Search Results (175)

Upon reacting with cellular components, Hg(II) ions elicit the production of reactive oxygen species (ROS). While the ROS-promoted cytotoxic and genotoxic effects induced by Hg(II) have been widely described in eukaryotes, such effects have been less studied in bacteria. In this work, the prokaryotic environmental model Bacillus subtilis was employed to evaluate the cytotoxic and genotoxic impact of Hg(II) over strains proficient or deficient in SOS, general stress and antioxidant responses, as well as the global transcriptional response elicited by this ion. The exposure to HgCl₂ significantly increased the mutation frequency to rifampicin resistance (Rif^R) in WT and mutant strains, suggesting a major contribution of these pathways in counteracting the genotoxic effects of Hg(II). Detection of A → T and C → G transversion mutations in the rpoB gene of Hg(II)-exposed cells suggested the generation of 8-oxo-guanines (8-OxoGs) and other oxidized DNA bases. The RNA-seq study revealed upregulation of genes involved in efflux and/or reduction of metal ions, synthesis of sulfur-containing molecules, and downregulation of genes implicated in iron metabolism and cell envelope stress. Therefore, our results indicate that metal extrusion and scavenging of Hg(II) by thiol-rich molecules may constitute a line of defense of B. subtilis that counteracts the noxious effects of ROS resulting from an imbalance in iron metabolism elicited by this ion. Full article

Sulfate availability critically influences plant growth, yet the role of small RNAs, particularly microRNAs (miRNAs), in regulating responses to sulfate deficiency remains poorly understood. Here, we conducted a temporal analysis of sulfate deficiency-responsive miRNAs in the roots and leaves of Solanum lycopersicum (tomato), using an updated miRNA annotation in the SL4.0 genome. We found 40 differentially expressed miRNAs, including 2 novel, tomato-specific miRNAs. Tomato miRNAs showed an important time- and organ-specific regulation, similar to the described response of the mRNA transcriptome. Integration with transcriptomic data and Degradome-seq analysis highlighted both canonical and non-canonical targets for sulfate-responsive miRNAs. miR395, the most extensively studied miRNA, was found to control not only its conserved targets involved in sulfate transport and assimilation, but also genes involved in redox homeostasis, photosynthesis and chloride transport. Notably, most targets were repressed in leaves, suggesting miRNA-mediated downregulation of energy-intensive processes, while root targets were predominantly upregulated, including genes related to protein remodeling and antioxidant defense. Comparative analysis with Arabidopsis thaliana revealed a broader functional repertoire in tomato, suggesting species-specific adaptations to sulfate deficiency. Overall, our results underscore the critical role of miRNAs in fine-tuning organ-specific metabolic reprogramming during nutrient stress, expanding the current understanding of the regulatory landscape underlying sulfate deficiency in plants. Full article

This study investigated individual/combined nitrogen (N) and potassium (K) deficiencies on ginseng root aroma using GC–MS metabolomics. Four treatments (normal supply, N deficiency (LN), K deficiency (LK), and dual deficiency (LNLK)) were analyzed. Deficiencies impaired growth, mineral accumulation, and induced oxidative stress, suppressing ginsenoside biosynthesis. From 1768 detected VOCs, 304 compounds (rOAV ≥ 1) significantly contributed to aroma. LN inhibited terpenoids (e.g., isoborneol) but upregulated sulfur compounds (e.g., di-2-propenyl tetrasulfide), intensifying pungency. LK enhanced sweet/woody notes (e.g., 2′-acetonaphthone) via flavonoid biosynthesis and toluene degradation. LNLK reduced esters (e.g., benzyl acetate) and terpenes, attenuating floral–balsamic nuances by coordinating aromatic degradation, glutathione metabolism, and ABC transporters. N–K nutrition dynamically shapes ginseng aroma by differentially regulating phenylpropanoid, terpenoid, and sulfur pathways, providing a foundation for precision fertilization and quality improvement. Full article

