Search Results (177)

Saline-alkali stress restricts crop yield by disrupting nutrient and water uptake, ionic balance, and oxidative homeostasis. Although myo-inositol enhances tolerance to abiotic stress, its role in sugar beet (Beta vulgaris L.) under saline-alkali conditions remains unclear. To investigate the effects of exogenous myo-inositol on sugar beet growth under saline-alkali soils, a pot experiment was conducted using six myo-inositol concentrations (0, 0.2, 0.4, 0.6, 0.8, and 1.0 g L⁻¹). Myo-inositol significantly influenced plant performance in a concentration-dependent manner. The 0.6 g L⁻¹ treatment produced the highest shoot and root fresh and dry weights, nearly doubling shoot biomass compared with the control. Shoot N and P contents increased markedly at 0.6 g L⁻¹, while their concentrations remained relatively stable, indicating biomass-driven nutrient accumulation. Myo-inositol reduced Na accumulation while maintaining stable K, Ca, and Mg concentrations, thereby improving ionic balance. Antioxidant capacity was enhanced, with superoxide dismutase and catalase activities significantly elevated. Root total length and surface area increased substantially, whereas specific root length and surface area decreased, suggesting improved root morphological development. Soil alkaline phosphatase activity was also stimulated at higher myo-inositol treatments. Overall, moderate myo-inositol application (with regression analysis indicating an optimum of approximately 0.56 g L⁻¹) improved sugar beet growth through enhanced nutrient acquisition, ionic balance, antioxidant capacity, and root development, offering practical insights for its use as a growth regulator in saline-alkali crop production. Full article

Rational fertilization is a key measure for improving grassland productivity; however, the optimal effects of nitrogen (N), phosphorus (P) and potassium (K) rationing vary across grasslands with different salinity–alkalinity conditions. To determine the optimum fertilization ratio for typical saline–alkaline degraded grasslands in the agro-pastoral transition zone of northern China, we carried out an experiment with different ratios of N, P and K to investigate the effects of fertilization on biomass, plant diversity, plant nutrient uptake and soil nutrient contents. The results showed that fertilization increased biomass, plant diversity, nutrient uptake and soil nutrient contents in all levels of saline–alkaline grasslands. Compared with the control, N2P2K2 treatment resulted in the significantly highest biomass, with an increase of 4.52 and 2.39 t ha⁻¹ in slightly and moderately saline–alkaline grasslands; N2P2K1 resulted in the significantly highest biomass, with an increase of 1.14 t ha⁻¹ in severely saline–alkaline grasslands. We integrated plant and soil properties to construct a second-order response surface model (RSM), and our recommended optimum N–P–K fertilization ratios for slightly, moderately and severely saline–alkali grasslands are 103.7–88.1–78.0, 125.5–91.5–74.1 and 85.2–68.1–58.2 kg ha⁻¹, respectively. Reasonable fertilization can improve soil fertility, biomass yield and plant diversity, while excessive fertilization has negative effects on soil and plant traits. Our results provide theoretical support and practical guidance for the scientific fertilization of grasslands with varying salinity and alkalinity. Full article

The highly chitinolytic marine bacterium Vibrio jasicida KMM 6832, which exhibits potent antifungal activity, possesses an atypical Glycosyl Hydrolase family 19 (GH19) chitinase (ChitVjs). This is the first report of a GH19 gene in V. jasicida, an enzyme generally absent in this species and rare within the Harveyi clade. Phylogenetically, ChitVjs-like enzymes from the genera Vibrio and Aeromonas form a distinct cluster, separate from typical plant and bacterial GH19 counterparts. Despite high sequence identity (80–94%) with characterized homologs from V. parahaemolyticus and V. cholerae, ChitVjs is distinguished by its obligate halophilicity (optimum 0.3–0.4 M NaCl), an acidic isoelectric point (pI 4.72), and a broader cation-activation profile (K⁺, Ni²⁺, Ca²⁺, Cu²⁺, Co²⁺). The recombinant ChitVjs was produced in E. coli as a soluble 63 kDa protein. It functions as a stable, salt-dependent endo-chitinase/chitosanase, exhibiting optimal activity at 40 °C and pH 7.0. The enzyme displays high affinity for colloidal chitin (K_M 0.377 mg·mL⁻¹), is activated by DTT and Tween 80, and shows moderate stability in organic solvents. Furthermore, unlike its primarily catabolic relatives, ChitVjs suppresses conidial germination in marine-derived Aspergillus strains. These findings suggest that ChitVjs significantly contributes to the competitive fitness of V. jasicida KMM 6832 in high-salinity marine environments through both nutrient acquisition and antagonism. Full article

