Search Results (3,086)

Against the backdrop of increasingly scarce global arable land resources, the remediation and resource utilization of saline–alkali soils have become a critical issue in circular agriculture. This study proposes micro-nano bubble (MNB) irrigation technology as a green, low-carbon strategy for saline–alkali soil remediation, highlighting its multi-level driving mechanism through pot experiments at different aeration frequencies. Results indicated that MNB irrigation significantly enhanced salt leaching and acid-base neutralization by reducing the soil pH (11.75%) and electrical conductivity (53.41%). Meanwhile, soil organic matter, cation exchange capacity, and available nitrogen, phosphorus, and potassium increased to normal soil levels. MNBs also strongly activated native enzymes (urease and alkaline phosphatase), raising the total enzyme activity by 68.54%, which is linked to carbon, nitrogen, and phosphorus metabolism. These results were also validated by microbial analysis, which indicated that MNBs shifted the community structure from one dominated by salt-tolerant taxa (i.e., Pseudomonadota) to a more functionally beneficial composition (i.e., Bacillota). Through these changes, the microbial diversity and network connectivity were enhanced, with Qipengyuania and Psychrophilus identified as critical nodes. This study reveals the multi-level driving mechanism of MNB technology, providing new technical pathways and theoretical support for the remediation, resource recovery, and circular utilization of agricultural waste soils. Full article

Plant growth-promoting bacteria (PGPB) could be an alternative for alleviating salinity problems in different plants grown under salinity conditions. The study aimed to evaluate the ability of a bacterial consortium, isolated from the rhizosphere of the species Lycium chinense (LC), with the common name Goji, , to alleviate the effect of salt stress on the crop response of two treated Lycium species. The bacterial consortium was applied in a pot experiment under controlled conditions to evaluate whether the consortium had any plant growth promoting effect on plants. Specifically two Lycium species Lycium chinense (LC) and Lycium barbarum (LB) were grown under saline (Ts) and not saline irrigation (Tc), and with (I) or without (NI) consortium inoculation. Inoculation of LB under salinity stress (Ts) significantly improved the leaf area compared to the uninoculated treatment (NI), i.e., 88.8 cm² LB-I-Ts vs. 48.5 cm² LB-NI-Ts. In LC, no significant difference was reported in the leaf area. Under salinity stress (Ts), the dry matter for both Lycium species significantly increased when inoculation occurred. The I treatment led to a higher WUE under the Ts treatment in both LC and LB. The inoculation (I) had a significant effect on the RWC. It was significantly higher under the I than the NI treatment, i.e., 82.5% vs. 77.0% at p ≤ 1%. The analysis of our results highlights that inoculation with the bacterial consortium has a substantially beneficial effect on plants in the presence of salt stress compared to non-saline plants. Furthermore, among the two Lycium species, the beneficial effect of inoculation with PGPB, in conditions of salt stress, is more evident in LB than in LC. Although the detailed mechanism underlying the PGPB activity was not elucidated, the results obtained support the potential beneficial use of soil bacterial species adapted to harsh conditions in the development of productive agricultural systems in saline environments. Full article

Rhizosphere nitrogen-fixing bacteria play a critical role in sustainable crop production by enhancing nitrogen availability and improving soil fertility. This study aimed to isolate and characterize native rhizospheric nitrogen-fixing bacteria (NRNFB) associated with baby maize (Zea mays L.) roots and evaluate their nitrogen-fixing potential. Thirty root samples were collected, and ten bacterial isolates (V1–V10) were obtained using selective media. Morphological, biochemical, and physiological analyses identified strain V3 as the most promising candidate, exhibiting strong growth on nitrogen-free Burk medium and high oxidase, catalase, and urea hydrolysis activities. The strain demonstrated broad environmental tolerance, including salinity up to 4% NaCl, temperatures ranging from 15 to 45 °C, and pH values between 5.0 and 8.0. Molecular identification based on 16S rRNA gene sequencing revealed 100% sequence similarity with Peribacillus simplex LT4 (strain LT4). Nitrogenase activity analysis showed a peak during the exponential growth phase, accompanied by increased nitrogen accumulation in the culture medium, confirming active biological nitrogen fixation. These findings highlight the physiological adaptability and functional efficiency of strain LT4, supporting its potential development as a biofertilizer for sustainable maize production systems. Full article

