Search Results (327)

Porphyridium species are known red microalgae for producing valuable bioactive compounds such as sulfated exopolysaccharides (EPS) with diverse industrial biomedical applications due to their functional and rheological properties. Recent studies have investigated how abiotic stresses, particularly nitrogen deprivation, affect Porphyridium’s metabolic regulation and EPS production through transcriptomic analysis. Still, the mechanisms governing EPS biosynthesis and the involvement of carbohydrate-activated enzymes (CAZymes) remain poorly understood. This study investigated the progressive effects of nitrate consumption on the unicellular red alga, P. purpureum, by integrating physiological, biochemical, and transcriptomic analyses through RNA-Seq, further validated by RT-qPCR. P. purpureum displayed a gradual, phase-dependent metabolic response to progressive nitrogen stress. EPS release coincided with the decline in nitrate uptake, linking nitrogen availability to carbon redirection towards polysaccharide secretion. Transcriptomic data revealed global metabolic downregulation with targeted upregulation of stress-responsive, carbohydrate catabolic, and nucleotide–sugar synthesis pathways, including the upregulation of CAZyme families GT4, GT8, and GT77. Our results give insights into the coordinated nitrogen and carbon metabolic regulation underlying polysaccharide biosynthesis, while opening future perspectives on enzyme compartmentalization and regulatory flux distribution under nitrogen stress in P. purpureum. Full article

Group A rotaviruses (RVAs) remain the leading cause of acute gastroenteritis (AGE) in young children in low- and middle-income countries. In Brazil, the oral attenuated RVA vaccine (Rotarix^®), monovalent genotype G1P[8], is distributed by the national immunization program and has drastically reduced morbidity and mortality associated with RVA etiology. In this study, Rotarix^® G1P[8] was detected using specific qRT-PCR from the fecal shedding of children living in the Amazon region, and 18.3% (29/158) were positive and 75.8% (22/29) presented with AGE. The VP4 (VP8*) gene of these sheddings, submitted to Sanger nucleotide sequencing, showed an occurrence of mutations, including the silent mutation at 144C > G (one child) and the following missense mutations— 499T > C (F167L) (two children), 644G > C (C215S) (one child), and 787G > A (E263K) (one child). These mutations had no impact on the protein model structure in silico deduced from the VP4 (VP8*) mutants. The in silico protein model deduced from the VP4 (VP8*) nucleotide sequences, bound to type 1H sugar antigens (H1) and its precursor Lac-para-N-biose (LNB), had a stronger binding to the G1P[8] genotype, when compared to G3P[8]. Rotarix^® shedding was higher in HBGA secretors than in non-secretors (79.3%; 23/29). A total of 11.4% (18/158) of children with Rotarix^® G1P[8] shedding were unvaccinated, indicating the occurrence of indirect protection. Stability evidence of Rotarix^® VP4 (VP8*) spike protein from samples collected in vivo is presented. Full article

Type 2 diabetes mellitus (T2D) affects hundreds of millions worldwide, with recent estimates indicating approximately 589 million adults living with diabetes, most with type 2 disease. Beyond classical insulin signaling pathways, increasing evidence implicates altered protein glycosylation in metabolic dysfunction. The solute carrier 35 (SLC35) family of nucleotide sugar transporters mediates the import of activated sugars into the endoplasmic reticulum and Golgi lumen, thereby influencing global glycosylation patterns. Dysregulation of these transporters can perturb glucose homeostasis, insulin responsiveness, and nutrient-sensing pathways through changes in glycosylation flux. In this review, we dissect the molecular mechanisms by which these transporters modulate glucose homeostasis, insulin signaling pathways, protein O-GlcN acylation, and broader glycosylation processes. We integrate findings from human genetic studies, rodent models, and in vitro functional analyses to characterize how altered SLC35 activity is associated with T2D and metabolic syndrome. Four members demonstrate particularly compelling evidence: SLC35B4 modulates hepatic glucose metabolism, SLC35D3 mutations impair dopaminergic signaling and energy balance, and SLC35F3 variants interact with high-carbohydrate intake to increase metabolic-syndrome risk. SLC35A3, though less studied, may influence glycosylation-dependent insulin signaling through its role in N-glycan biosynthesis. Beyond these characterized transporters, this review identifies potential metabolic roles for understudied family members, suggesting broader implications across the entire SLC35 family. We also discuss how such alterations can lead to disrupted hexosamine flux, impaired glycoprotein processing, aberrant cellular signaling, and micronutrient imbalances. Finally, we evaluate the therapeutic potential of targeting SLC35 transporters, outlining both opportunities and challenges in translating these insights into novel T2D treatments. Full article

