Salinity stress is one of the most detrimental abiotic factors affecting plant development, harming vast swaths of agricultural land worldwide. Silicon is one element that is obviously crucial for the production and health of plants. With the advent of nanotechnology in agricultural sciences, the application of silicon oxide nanoparticles (SiO-NPs) presents a viable strategy to enhance sustainable crop production. The aim of this study was to assess the beneficial effects of SiO-NPs on the morpho-physio-biochemical parameters of rice (Oryza sativa L., variety: DRR Dhan 73) under both normal and saline conditions. To create salt stress during transplanting, 50 mM NaCl was injected through the soil. 200 mM SiO-NPs were sprayed on the leaves 25 days after sowing (DAS). It was evident that salt stress significantly hindered rice growth because of the reductions in shot length (41 %), root length (38 %), shot fresh mass (40 %), root fresh mass (47 %), shoot dry mass (48 %), and root dry mass (39 %), when compared to controls. Together with this growth inhibition, elevated oxidative stress markers including a 78 % increase in malondialdehyde (MDA) and a 67 % increase in hydrogen peroxide (H2O2) indicating enhanced lipid peroxidation were noted. Increasing the chlorophyll content (14 %), photosynthetic rate (11 %), protein levels, total free amino acids (TFAA; 13 %), and total soluble sugars (TSS; 11 %), all help to boost nitrogen (N; 16 %), phosphorous (P; 14 %), potassium (K; 12 %), and vital nutrients. The adverse effects of salt stress were significantly reduced by exogenous application of SiO-NPs. Additionally; SiO-NPs dramatically raised the activity of important antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX), and catalase (CAT), improving the plant's ability to scavenge reactive oxygen species (ROS) and thereby lowering oxidative damage brought on by salt. This study highlights SiO-NPs' potential to develop sustainable farming practices and provides significant new insights into how they enhance plant resilience to salinity, particularly in salt-affected regions worldwide.

Moderate nitrogen addition can enhance plant growth performance under salt stress. However, the regulatory effects of nitrogen addition on the growth of the leguminous halophyte medicinal plant, Sophora alopecuroides, under salt stress remain unclear. In this study, a two-factor pot experiment with different NaCl levels (1 g/kg, 2 g/kg, 4 g/kg) and NH4NO3 levels (0 mg/kg, 32 mg/kg, 64 mg/kg, 128 mg/kg) was set up to systematically study the response of S. alopecuroides plant phenotype, nodulation and nitrogen fixation characteristics, nitrogen (N), phosphorus (P), potassium (K) nutrient absorption and utilization efficiency, plant biomass and nutrient accumulation to nitrogen addition under salt stress. The results demonstrated that under mild (1 g/kg NaCl) and moderate (2 g/kg NaCl) salt stress, S. alopecuroides exhibited a relatively low nitrogen demand. Specifically, low (32 mg/kg N) and medium (64 mg/kg N) nitrogen levels significantly enhanced nodule nitrogenase activity and nitrogen fixation capacity. Furthermore, the uptake of essential nutrients, including N, P, and K, in the aboveground biomass was markedly increased, which in turn promoted the accumulation of major nutrients such as crude protein, crude fat, and alkaloids, as well as overall biomass production. However, under severe (4 g/kg NaCl) salt stress, S. alopecuroides exhibited a preference for low nitrogen levels (32 mg/kg N). Under S3 conditions, excessive nitrogen application (e.g., 64 mg/kg and 128 mg/kg N) exacerbated the damage caused by salt stress, leading to significant inhibition of nitrogen fixation and nutrient uptake. Consequently, this resulted in a substantial reduction in biomass. This study provides a theoretical basis for nitrogen nutrition management of S. alopecuroides under salt stress conditions and offers valuable insights for optimizing fertilization and nutrient management strategies in saline-alkali agricultural production.

The global escalation of soil salinization has led to increased water erosion, adversely impacting plant growth and development. Heat shock proteins (HSPs) are highly conserved proteins found across a wide range of organisms. When biological organisms are stimulated by the external environment, they will express themselves in large quantities. HSPs play a pivotal role in mediating plant responses to abiotic stress. This study identified 22 members of the PcHsp20 gene family with complete open reading frames (ORFs) through transcriptomic analysis conducted under Pugionium cornutum salt stress, and evaluated their expression levels. Notably, PcHsp18.1 was significantly upregulated in the leaves of Pugionium cornutum (L.) Gaertn. Based on this, we cloned the PcHsp18.1 gene and determined through subcellular localization that PcHsp18.1 is localized in both the cytoplasm and nuclear membrane. Subsequently, we transformed the PcHsp18.1 gene into Arabidopsis thaliana to investigate its involvement in the response to salt stress. The results indicated that the overexpressing (OE) plants exhibited improved growth conditions, higher seed germination rates, increased root lengths, a greater number of lateral roots, reduced relative conductivity, and elevated relative chlorophyll content compared to the wild-type (WT) plants. These findings suggesting that the transgenic line possesses enhanced salt tolerance. Moreover, the concentrations of malondialdehyde (MDA) and relative conductivity in the overexpressing (OE) plants were significantly lower than those observed in the wild-type (WT) plants, suggesting a reduced extent of damage to their cell membranes. In comparison to the wild type (WT), the transgenic line (OE) exhibited elevated activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), along with increased proline content, suggesting that the transgenic plants possess enhanced resistance to abiotic stress and a greater capacity for scavenging reactive oxygen species (ROS). Meanwhile, salt treatment resulted in the significant expression of stress-related genes in the transgenic plants. These results indicate that PcHsp18.1 positively regulates salt stress in Arabidopsis.

