Search Results (3,077)

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

Salinity stress severely limits barley production by disrupting physiological and biochemical processes critical for growth and yield. Although numerous studies have examined individual physiological or antioxidant responses to salinity, an integrated multivariate understanding of how these mechanisms collectively contribute to yield stability at the flowering stage remains limited. This study aimed to elucidate the integrated antioxidant and physiological mechanisms underlying salinity tolerance in barley genotypes during flowering. Barley plants were subjected to controlled salinity treatments, and a comprehensive set of phenolic compounds, antioxidant capacity indices, physiological traits, and yield components were measured. Multivariate analyses, including redundancy analysis (RDA) and partial least squares regression (PLSR), identified key traits contributing to yield stability under salinity. Multivariate analyses revealed also genotype-specific physiological strategies underlying contrasting salinity tolerance levels. Antioxidant defenses, such as total phenolics, DPPH and ABTS radical scavenging activities, and α-tocopherol, along with osmotic regulators like proline and soluble sugars, were closely associated with improved water status and reduced oxidative damage. These coordinated responses correlated strongly with yield components, including thousand-grain weight and main spike seed number. Notably, this study provides new insights into the predictive relevance of selected biochemical and physiological markers for yield performance under salt stress using PLSR at the flowering stage. PLSR further demonstrated the high predictive power of a limited subset of biochemical and physiological markers for yield traits under salt stress. Collectively, these findings reveal that the interplay between antioxidant machinery and osmotic adjustment at flowering is critical for barley resilience to salinity, providing valuable physiological markers to inform breeding strategies aimed at improving salt tolerance. Full article

Modern agriculture is increasingly challenged by fungal diseases, with phytopathogens such as Fusarium species causing substantial yield and quality losses in major crops globally. Although synthetic fungicides remain widely used, their intensive application raises serious concerns regarding environmental safety, human health, and the rapid emergence of resistant pathogen populations in the environment. These limitations have accelerated the search for sustainable, biologically based alternatives. In this context, Bacillus species isolated from saline and hypersaline habitats have emerged as a distinctive and still underexplored group of microorganisms with dual functionality as biological control agents (BCAs) and plant growth–promoting rhizobacteria (PGPRs) in salt-affected agroecosystems. Their novelty lies in their combined ability to suppress phytopathogens, enhance plant growth, and tolerate or mitigate salinity stress. Owing to their exceptional metabolic adaptability, these bacteria remain active under osmotic stress and produce a wide range of bioactive compounds that collectively contribute to their antifungal activity and improved plant performance. This review critically synthesizes advances published over the last six years (2019–2025), providing a comprehensive overview of the current understanding of the mechanisms underlying the biocontrol potential of halophilic/halotolerant Bacillus species against Fusarium spp. and other fungal phytopathogens. Particular emphasis is placed on ecological adaptations, molecular mechanisms, and the dual roles of these bacteria as BCAs and PGPR. The exploration and exploitation of saline-adapted Bacillus strains offer promising, eco-friendly, and cost-effective strategies for managing Fusarium diseases, thereby contributing to resilient and sustainable agricultural systems under increasing environmental constraints in the future. Full article

Pest insect-associated microbes display great phenotypic and genotypic diversity, with many members inhabiting broader ecological niche. Several of these bacteria are ubiquitous in nature and contribute to fruit spoilage. When microbes occur in both environmental niches and insect hosts, their ability to adapt to diverse substrates may facilitate their ecological success. This study focuses on characterization of the metabolic capability of three bacterial isolates belonging to the genera Acetobacter and Pantoea associated with Drosophila suzukii collected in the Netherlands. Carbon utilization patterns and tolerance to environmental stressors were assessed under varying conditions of salinity, pH, and antibiotics. The isolates differed in their metabolic profiles but collectively demonstrated the capacity to utilize a wide range of carbon sources. In addition, they exhibited tolerance towards different chemicals including salt and antibiotics. The metabolic flexibility of bacteria associated with D. suzukii may facilitate their persistence within fruit environments and contribute to host ecology. Overall, this study provides functional insight into insect-associated bacteria and underscores the importance of metabolic characterization in understanding their ecological significance. Full article