Nelumbo nucifera (Lotus) is an economically important aquatic crop frequently challenged by abiotic stresses. The plant cell wall, a primary interface with the environment, undergoes dynamic remodeling to balance structural integrity with adaptation. UDP-glucuronic acid decarboxylase (UXS), a key enzyme synthesizing the nucleotide sugar precursor UDP-xylose, exists in distinct membrane-bound (e.g., Golgi) and cytosolic forms, channeling substrates into compartmentalized polysaccharide biosynthesis pathways and positioning the UXS family as a crucial regulator linking cell wall metabolism to plant adaptation. Here, we systematically characterized the NnUXS gene family in lotus through genome-wide identification, evolutionary synteny analysis, and functional validation. Integrated bioinformatic analysis revealed their physicochemical properties, motif patterns, and regulatory cis-elements, suggesting potential roles in growth and salt stress responses. Among the family, NnUXS3 was prioritized due to its preferentially upregulated in small plant architecture (SPA) varieties, its early induction under salt stress (0.5 days, 200 mM NaCl), and its highest predicted binding affinity for UDP-GlcA (−8.9 kcal/mol). Subsequent functional validation confirmed its dual role: heterologous overexpression in tobacco reduced plant height (47.22%) and leaf area (67.61%), while transient overexpression in lotus enhanced salt tolerance and shortened the petioles. This enhanced tolerance was achieved by upregulating key genes involved in polysaccharide biosynthesis (NnCSLC4, NnXTH22, NnCESA1) and antioxidant defense (NnSOD, NnPOD). Our findings establish NnUXS3 as a key mediator in balancing plant architecture and abiotic stress resilience. This work not only identifies a valuable genetic target for lotus breeding but also provides insights into the growth-stress trade-off, highlighting the importance of UXS subcellular localization in tailoring cell wall remodeling for environmental adaptation. Full article

To elucidate the physiological and molecular mechanisms underlying cold tolerance in the mangrove species Kandelia obovata Sheue & al, this study measured the antioxidant enzyme activities and photosynthetic pigment contents of two populations—cold-tolerant and -sensitive—under natural overwintering conditions. In addition, transcriptome sequencing was performed to analyze differentially expressed genes (DEGs), transcription factor families, single nucleotide polymorphisms (SNPs), and alternative splicing events. The results showed that catalase activity was significantly elevated in the cold-tolerant population, which enhanced the efficiency of hydrogen peroxide scavenging. In contrast, although the superoxide dismutase activity was relatively high in the cold-sensitive population, its downstream scavenging capacity was insufficient, resulting in an overall lower antioxidant efficiency. The KEGG enrichment analysis indicated that pathways such as phenylpropanoid biosynthesis, amino sugar metabolism, and plant hormone signal transduction might be involved in the response to low-temperature stress. Further analysis revealed that transcription factors such as WRKY, NAC, MYB, and ERF were differentially expressed at significant levels in the cold-tolerant population, suggesting that they may play important roles in low-temperature adaptation. In addition, the diversity of SNPs and alternative splicing events may enhance protein function and contribute to improved cold tolerance. In summary, the cold-tolerant K. obovata population achieves low-temperature tolerance through multiple mechanisms, including antioxidant defense, metabolic regulation, and transcriptional as well as post-transcriptional regulation. This study provides a theoretical basis for elucidating the molecular foundations of cold tolerance in K. obovata. Full article

