SEARCH · PubMed Health

Results for “nitrate”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed2025

Nitrate modulates pectin metabolism and cell wall mechanics during cell expansion in Arabidopsis.

Nitrate is a key nutrient and one of the most important nitrogen sources for land plants. Besides its nutritional role, nitrate is a signal molecule that regulates plant gene expression, metabolism, physiology, growth, and development. In cotyledons and true leaves, nitrate promotes growth by inducing cell expansion. Plant cell expansion requires changes in the cell wall. However, there is scant information on the influence of nitrate on cell wall metabolism and properties during cell expansion and growth. Here, we demonstrate that nitrate availability modulates pectin metabolism, a major polysaccharide of the primary cell wall. Using colorimetric assays, immunohistochemistry, and confocal microscopy, we show that nitrate enhances methylesterified pectin during cotyledon cell expansion. This is achieved by increasing galacturonic acid (GalA) deposition as homogalacturonan (HG) and by decreasing global PME activity. We further show that this regulation is dependent on nitrate signaling pathway components, including NRT1.1 and NLP7. Pectin methylesterification state impacts the mechanical properties of the cell wall. We characterized cell wall elasticity changes during nitrate-induced expansion using atomic force microscopy (AFM) and automatic confocal microextensometry (ACME). We found that nitrate induces cell wall softening at both cellular and whole-tissue levels during this expansion process. Our results indicate pectin metabolism plays an important role in nitrate-induced cell expansion and cotyledon growth in Arabidopsis. We provide insights into the interplay between nitrate signaling, cell wall metabolism, and biomechanical properties for cell expansion. Our results contribute to our understanding of how plants sense and respond to environmental cues for growth.

Pectins↗

PubMed2026

The TANG cluster comprising ten nitrate transporter genes controls fruit sweetness and size in tomato.

Sucrose is a major transport form of photoassimilated carbon in tomato, Arabidopsis, and many other plant species, and plays a critical regulatory role in plant growth, development, and fruit quality. Plant vacuoles function as storage organelles, accumulating substantial quantities of metabolically inactive nitrates as a nitrogen reserve and soluble sugars as a carbon reserve. Consequently, the balance between nitrate and sucrose accumulation determines plant growth dynamics and fruit taste. In this study, we identified a gene cluster designated TANG (Total soluble solidsAccumulation viaNitrate transporterGene cluster), comprising ten nitrate transporter genes that are significantly associated with sucrose accumulation in tomato. This gene cluster mediates the transport of nitrate between the cytoplasm and vacuole, thereby influencing its storage. Functional disruption of TANG8, a member of the gene cluster, results in either enhanced sugar accumulation or increased fruit size. Selective disruption of multiple TANG cluster members yields fruits with elevated sweetness and increased fruit size in S. pimpinellifolium. The interaction between the TANG members and a tonoplast localized Sucrose Transporter 4 provides insight into the competitive accumulation of nitrate and sugar. The multiplex editing of a gene cluster provides a successful example of engineering crops with high quality and yield.

Gene cluster↗

PubMed2026

Expansion and Nitrate-Responsive Expression of NRT3 Transport Regulators in Maritime Pine.

Nitrate uptake in plants is mediated by coordinated transporter systems, which include NPF, NRT2 and NRT3 proteins. While these families have been extensively studied in angiosperms, their evolution and regulation in conifers are still not well understood. In this work, we examined the NRT3 family in maritime pine (Pinus pinaster) and in representative plant lineages. Phylogenetic analyses of nucleotide sequences and the NRT3 protein revealed a broad expansion in gymnosperms, particularly in conifers, while copy number increases among angiosperms appeared to be more lineage-specific. In addition, we evaluated the expression of nitrate transporter genes in cotyledons, hypocotyls and roots of P. pinaster seedlings exposed to low and high concentrations of nitrate. Several NRT3 genes, particularly PpNRT3.1, PpNRT3.3 and PpNRT3.5, were significantly induced by nitrate, while most NPF and NRT2 genes showed weaker or non-significant transcriptional responses. Correlation analysis revealed distinct expression associations among the NRT3, NRT2 and NPF transporters, including a specific association between PpNRT3.4 and PpNRT2.1, as well as broader correlations among other NRT3 paralogs and NPF genes. These results indicate that the expansion of NRT3 in conifers was accompanied by transcriptional divergence among paralogs and identify potential regulatory relationships for future functional studies.

