Search Results (290)

This study examined the chemical composition and quantitative source contributions of coarse (PM_10–2.5) and fine (PM_2.5) particles in ship-based PM₁₀ and PM_2.5 filter samples from 2020 to 2024 across the Yellow Sea. The observations were primarily conducted during the spring season, when the influence of continental air masses from East Asia is pronounced, and detailed analyses of water-soluble ions and elemental species were performed. In coarse particles, sea salt components (e.g., Na⁺ and Cl⁻) and soil-derived species (e.g., nss-Ca²⁺ and CO₃²⁻) were predominant, whereas fine particles were dominated by secondary inorganic species such as nss-SO₄²⁻, NO₃₋, and NH₄⁺. Source contributions were estimated using Dispersion Normalized Positive Matrix Factorization (DN-PMF), and eight common factors were identified, including sea salt, soil, secondary nitrate, secondary sulfate, oil combustion, biomass burning, marine biogenic emissions, and plant growth. Additionally, an industry factor was uniquely resolved in coarse particles, whereas a mobile source factor was identified in fine particles. In coarse particles, sea salt (30.9%) and soil (15.1%) were the major contributing sources, whereas fine particles were dominated by secondary nitrate (48.6%) and secondary sulfate (15.6%). Potential Source Contribution Function (PSCF) analysis indicated that the sea salt and oil combustion factors in coarse particles were associated with coastal regions of the Yellow Sea and the East China Sea, while the soil factor corresponded spatially with inland regions of northern China. In contrast, the secondary nitrate, secondary sulfate, and biomass burning factors in fine particles showed strong associations with inland regions of eastern China. Using size-resolved DN-PMF and five years of repeated observations over the same marine region, this study provides the first quantitative source apportionment analysis of interannual atmospheric composition variability and long-range transport affecting air quality over the Yellow Sea. Full article

Soil salinization threatens agricultural production, and increasing extreme rainfall may alter natural leaching processes in coastal saline–alkaline soils. However, the relationships among salt ion migration, alkalinity changes, nutrients, and bacterial communities under natural rainfall leaching remain unclear. Therefore, a phased natural rainfall leaching experiment was conducted from June to September 2025 using moderate to severe NaCl-type saline–alkaline soil from Dongying in the Yellow River Delta. The results showed that natural rainfall leaching significantly reduced soluble salt ions, especially Na⁺, Cl⁻, and SO₄²⁻, and rapidly alleviated early salt stress. However, soil pH did not decline continuously with salt reduction, but fluctuated under the buffering effect of the carbonate system, indicating that desalination was not necessarily accompanied by alkalinity alleviation. Available nutrients showed stage-dependent changes, with HN and AK increasing around the middle leaching stage. Bacterial community composition and co-occurrence networks also changed during leaching, and these changes were more closely associated with salt ions and HCO₃⁻/pH than with available nutrients. These results suggest that post-rain management of saline–alkaline soils should not rely only on total salinity, but should also consider major salt ions, pH/HCO₃⁻, and nutrient availability. Full article

To combat coastal wind erosion and develop sustainable stabilization technologies, a resource-efficient technique was developed based on the Enzyme-Induced Carbonate Precipitation (EICP) principle in the coastal regions of China. Utilizing seawater as a multi-ion source and discarded soybean hulls (Glycine max (L.) Merr.) as a crude urease source, this method is synergized with vegetation to form an environmentally friendly anti-erosion strategy. This study first explored the feasibility of soybean hull-derived urease, then analyzed the impacts of urease activity, reaction liquid volume, and seawater concentration on the germination and growth of Kalimeris indica. The results show that the biochemical mineralization process effectively sequesters soluble Ca²⁺ and Mg²⁺ from seawater into stable mineral phases, thereby mitigating salt-induced osmotic stress. Optimal plant growth was achieved at a seawater concentration of 0.2 mol·L⁻¹ and a liquid volume of 200 mL. Furthermore, the biocementation provided robust protection for initial plant growth, achieving an approximately 92.3% reduction in soil loss. Despite the presence of nitrogenous byproducts, the synergistic effect of EICP crusts and developing root systems ensures long-term wind erosion resistance and ecological integrity. This study highlights a functional transition from artificial mineralization to biological anchoring for sustainable coastal restoration. Full article

