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Soil salinization is increasingly threatening global agricultural productivity and food security, currently affecting over 6% of the world’s land and one-third of irrigated areas. Tomato (Solanum lycopersicum L.), a major vegetable crop worldwide, exhibits moderate sensitivity to salinity, which limits both its yield and fruit quality. In recent years, epigenetic regulation has gained attention as a key mechanism enabling flexible and reversible control of gene expression without altering DNA sequences. This review synthesizes current knowledge on the epigenetic control of salt stress responses in tomato, focusing on three interconnected levels: DNA methylation dynamics, RNA-directed DNA methylation (RdDM), and histone modifications. We explore how DNA methyltransferases reshape the methylome under salinity, using examples such as PKE1 and SlGI to illustrate functional gene-body methylation. The RdDM pathway is discussed with emphasis on the unexpected role of SlAGO4A as a negative modulator of stress tolerance and the growing evidence for RdDM-mediated regulation of transcription factors. We also examine the balanced regulation of histone acetylation and deacetylation, highlighting the conserved role of GCN5 in maintaining cell wall integrity and the diverse functions of histone deacetylases, such as SlHDA1, SlHDA3, and SlHDA5, in stress adaptation. Additionally, insights from wild tomato species and grafting-induced epigenetic changes are presented, revealing new dimensions of stress memory. Collectively, these epigenetic mechanisms constitute a complex regulatory framework that integrates stress responses with growth and development, providing potential targets for epigenetic breeding of salt-tolerant tomatoes. Full article

Global warming and associated environmental changes are reducing arable land and intensifying salinization risks, posing growing threats to food security. Soil salinity is an increasing threat to agricultural productivity worldwide, particularly in arid and semi-arid areas. Wheat (Triticum aestivum L.) is one of the most important and widely cultivated cereal crops for human consumption and livestock feed. However, with increasing water scarcity and the incidence of salt-affected lands, wheat productivity is increasingly affected by salinity. Previous studies have investigated salinity tolerance mechanisms mainly at the seedling and reproductive stages of wheat; however, comparatively fewer studies integrate rapid biochemical and physiological responses during the first hours of germination stress exposure together with transcriptional analyses during early seedling establishment, even though this stage is critical for stand establishment. Here, we evaluated early physiological and transcriptional responses of salt-tolerant, moderate, and sensitive wheat cultivars exposed to 0 or 150 mM NaCl during germination and the early seedling stage. Tolerant and sensitive cultivars showed contrasting germination performance under salinity. Physiological analysis showed that salt-tolerant cultivars exhibited higher proline accumulation and higher antioxidant enzyme activities (CAT, SOD, and GR), while maintaining lower MDA levels under salinity compared with sensitive cultivars. Notably, tolerant cultivars showed marked upregulation of TaHKT1;4, TaP5CS, TaMYB, and TaDHN genes associated with ion homeostasis, osmoprotectant metabolism, and stress-responsive regulation. These responses represent integrated early-stage biochemical, physiological, and transcriptional indicators of salinity responsiveness rather than direct predictors of final yield performance. 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

Soil salinization is a major abiotic stress limiting maize (Zea mays L.) growth and productivity worldwide. Recently, many genes involved in salt stress have been identified. However, the molecular mechanisms underlying salt tolerance in maize remain largely elusive. In this study, we identified a member of the ZmPIRIN family genes, ZmPRN1, acting as a negative regulator in response to salt stress. The expression levels of ZmPRN1 were down-regulated under salt and H₂O₂ treatment. Subcellular localization analysis showed that ZmPRN1 is localized to the chloroplast. Under salt stress, the Zmprn1-Mu mutant exhibited higher survival rates and lower reactive oxygen species (ROS) accumulation compared to wild-type plants. Whereas, ZmPRN1 overexpression lines were more sensitive to salt stress, and had higher ROS levels and lower chlorophyll content than wild-type plants. Transcriptome analysis showed that the differentially expressed genes (DEGs) were mainly involved in the oxidation-reduction process. Furthermore, yeast-two hybrid and split-luciferase complementation assays revealed that ZmPRN1 can interact with the chloroplast NDH complex subunit NDF4, the RING-type E3 ubiquitin ligase RING371, and the auxin-responsive protein IAA27. Collectively, our findings demonstrated that ZmPRN1 negatively regulates salt tolerance in maize by modulating ROS homeostasis, providing a valuable genetic resource for breeding salt-tolerant maize varieties. Full article