NPF↗

PubMed2026

The effects of nitrate and nitrite supplementation on mitochondrial respiration in permeabilized muscle fibres in young healthy adults.

Nitric oxide (NO) is a direct regulator of mitochondrial respiration. Nitrate (NO3-) and nitrite (NO2-) are good sources of NO, but whether their effects on mitochondrial respiration differ between in vivo and in vitro administration remains unclear. In Study 1, 8 participants consumed NO3- -rich beetroot juice (BR) (∼12.8 mmol NO3-) and NO3- -depleted placebo beetroot juice (PL) (∼0.08 mmol NO3-) acutely and chronically for 2 weeks in a randomised, double-blind, crossover design. A substrate-uncoupler-inhibitor titration (SUIT) protocol was used to assess mitochondrial respiration using high-resolution respirometry (oxygen tension: ∼200-450 μM) in permeabilized muscle fibres. In Study 2, skeletal muscle samples were collected from 11 participants. In a randomised, crossover design, different doses (0, 1.5, and 3.0 μM) of sodium nitrite (NaNO2) were administered to permeabilized muscle fibres. Mitochondrial respiration was measured using the same SUIT protocol under lower oxygen tension (∼50-200 μM). Although muscle NO3- concentration significantly increased after both acute and chronic BR supplementation, mitochondrial respiration and exercise performance did not differ between PL and BR in either condition. Similarly, absolute oxygen flux across different respiratory states were not different between different doses of NaNO2. However, the leak control ratio, reflecting the degree of uncoupling of mitochondrial respiration, was significantly higher with 3.0 μM NaNO2 administration (0.12 ± 0.05) compared to 0 μM NaNO2 administration (0.09 ± 0.04, P = 0.03). These findings, involving both in vivo and in vitro administration approaches, albeit in the presence of relatively high oxygen concentrations, suggest that neither NO3- nor NO2- improves mitochondrial respiration, at least in young healthy adults.

Humans↗

PubMed2025

Coupling of spectroscopy and nitrogen-oxygen isotopes unveils the mechanisms of dissolved organic matter and nitrate pollution in lakes within the agro-pastoral transition zone.

Lakes in arid and semi-arid regions are subjected to severe ecological stress, such as organic pollution, eutrophication, and salinization, due to climate change and human activities. This study investigates Chagannur Lake, a typical arid-region lake that is representative and ecologically sensitive in Northern China's agro-pastoral ecotone, to uncover its pollution characteristics and mechanisms. We employed fluorescence spectroscopy and stable isotope analysis to trace dissolved organic matter (DOM) and nitrate sources. The DOM composition was dominated by microbial metabolic byproducts and protein-like substances, suggesting that microbial processes are key to organic matter transformation. Source apportionment revealed that pollutants primarily originated from livestock and poultry manure (37.6 %), agricultural fertilizers (35.6 %), and soil erosion (24.7 %), with agricultural fertilizers contributing most significantly in the Gogstai River (63.3 %). A structural equation model (SEM) coupling spectral and mass spectrometric data revealed that microbial transformation significantly impairs the lake's self-purification capacity, thereby promoting pollutant accumulation (path coefficient = 0.91,*p < 0.05). Moreover, microbial processes link endogenous and exogenous pollution, a mechanism effectively traced by isotopic and fluorescence indices (path coefficient = 0.55, ⁎⁎p < 0.01). These findings enhance the understanding of pollution sources and transformation mechanisms in arid-region lakes and offer foundational theoretical support for policymakers engaged in pollution control strategies.

Lakes↗

PubMed2026

Deciphering the effects of sulfonamide antibiotics on denitrification from a metagenomic perspective: Inhibition of nitrite reduction and succession patterns of functional microorganisms.