Vitamin E and lutein both belong to food functional factors, which have cytoprotective potential and antioxidant effects. However, mechanism details at cell level remain scarce. In this study, HepG2 cells were utilized to inquire and compare the ameliorative effects of vitamin E and lutein under H₂O₂-induced oxidative stress through a combined transcriptomic and metabolomic profiling, in addition to physiology and biochemistry determination. Cell cytotoxicity caused by H₂O₂ was ameliorated by vitamin E or lutein as evidenced by elevating cell viability and balancing the redox system. Vitamin E had greater efficacy on ameliorating oxidative cytotoxicity than lutein. Transcriptome data revealed that differentially expressed genes were mainly enriched in the transport-related, enzyme-related, and oxidative stress-related GO terms with vitamin E pretreatment. Extracellular organization-related, biological process-related, and apoptosis-related GO terms were meaningfully enriched with lutein pretreatment. Metabolome data showed that with vitamin E ameliorative effects, the disturbed metabolic pathways included thiamine metabolism, vitamin digestion and absorption, and ABC transporters. With lutein ameliorative effects, KEGG pathway analysis showed enrichment of amino sugar and nucleotide sugar metabolism, pyrimidine metabolism, and starch and sucrose metabolism. Collectively, our study provides essential insights into utilization of vitamin E and lutein as a potential supplement for effective therapy of disease associated with oxidative stress. Full article

Teleost social behavior plays an important role in foraging, reproduction, and aquaculture management, yet its physiological basis remains poorly understood. This study investigated individual differences in sociability in the large yellow croaker (Larimichthys crocea) using behavioral assays and metabolomic profiling in the brain–intestine axis. Behavioral tests revealed that high-sociability (HS) fish spent significantly more time near conspecifics than low-sociability (LS) fish, indicating clear behavioral divergence between groups. Targeted metabolomics of brain tissue showed distinct neurotransmitter signatures between HS and LS individuals, including significant differences in acetylcholine, DOPAC, xanthurenic acid, and glutamine. Untargeted intestinal metabolomics identified 65 differential metabolites between groups. Intestinal metabolites such as LEA and CEA exhibited significant group-specific variation and were functionally associated with CB1 and CB2 cannabinoid receptors, suggesting a potential endocannabinoid-mediated contribution to sociability differences. Differential metabolites enriched in amino–sugar and nucleotide–sugar metabolic pathways. Integration of behavioral and metabolomic data suggests that neurotransmitter regulation and gut–brain metabolic signaling jointly contribute to sociability differences in large yellow croaker. These findings provide mechanistic insights into social behavior and offer potential biomarkers for welfare assessment and selective breeding in aquaculture. Full article

Microorganism employs sophisticated strategies to adapt to acidic environments, with transcription factors occupying pivotal nodes within their hierarchical regulatory networks. In this study, we performed functional characterization of the AraR transcription factor LP_RS14895 via integrated multiomics approaches. RNA sequencing revealed 40 acid-responsive targets that were enriched in pathways related to pentose/glucuronate interconversions and amino sugar and nucleotide sugar metabolism. A genome-wide binding analysis via DAP-seq identified 1279 interaction sites and the most significantly enriched motif is “ARCCMATMAHC”. The results revealed that AraR plays a crucial role in regulating acid tolerance and metabolizable sugar (including arabinose, glucose, fructose, ribose, mannose, and trehalose). Overall, these findings offer mechanistic insights into microbial stress responses and provide a valuable method for addressing inhibitory processes of carbohydrate metabolizability under high-acid conditions. Full article