Jasmonic acid (JA) signaling plays a pivotal role in plant stress response, with Jasmonate ZIM-domain (JAZ) proteins acting as key transcriptional repressors. Quinoa (Chenopodium quinoa Willd.) is highly stress-tolerant, but its JAZ gene family remains poorly characterized. In this study, we identified 11 CqJAZ genes in the quinoa genome and systematically analyzed their phylogenetic relationships, gene structures, conserved motifs, and cis-acting elements in their promoters. Expression profiling revealed distinct response patterns of CqJAZ genes to salt, drought, and saline-alkali stresses, among which CqJAZ1 was significantly down-regulated under all three conditions. Subcellular localization analysis indicated that CqJAZ1 is localized to the nucleus. Ectopic overexpression of CqJAZ1 in Arabidopsis thaliana inhibited root growth and reduced survival rates under salt, saline-alkali, and osmotic stresses. Physiologically, CqJAZ1-overexpressing lines had elevated malondialdehyde (MDA), decreased superoxide dismutase (SOD) and peroxidase (POD) activities, and reduced endogenous JA accumulation under stress conditions. Furthermore, they showed reduced methyl jasmonate (MeJA) sensitivity. Collectively, CqJAZ1 negatively regulates quinoa stress tolerance by modulating JA homeostasis and compromising antioxidant defense capacity, shedding light on quinoa’s JA signaling and stress-resistance mechanisms. Full article

To decipher the molecular response mechanism of melon to saline–alkaline stress, seedlings of the melon cultivar “Xikaixin” were treated with 50 mmol·L⁻¹ mixed solutions of NaCl and NaHCO₃ at ratios of 1:1, 1:2, and 2:1 to simulate saline–alkaline stress. Transcriptome sequencing of roots (four biological replicates per group, with each replicate consisting of one pot containing four robust seedlings as the experimental unit) yielded 78.98 Gb of clean data (≥6.02 Gb per sample) with Q30 ≥ 96.61% and genome alignment rates of 97.00–98.02%, identifying 588, 686, and 1107 differentially expressed genes (DEGs) in the 1:1, 1:2, and 2:1 groups, respectively. Notably, the 1:1 treatment—mimicking the natural NaCl:NaHCO₃ ratio of saline–alkaline soil in southern Xinjiang—had 588 DEGs with the plant hormone signal transduction pathway as its most significantly enriched pathway, representing the core molecular response of “Xikaixin” to near-natural saline–alkaline stress. DEGs were significantly enriched in 50 pathways categorized into five major classes, with the plant hormone signal transduction pathway showing the highest enrichment across all treatments. A key observation from gene expression patterns is a potential auxin–ABA balance modulation, inferred from the differential expression of annotation-based auxin-related and ABA-related genes/pathways (no direct measurement of hormone levels or signaling was performed): two auxin-related genes (auxin-induced protein gene MELO3C013403 and auxin response factor gene MELO3C004381) were specifically upregulated (≥two fold vs. control) in the high-salt 2:1 group, while ABA-related genes were upregulated and auxin/jasmonic acid/gibberellin-related genes were downregulated in the 1:2 group, indicating a putative cultivar-specific hormone-related gene expression pattern associated with auxin–ABA crosstalk in “Xikaixin” under saline–alkaline stress. In contrast, photosynthesis-antenna protein genes (e.g., MELO3C021567) were significantly downregulated (to 32% of the control) under the 2:1 treatment. RT-qPCR validation confirmed the consistency of these candidate genes’ expression with transcriptomic data. Therefore, melon may respond to saline–alkaline stress by regulating the plant hormone signal transduction (especially auxin–ABA balance), photosynthesis, and carbon metabolism pathways. This study provides novel candidate genes and a theoretical basis for the genetic improvement of saline–alkaline-tolerant melon cultivars, with the unique auxin–ABA balance modulation as a key original contribution. Full article

The increasing global population and progressive soil salinization threaten future food security and sustainable agriculture. Halophytes, as salt-tolerant plants adapted to saline environments, represent promising alternative crops and valuable sources of nutrients and bioactive compounds. This review presents a structured synthesis of selected halophytes, with emphasis on wild species of ethnobotanical relevance. The nutritional value of halophytes is discussed with respect to proteins, polysaccharides, lipids, minerals, and vitamins, together with their diverse profiles regarding bioactive compounds, such as polyphenols, terpenes and terpenoids (including carotenoids), alkaloids, saponins and chlorophylls. In addition, the biological activities and available clinical evidence of halophyte-derived compounds are summarized, with Lobularia maritima presented as a representative example. By organizing nutritional and phytochemical data according to compound classes, this review provides a perspective largely absent from previous studies and highlights the potential of halophytes as innovative ingredients for the food and pharmaceutical industries, as well as outlining future research challenges and prospects. Full article

