Search Results (227)

Gastrodia elata Blume is an important medicinal orchid, yet its large-scale cultivation is increasingly threatened by fungal diseases. The 4-coumarate–CoA ligase (4CL) gene family directs a key step in phenylpropanoid metabolism and plant defence, but its composition and function in G. elata have not been investigated. We mined the G. elata genome for 4CL homologues, mapped their chromosomal locations, and analysed their gene structures, conserved motifs, phylogenetic relationships, promoter cis-elements and codon usage bias. Publicly available transcriptomes were used to examine tissue-specific expression and responses to fungal infection. Subcellular localisation of selected proteins was verified by transient expression in Arabidopsis protoplasts. Fourteen Ge4CL genes were identified and grouped into three clades. Two members, Ge4CL2 and Ge4CL5, were strongly upregulated in tubers challenged with fungal pathogens. Ge4CL2 localised to the nucleus, whereas Ge4CL5 localised to both the nucleus and the cytoplasm. Codon usage analysis suggested that Escherichia coli and Oryza sativa are suitable heterologous hosts for Ge4CL expression. This study provides the first genome-wide catalogue of 4CL genes in G. elata and suggests that Ge4CL2 and Ge4CL5 may participate in antifungal defence, although functional confirmation is still required. The dataset furnishes a foundation for functional characterisation and the molecular breeding of disease-resistant G. elata cultivars. Full article

Melastoma dodecandrum is primarily propagated through stem cuttings, which limits genetic variation and constrains breeding efforts. To overcome this limitation and facilitate molecular breeding, the establishment of a reliable and efficient regeneration system is essential. This study investigated the effects of plant growth regulators (PGRs) and culture media on the in vitro regeneration system of M. dodecandrum. The highest rate of callus induction (96.67%) was achieved when sterile leaf explants were cultured on Murashige and Skoog (MS) basal medium supplemented with 2.00 mg·L⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.50 mg·L⁻¹ 6-benzylaminopurine (6-BA). For callus differentiation, the optimal formulation of MS + 2.0 mg·L⁻¹ 6-BA + 0.5 mg·L⁻¹ naphthylacetic acid (NAA) resulted in a differentiation frequency of 83.33%. The optimal PGR combinations for shoot proliferation were 1.5 mg·L⁻¹ 6-BA + 0.1 mg·L⁻¹ NAA and 0.5 mg·L⁻¹ 6-BA + 0.2 mg·L⁻¹ NAA. The optimal rooting media were MS medium supplemented with 0.1, 0.2, or 0.5 mg·L⁻¹ indole-3-butyric acid (IBA) or 1/2MS medium supplemented with 0.1 mg·L⁻¹ IBA. Additionally, this study investigated the dynamic changes in endogenous hormones during the regeneration process. The levels and ratios of hormones, including gibberellin (GA₃), abscisic acid (ABA), indole-3-acetic acid (IAA), and zeatin (ZT), collectively regulated the regeneration process. Elevated levels of ABA and GA₃ may promote callus initiation as well as the growth and development of adventitious roots during the early induction stage. Reduced levels of ABA and IAA favored callus differentiation into shoots, whereas elevated GA₃ levels facilitated proliferation of adventitious shoots. Throughout the regeneration process, fluctuations in ZT levels remained relatively stable. This study successfully established an in vitro regeneration system for M. dodecandrum using leaf explants, providing theoretical guidance and technical support for further molecular breeding efforts, genetic transformation, and industrial development. Full article

Botanical gardens serve as vital centers for ex situ conservation, maintaining diverse plant species under controlled conditions. Terrestrial orchids, despite their wide diversity and distribution, often occur in small and declining populations, making their conservation increasingly urgent. This study aimed to examine the potential for establishing the first specialized orchidarium in Serbia, focusing on the native orchid species of the Fruška Gora region. A SWOT analysis, combined with site assessment data, was employed to identify key strengths, weaknesses, opportunities, and threats, informing the development of a functional zoning plan. The results indicate that such an orchidarium would offer a threefold benefit: strengthening ex situ conservation, advancing scientific research and environmental education, and promoting sustainable tourism. The proposed design consists of eight distinct zones, three of which reflect natural habitats of selected orchid species. The planned integration of a seed gene bank in the central zone, along with living plant collections and a nearby in vitro culture laboratory, establishes a comprehensive framework for the sustainable management of orchid genetic resources in the region, forming a foundation for future research and preservation. Full article