Salinity is an important environmental stressor in arid, semi-arid, and coastal regions, primarily due to poor drainage, excessive fertilization, and proximity to the sea. Treating plants with exogenous organic acids may enhance their ability to survive under stressful conditions. In the present experiment, the effects of oxalic acid (OA) on strawberry plant growth and fruit quality were studied under salinity conditions. Day-neutral 'Albion' strawberry cultivar strawberry plants were planted in pots and 1 month after planting, salinity (35 mM Sodium chloride) and OA treatments (2.5, 5, 10 and 20 mM) were carried out. The plants were evaluated 60 days after the treatment's initiation. OA treatments decreased the electrical conductivity (EC) value of the soil under salinity. Salinity stress decreased root:shoot dry weight and the relative growth rate of plant biomass. OA treatments improved leaf cortical cell expansion and xylem conduit diameter under salinity conditions. L-ascorbic acid and malic acid increased with OA treatments. The study revealed that a 10-mM dose of OA was more effective than the other doses, indicating reduced salt stress damage. The results demonstrate that OA can be effectively used in strawberry cultivation under saline conditions.

Soil salinity, a critical environmental stressor, substantially impacts plant growth and productivity. It induces osmotic stress, disrupts ion homeostasis, and triggers the excessive production of reactive oxygen species (ROS), which can lead to oxidative damage within plant cells. To counteract these detrimental effects, plants have evolved sophisticated defense mechanisms, one of which involves the production of secondary metabolites (SMs). These SMs function as biostimulants that bolster antioxidative defenses and modulate signal transduction pathways, thus enhancing the plant's tolerance to salt stress. Recent evidence reveals SMs like sulforaphane (glucosinolate-derived) uniquely stabilize redox cofactors and reprogram stress-responsive miRNAs. Furthermore, they influence key signaling cascades, such as the mitogen-activated protein kinase (MAPK) pathway and various hormone-regulated pathways, which are instrumental in orchestrating adaptive responses to saline conditions. The regulation of SMs biosynthesis under salt stress is mediated by transcription factors like MYB, WRKY, and bHLH, which are essential for activating the genes involved in these metabolic pathways. Elucidating the intricate mechanisms by which SMs operate as biostimulants not only advances our understanding of plant stress responses but also paves the way for developing sustainable agricultural practices aimed at improving crop resilience in saline environments. This knowledge is instrumental for cultivating crops that can thrive under challenging soil conditions, ultimately contributing to global food security.

These days, one of the main issues preventing agricultural development is salinized soils. Potassium fulvic acid (PFA) not only regulates plant growth, but also improves the soil nutrient content and physical structure, which makes it a soil conditioner worth promoting. Nevertheless, the research conducted thus far on the subject of PFA with regard to plant growth and inter-root microbial communities remains somewhat limited in scope. In this study, a pot experiment was conducted to simulate both the normal environment and salt stress environment. The objective of this experiment was to verify the effect of PFA on the growth of blueberry (Vaccinium corymbosum L.) as well as its effect on the soil physical and chemical indices and the soil microbial community structure. The findings demonstrated that the implementation of potassium fulvic acids exhibited a minimal impact on the growth of blueberry plants under standard environmental conditions. However, it was observed to exert a substantial effect on enhancing various physiological parameters, including plant height, root activity, and chlorophyll synthesis, particularly in response to salt stress. PFA led to a substantial augmentation in the soil organic matter content, alongside a notable rise in the alkali-hydrolyzable nitrogen (AN) and available potassium (AK) content. Concurrently, PFA caused a notable escalation in the activities of soil urease, sucrase, acid phosphatase, and catalase (p < 0.05) in the salt-stressed environment. PFA increased the abundance of Acidobacteria, Myxococcota, Ascomycota, and Fungi_phy_Incertae_sedis under salt stress, which was mainly related to the decrease in electrical conductivity (EC) values and increase in soil acid phosphatase (S-ACP) activity. It is evident that the implementation of PFA is advantageous in enhancing the saline environment, mitigating the impact of salt damage on blueberries and establishing a foundation for the expansion of cultivated areas and the sustainable cultivation of blueberries.