Constructing heterojunction photocatalysts with efficient interfacial charge transfer is critical for solar-driven hydrogen evolution. In this study, a highly dispersed MoS₂/g-C₃N₄ composite was successfully synthesized via a stirring-assisted hydrothermal in situ growth strategy. The introduction of stirring during synthesis significantly enhanced the uniform dispersion of MoS₂ nanosheets and exposed abundant edge sites, leading to well-integrated heterojunctions with enhanced interfacial contact. Comprehensive structural and photoelectronic characterizations (XRD, SEM, TEM, EDS mapping, UV–Vis, TRPL, EIS, EPR) confirmed that the composite exhibited improved visible-light absorption, accelerated charge separation, and suppressed recombination. Under simulated solar irradiation with triethanolamine (TEOA) as a sacrificial agent, the optimized 24% MoS₂/g-C₃N₄-S catalyst achieved a high hydrogen evolution rate of 14.33 mmol·g⁻¹·h⁻¹ at a catalyst loading of 3.2 mg, significantly outperforming the unstirred and pristine components, and demonstrating excellent cycling stability. Mechanistic studies revealed that the performance enhancement is attributed to the synergistic effects of Type-II heterojunction formation and edge-site-rich MoS₂ co-catalysis. This work provides a scalable approach for non-noble metal interface engineering and offers insight into the design of efficient and durable photocatalysts for solar hydrogen production. Full article

While Forgetting Factor Recursive Least Square (FFRLS) algorithms with evaluation mechanisms have been developed to address SOC-dependent parameter mapping shifts and their efficacy has been proven in Li-ion batteries, their applicability to lithium–sulfur (Li-S) batteries remains uncertain due to different electrochemical characteristics. This study critically evaluates the applicability of a Fisher information matrix-constrained FFRLS framework for online parameter identification in Li-S battery equivalent circuit network (ECN) models. Experimental validation using distinct drive cycles showed that the identification results of polarization-related parameters are significantly biased between different current excitations, and root mean square error (RMSE) variations diverge by 100%, with terminal voltage estimation errors more than 0.05 V. The parametric uncertainty under variable excitation profiles and voltage plateau estimation deficiencies confirms the inadequacy of such approaches, constraining model-based online identification viability for Li-S automotive applications. Future research should therefore prioritize hybrid estimation architectures integrating electrochemical knowledge with data-driven observers, alongside excitation capturing specifically optimized for Li-S online parameter observability requirements and cell nonuniformity and aging condition consideration. Full article

Cilantro (Coriandrum sativum L.) is a popular annual culinary herb grown for its leaves or seeds. With the increase in hydroponic herb production in controlled environments, a need exists for leaf tissue nutrient standards specific to this production system. The objective of this study was to develop comprehensive foliar mineral nutrient interpretation ranges for greenhouse-grown cilantro. Cilantro plants were grown in a hydroponic sand culture system to induce and document nutritional disorders. Plants were supplied with a modified Hoagland’s solution, which was adjusted to individually add or omit one nutrient per treatment while holding all others constant. Deficiency and toxicity symptoms were photographed, after which the plant tissue was collected to determine plant dry weight and critical tissue nutrient concentrations. Nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), boron (B), iron (Fe), and zinc (Zn) deficiencies, as well as B toxicity, were induced. Deficiencies of copper (Cu), manganese (Mn), and molybdenum (Mo) were not observed during the experiment. Additional foliar tissue analysis data (n = 463) were compiled to create nutrient interpretation ranges for 12 essential elements based on a hybrid meta-analysis Sufficiency Range Approach (SRA). This approach defines ranges for deficient, low, sufficient, high, and excessive values. For each element, the optimal distribution was selected according to the lowest Bayesian Information Criterion (BIC) value. A Normal distribution best represented K and S. A Gamma distribution best represented P, Ca, Mn, and Mo, whereas a Weibull distribution best represented N, Mg, B, Cu, Fe, and Zn. These interpretation ranges, along with descriptions of typical symptomology and critical tissue nutrient concentrations, provide useful tools for both diagnosing nutritional disorders and interpreting foliar nutrient analysis results of greenhouse-grown cilantro. Full article

N, as plants’ most essential nutrient, profoundly shapes root system architecture (RSA), with LRs being preferentially regulated. This review synthesizes the intricate molecular mechanisms underpinning N sensing, signaling, and its integration into developmental pathways governing LR initiation, primordium formation, emergence, and elongation. We delve deeply into the roles of specific transporters (NRT1.1, nitrate transporter 2.1 (NRT2.1)), transcription factors (Arabidopsis nitrate regulated 1 (ANR1), NLP7, TGACG motif-binding factor (TGA), squamosa promoter-binding protein-like 9 (SPL9)) and intricate hormone signaling networks (auxin, abscisic acid, cytokinins, ethylene) modulated by varying N availability (deficiency, sufficiency, excess) and chemical forms (NO₃⁻, NH₄⁺, organic N). Emphasis is placed on the systemic signaling pathways, including peptide-mediated long-distance communication (CEP—C-terminally encoded peptide receptor 1 (CEPR1)) and the critical role of the shoot in modulating root responses. Furthermore, we explore the emerging significance of carbon–nitrogen (C/N) balance, post-translational modifications (ubiquitination, phosphorylation), epigenetic regulation, and the complex interplay with other nutrients (phosphorus (P), sulfur (S)) and environmental factors in shaping N-dependent LR plasticity. Recent advances utilizing single-cell transcriptomics and advanced imaging reveal unprecedented cellular heterogeneity in LR responses to N. Understanding this sophisticated regulatory network is paramount for developing strategies to enhance nitrogen use efficiency (NUE) in crops. This synthesis underscores how N acts as a master regulator, dynamically rewiring developmental programs through molecular hubs that synchronize nutrient sensing with root morphogenesis—a key adaptive strategy for resource acquisition in heterogeneous soils. Full article

