Search Results (871)

In the present research, the application of a photocatalytic reactor operated under simulated solar-light-assisted air gap membrane distillation (AGMD) is proposed to remove ketoprofen from seawater. TiO₂ at a concentration of 1 g/L, containing sulfur, was applied as a photocatalyst. The AGMD process was carried out under a feed temperature of 60–80 °C and a membrane area of 131 cm² during long-term operation. Simulated solar light was applied as an irradiance source. At the first stage of the process, the feed was concentrated for 73 h, and after that, the solution of seawater spiked with ketoprofen was photocatalytically treated for 96 h. Based on the experiments, it was found that 51% of ketoprofen was removed after the solar-driven photocatalysis process. Pure distillate without salts (conductivity below 2 µS/cm) and ketoprofen were obtained after 73 h. The performance of the membrane exhibited ca. two times higher permeate flux at an operation temperature of 80 °C in comparison with 60 °C, i.e., 24.7 L/h·m² and 47.3 L/h·m², respectively. Despite the presence of small deposits on the membrane surface, no membrane wetting was observed. The concentration of ketoprofen in the concentrates during the AGMD process and solar-driven photocatalysis can remove this pharmaceutical even from matrices enriched with salts (high AGMD concentrate), with good efficiency. Full article

The long-term durability of repair systems combining normal concrete (NC) and ultra-high-performance concrete (UHPC) in marine environments depends on the response of the near-interface composite region to sequential carbonation and seawater exposure. However, the effects of seawater immersion following pre-carbonation remain insufficiently understood. This study compared an unexposed reference (REF), specimens carbonated for 28 d (C28), and specimens carbonated for 28 d and then immersed in simplified artificial seawater for 60 d (C28-SW60) using X-ray diffraction, thermogravimetry, backscattered electron imaging with energy-dispersive X-ray spectroscopy, and mercury intrusion porosimetry. Pre-carbonation promoted portlandite consumption, carbonate formation, and pore refinement. Subsequent seawater immersion further enhanced calcite-related diffraction and carbonate decomposition signals, while no typical crystalline salt-attack product was detected as dominant. The initial Ca-rich-to-Si-rich gradient from the NC side through the overlay transition zone to the UHPC side was accompanied by marked Cl accumulation and further S and Mg enrichment and redistribution. After seawater immersion, the measured total intrusion volume increased from 0.026 to 0.043 mL/g, the volume-based median pore-entry diameter increased from 27.49 to 58.42 nm, and the >1000 nm pore-volume fraction reached 39.82%, a change consistent with a shift toward coarser mercury-accessible pore entries. Together, the results link the initial heterogeneity of the NC–Overlay transition zone (OTZ)–UHPC region to a sequence-dependent response in which carbonate enrichment coexisted with multi-ion redistribution and transport-relevant defects, distinguishing carbonate accumulation from sustained near-interface refinement. Full article

SWEET (Sugars Will Eventually be Exported Transporter) proteins constitute a conserved family of sugar transporters that play pivotal roles in carbohydrate allocation and stress responses. In this study, we systematically identified 14 SWEET homologs in the genome of sacred lotus (Nelumbo nucifera) and validated their transport activity for both hexoses and sucrose. Subsequent analysis revealed that stress-responsive elements are the most enriched promoter sequences of NnSWEET genes. Quantitative expression profiling of the members found that NnSWEET4a was strongly upregulated under salt stress. NnSWEET4a was localized at the plasma membrane; its expression conferred salt sensitivity in both yeast and Arabidopsis thaliana. Transgenic Arabidopsis lines overexpressing NnSWEET4a exhibited substantial downregulation of the SOS3–SOS2–SOS1 signaling module and concomitant alterations in cellular sugar homeostasis. Further analysis revealed that exogenous sugar application aggravated salt sensitivity and SOS pathway inhibition in NnSWEET4a transgenic plants, and NnSWEET15-overexpressing Arabidopsis recapitulated identical phenotypic and molecular responses, including salt sensitivity and repression of SOS genes. These findings indicate that NnSWEET4a impairs salt tolerance through disruption of sugar homeostasis. The results establish a mechanistic framework for future investigations into SWEET-dependent regulation of sugar homeostasis and salt stress adaptation. Full article

