Search Results (234)

Background: Flower color is a primary determinant of ornamental value in flowering plants. Although the biosynthetic pathways of major petal pigments have been extensively documented, the systems-level mechanisms coordinating color diversification across multiple cultivars of Kalanchoe blossfeldiana remain less understood. This study aimed to establish a comparative metabolomic and transcriptomic framework to elucidate these mechanisms. Methods: Petal tissues were collected from five cultivars with white, yellow, orange, red, and purple–red flowers at the full-bloom stage. Metabolomics was performed for flavonoids and carotenoids using UPLC-MS/MS, and transcriptome sequencing was conducted via Illumina NovaSeq 6000. Integrative analysis of metabolome and transcriptome data, together with weighted gene co-expression network analysis, was employed to identify key metabolites, differentially expressed genes, and associated regulatory networks. Quantitative PCR was used to validate the expression patterns of key structural genes. Results: Petal color variation was shaped by coordinated flux partitioning between flavonoid and carotenoid networks rather than by isolated activation of single pathways. A metabolic relay pattern was observed in the phenylpropanoid–flavonoid axis, wherein shared upstream activation fed divergent downstream branches that directed accumulation toward distinct anthocyanin or flavonol profiles. Notably, yellow pigmentation relied more heavily on flavonoid flux than on carotenoid accumulation, and orange coloration arose from the synergistic co-accumulation of multiple pigment classes. Transcriptional module analysis identified gene networks associated with specific color phenotypes. Conclusions: These findings provide a systems-level understanding of pathway crosstalk in flower color formation and offer candidate targets for molecular breeding in K. blossfeldiana and related ornamental plants. Full article

As the primary component of harmful algal blooms, cyanobacteria exhibit unique adaptation strategies under environmental stress. The impact of erythromycin (ETM), a common macrolide antibiotic in aquatic environments, on colonial cyanobacteria remains unclear. This study examined the chronic toxic effects of different ETM concentrations (0.01, 0.1, 1, 10, 20 and 100 μg/L) on colonial Microcystis aeruginosa (M. aeruginosa) under varying nutrient conditions. Results showed that at 0.01–1 μg/L, ETM could promote the growth of M. aeruginosa, while high concentrations of ETM (≥10 μg/L) significantly inhibited growth (p < 0.05). Low-level ETM exposure accelerates M. aeruginosa growth by boosting PSII efficiency, extracellular polymeric substance (EPS) production, and the activities of superoxide dismutase (SOD) and catalase (CAT). Metatranscriptomic and metabolomic analyses further reveal that this stimulation is underpinned by enhanced trace-element uptake, reinforced carbon cycling, and increased biosynthesis of proteins, polysaccharides, and chlorophyll precursors. High-level ETM exposure inhibited the growth of M. aeruginosa, as evidenced by decreased photosynthesis, damaged membranes and suppressed metabolic activity. Metatranscriptomic and metabolomic analyses showed the upregulation of photosynthesis andpathways, metabolic pathways, and the accumulation of potent allelochemicals in P-limited cells exposed to 10 µg/L ETM relative to 10 µg/L ETM in nutrient-replete BG11 medium. Furthermore, phosphorus deficiency may enhance the potential of net methane formation. These findings underscore the complex interactions between antibiotic exposure and nutrient stress in cyanobacteria, with significant implications for environmental management of antibiotic contamination. Full article