Soil salinity is one of the most critical threats to plant development and agricultural productivity. Stress priming enhances plant resilience to subsequent severe stressors through prior exposure to mild stress. Understanding the mechanisms underlying priming-conferred salt tolerance and developing effective strategies are therefore crucial for sustainable agriculture. In the present study, creeping bentgrass (Agrostis stolonifera cv. ‘PennA4’) plants were pretreated with salt priming (150 mM NaCl) for 7 days, followed by exposure to severe salt stress (300 mM NaCl) for 14 days. Salt-primed plants exhibited superior growth performance under salt stress, with significant increases in leaf relative water content, chlorophyll content, and catalase activity, as well as decreases in electrolyte leakage and malondialdehyde content compared to non-primed plants. Lipidomic profiling analysis revealed that salt priming resulted in a 29.05% increase in the total lipid content during the priming stage. During subsequent salt stress, salt-primed plants maintained higher total glycolipid (21.70%) and monogalactosyl diacylglycerol (MGDG) (34.58%) levels than non-primed plants. Furthermore, salt priming increased the contents of specific glycolipid molecular species, including DGDG36:6, MGDG34:3, MGDG34:4, and MGDG36:6, resulting in increased unsaturation levels of digalactosyl diacylglycerol (DGDG) and MGDG. These findings demonstrate that salt priming enhances salinity tolerance by elevating the antioxidant capacity and promoting glycolipid remodeling, which are consistent with the preservation of chloroplast membrane integrity and thylakoid fluidity. This study thus establishes that enhanced antioxidant capacity and glycolipid reprogramming are important mechanisms for priming-induced stress adaptation, providing a theoretical foundation for improving plant resilience in saline soils. Full article

Background/Objectives: Rice fragrance is mainly determined by 2-acetyl-1-pyrroline (2-AP), which is negatively regulated by OsBADH2. However, the contribution of its paralog OsBADH1 to aroma-associated metabolism and GABA-linked abiotic stress responses remains unclear. This study investigated whether simultaneous disruption of OsBADH1 and OsBADH2 further enhances 2-AP accumulation while affecting stress tolerance in rice. Methods: Independent osbadh1 and osbadh2 knockout lines were generated using CRISPR/Cas9 and crossed to obtain homozygous osbadh1 osbadh2 double mutants. Wild type, single mutants, and double mutants were compared for 2-AP accumulation, GABA content, agronomic traits, abiotic stress responses, and expression of genes associated with GABA metabolism and stress responses. Results: The osbadh2 mutant showed a marked increase in 2-AP, and the osbadh1 osbadh2 double mutant exhibited the highest level, corresponding to a 7.1-fold increase over the wild type. In contrast, the GABA content progressively decreased and reached 0.46-fold of the wild-type level in the double mutant. Under normal growth conditions, the double mutant showed no major agronomic defects. However, under salinity and drought stress, its survival declined to 0.41-fold and 0.40-fold of the wild-type levels, respectively. KEGG and expression analyses further indicated coordinated disruption of GABA-associated metabolic and stress-responsive pathways in the double mutant. Conclusions: Combined disruption of OsBADH1 and OsBADH2 enhanced aroma-associated metabolism but weakened GABA-linked abiotic stress tolerance, revealing a trade-off between increased fragrance and reduced stress resilience in rice. Full article