Limited research has thoroughly elucidated the impact mechanisms of antibiotics on the denitrification process at the genomic and gene levels, which has hindered the optimization and development of nitrogen removal technology for antibiotic-containing swine wastewater. Lab-scale sequencing batch reactors were constructed in this study to treat synthetic wastewater containing different sulfonamides and nitrate. Investigations were carried out on denitrification performance, microbial community diversity, denitrifier succession patterns, and functional gene distribution. The stress of sulfonamides inhibited the nitrite reduction process, transforming complete denitrification into partial denitrification and causing significant nitrite accumulation. The average nitrogen removal efficiency in the treatment groups decreased from 81.0% ± 2.2-40.1% ± 6.1%. Alicycliphilus and Thauera were identified as the key taxa, accounting for 32.2% and 16.9% of all potential denitrifying bacteria, respectively. Although metagenome-assembled genomes (MAGs) from Thauera were enriched with genes encoding nitrate reductases (nap, nar) and nitrite reductases (nir), this genus preferentially utilized nitrate as an electron acceptor, resulting in the preferential nitrate reduction and subsequent nitrite accumulation. In contrast, Alicycliphilus MAGs developed tolerance to the sulfonamides stress during later stages, with concomitant enrichment of associated functional genes. They replaced Thauera to reemerge as the dominant group, thereby restoring complete denitrification. This study provides new insights into the regulatory mechanisms governing complete versus partial denitrification in nitrogen removal from antibiotic-containing wastewater.

Denitrifier succession↗

PubMed2026

Mechanism exploration of divergent partial denitrification performance under tetracycline stress: Insights from functional gene, electron transport and molecular docking.

Nitrates and antibiotics like tetracycline (TC) coexist in wastewater and inhibit nitrite (NO₂--N) accumulation during partial denitrification (PD), restricting anammox coupling. A moving bed biofilm reactor (PD-MBBR) and a sequencing batch reactor (PD-SBR) were compared under TC stress (0-8 mg/L). The PD-MBBR proved more robust, sustaining a high nitrate transformation ratio (NTR) of 95.11% and ∼53% TC removal. Metagenomic sequencing, quantitative polymerase chain reaction (qPCR), and molecular docking revealed this tolerance stemmed from physical shielding and metabolic compensation. Carrier-attached growth promoted extracellular polymeric substances (EPS) overproduction, forming a dense barrier preventing TC from binding to key denitrifying enzymes. The biofilm maintained stable nitrate reductase (NAR) activity via high narG and napA gene abundances, while nitrite reductase (NIR) was inhibited, ensuring efficient NO₂--N accumulation. This was supported by hyperactivated electron transport chain components, with complex III relative abundance increasing 15.08% and peak enzymatic activity reaching 149.02%. While IntI1-mediated horizontal gene transfer fortified community defense, concentrated antibiotic resistance genes (ARGs) within the biofilm pose a secondary dissemination risk. Thus, PD-MBBR provides an efficient pretreatment strategy for anammox, though downstream ARGs management is warranted.

Denitrification↗

PubMed2026

A study on the differences in recovery effects of different types of nutritional supplements on competitive performance of esports athletes under mental fatigue.

BACKGROUND: To compare the effects of different nutritional supplements on the recovery of core competitive performance abilities in esports athletes following mental fatigue and to observe changes in the autonomic nervous system during recovery after nutritional supplementation by monitoring heart rate variability (HRV). METHODS: A randomized crossover within-subject controlled experimental design was adopted, including nutritional supplement type (caffeine, nitrate, Ginkgo biloba extract, catechins, placebo) × mental fatigue state (initial, fatigued, post-supplementation). Twenty high-level first-person shooter (FPS) esports athletes were recruited. Mental fatigue was induced using a Stroop task. After ingesting the different supplements and resting for 60 minutes, the participants completed assessments of shooting accuracy, shooting stability, spatial localization, and multitasking ability using the KovaaK's simulation trainer. HRV indices were also recorded to evaluate changes in autonomic regulation. RESULTS: For shooting accuracy, compared with the placebo condition, all four supplements significantly improved shooting accuracy scores following mental fatigue (all p < 0.05); however, no significant differences were observed among the effects of the different supplements. For shooting stability, caffeine, nitrate, and catechins produced significant recovery effects on shooting stability (all p  < 0.05); however, no significant differences were observed among the effects of these three supplements. For spatial localization and multitasking ability, the improvements in these two abilities in the post-supplementation state may have resulted from natural recovery, and none of the four nutritional supplements demonstrated a significant recovery effect. The HRV results showed that indices including RMSSD and SDNN changed under some supplement conditions. CONCLUSIONS: Mental fatigue significantly reduced the competitive performance of esports athletes. Four types of nutritional supplements all promoted the recovery of shooting accuracy, while caffeine, nitrate, and catechins promoted the recovery of shooting stability. However, no additional recovery advantages of the nutritional supplements over placebo were identified for spatial localization or multitasking ability. Changes in HRV may reflect changes in autonomic regulation during recovery, but further research is still warranted.