Global crop production faces serious threats from soil salinization. Microbial resources are often exploited to be used as fertilizers or seed coatings to address this issue. Parametarhizium changbaiense, as a novel beneficial microorganism, has been discovered to be capable of assisting limited crops such as mung bean in resisting salt–alkali stress. To investigate the effects of P. changbaiense on sugar beet under salt–alkali stress, the salt (NaCl:Na₂SO₄, molar ratio 9:1) and alkali (NaHCO₃:Na₂CO₃, molar ratio 9:1) stress were set on sugar beet germplasm 780016B. Results demonstrated that P. changbaiense improved the phenotypic characteristics of sugar beet seedlings under salt–alkali stress. The biomass parameters such as plant height and fresh weight significantly increased by growth-promoting effect. The elevated antioxidant enzyme activity could help protect plants from ROS damage induced by stress. Relative electrical conductivity and MDA content decreased with inoculation, thereby mitigating membrane lipid peroxidation and improving membrane system stability. The higher content of soluble sugar could maintain cell turgor pressure and alleviate osmotic stress. Inoculation with P. changbaiense enhanced chlorophyll content, fluorescence, and photosynthetic capacity. The more superior root vitality and architecture were suitable for the functions of metabolism and absorption. P. changbaiense could promote the growth and physiological characteristics under salt–alkali stress, so it has practical application value in agricultural production. Full article

Inland water management is increasingly important under climate change due to the need for landscape-scale water retention, but in situ studies are limited by fluctuating, shallow, and intermittent water cover. This study simulated prolonged waterlogging under controlled laboratory conditions. Four agricultural soils (Calcisol, Arenosol, Chernozem, and Solonetz) were flooded for 40 days using identical 1:5 soil-to-water ratios at two temperature regimes, at 4 and 22 °C. Given that periodic water cover may conflict with agricultural production, particular attention was paid to crop-relevant indicators, including pH, water-soluble salts, and N, P, K. The laboratory simulation revealed significant differences among soil types and between temperature treatments. Elevated Mg concentrations limited the irrigation suitability of leachate derived from Calcisol, with Mg% values ranging from 57 to 64%, exceeding the 50% guideline threshold. Soil buffering capacity controlled phosphorus and potassium dynamics, resulting in stable or slightly increasing AL-soluble nutrient levels, except in low-buffering sandy soils where up to 3–4-fold variability was observed. Reductive conditions developed early in the Calcisol samples, supported by dissolved oxygen saturation values below 20% during the first days of the experiment. Oxygen saturation increased later, only exceeding 60% twice in the cooled Calcisol treatment, while nitrate–ammonium dynamics reflected changing redox conditions. Temperature significantly affected solubility and nutrient mobility, partly through its influence on microbial activity. These findings improve our understanding of inland water–soil interactions and support the development of sustainable, water-retentive land management strategies. Full article

According to an FAO report, the total area of saline-alkali land worldwide is approximately 954 million hectares, accounting for about 20% of global cultivated land. Saline-alkali stress significantly reduces soybean (Glycine max L.) yield and quality, and saline-alkali-tolerant plant growth-promoting bacteria (PGPB) have shown important application value for soybean planting in such farmlands. In this study, 15 strains of saline-alkali-tolerant bacteria were isolated from saline-alkali soil in Anda City, Heilongjiang Province, China, and identified morphologically, belonging to the genera Enterobacter, Bacillus, Chryseobacterium, Acinetobacter, Enterococcus, and Pseudomonas. Through tests for nitrogen fixation, phosphorus solubilization, potassium solubilization, hydrolase production (including pectinase, amylase, and protease), and germination promotion assays, Bacillus pumilus AD14 was identified as having the best growth-promoting effect on soybean seedlings. Pot experiments in saline-alkali soil showed that AD14 significantly promoted soybean seedling growth, increasing plant height by 5.63–6.37 cm and root length by 3.58–3.99 cm compared to the control. AD14 also enhanced saline-alkali tolerance by improving the activity of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) and increasing soluble sugar and protein contents. Meanwhile, soil pH decreased by 10.94–12.15% and soluble salt content decreased by 9.59–13.39% after planting, and soil enzyme activities (including urease, sucrase, and catalase) increased markedly. These results demonstrate the great potential of AD14 for soybean planting in saline-alkali soil. This study provides a relevant reference for enriching the resources of saline-alkali-tolerant PGPB and developing new biological agents suitable for soybean planting in saline-alkali soils. Full article