The ability of plants to survive oxygen deficiency is associated with significant changes in metabolism. Metabolic profiling of wheat seedlings under anoxia and subsequent reoxygenation conditions was performed using GC-MS. A total of 374 and 298 compounds were detected in root and shoot metabolomes, respectively. All intermediates of central metabolism were identified. Early anoxic responses of root and shoot metabolomes showed similarity, leading to the accumulation of amino acids (Ala, GABA and Tyr), carboxylates (lactate and succinate), nucleotides and amines, together with a decrease in sugars. The metabolic response to long-term anoxia varied significantly in the roots and shoots of wheat seedlings and was related to the redistribution of carbon flux from glycolysis predominantly to lipids in the roots, while it was directed to carboxylates and GABA in the shoots. Imposition of 24 h of reaeration after short-term anoxia (6 h) switched the metabolome toward a normoxic profile, predominantly in roots. Anaerobically down-regulated metabolites were accumulated, while anaerobic intermediates were depleted post-anoxia. The effects of more prolonged anoxia on wheat seedling metabolomes were less reversible, particularly in shoots. Interestingly, several metabolites with not fully understood roles (e.g., hydroxyl carboxylates, α,ω-dicarboxylic acids, polyols) were detected under anoxic conditions in wheat seedlings, which could potentially serve as markers of plant sensitivity to oxygen deficiency. Full article

Flowering often perturbs carbon allocation in sugarcane, yet its transcriptomic–metabolomic basis remains unclear. We profiled two contrasting cultivars, Gui Tang 16-3285 (sugar increases during flowering) and Gui Tang 44 (sugar decreases), sampling apical tissues at five stages (Non-spikelet-bearing stage (NSB), Early booting stage (ESB), Late booting stage (LSB), Tasseling stage (TS), and Flowering stage (FS)). RNA-seq and untargeted LC–MS revealed a strong stage/genotype structure (PCA) with high reproducibility. Pairwise contrasts (FS vs. earlier stages) and time series clustering (Mfuzz) showed extensive, stage-resolved reprogramming with small cross-cultivar overlaps. GO/KEGG indicated that GT16 is enriched for central carbon processes and glucose response, whereas GT44 favors cell-wall remodeling (xylan/xyloglucan), amino/nucleotide sugar, and phenylpropanoid pathways. Integrated analysis identified opposing temporal features across omics layers: in GT16, late-rising metabolites—including sedoheptulose—were consistent with enhanced pentose phosphate/Calvin coupling that regenerates fructose-6-phosphate for sucrose biosynthesis; in GT44, early activation of wall and secondary sinks, together with trehalose/(trehalose-6-phosphate) T6P signatures, paralleled declining soluble sugars. Across cultivars we resolved 11 and 18 genes in reciprocal opposite-trend sets (most with clear temporal order) and eight vs. five metabolites with mirrored dynamics, nominating actionable biomarkers (e.g., sedoheptulose/S7P) and regulatory nodes. These results provide a mechanistic framework linking flowering stage to carbon partitioning and suggest practical levers—timing growth moderation/ripeners, prioritizing sucrose phosphate synthase/Sucrose Phosphate Phosphatase, tempering wall flux, to sustain sucrose during reproductive development and inform breeding for high-sugar, flowering-resilient ideotypes. Full article

Pearl color is the primary determinant of its value, and the mantle donor tissue (saibo) used in pearl culture plays a critical role in color formation. To elucidate the molecular mechanisms underlying nacre color, we performed comparative transcriptomic analyses of saibo tissues from Sinohyriopsis cumingii displaying three representative phenotypes: white (W), purple (P), and golden (G). A total of 364 differentially expressed genes (DEGs) (102 upregulated and 162 downregulated genes) were identified in W vs. P. A total of 770 DEGs (467 upregulated and 303 downregulated genes) were identified in W vs. G. KEGG pathway analysis revealed significant differences in the expression of genes mainly involved in pigment-based and structural coloration, including amino sugar and nucleotide sugar metabolism (ko00520), cell adhesion molecules (ko04514), tyrosine metabolism (ko00350), ECM-receptor interaction (ko04512), and PI3K-Akt signaling pathway (ko04151). Subsequent integrative analyses across W vs. P and W vs. G groups identified 45 key regulatory genes, which were classified into four functional categories: extracellular matrix protein synthesis and biomineralization (e.g., chit, silkmaxin, bmp2/7, profilin, perlucin2), organic pigment metabolism (e.g., tyr, typ, dbh, bco2, gst5, ldlr, cpox, pks-like 1, pks15), metal ion metabolism and accumulation (e.g., hip-like, fcr1, ferritin 2), and epigenetic regulation (e.g., metK, mbd4/6, mettl24/27, alkbh6). Taken together, our findings reaffirm the complex nature of pearl coloration and reveal that structural coloration, pigment biosynthesis, and epigenetic modulation collectively shape nacre color formation, which paves the way for further functional elucidation of color-related genes and facilitates selective breeding practices in S. cumingii. Full article