Objectives: This study aims to provide a theoretical basis for a deeper understanding of the transcriptional regulatory network underlying the formation of Primula forbesii floral scent, and also offers important genetic resources for the molecular improvement of floral scent traits in Primula species. Methods: Using the P. forbesii cultivar ‘Pink violet’ as experimental material, we cloned PfbHLH131 and analyzed its expression pattern. We also validated its function via virus-induced gene silencing (VIGS) and used gas chromatography–mass spectrometry (GC-MS) to analyze changes in floral aroma components in silenced plants. Additionally, we detected the expression levels of key structural genes involved in floral aroma biosynthesis in silenced plants via qRT-PCR to elucidate the regulatory role of PfbHLH131 in the biosynthesis of P. forbesii floral aroma. Results: The cloned PfbHLH131 open reading frame is 922 bp in length, encoding a total of 307 amino acids, and contains a bHLH_AtBPE_like domain characteristic of the bHLH gene family. Quantitative real-time PCR (qRT-PCR) revealed that PfbHLH131 is highly expressed in floral organs, peaking during full bloom. Subcellular localization studies indicated that it is localized to the nucleus. VIGS-mediated transient silencing of PfbHLH131 significantly reduced the release of terpenoid and phenylpropanoid floral odor compounds and suppressed the expression of multiple key structural genes in both synthetic pathways. Conclusions: PfbHLH131 is a positive regulator of scent biosynthesis in P. forbesii. Full article

Lilac (Syringa oblata Lindl.) is an important eco-economic aromatic shrub in northern China; however, the key volatile organic compounds (VOCs) responsible for its floral aroma and their origin remain largely unexplored. In this study, we conducted an integrated analysis of volatile metabolomics and transcriptomics to elucidate the composition, dynamic changes, and potential regulatory network of VOCs across different floral organs and petal developmental stages. A total of 1440 VOCs were identified in the stamens, pistils, and petals, with petals being the primary contributors to the overall floral aroma. Analysis of different petal developmental stages revealed that the full-bloom stage (S3) is critical for VOCs emission. The floral aroma of S. oblata is primarily composed of terpenoids, alcohols, and aldehydes. By relative odor activity value (rOAV) with multivariate statistical screening, seven key VOCs with high contributions to the floral aroma were identified. Transcriptome analysis identified 69,935 differentially expressed genes (DEGs) across petal developmental stages, which were predominantly enriched in metabolic pathways and the biosynthesis of secondary metabolites. The expression patterns of these DEGs were highly consistent with the accumulation trends of VOCs, increasing at stages S2 and S3 and subsequently declining at stage S4. Integrative analysis of VOCs and gene expression further identified candidate genes significantly correlated with the key aroma volatiles. Specifically, the carotenoid pathway-related genes CYP97A3 and LYC may influence the formation of carotenoid-derived volatiles and floral aroma. Additionally, genes associated with the fatty acid-lipoxygenase pathway, transport-related genes, and transcription factors are potentially involved in the formation and regulation of aldehyde and alcohol volatiles. These findings advance our understanding of the floral aroma formation in S. oblata and provide metabolic basis, candidate gene resources and a theoretical foundation for the genetic improvement of aroma traits and the breeding of new cultivars. Full article

Inflorescence degeneration in Areca catechu L. is characterized by growth arrest, tissue shrinkage and browning, ultimately compromising functional inflorescence formation and yield stability. To investigate its developmental window and regulatory basis, inflorescences from different leaf positions at the full-bloom stage were analyzed using anatomical observation, morphological measurements, carbohydrate and hormone assays, and RNA-seq-based transcriptomic analysis with qRT-PCR validation. Inflorescence degeneration was mainly concentrated in axillary inflorescences at the third and fourth leaf positions (BY3 and BY4). Compared with adjacent normal inflorescences, degenerated inflorescences showed reduced sucrose, starch and trehalose contents, increased ABA, JA and MeJA levels, and decreased cZR levels. Transcriptomic analysis revealed clear separation between degenerated and normal inflorescences, and differentially expressed genes were enriched in starch and sucrose metabolism, plant hormone signal transduction and transcriptional regulation. Co-expression network analysis identified modules associated with the degeneration window and key physiological traits, highlighting six candidate hub genes: AcAHP2, AcTIFY4B, AcTPS9-2, AcHXK2, AcWRKY3 and AcMPK1. These findings suggest that inflorescence degeneration is closely associated with carbon metabolic imbalance, hormone network remodeling and co-expression network reprogramming within a specific developmental window, providing a basis for future mechanistic studies and control strategies. Full article