Background/Objectives: Soybean (Glycine max) productivity is increasingly constrained by soil salinity. WIP transcription factors, a subfamily of C2H2-type zinc finger proteins, regulate cell division, differentiation, and tissue patterning in several plant species, but this gene family had not previously been systematically characterized in soybean or any other major legume crop. This study aimed to identify and characterize the GmWIP gene family genome-wide and evaluate its potential involvement in the soybean salt-stress response. Methods: Genome-wide identification of GmWIP genes was performed using sequence similarity and domain-based searches against the Wm82.gnm4.ann1 reference genome, followed by characterization of physicochemical properties, chromosomal distribution, phylogenetic relationships, gene duplication, conserved motifs, gene structure, and promoter cis-acting elements. Tissue-specific expression was examined using transcriptome data, and GmWIP responses to salt stress were profiled by RT-qPCR in roots, stems, and leaves of a salt-tolerant cultivar (HN531) and a salt-sensitive cultivar (HN563), alongside physiological measurements of oxidative stress and osmotic adjustment. Results: Thirty GmWIP genes were identified, with molecular weights from 26.90 to 57.52 kDa, distributed unevenly across 15 soybean chromosomes, with chromosomes 11, 12, and 13 forming a major hotspot (53.3% of the family). Duplication analysis detected 54 reconciled segmental duplicate gene pairs, all exhibiting Ka/Ks values < 1 (ranging from 0.0351 to 0.4471; mean 0.214), consistent with purifying selection acting on this gene set. GmWIP promoters were enriched for ABRE, MBS, and MeJA cis-acting elements. RT-qPCR showed genotype- and tissue-dependent differential expression under salt stress (e.g., up to 14.9-fold induction of GmWIP22 in HN531 stems), paralleled by superior proline accumulation (+45%), soluble sugars, and CAT activity (+38%) alongside reduced MDA accumulation in the tolerant cultivar. Conclusions: The GmWIP gene family has expanded substantially in soybean relative to previously characterized species and shows genotype-dependent transcriptional responses to salt stress, suggesting that specific GmWIP members are candidate regulators of salt tolerance and warrant further functional investigation. Full article

β-D-Xylosidases (BXLs) are members of glycoside hydrolase family 3. They play essential roles in cell wall remodeling, plant development, and abiotic stress responses. BXL gene families have been systematically characterized in several crop species. However, a comprehensive analysis of BXL genes in cotton (Gossypium hirsutum), a globally important fiber and oilseed crop, is still lacking. In this study, we performed a genome-wide identification of BXL genes in allotetraploid cotton. A total of 25 GhBXL genes were identified and classified into six phylogenetic clades. Gene structure and conserved domain analyses showed that all GhBXL proteins possess the characteristic tripartite GH3 domain architecture. Chromosomal distribution and synteny analyses indicated that the expansion of the cotton BXL family may be associated with whole-genome duplication and allopolyploidization. Promoter cis-element analysis detected stress-responsive regulatory motifs in the GhBXL promoters, including STRE, W-box, DRE core, and as-1 elements. Under PEG-simulated drought and salt stress, expression profiling, independently confirmed by qRT-PCR, showed distinct temporal response patterns among GhBXL members. Weighted gene co-expression network analysis (WGCNA) further identified GhBXL-8, GhBXL-9, and GhBXL-20 as hub genes in stress-responsive modules. Their co-expressed partners were enriched in transcription factors, kinases, and stress-related proteins. These findings provide a systematic foundation for understanding the evolutionary dynamics and functional roles of BXL genes in cotton. They also highlight candidate genes for future functional investigation. Full article