Artemisia maritima holds potential applications in the rehabilitation of degraded environments, particularly in salt-affected areas, for biosaline agriculture aimed at biomass production for further valorization and green biotechnology. The aim of the present study was to investigate the response of A. maritima to alterations in soil chemical composition, including differences in mineral supply, the addition of various sodium salts, and contamination with several heavy metals (cadmium, lead, copper, manganese, zinc), in order to establish a scientific basis for further applied research. Under standard fertilization conditions, the growth of A. maritima plants was restrained by nitrogen deficiency. Surplus nitrogen enhanced mineral uptake and growth, especially for shoots, and stimulated clonal development. Low to moderate (50 and 100 mmol L⁻¹) NaNO₃ treatment significantly stimulated shoot growth, while Na₂HPO₄ and NaHCO₃ treatments exhibited the most adverse effects at 200 and 400 mmol L⁻¹, resulting in reduced growth and biomass, and even the deterioration of the aboveground parts. Chlorophyll fluorescence parameters served as reliable early indicators of the detrimental effects of salinity associated with individual anions. Shoot macronutrient levels remained unchanged for phosphorus and calcium, while nitrogen increased in nitrate treatments. Root mineral nutrient content was more susceptible to salinity, with significant changes observed for all macro- and micronutrients, varying depending on the specific element and anion type. The alterations in mineral nutrition observed for each anion treatment exhibited distinct characteristics. A. maritima plants demonstrated high tolerance to all heavy metals, with roots being more susceptible compared to shoots. At the shoot level, statistically significant growth inhibition was evident only for 1000 mg L⁻¹ lead and 1000 mg L⁻¹ zinc treatments. A. maritima plants can be characterized as high accumulators of cadmium, lead, manganese, and zinc, and as extreme accumulators of copper in shoots. Nitrophily, clonal expansion with a help of bud-bearing roots, and the ability to accumulate relatively high concentrations of mineral elements in shoots are among the important physiological characteristics of A. maritima plants, enabling them to exhibit high resilience in environmentally heterogeneous habitats. Full article

Structures made of wood are used extensively in applications that require mechanical reliability under variable environmental conditions. Several softwood species were investigated, including pine (Pinus sylvestris L.), spruce (Picea abies), and larch (Larix decidua). This study investigated the tensile deformation behavior of each species with a special focus on the mechanical energy demand of the tensile process. Samples were conditioned in an aqueous saline medium for defined exposure periods and compared with controls. The energy of deformation was determined from stress–strain relationships of tensile tests under identical loading conditions. Results indicate that saline conditioning alters the tensile response of the examined wood species in a species-dependent way. Tensile strength increased in pine wood after exposure, whereas spruce and larch showed different trends depending on conditioning duration. A wide range of tensile strengths was recorded for all samples, ranging from 5.4 MPa to 102.0 MPa. Controlled saline exposure significantly influences the mechanical behavior of softwood species, as indicated by the findings. Evaluating wood performance under modified environmental conditions, both deformation energy and strength parameters should be considered. The main novelty of this study is the introduction of an energy-based description of tensile deformation, in which the total tensile work is calculated from force–displacement relationships, enabling differentiation of specimens with similar tensile strengths but fundamentally different deformation and failure properties. A practical advantage of the proposed energy-based approach is that it provides additional insight into the deformation tolerance and failure behavior of saline-conditioned wood, thus enabling a more reliable assessment of material performance under unpredictable environmental conditions. Full article

Environmental pollution caused by persistent chemical compounds, particularly heavy metals, poses a significant global challenge. Current strategies focus on eco-friendly and sustainable approaches, such as the application of microorganisms, to mitigate this issue. In this study, four strains of Bacillus and Pseudomonas were phylogenetically identified and assessed for their resistance to three heavy metals: copper (Cu), chromium (Cr), and cadmium (Cd) up to 500 µg/mL. Various tolerance mechanisms related to heavy metal resistance were elucidated, including salinity tolerance, antibiotic resistance, production of exopolysaccharides (EPS), and biosurfactant synthesis. The antifungal activities of these strains were evaluated against the fungal isolates Fusarium oxysporum fs. phaseoli (Fop) and Stemphylium botryosum (St-bt) using dual culture assays. Phylogenetic analysis revealed that three strains belong to the genus Bacillus, while one strain is classified under Pseudomonas. Additionally, these strains exhibited diverse mechanisms for heavy metal tolerance, including salinity tolerance (up to 600 mM), multi-antibiotic resistance (to imipenem, ampicillin, and sodium fusidate), and the production of viscous, slimy colonies indicative of EPS synthesis. Biosurfactant production led to a significant reduction in surface tension, ranging from 10.51 ± 3.87% to 82.89 ± 5.01%. The antifungal assays demonstrated that the strains effectively inhibited the mycelial growth of the fungal isolates, with inhibition percentages varying from 0% to 83.34 ± 2.22%. The strains characterized in this study exhibit considerable potential for application in the bioremediation of metal-contaminated soils and as biocontrol agents. Full article