Drought and salt stresses severely impair plant growth and development worldwide. DEHYDRATION-RESPONSIVE ELEMENT BINDING proteins (DREBs), as a subfamily of the AP2/ERF transcription factor superfamily, play critical regulatory roles in plant biological processes including growth and development, as well as the adaptive response to various abiotic stresses. Based on the transcriptome data analysis of Medicago truncatula under saline-alkali stress previously conducted in our laboratory, a gene responsive to saline-alkali stress, Medtr3g110205, was identified, and its homologous gene in Arabidopsis thaliana, AtERF41 (AT5G11590), was obtained via BLAST (version BLAST+ 2.17.0.). The mutant erf41 was used to explore its biological functions in response to drought and salt stresses. The results showed that under salt and drought stress conditions, the seed germination rate, and growth status of the erf41 mutant were all better than those of the wild type. Further determination of physiological and biochemical indicators revealed that the leaf contents of superoxide dismutase (SOD) and proline (Pro) in the leaves of the mutant plants were significantly higher than those in the wild type, while the malondialdehyde (MDA) content was significantly decreased. In conclusion, the AtERF41 gene negatively regulates salt and drought tolerance in Arabidopsis thaliana, providing a potential target for the genetic improvement of crop stress tolerance. This study not only deepens our understanding of the role of DREB transcription factors in plant stress response but also provides a theoretical basis for improving crop stress tolerance using genetic engineering technology in the future. Full article

Water resources in arid oases are extremely scarce, and the quality of irrigation water and groundwater depth are key factors affecting soil secondary salinization and maintaining high and stable crop yields. This study focuses on the oasis irrigation area of the 38th Regiment in Qiemo County, located in the extremely arid region at the southeastern edge of the Tarim Basin. For the first time, irrigation experiments with different water qualities, ranging from 0.5 to 3.0 g/L, were conducted under varying groundwater depths for multiple crops. Through indoor soil column experiments and numerical simulations of water and salt in the unsaturated zone, the study reveals the water and salt migration patterns in the root zones of watermelon, corn, jujube, and peanuts. It was found that the process of soil water and salt transport exhibits significant differentiation characteristics in the vertical direction, with the surface layer responding most rapidly to changes in moisture and salinity, while the middle and deep layers show certain lag and buffering effects. The study also examined the spatiotemporal distribution trends of soil water and salt under different water quality and quantity irrigation conditions, drawing nonlinear threshold response curves for groundwater depth and determining the optimal groundwater depth under various irrigation conditions. The results indicate: (1) for the four crops under freshwater (0.5 g/L) irrigation and actual irrigation water conditions, soil salinity is safe at groundwater depths of 1–2 m; (2) under slightly saline water (2.0 g/L) irrigation, the safe groundwater depth (GWD) ranges for corn, peanuts, watermelon, and jujube root zones are 3.5–4.2 m, 1.2–3.5 m, ≥2.9 m, and ≥1.6 m, respectively, with crop sensitivity ranking as “corn > peanuts > watermelon > jujube”; and (3) under saline water (3.0 g/L) irrigation, the salinity tolerance thresholds for corn and peanuts root zones are exceeded regardless of shallow or deep groundwater depths, while the upper limits of salinity tolerance thresholds for watermelon and jujube correspond to groundwater depths of 2.9 m and 2.1 m, respectively, with increased groundwater depth making soil salinity increasingly safe. The study proposes a “sensitive-suitable-reinforced” three-zone paradigm and constructs a threshold table for optimal crop layout in arid areas based on the synergistic dual factors of “water quality–water quantity,” providing a theoretical basis for crop layout considering the spatial heterogeneity of groundwater occurrence. This has guiding value for arid oases in addressing the dual stress of water quality deterioration and salinization. Full article

Salinity is a major abiotic stress limiting rice production worldwide. This study aims to elucidate the effects of heading date on salt tolerance in rice. Five near-isogenic lines (NILs) developed from the SL2038/Koshihikari backcross population were grown with or without salt stress. SL2038 is a salt-tolerant line with delayed heading (~18 days) compared to the salt-sensitive background Koshihikari. The results showed that late-heading NILs produced significantly higher plant dry weight, panicle weight, percentage of filled grains, and grain weight (p < 0.05) under long-term salt stress. In Koshihikari, which exhibited delayed heading due to long-day treatment, the percentage of white heads was low, and panicle and grain weights were significantly higher under salt stress. Experiments with different sowing times indicated that late heading, such as sowing in June, resulted in higher grain weights. This is the first report to assess the impact of heading date on agronomic and yield-related traits under salt stress. In conclusion, even with a prolonged salt treatment period, heading during periods of low temperature and solar radiation results in higher grain weight under salt stress. This is proposed as one of the strategies for salt escape. These findings can be used to improve rice yield and implement crop management in salt-affected regions. Full article