Orchids and other flowering plants offer a wide range of floral traits. Within the Orchidaceae family, the Vanilla genus is one of the most valued plants in the commercial flavor industry. In vitro biotechnological approaches to Vanilla, such as germplasm conservation, massive propagation, and genetic engineering, have played a key role in breeding programs. There are, however, few studies that elucidate the physiological, molecular, and genetic aspects of vanilla orchid flowering and in vitro induction. This review’s main objective is to provide updated and complete data on in vitro floral induction and flowering of tropical and vanilla orchid species. A bibliographic search was carried out for scientific reports in academic databases (Scopus, Web of Science, PubMed, and ScienceDirect), and a total of 39 documents from 2014 and 2025 were analyzed. This review discusses the most important factors that affect in vitro flowering in Vanilla, including the monopodial genotypes, photoperiod, irradiance, temperature, nutrition, plant growth regulators, explant types, and culture methods. Consequently, this revision incorporates a number of studies on orchid in vitro flowering, with a focus on vanilla species. In conclusion, there still exists limited progress in Vanilla compared to other orchid species; however, the use of biotechnological techniques like in vitro flowering offers a fundamental framework for orchid breeding. Full article

Phalaenopsis is a widely cultivated ornamental plant of considerable economic value worldwide. However, traditional growing medium, sphagnum moss, is limited and non-renewable. It also decomposes slowly and is prone to environmental issues. Therefore, there is an urgent need to identify more environmentally friendly and efficient alternatives. Biochar, a sustainable material with excellent physical and chemical properties, has been recognized as an effective promoter of plant growth. In this study, we investigated the influence of biochar derived from three raw materials (corn straw, bamboo, and walnut) mixed1 with coconut shell at ratios of 1:2, 1:10, and 4:1, on the growth of Phalaenopsis ‘Big Chili’. Over a 150-day controlled experiment, we evaluated multiple growth parameters, including plant height, crown width, total root length, total projected area, total surface area, and root volume. Compared to the traditional growing medium, the optimal biochar-coconut shell mixture (maize straw biochar: coconut shell = 1:2) increased plant height and crown width by 7.55% and 6.68%, respectively. Root metrics improved substantially, with total root length increasing by 10.96%, total projected area by 22.82%, total surface area by 22.14%, and root volume by 38.49%. Root biomass in the optimal treatment group increased by 42.47%, while aboveground and belowground dry weights increased by 6.16% and 77.11%, respectively. These improvements were closely associated with favorable substrate characteristics, including low bulk density, high total and water-holding porosity, moderate aeration, and adequate nutrient availability. These findings demonstrate that substrate characteristics critically influence plant performance and that biochar–coconut shell mixtures, particularly at a 1:2 ratio, represent a viable and sustainable alternative to sphagnum moss for commercial cultivation of Phalaenopsis. Full article

Background/Objectives: Changnienia amoena is a rare and endangered terrestrial orchid endemic to China, valued for its ornamental and medicinal properties. However, limited genomic resources hinder its effective conservation strategies and sustainable utilization. This study aimed to generate comprehensive plastome resources and develop molecular markers to support the phylogenetics, identification, and conservation management of C. amoena. Methods: Genome skimming was employed to assemble and annotate the complete plastomes of seven geographically distinct C. amoena accessions. Comparative analyses were conducted to assess structural features and sequence divergence within C. amoena and across related species in the Calypsoinae subtribe. Phylogenetic relationships were inferred from protein-coding genes. Simple sequence repeats (SSRs), dispersed repeats, and hypervariable regions were identified from the plastomes, while nuclear SSRs were developed from assembled nuclear sequences. Results: All seven plastomes exhibited a conserved quadripartite structure with identical gene content and order, showing only minor variations in genome size. Sequence divergence was mainly confined to non-coding regions. Across Calypsoinae species, mycoheterotrophic taxa exhibited reduced plastomes. Phylogenetic analyses resolved four well-supported intergeneric clades within Calypsoinae and revealed a notable divergence between the HuNGZ accession and other C. amoena accessions, which otherwise showed low plastome-level differentiation. We also identified 69–74 plastome-derived SSRs, 22–25 dispersed repeats, and three hypervariable regions that may serve as informative molecular markers for C. amoena. Additionally, 16 polymorphic nuclear SSRs were developed from assembled nuclear sequences. Conclusions: These findings significantly expand the genomic resources available for C. amoena and provide essential insights for its phylogeny, molecular identification, conservation management, and future breeding efforts. Full article