Freshwater scarcity severely limits sustainable cotton production in arid regions. This study aimed to establish the optimal salinity threshold for staged saline water supplemental irrigation (SWSI) and elucidate its canopy-level mechanisms in optimizing within-boll yield components and fiber quality. A two-year field trial (2023–2024) was conducted in Awati County, Xinjiang, using mulched drip irrigation at five SWSI levels (3.5–9.5 g L⁻¹) and a freshwater control (CK). Compared with CK, 3.5 g L⁻¹ treatment significantly increased lint yield by 31.4%, boll number per plant by 22.45%, and fibers per seed by 6.01–10.59%, while fiber length and strength rose by 6.98–10.38% and 2.69–6.00%, respectively. When salinity reached 8.0 g L⁻¹, yield declined by 8.5%, and a salinity of 9.5 g L⁻¹ reduced yield by 24.52%. Spatially, mid-fruiting branches (nodes 4–6) remained stable, maintaining high lint mass per seed even under high salinity, whereas upper branches (≥node 7) were most sensitive; at 9.5 g L⁻¹, the boll number (0.36) was 56.6% lower than at 3.5 g L⁻¹ (0.83), and the Q-score decreased by 6.7%. These results demonstrate that SWSI with ≤5.0 g L⁻¹ salinity (optimum 3.5 g L⁻¹) simultaneously enhances lint yield and fiber quality, providing a practical strategy for efficient saline water use in arid cotton regions. Full article

Soil salinity poses a critical threat to global agricultural productivity, exacerbating food security challenges in arid and semi-arid regions. This review synthesizes current knowledge on the physiological and biochemical impacts of salinity stress in plants, with a focus on the role of gibberellic acid (GA₃) in mitigating these effects. Salinity disrupts ion homeostasis, induces osmotic stress, and generates reactive oxygen species (ROS), leading to reduced chlorophyll content, impaired photosynthesis, and stunted growth across all developmental stages, i.e., from seed germination to flowering. Excess sodium (Na⁺) and chloride (Cl⁻) accumulation disrupts nutrient uptake, destabilizes membranes, and inhibits enzymes critical for carbon fixation, such as Rubisco. GA₃ emerges as a key regulator of salinity resilience, enhancing stress tolerance through various mechanisms like scavenging ROS, stabilizing photosynthetic machinery, modulating stomatal conductance, and promoting osmotic adjustment via osmolyte accumulation (e.g., proline). Plant hormone’s interaction with DELLA proteins and cross-talk with abscisic acid, ethylene, and calcium signaling pathways further fine-tune stress responses. However, gaps persist in understanding GA₃-mediated floral induction under salinity and its precise role in restoring photosynthetic efficiency. While exogenous GA₃ application improves growth parameters, its efficacy depends on the concentration- and species-dependent, with lower doses often proving beneficial and optimum doses potentially inhibitory. Field validation of lab-based findings is critical, given variations in soil chemistry and irrigation practices. Future research must integrate biotechnological tools (CRISPR, transcriptomics) to unravel GA₃ signaling networks, optimize delivery methods, and develop climate-resilient crops. This review underscores the urgency of interdisciplinary approaches to harness GA₃’s potential in sustainable salinity management, ensuring food security and safety in the rapidly salinizing world. Full article