Marine concrete structures are subjected to multiple aggressive ions that react with hydration products, driving dynamic phase evolution and altering ion transport pathways. This study develops a multi-scale lattice diffusion–reaction coupled framework grounded in a microstructural evolution model, incorporating a simplified analytical correction for the electrical double layer (EDL) effect. Validation against Poisson–Boltzmann numerical solutions across a pore size range of 1.5–50 nm confirms that the mean relative errors for monovalent, divalent, and trivalent ions remain within 10%. The phase evolution of cement paste under single-ion attack was simulated, and its impact on ion transport performance under multi-ion coupled ingress was systematically investigated. Under multi-ion attack, solid phases exhibit a highly ordered spatial zonation. Chloride ions completely displace monosulfate, forming a Friedel’s salt-enriched zone. Meanwhile, directly penetrating external sulfate generates a pronounced surface ettringite peak, while sulfate released from monosulfate decomposition in the Friedel’s salt zone induces secondary ettringite precipitation deeper within the material, producing a characteristic double-step ettringite distribution. A cracking criterion based on the critical capillary pore filling fraction captures the transition from pore filling to microcracking, yielding a three-zone profile for the relative diffusion coefficient. At 500 days of exposure, crystallization-induced microcracking triggers a more than 7-fold increase in surface relative diffusivity ($w/c$ = 0.35). Furthermore, at 250 days, once cracking initiates, low water-to-cement ratio ($w/c$ = 0.3) matrices display a higher relative diffusivity amplification factor of approximately 9, compared to approximately 6 for high water-to-cement ratio ($w/c$ = 0.4) matrices. The established framework provides a quantitative tool for assessing the durability of concrete structures under complex chemical attack environments. Full article

Salt stress severely limits wheat growth and seed yield; however, the mechanisms underlying plant-derived smoke (PDS)-induced salt tolerance remain unclear. The present study performs membrane proteomics to clarify how PDS solution enhances salt tolerance in wheat. Immunoblot analysis of subcellular marker proteins confirms successful enrichment of membrane fractions. Principal component analysis shows that 200 mM NaCl markedly alters membrane-protein composition in wheat roots, whereas 2000 ppm PDS solution largely restores these changes even under salt stress. At the protein level, mitochondrial ascorbate peroxidase increases in roots under salt stress but decreases with PDS-solution treatment, while leaves show the opposite trend. Salt stress reduces ATP content and H⁺-ATPase abundance; PDS-solution treatment restores both to near-control levels. In contrast, aquaporin levels increase under salt stress but decline after PDS-solution application. In addition, the expression of ammonium transporter was downregulated significantly under salt stress but recovered with PDS-solution treatment. These results suggest that PDS solution may confer salt-stress tolerance to wheat by regulating energy metabolism, water permeability, and ammonium absorption in the root membrane. Full article

Severely saline–alkaline land degradation poses a considerable challenge to sustainable agriculture, owing to high salinity, elevated pH, and nutrient deficiency. To address this, a salt-tolerant nitrogen-fixing bacterium (Bacillus sp.) and a microalga (Chlorella pyrenoidosa) were applied—alone, in combination, or with sheep manure—in a pot experiment with six treatments to examine their individual and combined effects on soil amelioration and wheat (Triticum aestivum L. cv. Jinchun 6) growth. We specifically assessed whether the three-component system outperforms single or dual applications. The bacterial–algal co-inoculation (BA) markedly outperformed single inoculations: shoot biomass increased by 117% and soil organic matter (SOM) by 130%, compared with the control. BA also alleviated oxidative stress, as evidenced by reduced malondialdehyde (MDA) content and elevated superoxide dismutase (SOD) and peroxidase (POD) activities. Scanning electron microscopy (SEM) observations confirmed tight bacterial attachment to algal surfaces. Incorporating sheep manure (BAM) further enhanced these benefits, achieving the lowest pH and electrical conductivity (EC), the highest SOM and available-nutrients, and the greatest wheat biomass. 16S rRNA sequencing showed that BAM increased microbial diversity, shifted community structure, and enriched beneficial genera (Sphingomonas, Flavihumibacter, and Fuscovulum) that were positively correlated with soil nutrient availability and plant stress tolerance, while the halophilic genus Halomonas declined. Collectively, the bacteria–algae–manure co-application establishes positive feedback between soil improvement and functional microbiome recruitment, offering a promising strategy for the remediation of severely saline–alkaline soil. Full article