Currently, the escalating global problem of soil salinization severely limits the yield and quality of processing tomatoes. However, the differential responses and salt-tolerance strategies among processing tomato genotypes with different salt tolerances under salt stress remain largely elusive. Therefore, this study used salt-tolerant genotype ‘S39’ and salt-sensitive genotype ‘S37’ as materials. Seeds were sown in plug trays, and seedlings at the two-leaf-one-heart stage were transplanted into hydroponic containers filled with Hoagland nutrient solution. When seedlings reached the four-leaf-one-heart stage, they were exposed to NaCl treatments of 0 mM (control), 120 mM (Na120), and 180 mM (Na180). Plant samples were collected at 3, 6, and 9 days after treatment to determine growth parameters, physiological indices, and gene expression levels, aiming to reveal the dynamic differential responses to salt stress between the two processing tomato genotypes. The results demonstrated that the inhibitory effect of NaCl on the growth of processing tomatoes was aggravated with increasing NaCl concentration and treatment duration. The most significant difference in salt tolerance between the two genotypes was observed at 9 days under 180 mM NaCl treatment. At this sampling point, the relative salt-stress indices of superoxide dismutase (SOD) activity, peroxidase (POD) activity, soluble sugar content, proline content, chlorophyll a, chlorophyll b, and total chlorophyll (a + b) in ‘S39’ were significantly higher than those in ‘S37’ by 31.55%, 53.40%, 66.70%, 65.07%, 20.80%, 15.74%, and 19.44%, respectively. In addition, Na contents in roots and stems, as well as K contents in stems and leaves, were significantly higher in ‘S39’ than in ‘S37’ by 43.40%, 8.67%, 22.08%, and 21.99%, respectively. In contrast, relative electrolyte leakage and malondialdehyde (MDA) content in ‘S37’ were 15.54% and 12.44% higher than those in ‘S39’. In addition, photosynthetic parameters, including net photosynthetic rate (A_net), stomatal conductance (g_s), intercellular CO₂ concentration (C_i), transpiration rate (E), and chlorophyll fluorescence parameters, were more stable in ‘S39’ than in ‘S37’. In conclusion, ‘S39’ possesses stronger salt tolerance via a multi-level regulatory strategy involving an enhanced antioxidant enzyme system, elevated accumulation of osmoregulatory substances, improved mineral ion balance, and increased stability of the photosynthetic apparatus. This study provides a comprehensive multi-level analysis of the differential salt tolerance mechanisms in processing tomato genotypes with contrasting salt tolerances and lays a theoretical basis for the screening and identification of salt-tolerant germplasm in processing tomatoes. Full article

Rice seedlings are typically grown in high-phosphorus nursery soils in practice, which reduces rice root growth and the plant’s ability to adapt to adverse conditions after transplantation to the paddy field. Thus, it is important to improve rice root development in high-phosphorus nursery soils. Rice root developments are closely connected with soil microorganisms. Arbuscular mycorrhizal fungi (AMF) can promote rice root growth and help improve rice performance in resisting adverse conditions. To illustrate the mechanisms of rice seedlings with AMF inoculation under suitable and high-phosphorus nursery soils in resisting adverse conditions, rice seedlings were cultivated in suitable and high-phosphorus nursery soils inoculated with AMF JD5 (Paraglomus sp.) and transplanted into soda saline–alkaline soils following successful AMF inoculation. Results showed that under high-phosphorus conditions, AMF JD5 inoculation significantly promoted plant height and root elongation, likely through increased total chlorophyll content. Concurrently, proline content was reduced, whereas soluble sugar and soluble protein contents were elevated, indicating alleviation of osmotic stress induced by saline–alkaline conditions. Moreover, AMF JD5-inoculated seedlings exhibited increased CAT activity, which efficiently scavenged reactive oxygen species (ROS) generated under salt–alkaline stress and reduced lipid peroxidation. However, thiobarbituric acid reactive substances (TBARS) content was significantly decreased with AMF inoculation in high-phosphorus conditions. Collectively, these findings suggest that AMF JD5 inoculation in high-phosphorus nursery soils establishes a physiological and biochemical foundation that maintains rice resilience against saline–alkaline stress throughout early growth. Full article