Sunflower (Helianthus annuus L.) is an essential oilseed crop known for its adaptability to harsh environments including drought. However, salinity stress, affecting over 20% of global agricultural land, poses a serious threat to its productivity. This study evaluated the response of 17 sunflower genotypes under salinity stress (200 mM NaCl) and optimum (0 mM NaCl) conditions in the laboratory. The experiment was arranged in a completely randomized design with three replications and was validated through a second experimental run. Measured parameters included germination percentage and speed, root and shoot length, biomass, and water content. Stress tolerance indices (STIs) for germination, seedling length, and biomass were calculated. Combined ANOVA showed that genotype and environment interactions significantly (p < 0.001) affected all measured traits. Salinity stress significantly reduced germination, seedling growth, and biomass across genotypes, with some experiencing complete germination inhibition. Genotypes 9, 14, 16, and 17 consistently maintained higher germination, seedling length, and biomass under stress, with high STIs, indicating tolerance to salinity stress during the early growth stages. These results identified genotypes 9, 14, 16, and 17 as promising candidates for breeding programs aimed at enhancing salinity tolerance, offering sustainable solutions for the utilization of saline soils and for enhancing food security. Future research should focus on the field-based validation of these genotypic responses. Full article

Excessive or improper fertilization not only salinizes soil but also reduces crop yield and quality. The objective of this study was to determine the optimum N, P, and K levels capable of improving tomato fruit quality and reducing environmental pollution for tomato plants under brackish water irrigation conditions. The ‘Jingcai 8’ tomato was used as the research object, and an orthogonal experimental design was used to set up three nutritional factors of N, P, and K. Each factor was set at three levels: N (mmol·L⁻¹): 2.00 (N1), 4.00 (N2), and 8.00 (N3); P (mmol·L⁻¹): 0.67 (P1), 1.33 (P2), and 2.00 (P3); K (mmol·L⁻¹): 8.00 (K1), 12.00 (K2), and 16.00 (K3). The effects of different levels of N, P, and K on plant growth indexes, root vigor and antistress enzymes, biomass and nutrients of plants and fruits, yield, quality, soil nutrients, and soil enzymes were investigated, and metabolomic measurements were performed on treatments ranked first (N:P:K ratio was 2:1.33:12) and ninth (N:P:K ratio was 8:1.33:8) for overall quality. In general, a N concentration of 8 mmol·L⁻¹ promoted plant vegetative growth and plant biomass accumulation by promoting the accumulation of aboveground nitrogen content, but it reduced the weight of single fruit and tomato quality due to an increase in soil EC and pH. In contrast, 0.67 mmol·L⁻¹ of P and 12 mmol·L⁻¹ of K were able to promote both plant vegetative growth and tomato quality formation. In addition, 0.67 mmol·L⁻¹ of P enhanced soil nutrient availability and enzyme activity, while 16 mmol·L⁻¹ of K reduced nutrient availability and enzyme activity and increased soil EC. The concentrations of ferulic acid, cinnamic acid, caffeic acid, coumarin, and (-)-epigallocatechin were generally higher in tomatoes from the T2 treatment (N:P:K ratio was 2:1.33:12) than in those from other treatments. Together, the optimum N:P:K ratio (2:1.33:12) of fertilization enhances tomato yield and quality under brackish water irrigation. Full article