Sulfur-containing medium-carbon microalloyed steel blooms are widely used for high-load automotive components, and reducing surface defects is important for improving product yield and lowering downstream processing costs. To address surface defects such as star cracks and microcracks in the continuous casting of these steel blooms, this study redesigned the mold flux on the basis of the steel’s solidification characteristics and crack susceptibility and carried out a twin-strand industrial comparative casting trial. Thermodynamic and thermophysical analyses indicated that the relatively high contents of S, Mn, and Ti/N in the steel promoted the precipitation of MnS and TiN–MnS complex inclusions along grain boundaries, severely weakening grain boundary cohesion. Meanwhile, the high specific heat capacity and low thermal conductivity further intensified thermal stress concentration in the solidifying shell, rendering the steel highly susceptible to cracking. Evaluation of the originally used mold flux (Flux A) revealed that its high melting temperature (1189 °C), long melting time (106 s), high break temperature (1170 °C), and poor crystallization behavior resulted in an excessively thin liquid slag layer (<5 mm) within the mold, making it difficult to provide adequate lubrication and stable heat transfer; these were key external factors inducing surface defects. Accordingly, the optimized mold flux (Flux B) was designed and prepared by increasing the basicity from 0.95 to 1.1, raising the Al₂O₃ content from 9.48% to 11.16%, increasing the F content from 4.93% to 5.58%, and reducing the carbon content from 13.85% to 6.97%. The rheological and crystallization properties of the flux were optimized in a coordinated manner, allowing uniform heat transfer through the crystalline slag layer while maintaining adequate lubrication. Industrial comparative trials demonstrated that Flux B stabilized the liquid slag layer at 8–10 mm, increased slag consumption to 0.56 kg/t, and significantly reduced surface defects such as star cracks and microcracks on blooms. The ultrasonic testing acceptance rate for rolled products increased to 98.6%, thereby meeting stringent quality requirements for the continuous casting of sulfur-containing, medium-carbon, microalloyed steel blooms. Full article

Flower color is a key ornamental trait in Nobile-type Dendrobium, yet the molecular basis underlying purple flower formation remains poorly understood. In this study, a white-flowered paternal cultivar and its purple-flowered filial line were used to investigate the regulatory mechanism of purple floral pigmentation. Comparative phenotypic analysis showed that floral color divergence was established early during flower development, and anthocyanidin profiling of full-bloom petals revealed that purple flowers accumulated substantially higher levels of most anthocyanidins than white flowers, with delphinidin- and cyanidin-derived anthocyanidins together accounting for 80.26% and 94.56% of the total anthocyanidins in white- and purple-flowered materials, respectively. Transcriptome profiling identified a total of 21,235 differentially expressed genes (DEGs), with significant enrichment of phenylpropanoid- and flavonoid-related pathways, and MYB transcription factors prominently represented among the candidate regulators across the three comparison groups. Among them, DntMYB1 was identified as a C1 subgroup R2R3-MYB associated with floral pigmentation, and transient overexpression assays in Phalaenopsis hybrid V3 and a Nobile-type Dendrobium hybrid supported its positive role in visible purple pigmentation. By integrating RNA-seq and DAP-seq analyses, we identified 3205 candidate downstream targets of DntMYB1 and established a DntMYB1-centered regulatory module. Among these candidates, one Dnt4CL1 gene and one DntF3′H1 gene were validated as robust direct targets of DntMYB1 through yeast one-hybrid, EMSA, and dual-luciferase assays. These findings suggest that DntMYB1 is associated with purple flower formation by coordinately regulating both upstream precursor metabolism and downstream anthocyanin biosynthesis, providing new insight into the molecular regulation of flower color in Nobile-type Dendrobium and useful candidate genes for ornamental trait improvement. Full article