Himantoglossum metlesicsianum is a threatened orchid with low population numbers and fragmented distribution, present in four of the Canary Islands. This study focused on assessing the genetic variability and population genetic structure of the natural populations known to date, identifying those characteristics of the species that condition the flow and genetic variation. For that purpose, we collected samples from eight sites in its distribution range and developed 14 polymorphic microsatellite markers. Despite its rarity, this orchid presents high levels of genetic diversity and a homogeneous population structure, characterised by a low degree of genetic differentiation and patterns consistent with high genetic connectivity among populations. Our results suggest that the species might show dichotomy in seed dispersal, combining long- and short-distance events. In addition, it is possible that pollen cross-pollination (pollinia) between adjacent sites may also be involved. In conclusion, these findings reveal unexpectedly high genetic diversity and connectivity among populations, despite the species’ rarity and fragmented distribution, highlighting key biological traits that should be considered in future conservation and recovery plans. Full article

Phylogenetic relationships within the subtribe Arethusinae (Arethuseae: Epidendroideae: Orchidaceae) remain unresolved, with particular uncertainty surrounding the phylogenetic positions of Anthogonium gracile and Eleorchis japonica. The monophyly of this subtribe remains contentious, making it one of the challenging taxa in Orchidaceae phylogenetics. In this study, we sequenced and analyzed the complete plastome sequences of A. gracile and E. japonica for the first time, aiming to elucidate their plastome characteristics and phylogenetic relationships. Both plastomes exhibited a conserved quadripartite structure, with 158,358 bp in A. gracile and 152,432 bp in E. japonica, and GC contents of 37.1% and 37.3%, respectively. Comparative analyses revealed strong structural conservation, but notable gene losses: E. japonica lacked seven ndh genes (ndhC/D/F/G/H/I/K), whereas A. gracile retained a complete ndh gene set. Repetitive sequence analysis identified an abundance of simple sequence repeats (68 and 77), tandem repeats (43 and 30), and long repeats (35 and 40). Codon usage displayed a bias toward the A/U termination, with leucine and isoleucine being the most frequent. Selection pressure analysis indicated that 68 protein-coding genes underwent purifying selection (Ka/Ks < 1), suggesting evolutionary conservation of plastome protein-coding genes. Nucleotide diversity analysis highlighted six hypervariable regions (rps8-rpl14, rps16-trnQ^UUG, psbB-psbT, trnT^UGU-trnL^UAA, trnF^GAA-ndhJ, and ycf1), suggesting their potential as molecular markers. Phylogenomic reconstruction, using complete plastome sequences, (ML, MP, and BI) indicated that Arethusinae was non-monophyletic. A. gracile formed a sister relationship with Mengzia foliosa and E. japonica, whereas Arundina graminifolia exhibited a sister relationship with Coelogyninae members. These results shed new light on the plastome characteristics and phylogenetic relationships of Arethusinae. Full article

As an endemic epiphytic orchid of Hainan Island, Dendrobium sinense exhibits remarkable ecological and economic value, serving important ornamental and medicinal purposes. The combination of its epiphytic growth habit and the distinct dry season in Hainan (November–May) under the subtropical monsoon climate makes D. sinense particularly vulnerable to recurrent drought stress. Therefore, elucidating its drought tolerance mechanisms offers critical insights for both conservation strategies and stress resistance studies in D. sinense. Using polyethylene glycol (PEG)-induced drought stress, chlorophyll content decreased significantly with increasing PEG concentration, while MDA and proline content, SOD, POD CAT, and APX activity showed a significant increase. The analysis of physiological indicators indicated that plants have been subjected to drought stress. We then conducted the joint analysis of the metabolomics and transcriptomics data. Cluster analysis of differentially expressed genes and metabolites showed that drought stress markedly upregulates phenylpropanoid biosynthesis, with ferulic acid (FA) identified as a pivotal metabolite. Exogenous FA application alleviated drought-induced chlorophyll degradation in D. sinense seedlings. Heterologous expression of DsCOMT (a key FA biosynthetic gene) in Arabidopsis thaliana significantly enhanced drought survival. These results demonstrate the crucial role of FA in drought resistance and provide key insights into drought-related metabolic mechanisms. Full article