Soil salinization is a source of major abiotic stress that severely limits the production of alfalfa (Medicago sativa L.), a globally critical forage legume for sustainable livestock production. Its complex autotetraploid genome and self-incompatibility greatly hinder salt tolerance genetic improvement, while the post-transcriptional regulatory mechanism of alfalfa salt stress response remains largely uncharacterized. This study aimed to narrow the gap between genome-wide genetic signals and causal regulatory mechanisms and identify core post-transcriptional regulators of alfalfa salt tolerance via a multi-layered integrative analysis pipeline. We performed a genome-wide association study (GWAS) using 220 globally collected alfalfa accessions, combined with public transcriptome integration, co-expression network analysis, 3′ untranslated region (3′UTR) motif discovery, and AlphaFold2-based protein-RNA docking simulation. We identified 20 significant salt tolerance-associated loci and prioritized the CCCH-type zinc-finger RNA-binding protein (RBP) MsCCCH20 as the core candidate regulator. We further screened 35 high-confidence target genes of MsCCCH20, detected conserved AU/AG-rich 3′UTR motifs, and provided structural predictions consistent with potential sequence-specific interactions (ipTM 0.70–0.79). Our findings establish a robust framework linking genetic association signals to post-transcriptional regulatory networks and provide high-confidence candidate genes and functional markers for the molecular breeding of salt-tolerant alfalfa. Full article

Brassica napus L. is a globally important crop and its productivity is constrained by multiple abiotic stresses (salinity, drought, and heat). Calcineurin B-like proteins (CBLs) act as calcium sensors and play key roles in regulating ion homeostasis and stress-responsive signaling pathways, thereby contributing to plant adaptation under unfavorable environmental conditions. Here, through detailed bioinformatics analyses, the BnCBL gene family has been identified along with its role in tolerance to multiple abiotic stresses. The identified 17 BnCBLs comprised four groups, as in Arabidopsis thaliana. The predicted molecular weights of the CBL proteins ranged from approximately 24.35 kDa (BnCBL3 and -9) to 29.7 kDa (BnCBL5), with protein lengths spanning 213 (BnCBL3, -9, -10, -12 and -15) to 260 amino acids (BnCBL5). Sequence, promoter, and structural analyses showed that BnCBL proteins harbor palmitoylation and myristoylation motifs in their EF-hand domains, contain hormone- and stress-responsive cis-elements, and exhibit characteristic post-translational modification sites and tertiary structures. RNA-seq and RT-qPCR expression analyses showed that several BnCBL genes (BnCBL2, -6, -9, -10, and -15) exhibit differential expression (3~6-fold) under NaCl, drought, and heat stresses, as well as in response to phytohormones (IAA, GA₃, ABA, and JA). In addition, BnCBL2, -3, -6, -8, -9, -11, -12 and -16 showed significant expression (around 7-fold) against biotic stresses (Sclerotinia sclerotiorum (Lib.) de Bary and Plasmodiophora brassicae (Woronin, 1877), indicating their roles in both biotic and abiotic stress tolerance and potential utility in biotechnological breeding of stress-enduring B. napus cultivars. Full article

Soil salinization, intensified by climate change, reduces soil quality and crop yields, posing a severe threat to food security. The present study focuses on the effects of two doses of a biostimulant, based on plant protein hydrolysates, on improving the root system and the quality of NaCl-affected soil. For this purpose, several experiments were conducted on Solanum lycopersicum plants that were grown for 60 days under four salinity conditions, obtained by combining two salinity levels and two irrigation water types (a total of 36 treatments). Several physical and chemical soil properties and root characteristics were evaluated, and it was shown that the application of the biostimulant (BALOX^®) significantly increased root length and total root area, even under high salinity conditions. An increase of up to 70% over the control was achieved, mostly in roots smaller than 2 mm in diameter, which are primarily responsible for nutrient absorption. It was also revealed that BALOX^®’s interaction with the root system favorably influenced soil properties, particularly Cation Exchange Capacity (CEC). Likewise, the Aggregate stability (AS) increased up to 36%, and the percentage of organic matter (OM) up to 6.4%. The CEC increased by 66–72% with the biostimulant application, and there were reductions in soil salinity and Na⁺ and Cl⁻ concentrations (20%, 19%, and 24%, respectively). In addition, BALOX increased the area and length of fine roots, thereby expanding the rhizosphere and enhancing its interaction with the soil. The use of the biostimulant may help prevent soil degradation and contribute to tomato plants’ tolerance mechanisms under salt stress. Full article