Humans↗

PubMed2026

Mikania micrantha invasion restructures rhizosphere nitrogen cycling through enzyme activation, microbial recruitment, and allelopathic regulation.

BACKGROUND: Plant invasions profoundly influence terrestrial ecosystems by reshaping nutrient cycling processes. However, the mechanisms through which invasive plants such as Mikania micrantha modulate soil nitrogen (N) cycling and microbial communities remain insufficiently explored. Moreover, comparative studies with indigenous congener are scarce, limiting insights into whether such effects reflect species-specific strategies or genus-wide traits. This study investigates how M. micrantha modulates nitrogen metabolic pathways and rhizosphere microecology using combined metagenomic and metabolomic analyses. RESULTS: Integrated analyses revealed that M. micrantha established a distinctive "high total nitrogen-low mineral nitrogen" profile in the rhizosphere soil. Metagenomic profiling showed consistent enrichment of key ammonium assimilation enzymes, including glutamine synthetase and glutamate dehydrogenase, promoting enhanced incorporation of NH₄⁺ into organic nitrogen pools. In contrast, genes encoding nitrate reductase and nitrate transporters were significantly lower in relative abundance, limiting nitrate assimilation. Mikania micrantha also selectively enriched nitrogen-fixing microbes (notably rhizobia genera) and plant growth-promoting rhizobacteria (PGPR), thereby enhancing biological nitrogen fixation capacity. Metabolomic analysis further identified several allelopathic compounds in invaded soils at higher relative abundance, particularly epicatechin, which exhibited inhibitory effects on nitrifying bacteria. Compared with the congener Mikania cordata, which exerted weaker impacts on soil nitrogen cycling and microbial assembly, M. micrantha deployed a more comprehensive strategy integrating biochemical, microbial, and metabolic regulation. CONCLUSIONS: These findings demonstrate that under greenhouse-controlled conditions, M. micrantha reconfigures rhizosphere nitrogen cycling through a multi-dimensional strategy that couples biochemical regulation, microbial recruitment, and metabolite-mediated interference, thereby suggesting a potential mechanism that may contribute to its ecological advantage in natural settings. Video Abstract.

Rhizosphere↗

PubMed2026

Low-Carbon-Residue Multi-Principal-Element Magnetic Alloys for Excellent Microwave Absorption.

Magnetic alloy/carbon composites are promising microwave absorbers due to abundant interfaces and multiple loss mechanisms. However, reducing carbon content while maintaining uniform magnetic component distribution remains challenging. We report a spray-drying strategy to address this. By tuning nitrate precursor ratios and optimizing thermal treatment, we synthesize low-carbon alloy/oxide microspheres with uniformly distributed alloy phases. Limiting carbon content improves impedance matching, while selective nitrate precipitation creates a magnetic alloy architecture that suppresses nanoparticle agglomeration and enhances interfacial polarization. For this multiscale synergistic polarization is achieved: highly conductive Cu maximizes conduction loss, insulating Al2O3 buffers impedance, and Mn provides abundant polarization centers. The resulting microspheres exhibit tunable, exceptional performance. The attenuation-dominated FeCuMn system achieves -48.2 dB minimum reflection loss at 1.5 mm thickness. The impedance-matched FeCuAl system delivers an ultra-broad effective absorption bandwidth (EAB) of 5.12 GHz. Additionally, the FeAlMn system demonstrates superior polarization miniaturization for optimal absorption at extremely thin matching thicknesses. This work provides a practical strategy for designing electromagnetic composite structures with tunable component distribution.

customizable multicomponent↗

PubMed2026

Abundance-transcription decoupling reveals functional partitioning in bioelectrochemical denitrification biofilms.