The early determination of the type and severity of stresses caused by nutrient deficiency is necessary for taking timely measures and preventing a remarkable yield reduction. This study is an effort to investigate the performance of a machine learning-based model that identifies the type and severity of nitrogen, phosphorus, potassium, and sulfur in rice plants by using the plant microRNA data as model inputs. The concentration of 14 microRNA compounds in plants exposed to nutrient deficiency was measured using an electrochemical biosensor based on the peak currents produced during the probe–target microRNA hybridization. Subsequently, several machine learning models were utilized to predict the type and severity of stress. According to the results, the biosensor used in this work exerted promising analytical performance, including linear range (10⁻¹⁹ to 10⁻¹¹ M), limit of detection (3 × 10⁻²¹ M), and reproducibility during microRNA measurement in total RNA extracted from rice plant samples. Among the microRNAs studied, miRNA167, miRNA162, miRNA169, and miRNA395 exerted the largest contribution in predicting the nutrient deficiency levels based on feature selection methods. Using these four microRNAs as model inputs, the random forest with hyperparameters optimized by the genetic algorithm was capable of detecting the type of nutrient deficiency with an average accuracy, precision, and recall of 0.86, 0.94, and 0.87, respectively, seven days after the application of the nutrient treatment. Within this period, the optimized machine was able to detect the level of deficiency with average MSE and R² of 0.010 and 0.92, respectively. Combining the findings of this study and the results we reported earlier on determining the occurrence of salinity, drought, and heat in rice plants using microRNA biosensors can be useful to develop smart biosensing platforms for efficient plant health monitoring systems. Full article

Sulfur-containing fertilizers increase production costs, which leads to low utilization of this nutrient. Thus, evaluating how the absence of sulfur influences the early development of Urochloa brizantha is essential. Study was conducted in a greenhouse at the Federal University of Rondonópolis in a completely randomized design, with six treatments in a 3 × 2 factorial scheme, and eight replications. Three cultivars of U. brizantha (Marandu, Xaraés and Piatã) were evaluated under two fertilization strategies: with or without sulfur fertilization. Sufur presence increased the number of leaves and forage mass, in which cultivar Xaraés presented the greatest means. Piatã was the cultivar most sensitive to sulfur deficiency at establishment, which reduced forage mass, number of leaves and number of tillers by 42%, 32%, and 45%, respectively. Despite these differences between cultivars, sulfur efficiently increased the forage yield. Sulfur fertilization increased the concentrations of nutrients in the plants without significantly affecting the uptake of nitrogen, phosphorus, potassium, calcium and magnesium. Sulfur omission resulted in increased phosphorus uptake in all grass. In contrast, Marandu grass exhibited the greatest reduction in sulfur uptake. Therefore, the use of sulfur in the fertilization of grasses is recommended, it is important to evaluate the responses of each cultivar to better adjust the fertilization management. Full article

Manganese (Mn) excess and low pH often coexist in some citrus orchard soils. Little information is known about the underlying mechanism by which raising pH reduces Mn toxicity in citrus plants. ‘Sour pummelo’ (Citrus grandis (L.) Osbeck) seedlings were treated with 2 (Mn2) or 500 (Mn500) μM Mn at a pH of 3 (P3) or 5 (P5) for 25 weeks. Raising pH mitigated Mn500-induced increases in Mn, iron, copper, and zinc concentrations in roots, stems, and leaves, as well as nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, copper, iron, and zinc distributions in roots, but it mitigated Mn500-induced decreases in nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, and boron concentrations in roots, stems, and leaves, as well as nutrient imbalance. Raising pH mitigated Mn500-induced necrotic spots on old leaves, yellowing of young leaves, decreases in seedling growth, leaf chlorophyll concentration, and CO₂ assimilation (A_CO2), increase in root dry weight (DW)/shoot DW, and alterations of leaf chlorophyll a fluorescence (OJIP) transients and related indexes. Further analysis indicated that raising pH ameliorated Mn500-induced impairment of nutrient homeostasis, leaf thylakoid structure by iron deficiency and competition of Mn with magnesium, and photosynthetic electron transport chain (PETC), thereby reducing Mn500-induced declines in A_CO2 and subsequent seedling growth. These results validated the hypothesis that raising pH reduced Mn toxicity in ‘Sour pummelo’ seedlings by (a) reducing Mn uptake, (b) efficient maintenance of nutrient homeostasis under Mn stress, (c) reducing Mn excess-induced impairment of thylakoid structure and PEPC and inhibition of chlorophyll biosynthesis, and (d) increasing A_CO2 and subsequent seedling growth under Mn excess. Full article