The current study focuses on a preliminary evaluation of the use of solid residues produced from the distillation of selected medicinal and aromatic plants (MAP) as fertilizers for alkaline soils. Specifically, the residues of hemp (Cannabis sativa L.), helichrysum (Helichrysum Italicum (Roth) G. Don), lavender (Lavandula angustifolia Mill.), oregano (Origanum vulgare L.), rosemary (Rosmarinus officinalis L.) and sage (Salvia officinalis L.) were added in an alkaline and calcareous soil at the rates of 0 (control), 1, 2, 4 and 8%, in three replications (treatments), and the treated soils were analyzed. The results showed that upon application of the residues, soil electrical conductivity (EC), organic C, total N and the C/N ratio significantly increased, especially at the 4 and 8% rates. The same was found for soil available P, K, B, Cu and Mn. The effects of the residues on soil pH, cation exchange capacity (CEC) and available Zn and Fe were rather inconclusive, whereas soil available N significantly decreased, which was somewhat unexpected. From the different application rates tested, it seems that all residues could improve soil fertility (except N?) when they were applied to soil at rates of 2% and above, without exceeding the 8% rate. The reasons for the latter statement are soil EC and available Mn: the doubling of EC upon application of the residues and the excessive increase in soil available Mn in treatments with 8% residues raise concerns of soil salinization and Mn phytotoxicity risks, respectively. This work provides the first step towards the potential agronomic use of solid residues from MAP distillation in alkaline soils. However, for the establishment of such a perspective, further research is needed in respect to the effect of residues on plant growth and soil properties, by means of at least pot experiments. Based on the results of the current study, the undesirable effect of residues on soil available N should be investigated in depth, since N is the most important essential element for plant growth, and possible risks of micronutrient phytotoxicities should also be studied. In addition, application rates between 2 and 4% should be studied extensively in order to recommend optimum application rates of residues to producers. Full article

Atriplex hortensis var. rubra (red orache, RO) is a halotolerant species rich in nutraceutical compounds, which makes it a valuable crop for human nutrition. This plant could also be exploited for phytoremediation of contaminated soil and wastewater, and for saline aquaponics. A root rot disease was observed on hydroponically grown RO plants, caused by Pythium deliense and Pythium Cluster B2a sp. Identification was based on morphology, molecular analysis (ITS and COI), and phylogenetic analysis. We assessed disease severity in plants grown in a growth chamber with nutrient solutions containing different NaCl concentrations (0, 7, and 14 g L⁻¹ NaCl). In vitro growth at different salinity levels and temperatures was also evaluated. Both Pythium species were pathogenic but showed different responses. Pythium deliense was significantly more virulent than Pythium Cluster B2a sp., causing a steady reduction in root dry weight (RDW) of 70% across all salinity levels. Pythium Cluster B2a sp. reduced RDW by 50% at 0 and 7 g L⁻¹ NaCl while no symptoms were observed at 14 g L⁻¹ NaCl. Pythium deliense grew best at 7 and 14 g L⁻¹ NaCl, while Pythium Cluster B2a sp. growth was reduced at 14 g L⁻¹ NaCl. Both pathogens had an optimum temperature of 30 °C. This is the first report of Pythium spp. causing root rot on RO grown hydroponically. The effective use of halophytic crops must consider pathogen occurrence and fitness in saline conditions. Full article

Graphene oxide (GO) was synthesized using the Hummers method and evaluated for lithium-ion removal from aqueous solutions. Characterization via X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD) confirmed the presence of oxygen-containing functional groups (C–O–C, C=O), which act as active adsorption sites. BET analysis revealed a surface area of 232 m²/g and a pore volume of 0.4 cm³/g, indicating its high porosity. Lithium adsorption was tested using synthetic Li-doped solutions under controlled conditions. Kinetics and equilibrium studies demonstrated that the process followed the pseudo-second-order model and the Redlich–Peterson isotherm, achieving an optimum lithium adsorption capacity of 179 mg/g. The adsorption efficiency was influenced by factors such as pH and salinity. Regeneration experiments showed that HNO₃ was the most effective desorbing agent, enabling GO to be reused multiple times with a moderate loss of adsorption capacity. These findings highlight GO’s exceptional efficiency in lithium removal and its suitability for wastewater treatment applications. Its recyclability and reusability further support a circular economy, making GO a highly promising material for sustainable lithium recovery and broader environmental remediation efforts. Full article