Background: Seed shattering enhances ecological adaptation in perennial grasses but severely limits harvestable seed yield in forage crops. Psathyrostachys juncea is an important perennial forage species in arid and cold regions, yet the genetic basis of its seed shattering remains largely unknown. Here we asked which genomic regions and biological pathways underlie natural variation in seed shattering in P. juncea, and whether cellulose synthase (CESA)-mediated cell-wall formation contributes to abscission-zone strength. Results: We evaluated seed shattering in a diverse association panel of P. juncea across four environment–-year combinations and performed a genome-wide association study (GWAS) using genotyping-by-sequencing single-nucleotide polymorphism (SNP) markers. The analysis identified 36 significant SNP loci distributed on multiple chromosomes, consistent with a highly polygenic and environment-responsive architecture. Candidate-gene annotation highlighted pathways related to cell-wall biosynthesis, hormone signaling and sugar transport. Notably, in the BT23SHT environment a cluster of association signals on chromosome 3D co-localized with several genes annotated as cellulose synthase (CESA). Abscission-zone transcriptome profiling and qRT-PCR at 7, 14, 21 and 28 days after heading revealed that CESA genes, including TraesCS3D02G010100.1 located near the lead SNP Chr3D_3539055, showed higher early expression in low-shattering lines and a decline toward baseline in high-shattering lines. Comparative analyses placed P. juncea CESA proteins within a broadly conserved but lineage-divergent framework among grasses. Conclusion: Together, these results define the genetic landscape of seed shattering in P. juncea and nominate cellulose-biosynthetic genes on chromosome 3D as promising targets for marker-assisted selection of low-shattering, high-seed-yield forage cultivars. Full article

Salt stress severely impairs rice (Oryza sativa L.) germination and seedling establishment. Exogenous spermidine (Spd) has been shown to regulate stress tolerance in plants, but whether it acts during rice germination and seedling establishment under salt stress remains unclear. Here, rice seeds (cv. Jindao 919) were exposed to 75 mM NaCl with different Spd concentrations (0–1.4 mM), and physiological, biochemical, and transcriptomic responses were evaluated. The findings showed that salt stress had a pronounced inhibitory effect on both seed germination and seedling development. Exogenous Spd effectively alleviated these negative effects, with the most significant improvements observed at 1.0–1.2 mM: germination rate increased by 3.98–8.52%, seedling root length increased by 17.74–37.68%, soluble sugar content increased by 29.83–230%, and SOD and POD activities increased by 29.81–40.3% and 18.45–44.0%, respectively, while MDA content decreased by 36.28–40.3%. Further transcriptomic analysis identified a total of 1835 differentially expressed genes (DEGs). KEGG enrichment analysis revealed these genes were concentrated in key pathways including terpenoid biosynthesis, phenylpropanoid biosynthesis, and amino sugar and nucleotide sugar metabolism, thus alleviating the negative impact of salt stress on rice germination and seedling development. These pathways are closely related to gibberellin metabolism, lignin biosynthesis, and amino sugar metabolism, further revealing the regulatory role of Spd. Overall, 1.0–1.2 mM Spd was most effective in alleviating salt stress by synergistically regulating antioxidant defense, osmoregulation, and metabolic reprogramming, enhancing rice’s overall stress tolerance. This study provides theoretical guidance for precise regulation of Spd concentration to improve rice performance in saline-alkaline soils, and reveals the sustained promoting effects of Spd across various developmental stages of rice and its underlying molecular mechanisms. Full article