Glaze flaking is widespread in Hongzhou kiln celadon dating from the Eastern Han to the Tang Dynasty, yet its underlying mechanism cannot be attributed to a single factor. In this study, 11 Hongzhou kiln celadon specimens from the Eastern Han, Southern Dynasties, and Sui–Tang periods were examined using microscopic observation, SEM–EDS, Raman spectroscopy, crack-width measurements, glaze-area analysis, water-absorption tests, and burial environment analysis to investigate the characteristics and causes of glaze flaking. The results show that crazing-crack width is significantly and positively correlated with the extent of glaze flaking. The body–glaze interlayer generally exhibited heterogeneous features, including anorthite crystallization, unmelted quartz grains, bubbles, and locally phase-separated droplets. Anorthite crystals and adjacent regions were frequently associated with crystal-shaped corrosion pits, irregular voids, and localized structural loosening; degraded areas showed depletion of Ca and Si and relative enrichment of Al and Fe. The burial soils were generally neutral to slightly alkaline and showed no evident salt accumulation, suggesting that high salinity was not the primary direct cause of glaze flaking in these samples. These findings suggest that glaze flaking in Hongzhou kiln celadon results from the interaction between firing-induced heterogeneity at the body–glaze interface and prolonged post-burial corrosion. Crazing and interconnected cracks acted as pathways for moisture and soluble ions to penetrate the body–glaze interlayer, triggering selective corrosion of Ca-rich crystalline phases and adjacent glassy phases and ultimately causing interfacial destabilization and glaze loss. Full article

Soil salinity limits ginger productivity, but the underlying molecular mechanisms remain largely unclear. The 14-3-3 proteins are conserved regulators in stress signaling. Here, we genome-wide characterized the 14-3-3 family in Zingiber officinale and examined the possible involvement of Zo14-3-3-03 in salt response. A total of 21 Zo14-3-3 genes were identified and classified into four groups with uneven chromosomal distribution. Among them, Zo14-3-3-03 was strongly salt-responsive: transcript levels increased 9.91- to 33.82-fold during 1–7 days of treatment and reached 62.47-fold in leaves at day 14. NaCl treatment elevated GUS expression driven by the Zo14-3-3-03 promoter. Virus-induced gene silencing (VIGS) of Zo14-3-3-03 resulted in silenced plants exhibiting higher malondialdehyde (up to 73.6%), lower antioxidant enzyme activities (SOD, POD, CAT, and APX: 18.9–31.9% reduction), reduced osmolytes (proline, soluble protein, sugars, and ascorbic acid: 23.2–36.2% reduction), excessive reactive oxygen species, and decreased relative water content. Several antioxidant-related genes were significantly downregulated. Protein interaction assays suggested a possible interaction with ZoSOS2, and the expression of SOS2 pathway genes was altered in silenced plants, indicating a potential link to calcium signaling and ion homeostasis. Taken together, these results suggest that Zo14-3-3-03 participates in ginger salt stress response possibly through redox balance, osmotic adjustment, and calcium-mediated pathways which would provide a basis for understanding 14-3-3-mediated stress responses and nominates Zo14-3-3-03 as a candidate requiring deeper validation for salt tolerance improvement in ginger. Nevertheless, due to limited functional validation, its role as a positive regulator and breeding target remains preliminary. Further genetic and mechanistic studies are needed to confirm causality and assess field-level applicability. Full article