Bioelectrochemical denitrification (BED) is often attributed to electroactive microorganisms that access electrode-derived electrons, yet the relative functional contribution of electroactive taxa and denitrifying populations within complex BED biofilms remain unclear. Here, we integrated reactor measurements with genome-resolved metagenomics and metatranscriptomics to examine microbial community structure, functional potential, and gene transcription across contrasting BED operational regimes differing in dissolved oxygen (DO), hydraulic retention time (HRT)/loading, and poised potential. Nitrate removal exceeded 90% across all tested conditions, but nitrogen intermediate accumulation, current generation, and theoretical electron balance differed substantially. Electroactive taxa such as Geobacter dominated (>80% abundance) under longer HRT and stronger poised potential, but contributed minimally to the transcription of canonical denitrification genes. Weaker cathodic potential enriched transcriptionally active denitrifying taxa such as Stutzerimonas, Acidovorax, and MR-S7, while oxygen exposure induced redox-stress responses and reshaped nitrogen metabolism beyond being a competing electron acceptor. Together, these results reveal a decoupling between taxonomic abundance, genomic functional potential, and transcriptional contribution in BED biofilms, indicating that nitrate-removal performance cannot be inferred from current generation or electroactive-taxon abundance alone.

Bioelectrochemical system↗

PubMed2026

Enhancement of secondary organic aerosol formation from isoprene photooxidation by ammonia.

Ammonia (NH3) can participate in atmospheric secondary organic aerosol (SOA) formation by reacting with organic acids and carbonyl compounds in particle phase, but its influence on the gas phase chemistry remains unclear. This study performed a series of smog chamber experiments to investigate the influence of NH3 on the formation of SOA from isoprene photooxidation by OH radicals. Both gas and particle phase products were measured with a series of state-of- art instruments including a nitrate ion chemical ionization mass spectrometer (nitrate-CIMS) and high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS). Our results showed that in the presence of NH3 SOA in the chamber significantly increased, along with an enhanced oxidation of isoprene. CIMS analysis further showed that NH3 in the chamber homogeneously reacts not only with gas-phase organic acids but also with gaseous low volatility oxygenated organic molecules (OOMs) to generate extremely low volatility and ultralow volatility NH3-OOMs clusters. Quantum chemical calculation showed that NH3 can spontaneously interact with OOMs to form NH3-OOMs clusters by forming hydrogen bonds with RCOOH, R-OOH, and R-OH. These clusters can promote new particles formation and particle growth through nucleation and condensation, directly enhancing the isoprene SOA production with a contribution of 78% to the enhanced SOA. Moreover, the formation of NH3-OOMs clusters also results in more isoprene consumed by OH radicals, indirectly increasing the SOA production with a contribution of 22 % to the enhanced SOA. Our work for the first time clarified a synergetic effect of NH3 on isoprene SOA formation, which should be accounted for by models.

Aerosols↗

PubMed2026

Metabolic niche differentiation and napA evolution stabilize partial denitrification in wastewater ecosystems.

Although partial denitrification (PD) is increasingly applied as a nitrite-supplying strategy for anammox-based nitrogen removal, the ecological distribution, metabolic specialization, and genomic determinants of stable nitrite accumulation remain poorly understood at the ecosystem scale. Here, we reconstructed 516 high-quality metagenome-assembled genomes (MAGs) using high-depth metagenomic sequencing of 107 wastewater treatment plants and classified denitrifiers according to their nitrite production or consumption capacities. Of these genomes, 23% (120 MAGs) were classified as partial denitrifiers, 41% (211 MAGs) as complete denitrifiers, and 36% (185 MAGs) as nitrite-reducing denitrifiers, revealing pronounced functional partitioning rather than dominance by complete denitrification pathways. Comparative genomics showed that partial denitrifiers possess metabolic architectures favoring rapid carbon oxidation and NADH generation while exhibiting constrained NADPH production and biosynthetic investment, thereby promoting nitrate-to-nitrite conversion but limiting subsequent nitrite reduction. Nitrite accumulation does not result from incomplete denitrification pathways but from metabolic niche differentiation. These metabolic trade-offs were further associated with the evolutionary divergence of the periplasmic nitrate reductase gene, napA, which displayed distinct sequence characteristics and genomic contexts between partial and complete denitrifiers. Integration of carbohydrate-active enzyme repertoires further revealed metabolic complementarity between partial denitrifiers and anammox bacteria, supporting efficient carbon handoff without direct substrate competition. From an engineering perspective, operating conditions that impose moderate electron limitation, such as low or fluctuating C/N ratios and intermittent carbon feeding, may selectively enrich partial denitrifiers and enhance a stable nitrite supply for PD-anammox systems. Together, these findings identify PD as a predictable ecological state shaped by genome-encoded metabolic specialization and provide a mechanistic basis for designing robust, low-carbon nitrogen-removal processes.