Taxillus chinensis (DC.) Danser is an important hemiparasitic medicinal plant whose propagation is severely limited by the desiccation sensitivity of its recalcitrant seeds. Dehydrins (DHNs), which protect plants against dehydration-induced stresses such as salinity, drought, and low temperatures, may play a critical role in protecting recalcitrant seeds. However, the role of DHNs in the seeds of T. chinensis remains unclear. In this study, a differentially expressed gene was identified from the seed transcriptome of T. chinensis and designated TcDHN1. Sequence alignment and phylogenetic analyses revealed that TcDHN1 encodes a dehydrin protein. Heterologous overexpression of TcDHN1 in Arabidopsis did not affect growth under normal conditions. Under salt, drought, and cold stresses, transgenic lines exhibited higher seed germination rates, longer primary roots, and improved seedling growth compared with wild-type (WT) plants. The transgenic lines showed significantly increased activities of antioxidant enzymes, including superoxide dismutase, catalase, and peroxidase. In addition, ectopic overexpression of TcDHN1 in Arabidopsis conferred enhanced tolerance to abiotic stresses compared to WT plants, accompanied by increased expression of the stress-responsive genes Responsive to Desiccation 29A (AtRD29A) and Heat Shock Protein 70-1 (AtHSP70-1). The above results indicate that TcDHN1 confers enhanced tolerance to abiotic stresses. This study provides a functional characterization of an abiotic stress-responsive gene from recalcitrant seeds and identifies a potential genetic resource for molecular breeding. This could potentially improve abiotic stress resistance in T. chinensis and related medicinal plants. Full article

Water salinization severely limits agriculture in semiarid regions. This study evaluated the efficacy of exogenous carnitine (CAR) application in mitigating salt stress in two gherkin cultivars (Cucumis anguria L.), ‘Liso Gibão’ and ‘Do Norte’. The experiment used a randomized block design (3 × 3 factorial), combining three electrical conductivity levels of irrigation water (ECiw: 0.5, 2.5, and 4.5 dS m⁻¹) and three foliar carnitine concentrations (0.0, 0.5, and 1.0 mM). The results indicated that increasing ECiw to 4.5 dS m⁻¹ caused drastic reductions in growth, production, and photosynthetic efficiency, resulting in a 54.87% decrease in the number of fruits, due to toxic accumulation of Na⁺ and Cl⁻. However, carnitine supplementation (optimally at 0.5 mM) attenuated such damage, promoting significant increases in biomass (up to 55.43% for total dry mass), fruit number (by 23.37%), and gas exchange rates. The CAR application was associated with reduced Na⁺ accumulation (reducing leaf Na⁺ by 40.23% under moderate stress) and improved K⁺ and Ca²⁺ homeostasis. The cultivar ‘Do Norte’ showed higher carnitine-mediated tolerance, outperforming ‘Liso Gibão’. Carnitine acts as an effective biostimulant, with its application associated with improved ionic balance and gas exchange, supporting gherkin production under saline conditions. Full article

Human hair waste represents a dense nitrogen reservoir (~15% N); however, its agricultural valorization is hindered by two concurrent barriers: the extreme recalcitrance of alpha-keratin and the high salinity derived from cosmetic treatments. While chemical hydrolysis generates secondary pollutants, biological composting often fails due to osmotic inhibition of non-adapted inoculants. Here, we report a biological strategy to circumvent this osmotic bottleneck using unwashed human hair collected from professional salons. We compared the degradation efficiency of a syntrophic Effective Microorganisms (EM) consortium with traditional single-strain inoculants (Trichoderma spp. and Bacillus spp.) in a 16-week co-composting system. Data revealed that the EM consortium displayed superior resilience, sustaining thermophilic sanitation (>45 °C) compliant with US EPA PFRP standards and achieving a Nitrogen Mineralization Rate of 883 mg N kg⁻¹ week⁻¹ (nearly triple the control), resulting in a final N content of 1.41% (14,133 mg kg⁻¹). Crucially, the EM treatment reduced electrical conductivity from a phytotoxic 7.23 mS cm⁻¹ to a tolerable level of 3.82 mS cm⁻¹, a mitigation effect likely mediated by humification-driven ion chelation. This performance suggests a “syntrophic succession” mechanism where initial acidification facilitates subsequent proteolytic attack. The final product presented a high sulfur-to-nitrogen ratio indicative of extensive disulfide bond cleavage. Preliminary economic estimates (~$60 USD ton⁻¹) confirm the process’s viability for decentralized scalability, though future molecular validation is recommended. We conclude that bio-augmentation with metabolically diverse consortia is essential to process chemically treated hair waste, converting a hazardous salon residue into a high-value proteinaceous biofertilizer. Full article