Urban farming microinterventions are small, place-based cultivation projects that operate under severe spatial and resource constraints yet can generate social learning and locally embedded resilience. The present paper examines how design decisions shape the effectiveness of such interventions through three design-led case studies: Blooming Structure (2018, Warsaw), a temporary hydroponic “laboratory” installation; Micro-cultivation (2018, Warsaw), a shopfront vertical demonstration farm; and Micro-cultivation 2 (2019), modular “cultivation furniture” for interiors and exhibition deployment. The analysis combines project documentation with practice-based observations and applies five interpretive dimensions: spatial fit, technical feasibility, communicative legibility, replicability, and social programming. Findings highlight that successful microinterventions align legible cultivation infrastructure with high visibility, accessibility and participatory formats that support skills transfer and copying-based scaling. Rather than offering universal claims about urban agriculture outcomes, the paper provides a reference set of design principles that may inform similar micro-scale interventions in other contexts, subject to local constraints. Limitations include the small sample size and the concentration on projects from Poland. Practically, the findings can support designers, municipalities, and civic organisations in structuring microinterventions as replicable, low-threshold prototypes and in aligning technical systems with maintenance capacity and public engagement. Full article

Marine mucilage events are intensifying in semi-enclosed seas under accelerating climate- and nutrient-driven pressures, yet their ecosystem-level consequences for aquaculture-linked coastal habitats remain insufficiently documented. This study provides an integrated spatiotemporal assessment of water quality, phytoplankton community structure, and biometric responses of Mytilus galloprovincialis during and after the 2025 mucilage outbreak in the Gulf of Erdek (Sea of Marmara, Türkiye). Mucilage accumulation was associated with sharp increases in turbidity, total suspended solids, and particulate organic matter, alongside declines in dissolved oxygen and pH. Phytoplankton assemblages exhibited marked seasonal restructuring: the mucilage period was characterized by the coexistence of mucilage-forming taxa, non-toxic bloomers, and multiple harmful algal bloom (HAB) groups, including DSP- and ASP-related species, whereas post-mucilage conditions were dominated by non-toxic diatoms with substantially reduced HAB representation. The dinoflagellate species representing the May period in terms of abundance were Noctiluca scintillans and Prorocentrum micans; the diatom species were Chaetoceros radiatus, Cylindrotheca closterium, Pseudo-nitzschia pseudodelicatissima, and Thalassiosira rotula; and the coccolithophore was Phaeocystis pouchetii. Mussel biometric analyses revealed biometric indices and condition values markedly below regional historical baselines during the mucilage event, alongside reduced meat yield, followed by pronounced compensatory growth during the post-mucilage period. Our findings demonstrate that mucilage acts as both a physical and biological stressor, driving short-term ecological shifts in phytoplankton diversity and imposing substantial but reversible physiological impacts on mussel stocks. These results underscore the need for continuous biodiversity monitoring frameworks that integrate mucilage dynamics, HAB occurrence, and aquaculture resilience in regions vulnerable to climate-enhanced organic aggregate formation. Full article

Background/Objectives: The orchid Dendrobium devonianum Paxt., valued for its ornamental and medicinal properties, is widely used in horticulture, medicine, and food industries. Methods: This study investigated dynamic changes in aroma-active volatile organic compounds (VOCs) and associated gene expression in D. devonianum flowers across four developmental stages (bud, half bloom, full bloom, and aging) using headspace solid-phase microextraction, gas chromatography–mass spectrometry, and transcriptome analysis. Results: Floral VOCs, particularly volatile terpenoids and esters, were most abundant at full bloom. Among the 664 VOCs identified, α-hemelene, β-bisabolene, δ-naphthalene, perillyl alcohol, L-perillyl alcohol, terpinen-4-ol, 2-(4-methylphenyl)propan-2-ol, cis-3-hexenyl butyrate, and α-pinene were likely to contribute to floral scent. Terpene biosynthesis pathways played a pivotal role in floral fragrance formation. A comprehensive terpenoid biosynthesis pathway for D. devonianum floral scent was proposed, and eight genes encoding key regulatory enzymes were identified. Conclusions: These results provide new insights into terpenoid metabolism in Dendrobium and may guide future research on the utilization of floral scent. Full article