Gene-editing technology provides innovative strategies for coping with crop stress, enhancing resistance to biotic stresses (fungal, bacterial, viral infections) and abiotic stresses (salinity, drought, heavy metals, temperature extremes). The CRISPR/Cas9 system is widely used to knock out susceptibility genes, activate resistance genes, or modulate stress-response genes, yielding many stress-resistant crop varieties. However, off-target effects, chimeric effects, and the complexity of multi-gene synergistic editing limit its application. By optimizing and integrating with other cutting-edge technologies, gene editing is expected to yield highly stress-resistant and high-yielding crop varieties, contributing significantly to sustainable agricultural development and ensuring global food security. Rice, a key staple and model plant, has been extensively studied in gene-editing-based research on stress resistance. The practical potential of gene editing for agricultural improvement has been demonstrated by the effective modification of many genes linked to drought, salinity, temperature extremes, and disease resistance using CRISPR/Cas9 and related technologies. This review discusses gene-editing applications in crop stress research, examining the effects of various stresses on crops and the use of gene editing to develop stress-tolerant varieties. It offers substantial guidance for improving crop stress tolerance through gene editing, creating highly resilient cultivars with greater adaptation to complex, variable environments. Full article

Soil salinization is a significant environmental factor limiting agricultural production. Developing salt–alkali-tolerant microbial resources is important for the improvement of saline–alkali land. Plant growth-promoting rhizobacteria stimulate crop growth by producing the plant growth hormone indole-3-acetic acid (IAA), but their fermentation process under salt stress still needs optimization. Single-factor experiments and response surface methodology (RSM) were used to systematically optimize the fermentation conditions of the salt–alkali-tolerant Vreelandella titanicae J113. Key influencing factors were screened using the single-factor experiment design, and optimal process parameters were determined using the Box–Behnken design. IAA production and cell biomass were used as evaluation indicators to study the interactions of carbon sources, nitrogen sources, inorganic salts, temperature, cultivation time, and inoculum size. The optimal fermentation process was obtained: starch concentration 17.5 g/L, NaCl concentration 32.5 g/L, yeast extract 5 g/L, cultivation temperature 30 °C, inoculum size 3%, and cultivation time 144 h. After optimization, IAA production reached 23.02 μg/mL, an increase of 115% compared with before optimization. Salt stress experiments showed that the strain could still maintain high IAA production under 3% NaCl, demonstrating good salt tolerance. Maize seed germination experiments demonstrated that the optimized fermentation broth significantly promoted seed germination and seedling growth under salt stress conditions, with root length, fibrous root number, and fresh weight increasing by 61–86%, 137–200%, and 25–57%, respectively, compared to the control group. This study established an efficient IAA fermentation process for the salt–alkali-tolerant Vreelandella titanicae J113, providing technical support for developing microbial plant growth regulators suitable for saline–alkali land. The optimized strain exhibits excellent growth-promoting potential under salt stress conditions, offering favorable application prospects. Full article