Soil salinization poses an escalating threat to global crop production. Extracellular polysaccharides (EPSs) secreted by plant growth-promoting rhizobacteria have the potential to improve the salt tolerance of crops. Here, we tested the effects of Pantoea alhagi NX-11 EPSs on the growth, physiological traits, and root proteomic profiles of rice under salt stress. We found that NX-11 EPSs effectively increased the salt tolerance of rice in soil, with 50 mg/kg EPS exhibiting the strongest plant growth-promoting effect. This effect was associated with increased the K⁺/Na⁺ ratio and soluble protein content in roots induced by NX-11 EPSs as well as reduced stomatal aperture and transpiration rate in leaves. Proteomic analyses revealed that NX-11 EPSs markedly changed the protein profiles of roots. Specifically, proteins associated with cyanoamino acid metabolism, glycolysis/gluconeogenesis, and fatty acid degradation were downregulated. Together, these results suggest that NX-11 EPSs improve rice performance under salt stress, accompanied by changes in physiological traits and root protein profiles. Full article

Soil salinity severely constrains strawberry production by disrupting ion homeostasis and provoking oxidative injury. This study investigated whether soluble silicon (Si) and activated carbon (AC) act to enhance salt tolerance in strawberry (Fragaria × ananassa). Under NaCl stress, plants showed pronounced growth inhibition, increased Na⁺ accumulation and a deteriorated K⁺/Na⁺ balance, accompanied by elevated reactive oxygen species (ROS) and lipid peroxidation. In contrast, combined AC + Si treatment consistently provided the strongest protection, improving seedling vigor and survival. Relative to NaCl alone, AC + Si increased shoot and root fresh weight by 67.5% and 78.5%, reduced shoot Na⁺ by 59.1%, and lowered shoot H₂O₂ and MDA by 62.6% and 66.5%, respectively, indicating marked improvement in ion–redox homeostasis. Beyond plant responses, AC-containing treatments alleviated salt-induced increases in soil electrical conductivity, coinciding with a clear restructuring of the rhizosphere bacterial community and enrichment of putatively beneficial taxa. Transcriptome profiling further supported coordinated reprogramming of ion transport, redox control and stress-responsive signaling pathways under the AC + Si regime. Collectively, the results indicated that Si and AC co-application enhances strawberry salt tolerance through an integrated soil–plant–microbiome mechanism that stabilizes ion homeostasis and reinforces redox homeostasis. Full article

Coastal saline–alkali farmland typically experiences poor crop growth and low yields. Clarifying soil quality and identifying the primary constraining factors are crucial for improving productivity. This study systematically investigated the spatial heterogeneity and vertical distribution of soil physicochemical properties in a coastal reclamation area using large-scale field sampling. The results revealed that the plow layer soil in the coastal reclamation zone is characterized by typical saline–alkali conditions, low fertility, and weak nutrient-holding capacity, with a pH range of 8.0 to 9.2. Over 60% of the region had soluble salt (SS) content exceeding 2.0 g/kg, and soil organic matter (SOM), total nitrogen (TN), and cation exchange capacity (CEC) ranged from 7.2 to 24.9 g/kg, 0.45 to 1.42 g/kg, and 1.4 to 15.7 cmol⁺/kg, respectively. Correlation analysis showed significant positive correlations between SOM and TN, available potassium (AK), and CEC, while a strong negative correlation was found between pH and AP. Vertically, the soil demonstrated a notable risk of salt efflorescence and nutrient leaching. Soil salinity and alkalinity increased with depth, while SOM, TN, available phosphorus (AP), and nitrate content decreased. In conclusion, effectively suppressing soil salinization, lowering pH, and increasing organic matter content are essential strategies for improving soil structure, enhancing nutrient retention, and boosting the quality of coastal saline–alkali farmland. Full article