Achnanthidium catenatum exhibits both epiphytic and planktonic ecological types and forms multiple large-scale diatom blooms in different drinking water reservoirs. This study determined its growth and physiological characteristics under different nitrogen (N) or phosphorus (P) conditions. The study found that N ≤ 2.5 mg/L promoted its growth, while the promoting effect weakened at ≥5 mg/L. The lag phase of the growth cycle was shorter, taking only 6 days to reach peak density; meanwhile, it showed strong adaptability to P (0.5–3.5 mg/L), with peak density occurring by approximately 12 days. It was found that N-induced blooms formed earlier and lasted longer, whereas P-induced blooms were relatively delayed, more intense, and shorter in duration. Low and high concentrations of N, as well as P concentrations (≥0.1 mg/L), significantly promoted the formation of multicellular chain colonies (p < 0.05). The percentage of chain colonies was relatively higher during the lag phase and tended to exist as single cells during the stationary phase, at which time the colloidal extracellular polymeric substance (CEPS) content was higher and significantly correlated with changes in cell density. Alkaline phosphatase activity (APA) and malondialdehyde (MDA) content varied markedly under different N or P concentrations (p < 0.05). These results reveal the potential impact of N or P variations on the bloom-forming capacity of A. catenatum. Full article

Grafted plants carrying DNA from both species are prone to new phenotypes. Specific long non-coding RNA (lncRNA) sequences are known to play roles in the formation and development of grafted plants. However, the roles of lncRNAs in phenotypic variation in grafts between peach and apricot remain unexplored. In this study, mixed tissues (leaves, buds and fully bloomed flowers) of peach branches from heterografts between apricot/peach (A/P) and peach/apricot (P/A) and homografted peach (SP) were collected for transcriptome sequencing. The differentially expressed genes (DEGs) and lncRNAs (DElncRNAs) between A/P and P/A were identified as candidates mediating the formation of divergent traits. Compared with SP, 1115 and 624 DEGs were detected in A/P and P/A, respectively. There were 173 DEGs shared between A/P and P/A, whereas the transcripts of 942 genes were specifically altered in A/P and 451 DEGs were specific to P/A. There were 29 DElncRNAs in A/P and 26 DElncRNAs in P/A, of which, 21 DElncRNAs were specific to A/P and 18 were specific to P/A. The biological functions of the DEGs and DElncRNAs were predicted via GO and KEGG enrichment analyses. A total of 24 co-expressed ‘lncRNA-mRNA’ pairs were identified, including 14 ‘lncRNA-mRNA’ pairs in A/P and 10 ‘lncRNA-mRNA’ pairs in P/A. The ‘MSTRG.17020.2-XM_007210198-2’ pair potentially participates in aminoacyl biosynthesis, and the ‘MSTRG.8395.1-XM_007217967.2’ pair may regulate galactose metabolism. The lncRNA MSTRG.6365.3 may regulate defense response through altering the levels of XM_020556240.1 and XM_020556234.1. These findings provide valuable insights into the molecular mechanisms underlying grafting-induced differential trait formation and establish a foundation for further research on the functional roles of ‘lncRNA-mRNA’ pairs in fruit tree grafting systems. Full article

High-salinity water environments, e.g., saline lacustrine basins and lagoons, represent significant sedimentary settings on Earth. They serve not only as crucial archives of paleoclimate and paleoenvironmental evolution but also as favorable realms for the development of high-quality hydrocarbon source rocks. Although traditional views suggested that high salinity inhibits biological activity and is thus detrimental to source rock formation; recent hydrocarbon discoveries in formations such as the Leikoupo Formation (Sichuan Basin) and Majiagou Formation (Ordos Basin) in China have confirmed the exceptional hydrocarbon generation potential of source rocks in such settings. Focusing on major sedimentary basins in China, this review synthesizes how high-salinity settings critically control the integrated “generation-storage” sequence of hydrocarbon source rocks. Research indicates that moderate salinity can promote blooms of halophilic microorganisms, e.g., algae, cyanobacteria, resulting in high primary productivity. Concurrently, salinity-driven stable water stratification creates a strongly reducing bottom water environment, which greatly facilitates the preservation of organic matter, establishing a synergistic enrichment model of “high productivity—excellent preservation.” Products of high-salinity environments, such as evaporites, e.g., gypsum, halite, can act as catalysts, lowering the activation energy for hydrocarbon generation and enhancing hydrocarbon yield. Additionally, associated organic salts provide supplementary material for hydrocarbon generation. Regarding reservoir quality, the laminated structures formed in high-salinity settings, combined with organic–inorganic synergistic diagenesis, e.g., dolomitization, organic acid dissolution, and hydrocarbon-generation overpressure, collectively shape high-quality reservoirs with significant heterogeneity. Despite important progress, challenges remain, including the quantitative analysis of primary factors controlling organic matter enrichment, the threshold of salinity inhibiting biological communities, and the prediction of strongly heterogeneous reservoirs. Saline settings serve as critical carbon sinks in the geological carbon cycle through high primary productivity, enhanced preservation conditions, and distinctive mineral assemblages, playing a particularly important role in the formation of hydrocarbon source rocks and long-term carbon sequestration. Future research should integrate modern saline lake observations with high-resolution characterization techniques to deepen the understanding of the formation mechanisms of high-salinity source rocks, aiming to provide theoretical guidance and exploration targets for petroleum systems in similar geological settings worldwide. Full article