The development of eco-friendly surfactants is pivotal for enhanced oil recovery (EOR). In this study, a novel lignin-derived zwitterionic surfactant (DMS) was synthesized through a two-step chemical process involving esterification and free radical polymerization, utilizing renewable alkali lignin, maleic anhydride, dimethylamino propyl methacrylamide (DMAPMA), and sulfobetaine methacrylate (SBMA) as precursors. Comprehensive characterization via ¹H NMR, FTIR, and XPS validated the successful integration of amphiphilic functionalities. Hydrophilic–lipophilic balance (HLB) analysis showed a strong tendency to form stable oil-in-water (O/W) emulsions. The experimental results showed a remarkable 91.6% viscosity reduction in Xinjiang heavy crude oil emulsions at an optimum dosage of 1000 mg/L. Notably, DMS retained an 84.8% viscosity reduction efficiency under hypersaline conditions (total dissolved solids, TDS = 200,460 mg/L), demonstrating exceptional salt tolerance. Mechanistic insights derived from zeta potential measurements and molecular dynamics simulations revealed dual functionalities: interfacial modification by DMS-induced O/W phase inversion and electrostatic repulsion (zeta potential: −30.89 mV) stabilized the emulsion while disrupting π–π interactions between asphaltenes and resins, thereby mitigating macromolecular aggregation in the oil phase. As a green, bio-based viscosity suppressor, DMS exhibits significant potential for heavy oil recovery in high-salinity reservoirs, addressing the persistent challenge of salinity-induced inefficacy in conventional chemical solutions and offering a sustainable pathway for enhanced oil recovery. Full article

The Arctic Ocean has a uniquely complex system associated with tightly coupled ocean–ice–atmosphere–land interactions. The Arctic Ocean is considered to be highly susceptible to global climate change, with the potential for dramatic environmental impacts at both regional and global scales, and its spatial differences particularly have been exacerbated. A comprehensive understanding of Arctic Ocean environmental responses to climate change thus requires classifying the Arctic Ocean into subregions that describe spatial homogeneity of the clusters and heterogeneity between clusters based on ocean physical properties and implementing the regional-scale analysis. In this study, utilizing the long-term optimum interpolation sea surface temperature (SST) datasets for the period 1982–2023, which is one of the essential indicators of physical processes, we applied the K-means clustering algorithm to generate subregions of the Arctic Ocean, reflecting distinct physical characteristics. Using the variance ratio criterion, the optimal number of subregions for spatial clustering was 12. Employing methods such as information mapping and pairwise multi-comparison analysis, we found that the 12 subregions of the Arctic Ocean well represent spatial heterogeneity and homogeneity of physical properties, including sea ice concentration, surface ocean currents, SST, and sea surface salinity. Spatial patterns in SST changes also matched well with the boundaries of clustered subregions. The newly identified physical subregions of the Arctic Ocean will contribute to a more comprehensive understanding of the Arctic Ocean’s environmental response to accelerating climate change. Full article

Biotechnological research and application of microbial enzyme production have consistently been focal points for scientific inquiry and industrial advancement. In this study, Bacillus subtilis Y4X3 was isolated from saline–alkaline soil in Xinjiang, China. Extracellular enzyme production analysis revealed that B. subtilis Y4X3 can secrete various enzymes, including cellulase, xylanase, protease, and amylase. Sequencing and assembly of the complete genome of this strain revealed a genome size of 4,215,636 bp with 43.51% C + G content, including 4438 coding genes. Genome annotation was performed with databases to predict gene functions in B. subtilis Y4X3, and a variety of genes related to carbohydrate metabolism were identified. A cellulase-encoding gene was subsequently cloned from the genome and heterologously expressed in Escherichia coli. The optimum pH and temperature for the purified cellulase Cel5A were 5.0 and 60 °C, respectively. Stability analysis revealed that Cel5A remained stable at pH 5.0–9.0 and 20–60 °C; after 1 h at pH 9.0, the relative enzyme activity still exceeded 60%. Additionally, Cel5A was positively affected by various metal ions and exhibited good tolerance to multiple chemical reagents. The results indicate that B. subtilis Y4X3 has the potential to produce a variety of industrial enzymes and could serve as a promising candidate for more efficient and cost-effective industrial applications; the characterized thermostable and alkali-resistant cellulase Cel5A also has potential applications in biotechnology and industry. Full article