Cold alpine salt-affected soils may retain carbon through mineral protection or suppressed microbial decomposition, but these processes remain difficult to distinguish. We measured soil physicochemical properties, four extracellular enzyme activities, soil organic carbon (SOC), and its dissolved (DOC), particulate (POC), and mineral-associated (MAOC) fractions across five soil types on the Qiangtang Plateau. Multivariate analyses and five XGBoost models interpreted using Shapley additive explanations (SHAP) characterized carbon-enzyme associations and identified leading predictors and nonlinear response transition points. Model performance varied among response variables (CV-R² = 0.4094–0.8815). Soda (SD) soil had a distinct carbon-pool composition, and no significant carbon-enzyme correlations remained after Benjamini–Hochberg correction. pH was the leading predictor of SOC and its fractions, whereas total nitrogen and total phosphorus ranked highest for overall enzyme activity. The fitted SHAP contributions changed from negative to positive between pH 8.50 and 9.00 for the carbon variables and at a total nitrogen concentration of 0.71 g·kg⁻¹ for enzyme activity. These model-dependent transition points indicate that carbon-pool restructuring and nutrient-related changes in enzyme activity occur over different environmental ranges. SD soil contained the highest carbon concentrations but the smallest MAOC proportion and the largest POC and DOC proportions, indicating relative enrichment of labile carbon fractions. By jointly analyzing carbon fractions and enzyme activity within an interpretable XGBoost-SHAP framework, this study helps distinguish high carbon stocks from stable sequestration and shows why total SOC alone may overestimate long-term carbon stability in alpine salt-affected soils. Full article

A systematic evaluation of salt tolerance at the seedling stage was conducted using 143 maize inbred lines under a 150 mM mixed-salt solution (NaCl:Na₂SO₄ = 9:1, EC = 16.78 dS/m) that mirrors the ionic composition of saline groundwater in the Yellow River Delta. The comprehensive salt tolerance index (D value) ranged from 0.15 to 0.85 across the population, with the elite line B114 exhibiting the highest D value (0.835) and the sensitive line PHT55 ranking near the bottom. Under salt stress, B114 displayed remarkable growth stability, with plant height decreasing by only 25.9%, fresh weight by 13.3%, and dry weight remaining unchanged, whereas PHT55 suffered severe growth inhibition (plant height: 61.5% decrease; fresh weight: 63.2% decrease; dry weight: 33.3% decrease). Time-series RNA-seq of root tissues across four time points (5, 8, 11, and 14 days) revealed markedly distinct transcriptional dynamics: B114 exhibited relatively stable temporal regulation (2261–9124 DEGs), whereas PHT55 showed a pronounced early transcriptional burst that progressively intensified (3728–10,108 DEGs). Using random forest-based machine learning, 50 core salt tolerance-related genes were unbiasedly identified from 16,194 significantly differentially expressed genes. Functional enrichment analysis revealed that these genes were primarily involved in redox regulation, ion homeostasis maintenance, and stress signal transduction pathways. qRT-PCR validation confirmed biphasic expression patterns, with Zm00001d024160 showing the strongest early induction (48-fold at 5 h). This study established a maize salt tolerance evaluation system closely aligned with field conditions and demonstrated that coordinated temporal transcriptional regulation represents a core molecular mechanism underlying high salt tolerance in maize. The elite salt-tolerant germplasm and key candidate genes identified here provide valuable genetic resources and a theoretical foundation for molecular breeding of salt-tolerant maize adapted to saline-alkaline soils. Full article