The Qiubudong silver deposit on the western margin of the Fuping ore cluster in the central North China Craton is a representative breccia-type deposit characterized by relatively high-grade ores, thick mineralized zones, and extensive alteration, indicating considerable potential for economic resource development and further exploration. Previous studies on this deposit have not addressed its genetic mineralogical characteristics. This study focuses on pyrite and quartz to investigate their typomorphic features, such as crystal morphology, trace element composition, thermoelectric properties, and luminescence characteristics, and their implications for ore-forming processes. Pyrite crystals are predominantly cubic in early stages, while pentagonal dodecahedral and cubic–dodecahedral combinations peak during the main mineralization stage. The pyrite is sulfur-deficient and iron-rich, enriched in Au, and relatively high in Ag, Cu, Pb, and Bi contents during the main ore-forming stage. Rare earth element (REE) concentrations are low, with weak LREE-HREE fractionation and a strong negative Eu anomaly. The thermoelectric coefficient of pyrite ranges from −328.9 to +335.6 μV/°C, with a mean of +197.63 μV/°C; P-type conduction dominates, with an occurrence rate of 58%–100% and an average of 88.78%. A weak–low temperature and a strong–high temperature peak characterize quartz thermoluminescence during the main mineralization stage. Fluid inclusions in quartz include liquid-rich, vapor-rich, and two-phase types, with salinities ranging from 10.11% to 12.62% NaCl equiv. (average 11.16%) and densities from 0.91 to 0.95 g/cm³ (average 0.90 g/cm³). The ore-forming fluids are interpreted as F-rich, low-salinity, low-density hydrothermal fluids of volcanic origin at medium–low temperatures. The abundance of pentagonal dodecahedral pyrite, low Co/Ni ratios, high Cu contents, and complex quartz thermoluminescence signatures are key mineralogical indicators for deep prospecting. Combined with thermoelectric data and morphological analysis, the depth interval around 800 m between drill holes ZK3204 and ZK3201 has high mineralization potential. This study fills a research gap on the genetic mineralogy of the Qiubudong deposit and provides a scientific basis for deep exploration. Full article

Sulfur (S) fertilizer is routinely applied together with other macronutrients by farmers across all regions to improve grain yield and quality, but its distinct effects on grain yield and aroma intensity in fragrant rice remain inadequately studied, especially when applied under varying existing soil S levels. This study aimed to determine the effects of S fertilizer application on grain yield and aroma intensity (2-Acetyl-1-Pyrroline, 2AP) in fragrant rice grown under varying soil S levels (very low, low, and medium). The premium Thai fragrant rice cultivar KDML105 was grown under field conditions during two cropping seasons in 2021 and 2022 in Surin province, northeastern Thailand. Sulfur fertilizer in the form of (NH4)₂SO₄ was applied at 0, 30, 60, 90, and 120 kg S ha⁻¹ at one time with the basal fertilizers phosphorus (P) and potassium (K) under varying soil S levels, using the same protocol in both cropping seasons. Plant growth parameters were evaluated at the tillering stage, and grain samples were harvested at maturity to evaluate grain yield and aroma intensity. The results showed that applying S at rates between 60 and 90 kg ha⁻¹ to soils with very low and low S increased grain yield from 4 to 20% compared to no S application, while no effect of S application was observed for the medium soil S level. The results were primarily attributed to the number of tillers and panicles per hill and the 1000-grain weight in both cropping seasons. Dissimilar effects of S application rates and soil S level were found for grain 2AP content. There was a higher grain 2AP content in the low and medium soil S levels compared to very low S, but the pattern varied according to the S application rate. Applying the appropriate rate of S fertilizer can significantly improve rice productivity, especially when cultivated under S-deficient soil, and higher soil S levels can promote the grain 2AP content of fragrant rice. Full article