Orthohalarachne attenuata and O. diminuata mites are parasites of the respiratory system of Pinnipeds. During hosts’ dives, mites must cope with changing conditions of oxygen availability in the nasal cavity. Adults and nymphs live inside the host, but larvae are active and responsible for colonizing new hosts. Hence, larvae are also exposed to environmental conditions with variable temperature and pressure, as well as to dehydration and changes in salinity. Although both species live within the respiratory tract of hosts, adults attach to different sections. Also, larvae have differential thermal tolerances and locomotion capacities. In this study, we show the effect of hypoxia, humidity and salinity on survival of O. attenuata and O. diminuata mite larvae. We found that both species are highly tolerant to hypoxia and can withstand it for long periods. In turn, both species showed low survival when exposed to direct air. Finally, hyperosmotic solution was highly harmful for O. attenuata, but not for O. diminuata. Our results show that humidity rather than oxygen availability is a constraint for survival and a limitation for dispersal when searching for new hosts. The present study expands our knowledge of ecophysiology and adaptations to changing conditions experienced during the dispersal of these marine parasite species. Full article

When subjected to a combination of abiotic stresses in the field, such as saline and thermal stress, plants can suffer devastating effects on their development. Regarding millet, little is known about the effects of temperature and salinity on its germination and initial development. Therefore, the objective of this study was to evaluate the germination responses and initial development of millet seedlings subjected to thermal and saline stresses. The experiment was conducted in a completely randomized design with 16 treatments in a 4 × 4 factorial scheme, four salinity levels (0.0—control, 100, 200, and 300 mM) and four temperatures (10, 20, 30, and 40 °C). The germination percentage, average germination time, germination speed index, shoot length, and primary root length of seedlings were evaluated. The different salinity concentrations and temperatures significantly influenced all the variables studied, gradually reducing with increasing salinity and decreasing temperature, with optimal ranges at higher temperatures and lower salinity levels. It is concluded that the ideal conditions for germination and initial development of millet are as follows: a temperature between 20 and 30 °C and the absence of salinity. They tolerate concentrations of up to 200 mM and temperatures of 40 °C. On the other hand, high salinity and low temperature can delay and/or inhibit germination. Full article

Salinity stress constitutes a major environmental constraint impeding crop establishment by limiting water uptake and disrupting osmotic homeostasis during seed germination and early growth. Plant growth-promoting bacteria (PGPB) offer as a sustainable and cost-effective strategy to mitigate these limitations in agricultural systems. In this study, whole-genome analysis of the salt-tolerant PGPB Priestia aryabhattai WJ45 identified its genomic potential for PGP and salinity adaptation, alongside evaluations of wheat germination under saline conditions. Genome analysis revealed that strain WJ45 harbors a coordinated set of genes associated with key plant growth-promoting traits, including exopolysaccharide production, phosphate solubilization, and siderophore biosynthesis, as well as genes involved in Na⁺/K⁺ transport and osmolyte metabolism. Consistent with these genomic predictions, germination assays demonstrated that WJ45 treatment increased the germination rate by 13.1%, under salt stress compared with the non-inoculated control, while coleoptile, radicle lengths, and fresh weight were enhanced by 17.0%, 15.7%, and 53.2%, respectively, indicating improved early seedling establishment. Collectively, these findings demonstrate that WJ45 possesses a genome-encoded capacity to facilitate crop establishment under saline conditions. While further seedling and large-scale evaluations are warranted, this study underscores the potential of this genome-informed microbial resource to enhance early plant growth and resilience in salt-affected environments. Full article