The rapid growth of tennis participation and the widespread use of lithium-ion batteries have led to increasing volumes of rubber waste and spent battery materials, underscoring the need for integrated recycling strategies. In this work, a thermochemical co-pyrolysis process is developed to convert waste tennis ball rubber particles (TBRPs) and spent lithium-ion battery (LIB) cathodes into valuable products. The decomposition of TBRPs generates reactive gaseous and liquid hydrocarbons that function as in situ reductants, enabling the breakdown of high-valence transition metal oxides in the cathode material. Subsequent magnetic separation and mild acid-washing yield nonmagnetic solids enriched in lithium compounds and carbonaceous residues. Structural and chemical analyses (SEM, XRD, TEM, EDS, and XPS) confirm extensive cathode reduction and the formation of Li₂CO₃ at optimized conditions (650 °C, 1 h, cathode-to-TBRPs mass ratio 1:0.65). The carbonized rubber evolves into a highly porous carbon material with a carbon purity of approximately 95.37 At%. This study demonstrates a low-energy, environmentally friendly pathway for the co-valorization of two challenging waste streams while simultaneously recovering lithium salts, reduced metal oxides, and functional porous carbon. Full article

Salinity restricts rice growth by disrupting cellular ion balance and promoting oxidative damage. Although exogenous melatonin can improve rice salt tolerance, whether expansion of the endogenous tryptophan pool enhances melatonin biosynthetic capacity and stress acclimation remains unclear. Here, we investigated a homozygous transgenic rice line constitutively expressing OASA1D, a feedback-insensitive D323N variant of the anthranilate synthase α-subunit OASA1. The OASA1D-expressing line exhibited strong resistance to 5-methyltryptophan and accumulated approximately twofold more tryptophan than wild-type plants in both shoots and roots under control and 150 mM NaCl conditions. The expanded tryptophan pool was accompanied by a 1.9–2.2-fold increase in endogenous melatonin and elevated expression of the melatonin biosynthetic genes OsTDC1, OsT5H, OsSNAT1, and OsASMT1. Under salt stress, OASA1D seedlings maintained greater shoot and root growth, biomass, and soil–plant analysis development (SPAD) values than wild-type seedlings. OASA1D also showed lower H₂O₂ and malondialdehyde accumulation and reduced electrolyte leakage, together with higher superoxide dismutase, catalase, and ascorbate peroxidase activities. Salt-induced expression of OsDREB2A, OsLEA3-1, OsP5CS1, OsWRKY45, OsHKT1;5, OsNHX1, and OsSOS1 was enhanced in OASA1D. Consistently, OASA1D shoots accumulated less Na⁺, retained more K⁺, and maintained a higher K⁺/Na⁺ ratio under salinity. Together, these results show that constitutive OASA1D expression expands the endogenous tryptophan pool and is associated with enhanced melatonin biosynthetic capacity, antioxidant defence, ionic homeostasis, and salt tolerance in rice. Full article

Soil salinity and bacterial spot of tomato (BST), caused by Xanthomonas perforans, are major abiotic and biotic stresses limiting tomato production, particularly in Florida. While their individual effects are well documented, the impact of soil salinity on BST has not yet been investigated. This greenhouse study evaluated how increasing irrigation water salinity (electrical conductivity [EC] = 0.5, 3, 5, or 7 dS m⁻¹) affected tomato growth, physiology, BST severity, fruit quality, and transcriptomic responses. Salinity reduced plant growth and BST severity but did not directly affect X. perforans populations. Results indicated that reduced plant physiological activity (net CO₂ assimilation [A], transpiration [E], and stomatal conductance [g_s]) contributes to lower disease levels. Increased salinity led to more solute concentrations, altered sugar metabolism, and improved perceived taste, as supported by taste panel, osmolality, and transcriptomic analyses. They also showed that transcriptional responses to salinity (EC = 7 dS m⁻¹) and X. perforans infection were strongly time-dependent. Salt-treated plants exhibited fewer differentially expressed genes following inoculation, whereas comparisons between EC 7-treated and control plants revealed extensive salinity-induced reprogramming. KEGG analysis indicated enrichment of photosynthesis, carbon metabolism, amino acid biosynthesis, and ribosome pathways, while defense-related pathways, including MAPK signaling and plant–pathogen interaction, were downregulated, suggesting that tomato prioritized adaptation to salinity over pathogen defense. Full article