Anammox↗

PubMed2026

Building biofilms for saline hydrogenotrophic denitrification from contrasting origins: Convergent acclimation, divergent performance.

Hydrogenotrophic denitrification is promising for deep nitrogen removal from saline, low-C/N wastewaters, but rapid establishment of stable biofilms at high salinity remains challenging. Here, two saline-adapted inocula from two representative, functionally contrasting habitats-a functionally-diversified inoculum from mangrove sediment and a functionally-focused inoculum from seabed sediment-were acclimated in parallel H2-based membrane biofilm reactors at constant 3.5% salinity. The Diverse-derived biofilm required 80 d to reach steady state and achieved only partial denitrification with 61.1% nitrate removal and considerable nitrite accumulation. In contrast, the Focus-derived biofilm rapidly established complete denitrification within ∼40 d, which was maintained for >50 d, with effluent NOx- below 1 mg-N·L-1 and 98.7% nitrate removal. Microbiome analyses showed that identical operation promoted convergence in community structure and enriched similar community-level functional potentials. However, genome-resolved analysis revealed distinct source-dependent functional organization among dominant microbial populations. Complete denitrifiers co-encoding denitrifying, hydrogenotrophic, and autotrophic functions were preferentially enriched in the Focus-derived biofilm, whereas these functions remained partitioned among different dominant populations in the Diverse-derived biofilm, coinciding with less complete denitrification. These findings indicate that saline hydrogenotrophic denitrification performance depends not only on which functions are enriched at the community level, but also on how key functions become organized among microbial populations, providing a previously overlooked criterion for inoculum selection in saline biological nitrogen control.

Complete denitrification↗

PubMed2026

Lifestyle Differentiation Among Marine Denitrifying Microorganisms.

Microorganisms carrying out denitrification in marine anoxic zones drive bioavailable nitrogen loss. Sequencing datasets have demonstrated the modularity of denitrification, with most populations having the genetic capability for only a subset of the pathway (NO3-➔NO2-➔NO➔N2O➔N2). Although previous work provided ecological explanations for this diversity among the functional modules, large trait variations exist within each functional module, and this within-module diversity and its biogeochemical implications remain unexplored. Here, we combine genomic data and modeling to explore how metabolic "lifestyle" strategies influence denitrifier community structure. We build a comprehensive genomic database of marine denitrifiers, and identify lifestyle differentiation among denitrifier functional groups. We then extend a mathematical ecosystem model by resolving two microbial functional types for each module representing a metabolic trade-off: a copiotroph, optimized for fast growth, and an oligotroph, optimized for high nutrient affinity. In the model, as the supply of organic matter relative to nitrate increases, the degree of copiotrophy among the community increases and then decreases. This suggests that oligotrophs are associated with either organic-matter- or nitrate-limiting conditions, whereas copiotrophic lifestyles are associated with an intermediate regime. Our model further associates NO2- reducers with oligotrophy and NO3- reducers with copiotrophy, particularly those producing greenhouse gas nitrous oxide (N2O), linking N2O production to substrate-replete conditions, which is consistent with our genome-based lifestyle estimates. Results provide insight into denitrifier ecological niches and thus the biogeochemical conditions that are associated with the production of intermediates, such as N2O, improving our understanding of how nitrogen cycling will change in a warming ocean.

Marine denitrifiers↗

PubMed2025

Companion cells with high florigen production express other small proteins and reveal a nitrogen-sensitive FT repressor.