Chinese Cymbidium are prized for their ornamental beauty, ecological significance, and economic value. However, genomic resources crucial for breeding studies within this genus remain scarce, which has hindered the identification of key genes controlling economically important traits and posed challenges for conservation efforts. We performed a comprehensive identification of whole-genome simple sequence repeats (SSRs) and single-nucleotide polymorphism (SNP) markers using the restriction-site associated DNA sequencing (RADseq) on C. goeringii and C. faberi. A total of 49,640 SSR loci were identified across both species, with an average density of 12.7 SSRs/Mb. Among these, 17,637 SSRs were common to both C. goeringii and C. faber, while 17,676 and 14,329 SSRs were uniquely identified in C. goeringii and C. faberi, respectively. Additionally, we identified 405,416 SNPs and 26,870 InDels, with average densities of 105.2/Mb and 6.5/Mb. Furthermore, we validated two SSRs (located at Chr01:78857480-78860461 and Chr01:93382182-93384869) and developed an efficient method for identifying hybrids among the progeny resulting from crosses between C. goeringii and C. faberi. We also validated two SNP markers that showed a close association with the petal and lip length using Sanger sequencing. Our findings revealed that the Chr01_99657375 SNP achieved 73% predictive accuracy for identifying long-petal/lip phenotypes. The results are expected to greatly benefit marker-assisted breeding efforts in Cymbidium orchids and lay a solid foundation for the molecular breeding process of improving flower shape traits in orchid plants. Full article

The R2R3-MYB transcription factor GAMYB plays crucial roles in plant growth and development, but the biological functions of SlGAMYB1 in tomato remain poorly understood. Here, we investigated the roles of SlGAMYB1 by overexpressing a miR159-resistant version (35S:SlGAMYB1^m) in tomato. Transgenic plants exhibited a dwarf phenotype with reduced internode elongation, which was associated with decreased bioactive gibberellin (GA) levels due to transcriptional repression of SlGA3ox1 and activation of SlGA2ox1/2/4/5. Additionally, 35S:SlGAMYB1^m altered leaf morphology by inhibiting cell proliferation through downregulation of cell cycle genes, resulting in larger but fewer epidermal cells. Intriguingly, 35S:SlGAMYB1^m plants displayed increased floral organ number, a process likely mediated by the upregulation of SlWUS rather than GA signaling. These findings demonstrate that SlGAMYB1 regulates diverse aspects of tomato development through both GA-dependent and independent pathways, providing new insights into the functional diversification of GAMYB genes and potential strategies for genetic improvement of tomato architecture and yield. Full article

Flower fragrance is a crucial ornamental and economic trait of Dendrobium chrysotoxum, and the most abundant and diverse aroma-active compounds are terpenes. Terpene synthase (TPS) is the ultimate enzyme for the biosynthesis of various types of terpenes, and TPS genes were identified as the key regulators governing the spatiotemporal release of volatile terpene compounds. Until recently, the TPS gene family in D. chrysotoxum has remained largely unexplored. Our study characterizes the TPS genes in D. chrysotoxum and identifies 37 DcTPS gene family members. It helped identify the DcTPS genes, gene characteristics, the phylogeny relationship, conserved motif location, gene exon/intron structure, cis-elements in the promoter regions, protein–protein interaction (PPI) network, tissue specific expression and verification of the expression across different flowering stages and floral organs. Three highly expressed DcTPS genes were cloned, and their functions were verified using a transient expressed in tobacco leaves. Further functional verification showed that the proteins encoded by these genes were enzymes involved in monoterpene synthesis, and they were all involved in the synthesis of linalool. This study comprehensively expatiates on the TPS gene family members in D. chrysotoxum for the first time. These data will help us gain a deeper understanding of both the molecular mechanisms and the effects of the TPS genes. Furthermore, the discovery that three TPS-b genes (DcTPS 02, 10, 32) specifically drive linalool-based scent in D. chrysotoxum, will provide new insights for expanding the TPS-b subfamily in orchids and identifying the linalool synthases contributing to orchid fragrance. Full article