The dried roots and rhizomes of Salvia miltiorrhiza are widely used and economically important traditional Chinese medicinal materials. Land salinization affects the growth of S. miltiorrhiza, resulting in a decline in its quality and yield. WNK kinases belong to a unique family of serine/threonine kinases. They act as key regulators of plant growth, development and abiotic stress responses. However, this gene family has not been systematically characterized in Salvia miltiorrhiza. In this study, nine SmWNK genes were identified at the whole-genome level in S. miltiorrhiza. Phylogenetic analysis classified them into four structurally conserved subgroups. These genes are distributed across eight chromosomes and contain two pairs of intraspecific syntenic genes. Interspecific collinearity is far stronger between S. miltiorrhiza and dicots than between S. miltiorrhiza and monocots. Cis-element prediction indicated these cis-elements participate in light signaling, hormone responses, stress responses and developmental regulation. Quantitative real-time PCR revealed that eight SmWNK genes were significantly induced by salt stress, and SmWNK7 was selected as the key candidate for functional validation. Functional assays via heterologous overexpression in tobacco demonstrated that SmWNK7 overexpression promoted root elongation and enhanced salt tolerance. Compared with wild-type tobacco plants, SmWNK7-overexpressing transgenic tobacco lines had higher catalase (CAT) and peroxidase (POD) activities, lower malondialdehyde (MDA) content, and stronger root viability. These changes alleviated oxidative damage by enhancing the antioxidant defense system. Yeast two-hybrid screening yielded 40 SmWNK7-interacting annotated proteins, including 6 transcription factors and 1 protein kinase, which were enriched in 81 GO terms and 27 KEGG pathways. These findings confirm SmWNK7 positively regulates root growth and salt tolerance, laying a theoretical foundation for exploring SmWNK genes’ role in plant stress adaptation. Full article

Soil salinization severely threatens agricultural productivity and ecosystem sustainability, particularly in coastal regions. Halophyte-based phytoremediation is a promising strategy, yet how rhizosphere soil legacy effects at different restoration ages influence subsequent plant growth and microbial communities remains poorly understood. Here, rhizosphere soils of Nitraria tangutorum at 1- (BC-1), 2- (BC-2), and 3-year (BC-3) restoration stages and non-rhizosphere bulk soil (CK) were sampled, with alfalfa cultivated as a bioindicator to assess soil physicochemical properties, plant growth, stress physiology, and rhizosphere microbiota. With increasing restoration age, rhizosphere soil shifted from a state of salt accumulation and nutrient deficiency to one of salt depletion and nutrient enrichment, with BC-3 exhibiting the highest soil organic matter, total phosphorus, and alkali-hydrolyzable nitrogen and the lowest total salt and soluble Na⁺. Alfalfa growth was suppressed in BC-1 and BC-2 soils, but significantly promoted in BC-3, accompanied by the lowest malondialdehyde and proline content, indicating effective alleviation of oxidative and osmotic stress. Microbial diversity peaked at BC-2, whereas the total proportion of halotolerant bacteria declined from 0.44 (BC-1) to 0.34 in BC-3 (significantly lower than CK), suggesting a successional shift from a stress-dominated community toward a functionally specialized consortium. Regression analyses identified soluble sodium as the variable most strongly associated with growth inhibition (R² > 0.80) for plant height and root length. We suggest soluble sodium may represent the principal factor associated with growth inhibition and that a positive-feedback loop among plant Na⁺ sequestration, microbial carbon sequestration, and soil maturation may sustain long-term saline–alkali soil improvement. These findings suggest a three-stage successional mechanism and highlight the critical role of restoration age in mediating plant–microbe–soil synergistic remediation of coastal saline soils. Full article