Nanoparticles and nanocomposites have been used in recent studies to improve oil reservoir recovery. With the introduction of a newly constructed smart water injection scenario, this work investigated the physicochemical characteristics of the polymeric carbon nitride/ZrO₂ nanocomposite (ZrO₂/g-C₃N₄), and the results were compared with pure ZrO₂ nanoparticles as a known enhanced oil recovery agent. The effects of ZrO₂/g-C₃N₄ and ZrO₂ on the wettability change, zeta potential, and interfacial tension under reservoir conditions (78 °C and 3800 psi) were determined after characterization experiments, which included X-ray powder diffraction (XRD), a Fourier transform infrared spectrometer (FTIR), transmission electron microscopy (TEM), a field emission scanning electron microscope (FESEM), energy-dispersive x-ray testing (EDX), and a Brunauer–Emmett–Teller (BET) analysis. Based on the highest zeta potential and the greatest reduction in the contact angle and interfacial tension, the optimum concentrations for ZrO₂/g-C₃N₄ and ZrO₂ were determined to be 30 and 40 ppm, respectively. Moreover, the ZrO₂/g-C₃N₄ nanocomposite demonstrated better results in enhancing the oil recovery parameters, and it was selected for low salinity flooding scenarios with three different salinities, including MgCl₂ + seawater (SW), CaCl₂ + SW, and MgSO₄ + SW, at 30 ppm of the nanocomposite. The best readings for the ZrO₂/g-C₃N₄ nanocomposite in its interfacial tension, contact angle, and zeta potential show that 1000 ppm has the best interfacial tension reduction among the tested concentrations of 500–50,000 ppm. At 30 ppm, MgCl₂ + SW had the maximum recovery (i.e., 49.36%), and this resulted from better interfacial tension reduction, contact angle reduction, and stability compared to other salinities. Full article

Controlled environment agriculture (CEA) facilitates the management of plant growth and development through innovative horticultural technologies. Specific features of obligatory halophytes require diverse cultivation conditions compared to leafy vegetables grown in CEA. An ice plant was grown in walk-in chambers, and the impact of the following aspects was evaluated: (I) photosynthetically active photon flux density (PPFD) of 150, 200, 250, 300 µmol m⁻² s⁻¹; (II) spectral composition of red (R), blue (B), RB, and RBFR (far-red); (III) 12 h, 16 h, and 24 h photoperiod; (IV) hydroponic solution pH at 5.0–5.5, 5.5–6.0, and 6.0–6.5; and (V) hydroponic solution salinity concentrations at 0, 50, 100, 150, and 200 mM L⁻¹ NaCl. Other cultivation parameters were maintained constant. The results demonstrate that the ice plant was not sensitive to lighting duration at a constant daily light quantity. However, to enhance the phytochemical and mineral content per biomass, it is suggested that 250 µmol m⁻² s⁻¹ be used. While growth remains unaffected, pH levels 6.0–6.5 lead to an increased accumulation of fructose, citric, malic, and fumaric acids. In contrast, pH levels of 5.0–5.5 enhance the accumulation of mineral elements. Nutrient solution salinity of 50 mM NaCl is potentially optimum for ice plant growth. Further research is needed to evaluate the complex effect of environmental conditions for halophytes cultivation in CEA. Full article