversion of β-ionone to dihydro-β-ionone, whereas CsDBR3 exhibited no detectable activity. Transient expression in Nicotiana benthamiana leaves further verified the in planta function of CsDBR1, CsDBR2, and CsDBR4, resulting in elevated production of dihydro-β-ionone upon infiltration of β-ionone. Substrate specificity assays revealed that CsDBR2 and CsDBR4 also reduced 1-octen-3-one, 3-nonen-2-one, and pulegone. Collectively, these findings demonstrate that CsDBR1, CsDBR2, and CsDBR4 are key enzymes responsible for dihydro-β-ionone biosynthesis in C. sinense, providing a genetic foundation for molecular breeding aimed at improving floral fragrance in orchids. Full article

Cymbidium faberi Rolfe is a Chinese flower famous due to its beautiful floral pattern and strong floral scent and is also a threatened terrestrial orchid. Moreover, the traditional propagation method through tillers and symbiotic seed germination with the correct fungus under nature conditions could not meet conservation and commercial needs. Here, an efficient procedure for asymbiotic seed germination and in vitro seedlings development of C. faberi was successfully established through evaluation of time of seed collecting, seed pretreatments, light conditions and composition of culture media, respectively. Seed pretreatment with 1% NaClO for 30 min, dark culture on 1/4 MS medium containing 0.5 mg·L⁻¹ 6-BA and 0.1 mg·L⁻¹ NAA for 30 days and subsequent long day condition (14 h light/10 h dark photoperiod) culture on this medium for 30 days could obviously enhance the seed germination rate of C. faberi. The highest germination rate (85.0 ± 0.79%) was achieved when seeds were collected at 120 d after cross-fertilization, and then germination percentages progressively decreased. Furthermore, histological analyses from protocorm formation to seedling growth were explored. This study not only offers a reliable and scalable system for mass propagation to meet commercial and conservation demands but also serves as a foundational reference for physiological and molecular studies in Cymbidium and related orchids. Full article

As a highly valued orchid species, Cymbidium ensifolium (C. ensifolium) exhibits a natural flowering period mainly from July to September, which does not align with the market demand and shows low flowering quality, thereby significantly constraining the development of the C. ensifolium floriculture industry. To address this key issue, the study used C. ensifolium ‘Longyan Su’ as the experimental material, with white light as the control and composite light with varying ratios of red and blue light as the treatments, and investigated the influence of light quality on flowering. The results showed that blue light could significantly advance the flowering time, while red light could markedly improve the flower quality. Blue light promoted the accumulation of soluble protein and soluble sugar during flower bud differentiation, while red light enhanced their accumulation during floral organ development. During the flower bud differentiation and development stage, blue light increased the synthesis of abscisic acid (ABA) in leaves, and red light promoted the production of gibberellic acid (GA₃) and zeatin riboside (ZR). The study provides an important foundation and reference for further analysis of the flowering mechanism of C. ensifolium under different light quality treatments, and also provides technical support for flowering regulation of orchids in practical production. Full article

Wild orchids, valued for their beauty and economic importance, are facing the challenges of distribution contraction and range shifts from climate change. The rare Cymbidium cyperifolium (class II in the List of National Key Protected Wild Plants in China, Vulnerable on the China Biodiversity Red List) remains understudied regarding its responses to climate variability. Utilizing an enhanced MaxEnt model, we predicted suitable habitats under diverse climate scenarios, revealing a potential distribution of 52.37 × 10⁴ km², concentrated in eastern Yunnan, western Guangxi, the Guizhou border, and southern Hainan. Cymbidium cyperifolium is sensitive to climate change, and temperature annual range (Bio 7) contributes a significant 77.42% of the distribution probability (i.e., habitat suitability), highlighting temperature’s pivotal influence on its distribution. Although the overall potential distribution area and low-suitability regions in China are predicted to decrease, medium and high-suitability areas are expected to expand. The center of mass of the high-altitude habitat is concentrated in southeastern Yunnan Province, migrating just slightly, yet tending westward and northeastward. Based on these findings, we recommend the expansion of existing protected areas or the establishment of new ones for C. cyperifolium, particularly in eastern Yunnan and western Guangxi. Additionally, our research can serve as a reference for the ex situ conservation of C. cyperifolium and other orchids with similar ecological habits, underscoring the broader implications in biodiversity preservation efforts. Full article