In nature, orchid seed germination is extremely low, making in vitro asymbiotic seed germination essential for the propagation and conservation of endangered Vanda coerulea. This study optimized a micropropagation protocol and evaluated the genetic homogeneity of regenerated orchids. The synergistic effect of kinetin (KN) with auxins in the Mitra (M) medium best supported protocorm formation and seedling development. The highest shoot multiplication (5.62 ± 0.09) was achieved with 1.2 mg L⁻¹ KN and 0.6 mg L⁻¹ IBA (indole-3-butyric acid) in the medium. Enhanced leaf production (4.81 ± 0.37) was observed when 3.2 mg L⁻¹ KN was combined with 1.8 mg L⁻¹ IAA (indole-3-acetic acid), while root development was superior when 3.2 mg L⁻¹ KN together with 2.4 mg L⁻¹ IAA was incorporated in the medium. Anatomical sections confirmed well-developed leaf and root structures. Genetic fidelity assessment using random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR), inter-primer binding site (iPBS), and start codon targeted (SCoT) markers revealed 97.17% monomorphism (240/247 bands) and low Nei’s genetic distances (0.000–0.039), indicating high similarity among the regenerants. Dendrogram clustering was supported by a high cophenetic correlation coefficient (CCC = 0.806) and strong resolution in Principal Coordinate Analysis (PCoA) (44.03% and 67.36% variation on the first two axes). The Mantel test revealed a significant correlation between both ISSR and SCoT markers with the pooled marker data. Flow cytometry confirmed the genome stability among the in vitro-propagated orchids, with consistently low CV (FL2-A) values (4.37–4.94%). This study demonstrated the establishment of a reliable in vitro protocol for rapidly propagating genetically identical V. coerulea via asymbiotic seed germination. Full article

Cymbidium are endangered and ornamental orchids, and the taxonomy and species identification of this genus have been debated due to some overlapping morphological features between taxa and limited data being available. The leaf morpho-anatomy of 12 Cymbidium species from China was investigated using light microscopy and paraffin sectioning. Based on a comparative analysis, some leaf morphological features that varied between species were selected and used for taxonomic differentiation as follows: (1) The shape and structure of leaves were varied and could be used for species delimitation. (2) Microscopic characteristics show that the leaves lacked trichomes and displayed polygonal to rectangular epidermal cells on both surfaces, with larger adaxial cells and more abaxial stigmata. Stomata were mostly distributed only on the abaxial side, but on both sides in Cymbidium mastersii, which exhibited a rare amphistomatic type. The stomatal complex was uniformly tetracytic in 11 species, while it was observed to be anomocytic in C. floribundum. (3) Anatomically, two distinct midrib configurations were identified, a shallow V-shape and V-shape. The mesophyll cells were homogeneous in 10 species, with the exception of a layer of parenchyma cells resembling palisade cells occurring in C. lancifolium and C. qiubeiense. The thickness of the cuticle varied between species, with the adaxial surface covered by a thicker cuticle than the abaxial surface and displaying either a smooth or corrugated surface. A fiber bundle was observed in six species, but absent in the other six. In the former group, the fiber bundle occurred adjacent to both epidermal cells in C. mastersii and C. hookerianum, while it was adjacent to the abaxial epidermis in four other species. The stegmata, with conical, spherical silica bodies, were associated with fiber bundles and mesophyll in seven species, but absent in the other five (C. kanran, C. defoliatum, C. floribundum, C. lancifolium, and C. serratum). Three kinds of crystals were identified, namely the terete bundle, the long tube bundle, and the raphide. (4) It was suggested that some of these variable features could be selected and used for the delimitation of the species and taxonomy of Cymbidium. In addition, a key to the 12 Cymbidium species based on their leaf morpho-anatomic features was proposed, which could lead to a better understanding of the taxonomy and conservation of Orchidaceae. Full article

Cycads, renowned as “living fossils”, are among the most ancient extant seed plants, playing a crucial role in understanding plant evolution and sex differentiation. Despite their importance, research on their genetics and sex differentiation remains scarce. This study investigates three species, represented by six samples, collected from various regions in Fujian Province, China, using whole-genome resequencing on the Illumina platform. The sequence data underwent rigorous quality control, alignment, and variant detection, focusing on SNP and InDel distribution and annotation. Among the studied species, Cycas revoluta exhibited the highest number of SNPs and the greatest heterozygosity values. Based on SNP data, phylogenetic trees and principal component analysis revealed distinct clusters, with the three C. revoluta samples forming one cluster, while the two C. szechuanensis samples and the C. taiwaniana sample were grouped separately. Gene function using COG and GO annotations, and KEGG enrichment analysis, all highlighted differences in genomic structure and functional gene distribution between male and female cycads. Notably, genes associated with sex differentiation, such as MADS-box and auxin-responsive protein genes, were shown, while other transcription factors showed distinct annotations and enrichment patterns based on sex. This study improves our understanding of genetic variation, evolutionary relationships, and gene enrichment in cycads, providing a foundation for conservation, cultivation, and insights into sex differentiation mechanisms in these ancient plants. Full article