The sweet cherry has become a commercially significant fruit crop, yet its cultivation in Xinjiang is severely constrained by saline-alkali soils. To address this, selecting salt-tolerant rootstocks is vital for sustainable crop production in salinized soils. This study investigated the physiological and biochemical responses of five major rootstock cultivars (‘Mahaleb CDR-1’, ‘Gisela 6’, ‘Colt’, ‘Daqingye’, and ‘Krymsk5’) to a gradient of NaCl stress (0, 50, 100, 150, 200, 250, 300 mmol·L⁻¹) under controlled environmental conditions. Key osmoprotectants and antioxidant systems showed a consistent trend across genotypes: the contents of soluble sugars, proteins, and proline, along with the activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), initially increased under moderate stress but subsequently declined as salinity stress intensified. Specifically, CAT activity peaked at 150 mmol·L⁻¹ NaCl in most genotypes, with significant increases ranging from 33.9% (‘Gisela 6’ at 100 mmol·L⁻¹) to 45.52% (‘Colt’ at 150 mmol·L⁻¹) compared to controls. SOD activity also reached maxima at 150 mmol·L⁻¹ in most cultivars, increasing by 11.30% to 19.38% relative to controls, while POD activity exhibited peak values at 150–200 mmol·L⁻¹, with increases of 4.12% to 10.45%. Notably, proline (PRO) accumulation peaked at 150 mmol·L⁻¹ NaCl, with ‘Mahaleb CDR-1’ demonstrating the highest concentration (29.81 μg·g⁻¹) and ‘Colt’ the lowest (25.85 μg·g⁻¹). Conversely, the malondialdehyde (MDA) content, an indicator of membrane lipid peroxidation, increased progressively with increasing salinity. The cultivar ‘Colt’ exhibited the most severe membrane damage. Its MDA content under 300 mmol·L⁻¹ NaCl stress was 80.84% higher than that under the control condition (0 mmol·L⁻¹ NaCl). These results demonstrate that under moderate salt stress, the rootstocks activated adaptive responses, as evidenced by elevated osmoprotectant levels and enzymatic activity, which were ultimately suppressed under severe conditions. A comprehensive analysis of all physiological and biochemical indices allowed for a clear ranking of salt tolerance: ‘Mahaleb CDR-1’ > ‘Daqingye’ > ‘Krymsk5’ > ‘Gisela 6’ > ‘Colt’. This study provides a robust physiological basis for selecting salt-tolerant rootstocks in saline-alkaline regions and offers valuable insights for breeding programs aimed at enhancing stress resilience. Full article

Soil salinization is a major environmental hazard, hindering rapeseed development due to sodium ion (Na⁺) toxicity and ionic imbalances in plant cells. Understanding tolerance mechanisms and categorizing reliable physiochemical indicators is vital for enhancing rapeseed tolerance. Herein, we aimed to enhance knowledge about the stress-responsive mechanism of ten rapeseed varieties (C71, C88, C91, C97, C123, C136, C196, C272, C280, and C320) exposed to five NaCl concentrations (0, 150, 200, 250, and 300 mM) through determining key factors related to salt tolerance at the seedling stage. Our results showed that salt stress significantly reduced seedling growth and biomass with increasing salt stress concentration in a similar pattern in all studied varieties, especially in sensitive seedlings. Furthermore, photosynthetic pigment, osmotic solutes, and MDA showed significant variations under salt treatment versus control in all studied varieties. Based on morpho-physiochemical trait analysis of ten rapeseed varieties, C71 and C272 were selected as tolerant and sensitive varieties to study stress responses during six weeks (weekly time points) in the leaf, petiole, stem, and root of seedlings under 250 mM NaCl. Current findings demonstrated superior osmotic adjustment of C71 through higher accumulation of total soluble sugars and protein, reflected in lower MDA levels, which contributed to maintaining cellular homeostasis and membrane integrity to improve resilience under salinity versus C272. Besides, total amino acid content was enhanced in C71 versus C272 seedlings, which was attributed to stress tolerance. In different tissues of C71 and C272, Na⁺ and K⁺ levels varied with increasing growing time, reaching the maximum increment at the 6th week under salt stress conditions. Moreover, Na⁺ initially accumulates in roots and enhances the K⁺ level in tolerant seedlings; besides, K⁺ was accumulated higher in the roots of tolerant seedlings, resulting in K⁺ homeostasis, thereby improving stress tolerance. Our results can be a great reference value for rapeseed plant breeders to develop salt-tolerant cultivars. Full article