This study aimed to investigate the regulatory mechanisms underlying the relationship between cardiac structure and function and plasma metabolic characteristics in Yili horses participating in an 80-km endurance, by integrating echocardiography, lipidomics, and energy metabolomics analyses. Twenty four competing Yili horses were selected and divided based on competition outcomes: Pre-Completion Group: PCG (n = 6); Post-Completion Group: PoCG (n = 6); Overtime Completion Group: OCG (n = 6); and Non-Completion Group: NCG (n = 6). Cardiac structural and functional parameters were assessed via echocardiography, and intergroup differences were analyzed using one-way ANOVA with a significance threshold of p < 0.05. Plasma lipids and energy metabolites were quantified using UPLC–MS/MS, applying screening criteria of variable importance in projection (VIP) > 1, p < 0.05, and fold change (FC) > 1.2 or FC < 0.833. Bioinformatics analyses were subsequently conducted to identify intergroup variations and correlations. Specifically, associations between cardiac structure/function and metabolites were examined using Pearson correlation analysis, with screening criteria of p < 0.05 and correlation coefficient > 0.8. The results revealed the following: (1) Regarding cardiac structure and function, the PCG group exhibited significantly superior indices, including End-diastolic left ventricular diameter (LVIDd), End-diastolic left ventricular volume (EDV), stroke volume (SV), and ejection fraction (EF), compared with OCG and NCG, and LVIDd showed a highly significant negative correlation with competition completion time. (2) In metabolomic analyses, few differential metabolites were found among groups before the competition (only 60 between PCG and NCG), whereas 234 differential lipids were detected between PoCG and PCG, mainly enriched in sphingolipid metabolism and fatty acid degradation pathways. Energy metabolites showed distinct exercise-responsive patterns, with 22 differential metabolites between PCG and NCG and 21 between PoCG and PCG, significantly enriched in amino sugar and nucleotide sugar metabolism and TCA pathways. Dynamic changes in key TCA intermediates, such as citrate and succinate, reflected enhanced aerobic oxidative metabolism during endurance exercise. (3) Carnitine C18:1, Carnitine C10:2, FFA (20:3), Cer (t17:2/23:0) and 3-phenyllactic acid were significantly correlated with cardiac indicators such as LVLD and LVFWs (p < 0.05). In summary, performance in the 80-km endurance of Yili horses was primarily influenced by enlarged LVIDd and EDV, as well as the regulation of sphingolipid–fatty acid metabolic pathways. Triglycerides, specific acyl compounds, and ceramides may serve as potential biomarkers for evaluating endurance performance, providing a theoretical basis for scientific training and breeding of endurance horses. Full article

Thermosensitive genic male sterility (TGMS) lines are vital for two-line hybrid breeding. However, the molecular mechanism in the reverse TGMS line 05ms in eggplant remains unclear. Weighted gene co-expression network analysis (WGCNA) of RNA-seq data revealed modules correlated with fertility conversion enriched in carbohydrate metabolism, lipid metabolism, and mRNA surveillance pathways. Hub genes within these modules were predominantly associated with sugar-related processes, fatty acid metabolism, and nucleotide processing. BSA-seq defined candidate genomic intervals. Integrated analysis of BSA-seq intervals and transcriptomic data identified a candidate gene, SmHTH, with consistently lower expression in 05ms compared to S63. Its homologs exhibited temperature-induced expression, possibly compensating for SmHTH deficiency under high temperatures to restore fertility. The homologs co-expressed with three transcription factors are likely intricately linked to this response. We propose a compensatory model demonstrating that low SmHTH expression at low temperatures disrupts key metabolic pathways, causing male sterility. Conversely, elevated expression of homologous genes and transcription factors (TFs) at higher temperatures compensates for the loss of SmHTH function, thereby restoring fertility. The findings of this research not only deepen the theoretical understanding of plant male sterility mechanisms but also provide valuable resources for developing stress-resilient vegetable varieties through modern breeding techniques. Full article