Rice cultivation faces major environmental challenges due to climate change, particularly soil salinity, which limits plant growth and productivity. Salt tolerance in rice is typically evaluated using physiological and biochemical traits, whereas leaf anatomical traits combined with advanced statistical analyses remain underexplored. This study investigated leaf anatomical characteristics of the rice cultivar Tubtim Chumphae at the seedling stage under different salinity levels (0, 25, 50, 75, and 100 mM NaCl). Seedlings were cultivated in a soil-based pot system for 42 days prior to treatment, and salinity stress was applied for 4 weeks. Data were analyzed using the Kruskal–Wallis test and multivariate approaches, including Discriminant Analysis of Principal Components (DAPC) and Partial Least Squares Discriminant Analysis (PLS-DA). The results revealed that several anatomical traits significantly varied with salinity, including vertical epidermal cell size of long cells (Epi-VL-LC), major vascular bundle size in the lamina (MVB-la-HL), major vascular bundle size in the midrib (MVB-mid-HL and MVB-mid-VL), as well as stomatal size (St-HL and St-VL) and stomatal density (StD) (p < 0.01). DAPC effectively distinguished salinity levels based on leaf anatomical traits, and the PLS-DA results further supported the robustness of the classification. Epidermal cell size, cell wall and cuticle thickness, stomatal traits, and vascular bundle dimensions were identified as key candidate anatomical biomarkers of salt tolerance. S75 (75 mM NaCl treatment) was suitable as a screening level and S100 (100 mM NaCl treatment) as a confirmation level. The findings provide a useful reference for evaluating salt tolerance in this rice cultivar and may be integrated with morphological, physiological, and biochemical traits to support future rice breeding programs. These findings provide a reference for evaluating salt tolerance in this cultivar and may complement morphological, physiological, and biochemical traits in future rice breeding programs. Full article

Soil salinization is one of the major abiotic stresses limiting agricultural production. As an economically important fruit tree worldwide, grapevine generally exhibits weak salt tolerance. Therefore, identifying key stress-tolerance genes is of great significance for improving stress resistance in grapevines. In this study, the transcription factor gene VvWRKY57, which is induced by salt stress, was cloned from the grape cultivar Vitis vinifera ‘Shine Muscat’. Its function under salt stress was systematically evaluated via heterologous overexpression in Arabidopsis thaliana. The full-length CDS of the VvWRKY57 gene is 915 bp, encoding a protein of 305 amino acids. The protein contains a typical WRKY conserved domain, belongs to group II of the WRKY family, and is localized in the nucleus and cytoplasm. Expression pattern analysis showed that VvWRKY57 was expressed in roots, stems, and leaves of grapevine. Based on this expression profile, transgenic Arabidopsis thaliana plants overexpressing VvWRKY57 were generated to further investigate its role in salt tolerance. Subsequent salt tolerance assays revealed that, compared with wild-type plants, the overexpression lines exhibited stronger resistance phenotypes under salt stress. This study demonstrates for the first time that grape-derived VvWRKY57 functions in enhancing salt tolerance in model plants, providing a novel genetic resource and theoretical basis for crop salt-tolerance molecular breeding using this gene. 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

Global agriculture faces the dual challenge of increasing productivity to meet the growing demand for food, feed, biofuels, and plant-based biomaterials while coping with soil degradation, climate change, and environmental pollution. Biostimulants have emerged as an innovative and sustainable strategy to enhance plant growth, nutrient uptake, and yield, as well as to mitigate the adverse impacts of abiotic and biotic stresses. Numerous studies show that biostimulant application can prevent 15–50% of potential yield losses caused by stressful environmental conditions. This review classifies major groups of biostimulants and examines mechanisms of their plant growth-promoting action at molecular, biochemical, physiological, and rhizospheric levels. Special emphasis is placed on their role in improving plant tolerance to drought, salinity, cold, heat, metal(loid) toxicity, and pest or pathogen attack. Limitations and challenges, including inconsistent results, variability in product efficiency, and the efforts on standardized formulations and application methods are also discussed. Finally, future research directions are highlighted, focusing on optimizing biostimulant performance to enhance crop resilience, productivity, and environmental sustainability. Full article