Abiotic stresses including drought, salinity, heat, cold, and heavy metal toxicity severely constrain plant productivity worldwide. Nitrogen (N), beyond its fundamental nutritional role, has emerged as a central regulator of plant stress responses through its involvement in metabolic reprogramming, osmotic adjustment, antioxidant defense, and hormonal signaling. This review synthesizes current advances in understanding how nitrogen availability and form influence plant tolerance to major abiotic stresses. Particular emphasis is placed on nitrogen-mediated modulation of reactive oxygen species (ROS) scavenging systems, nitrogen–carbon metabolic coordination, phytohormonal crosstalk, osmoprotectant biosynthesis, and regulation of stress-responsive gene expression. Recent molecular insights highlight the role of nitrogen transporters, nitrate signaling pathways, and nitrogen-use efficiency in stress adaptation mechanisms. Furthermore, agronomic and biotechnological strategies aimed at optimizing nitrogen management to enhance stress resilience are discussed, including precision fertilization, integrated nutrient management, and genetic approaches targeting nitrogen-responsive regulatory networks. By integrating physiological, biochemical, and molecular perspectives, this review provides a comprehensive framework for understanding nitrogen-driven mitigation strategies under abiotic stress conditions and outlines future research directions for sustainable crop production in changing environments. Full article

Salinity stress severely limits rice productivity and grain quality worldwide. Although exogenous foliar application of titanium dioxide nanoparticles (nano-TiO₂) has been reported to enhance crop stress tolerance, its regulatory roles in yield formation and grain quality in rice varieties with differing salt tolerance are not well understood. In the present study, two contrasting rice varieties, viz., Jingliangyou 3261 (JLY3261; salt-tolerant) and Yuxiangyouzhan (YXYZ; salt-sensitive), were applied with five nano-TiO₂ foliar application treatments—viz., CK: water spray; Ti1: 15 mg L⁻¹; Ti2: 30 mg L⁻¹; Ti3: 45 mg L⁻¹; and Ti4: 60 mg L⁻¹—at the jointing and panicle initiation stages. Plants were irrigated with 0.3% saltwater to simulate salt stress. The results showed that Ti2 and Ti3 treatments led to 8.59% and 14.80% increases in grain yield in JLY3261 and YXYZ, respectively, compared with CK. Ti2 and Ti3 treatments significantly increased the leaf area index, net photosynthetic rate, and aboveground biomass of both varieties at the heading stage. Meanwhile, the activities of antioxidant enzymes such as superoxide dismutase and peroxidase, as well as nitrogen metabolism enzymes including nitrate reductase and glutamine synthetase, were improved with a substantial reduction in malondialdehyde contents. Application of nano-TiO₂ upregulated the expression of ion transport-related genes such as OsSOSs, OsNHXs and OsHKTs, thus improving leaf K⁺ accumulation and reducing Na⁺ content to optimize the K⁺/Na⁺ ratio. In addition, Ti2 and Ti3 treatments improved the milled rice rate, head rice rate, and protein content, while they decreased the chalkiness degree of both rice cultivars. Principal component analysis showed that the aboveground biomass at the heading stage was a core evaluation index for both varieties. Overall, foliar application of 30–45 mg L⁻¹ nano-TiO₂ was found to be effective regarding growth and yield improvement in rice under saline conditions. This study provides a theoretical basis for agro-management strategies for rice cultivation in saline–alkaline soils. Full article

Abiotic stresses severely constrain the growth, yield, and quality of horticultural plants, collectively posing major challenges to sustainable production under changing climatic conditions. Nitric oxide (NO) is a key signaling molecule that modulates plant responses to abiotic stress by integrating with redox regulation systems, hormonal crosstalk pathways, ion homeostasis mechanisms, and transcriptional control networks. Rather than functioning as an isolated regulator, NO participates in dynamic signaling frameworks whose outcomes depend on concentration, timing, cellular redox status, and interaction with other signaling molecules. This review synthesizes current knowledge on NO-mediated mechanisms contributing to abiotic stress tolerance and examines their relevance to sustainable horticultural crop management. After outlining the historical recognition of NO as a plant signaling molecule, we discuss stress-responsive NO-dependent processes, including S-nitrosylation-based post-translational modification, NO–reactive oxygen species (ROS) interactions, and the modulation of stress-responsive transcriptional programs. The roles of NO in tolerance to drought, salinity, extreme temperature, and heavy metal stress are analyzed with emphasis on experimentally supported physiological and molecular responses. We further evaluate evidence from fruit, vegetable, ornamental, and medicinal crops, highlighting how NO-associated signaling correlates with yield stability, quality-related traits, and post-harvest performance under stress conditions. Finally, NO-based strategies such as priming, donor application, and integration with biostimulants are critically assessed in the context of climate-resilient and sustainable horticulture, with attention to translational constraints and field-level feasibility. By connecting mechanistic insights with applied considerations, this review provides a structured framework for evaluating the potential and limitations of NO-based approaches in abiotic stress management of horticultural crops. Full article