The precise onset of flowering is crucial to ensure successful plant reproduction. The gene FLOWERING LOCUS T (FT) encodes florigen, a mobile signal produced in leaves that initiates flowering at the shoot apical meristem. In response to seasonal changes, FT is induced in phloem companion cells located in distal leaf regions. Thus far, a detailed molecular characterization of the FT-expressing cells has been lacking. Here, we used bulk nuclei RNA-seq and single nuclei RNA (snRNA)-seq to investigate gene expression in FT-expressing cells and other phloem companion cells. Our bulk nuclei RNA-seq demonstrated that FT-expressing cells in cotyledons and true leaves showed differences especially in FT repressor genes. Within the true leaves, our snRNA-seq analysis revealed that companion cells with high FT expression form a unique cluster in which many genes involved in ATP biosynthesis are highly upregulated. The cluster also expresses other genes encoding small proteins, including the flowering and stem growth inducer FPF1-LIKE PROTEIN 1 (FLP1) and the anti-florigen BROTHER OF FT AND TFL1 (BFT). In addition, we found that the promoters of FT and the genes co-expressed with FT in the cluster were enriched for the consensus binding motifs of NITRATE-INDUCIBLE GARP-TYPE TRANSCRIPTIONAL REPRESSOR 1 (NIGT1). Overexpression of the paralogous NIGT1.2 and NIGT1.4 repressed FT expression and significantly delayed flowering under nitrogen-rich conditions, consistent with NIGT1s acting as nitrogen-dependent FT repressors. Taken together, our results demonstrate that major FT-expressing cells show a distinct expression profile that suggests that these cells may produce multiple systemic signals to regulate plant growth and development.

BROTHER OF FT AND TFL1↗

PubMed2025

Decoding nitrogen uptake efficiency in maize and sorghum: insights from comparative gene regulatory networks.

Nitrogen (N) is an essential macronutrient for plant growth and yield, yet optimizing nitrogen use efficiency remains a challenge in agriculture. To better understand the regulatory basis of plant responses to N availability, we constructed a maize-specific nitrogen uptake efficiency gene regulatory network (mNUEGRN) comprising 1625 protein-DNA interactions (PDI) between 70 promoters and 301 transcription factors using enhanced yeast one-hybrid assays. We also projected a sorghum NUE GRN (spNUEGRN) based on maize orthologs and analyzed N-responsive subnetworks in both species using transcriptome profiling under N stress of early deprivation and recovery. Cross-species comparison with an existing Arabidopsis GRN revealed about 18% conserved interaction, corresponding to 11% of the mNUEGRN, particularly within the nitrate assimilation pathways. Notably, bZIP18 and bZIP30 emerged as central regulators in mNUEGRN, forming highly connected feed-forward loops (FFLs). From our time series data, we identified 19 236 and 23 864 differentially expressed genes in maize and sorghum, respectively. Gini correlation analysis uncovered 764 and 638 FFLs in mNUEGRN and spNUEGRN, respectively, of which 22 FFLs in maize and 35 in sorghum were identified in both leaf and root for each species. These FFLs may represent candidate regulatory motifs that contribute to modulating transcriptional responses under fluctuating N conditions, but their potential roles require further investigation. Together, our findings reveal evolutionarily conserved and species-specific regulatory strategies that mediate early N responsiveness, offering a foundation for engineering crops with improved NUE.

Sorghum↗

PubMed2026

Genome sequence data of the chitinase-producing bacterium Paenibacillus mucilaginosus YWY-5.1.

Paenibacillus mucilaginosus is a beneficial bacterium widely applied as a biofertilizer in agriculture. To date, genomic information on this species remains limited; however, no genome assemblies from Vietnam have been reported. This work presented the draft genome of P. mucilaginosus YWY-5.1, a promising strain with strong chitin-degrading capability and agricultural potential, isolated from Yok Don National Park, Vietnam, using Illumina technology. Results showed that the assembled genome comprised 48 contigs with 4,076,146 bp and 73.8% GC-content. Genome annotation identified 3,611 protein-coding genes, 2 rRNA genes, and 53 tRNA genes. A total of 150 carbohydrate-active enzyme-related genes were predicted from the genome; among them, seven putative chitinolytic genes were identified, including 4 genes related to family 18 chitinase, 2 genes to family 20 β-N-acetylglucosaminidase, and one gene to auxiliary activity family 10. In addition, at least 32 genes related to plant growth-promoting functions were identified, including those associated with indole-3-acetic acid production, phosphate and potassium solubilization, siderophore biosynthesis, iron uptake, ACC metabolism, and nitrate transport and reduction. Furthermore, genome mining identified 4 biosynthetic gene clusters probably involved in secondary metabolite production, of which 3 displayed no similarity to previously reported clusters, indicating potential for novel bioactive compounds. These genomic data improved our understanding of the biodegradation capacity and agricultural potential of P. mucilaginosus YWY-5.1 isolated from Vietnam, and provided a valuable genomic resource for future functional and biotechnological investigations toward crop production and related fields.

Chitinases↗