Post-combustion technology is a new kind of low-nitrogen combustion technology. To achieve the combined removal of nitrogen oxides (NO_x) and sulfur dioxide (SO₂) emissions, the post-combustion technology combined with the sorbent injection in the furnace and post-combustion chamber is proposed. Experiments investigating the effects of the sorbent addition in a post-combustion chamber and post-combustion air arrangement on NO_x and SO₂ emissions were conducted in a 0.1 MWth circulating fluidized bed test platform. In addition, a comparative analysis of the NO_x and SO₂ emissions under both combined removal methods was also performed. The results indicated that adding sorbent to the post-combustion chamber can reduce SO₂ emissions, but further increasing the amount of sorbent will not significantly improve the desulfurization effect. The injection position of the post-combustion air will affect the emissions of NO_x and SO₂ in the flue gas. When the three-stage distribution of post-combustion air is adopted, the further back the third nozzle is distributed, the lower the temperature in the post-combustion chamber, which is beneficial to the control of NO_x and SO₂ emissions. Compared with the conventional combined removal method, the NO_x emissions were significantly reduced under the new combined removal method. Through secondary desulfurization in the furnace and post-combustion chamber, oxygen-deficient combustion in the furnace can achieve the combined removal of NO_x and SO₂. Full article

Spirodela polyrhiza is a suitable model organism for investigating plant developmental influences due to its intracolonial variations in response to various environmental fluctuations, like nutrient deficiency. In this study, transmission electron microscopy was used to examine age-dependent variation in chloroplast ultrastructure, while pigment levels (chlorophyll and anthocyanins), starch accumulation, and metabolic activity (photosynthetic and respiratory rates) were measured to determine metabolic responses to sulfur deficiency. For a comprehensive insight into electron transport efficiency and the redox states of the photosynthetic apparatus, rapid light curves, chlorophyll fluorescence (JIP test parameters), and modulated reflection at 820 nm were analyzed. Under S deficit, mother fronds relied on stored reserves to maintain functional PSII but accumulated reduced PQ pools, slowing electron flow beyond PSII. The first-generation daughter fronds, despite having higher baseline photosynthetic capacity, exhibited the largest decline in photosynthetic indicators (e.g., rETR fell about 50%), limitations in the water-splitting complex, and reduced PSI end-acceptor capacity that resulted in donor- and acceptor-side bottlenecks of electron transport. The youngest granddaughter fronds avoided these bottlenecks by absorbing less light per PSII, channeling electrons through the alternative pathway to balance PQ pools and redox-stable PSI while diverting more carbon into starch and anthocyanin production up to 5-fold for both. These coordinated and age-specific adjustments that provide response flexibility may help maintain photosynthetic function of the colony and facilitate rapid recovery when sulfur becomes available again. Full article

Ethylmalonic encephalopathy (EE) is a serious metabolic disorder that usually appears in early childhood development and the effects are seen primarily in the brain, gastrointestinal tract, and peripheral vessels. EE is caused by pathogenic variants in the gene that encodes the ETHE1 protein, and its main features are high levels of acidic compounds in body fluids and decreased activity of the mitochondrial complex IV, which limits energy production in tissues that require a large supply of energy. ETHE1 is a mitochondrial sulfur dioxygenase that plays the role of hydrogen sulfide (H₂S) detoxification, and, when altered, it leads to the accumulation of this gaseous molecule due to its deficient elimination. In this article, we characterised the pathophysiology of ETHE1 deficiency in cellular models, fibroblasts, and induced neurons, derived from a patient with a homozygous pathogenic variant in ETHE1. Furthermore, we evaluated the effect of the activation of the mitochondrial unfolded protein response (mtUPR) on the mutant phenotype. Our results suggest that mutant fibroblasts have alterations in ETHE1 protein expression levels, associated with elevated levels of H₂S and protein persulfidation, mitochondrial dysfunction, iron/lipofuscin accumulation, and oxidative stress. We also identified a cocktail of compounds consisting of pterostilbene, nicotinamide, riboflavin, thiamine, biotin, lipoic acid, and L-carnitine that improved the cellular and metabolic alterations. The positive effect of the cocktail was dependent on sirtuin 3 activation (SIRT3) and was also confirmed in induced neurons obtained by direct reprogramming. In conclusion, personalised precision medicine in EE using patient-derived cellular models can be an interesting approach for the screening and evaluation of potential therapies. In addition, the activation of the SIRT3 axe of mtUPR is a promising therapeutic strategy for rescuing ETHE1 pathogenic variants. Full article