Active substance-based Ballast Water Management Systems (BWMS) can generate disinfection by-products (DBPs) by reacting with dissolved organic matter (DOM). However, current IMO G9-based assessments often overlook qualitative DOM variations. This study investigated DBP formation following NaDCC treatment in natural seawater dominated by the diatom Skeletonema costatum and the dinoflagellate Akashiwo sanguinea. Laboratory-cultured DOM was also analyzed using ATR-FT-IR, PCA, and 2D-COS to evaluate structural differences. In field experiments, S. costatum treatment primarily produced brominated trihalomethanes (THMs) and specific haloacetic acids (HAAs) with a limited composition. Conversely, A. sanguinea treatment yielded a diverse range of DBPs, including nitrogenous DBPs (HANs). FT-IR results, supported by 2D-COS, revealed that A. sanguinea-derived DOM underwent non-monotonic structural changes and distinct sequential functional group reactions, suggesting multiple, time-delayed precursor interactions. These findings demonstrate that phytoplankton species-specific DOM composition significantly dictates DBP profiles and temporal dynamics. Therefore, environmental risk assessments for BWMS must incorporate the qualitative characteristics of biogenic DOM and dominant species traits, particularly during coastal bloom events, to ensure more accurate management strategies. Full article

The dinoflagellate Akashiwo sanguinea is a prominent harmful algal bloom (HAB) species responsible for significant mortalities of marine fauna. Its life cycle, which includes a benthic resting cyst stage, is fundamental to its bloom dynamics and geographic dispersal. This study investigates the effects of Taebaek coal powder, a silicate-rich mineral supplement, on the growth and life-stage transitions of A. sanguinea. Cultures were grown in standard f/2 medium (control) and f/2 medium amended with an extract of the coal powder. We monitored culture performance using fluorometry for quantitative biomass assessment and imaging flow cytometry (FlowCam) for qualitative life-stage analysis. The coal powder amendment conferred a distinct advantage, promoting both vegetative proliferation and the formation of resting cysts. Fluorescence-based measurements showed that the coal powder-amended cultures reached a density equivalent of 3851 ± 214 cells mL⁻¹ by day 4, significantly outpacing the control (2963 ± 351 cells mL⁻¹). Peak vegetative abundance in the treated cultures reached 6967 ± 423 cells mL⁻¹ on day 14, compared to 5979 ± 288 cells mL⁻¹ in the control. Critically, resting cyst production was substantially enhanced in the coal powder treatment, with densities reaching 32–37 cysts mL⁻¹ by the end of the experiment, compared to 22–26 cysts mL⁻¹ in the control. These findings demonstrate that mineral supplementation with Taebaek coal powder can significantly augment both vegetative growth and encystment in A. sanguinea, suggesting a potential link to micronutrient availability, though the underlying mechanisms remain to be elucidated. This enhanced cyst production method may prove valuable for harvesting cysts for ecophysiological research and highlights the need to explore how mineral-induced life-cycle shifts could influence bloom dynamics in a context-dependent manner. Full article