Background and aimsCalcium salts are prevalent in soils, and excessive amounts of these salts can subject crops to abiotic stress, leading to yield reduction or death. While the effects of Ca2+ in calcium salt stress have been widely reported, the role of the anions remains unclear.MethodsThe response of the calcium-secreting plant Ceratostigma willmottianum to five (0, 25, 50, 100, and 200 mM) equimolar concentrations (also iso-osmotic) of Ca(NO3)2 and CaCl2 in terms of growth, morpho-anatomy, photosynthesis, physiology and biochemistry, and ion content was evaluated.ResultsPlants were more sensitive to CaCl2 than to equal concentrations of Ca(NO3)2, which caused more severe water deficit, oxidative damage, and inhibition of photosynthesis and growth. The CaCl2 sensitivity may be related to the toxicity of Cl-, which accumulates in large amounts in leaves (661-2149 mM); however, under the Ca(NO3)2 treatments, the leaf NO3- concentrations were 42-210 mM. Cl- inhibited chlorophyll synthesis and accelerated chlorophyll degradation, leading to photosystem disruption, and its inhibition of photosynthesis may involve both stomatal and nonstomatal limitation. In contrast, NO3- was not ionotoxic but rather promoted nitrogen assimilation and chlorophyll synthesis. The inhibition of photosynthesis by 100-200 mM Ca(NO3)2 originated mainly from stomatal limitation triggered by osmotic water loss. In addition, the Ca2+ secretion rate increased under calcium salt stress, which may represent a strategy for adaptation to high-calcium environments.ConclusionThe present study provides valuable information for a comprehensive understanding of calcium salt injury mechanisms and plant adaptation to high-calcium environments.

Background Cotton is a vital economic crop and reserve material and a pioneer crop planted on saline-alkaline soil. Improving the tolerance of cotton to saline alkaline environments is particularly important. Results Salt-tolerant and salt-sensitive cotton plants at the three-leaf stage were subjected to 200 mM NaCl stress treatment, thereafter, microstructural observations beside physiological and biochemical analyses were performed on cotton leaves at 0 h (CK), 48 h (NaCl) and re-watering (RW) for 48 h. Salt stress altered microstructural observations and physiological and biochemical in ST and SS (p < 0.05). After re-watering, ST recovered fully, while SS sustained permanent oxidative and structural damage, indicating distinct salt tolerance. Transcriptome analysis was performed on cotton leaves under salt stress and re-watering conditions. KEGG analysis revealed that the response of cotton to salt stress and its adaptation to re-watering may be related to major protein families such as photosynthesis (ko 00195), photosynthesis-antenna protein (ko 00196), plant hormone signal transduction (ko 04075), starch and sucrose metabolism (ko 00500), and porphyrin and chlorophyll metabolism (ko 00860). A gray coexpression module associated with cotton restoration under salt stress was enriched according to WGCNA. Conclusions Salt stress did not only affect the physiological and biochemical levels of cotton but also induced structural changes in cells and tissues. Re-watering was relatively effective in stabilizing the physiological and biochemical parameters, as well as the leaf microstructure, of cotton plants under salt stress. WGCNA revealed enriched gray coexpression modules related to the recovery of cotton plants under salt stress, and screening of the pivotal genes in the gray module revealed five critical hubs, namely, GH_A01G1528, GH_A08G2688, GH_D08G2683, GH_D01G1620 and GH_A10G0617. Overall, our findings can provide new insights into enhancing cotton salt tolerance and exploring salt tolerance genes in cotton,including screening cotton genetic resources using those potential responsive genes. This study provides a theoretical basis for further exploration of the molecular mechanism of cotton salt tolerance and genetic resources for breeding salt-tolerant cotton.

Soil salinization has been the major form of soil degradation under the dual influence of climate change and high-intensity human activities, threatening global agricultural sustainability and food security. High salt concentrations induce osmotic imbalance, ion stress, oxidative damage, and other hazards to plants, resulting in retarded growth, reduced biomass, and even total crop failure. Halo-tolerant plant growth promoting rhizobacteria (HT-PGPR), as a widely distributed group of beneficial soil microorganisms, are emerging as a valuable biological tool for mitigating the toxic effects of high salt concentrations and improve plant growth while remediating degraded saline soil. Here, the current status, harm, and treatment measures of global soil salinization are summarized. The mechanism of salt tolerance and growth promotion induced by HT-PGPR are reviewed. We highlight that advances in multiomics technologies are helpful for exploring the genetic and molecular mechanisms of microbiota centered on HT-PGPR to address the issue of plant losses in saline soil. Future research is urgently needed to comprehensively and robustly determine the interaction mechanism between the root microbiome centered on HT-PGPR and salt-stressed plants via advanced means to maximize the efficacy of HT-PGPR as a microbial agent. Halo-tolerant plant growth promoting rhizobacteria (HT-PGPR) are a valuable biological tool for mitigating the toxic effects of high salt concentrations. And the microbiome centered on HT-PGPR is solutions for sustainable agriculture in saline soils.

Soil salinization threatens sustainable agriculture, necessitating innovative restoration strategies. Suaeda salsa (L.) Pall., a halophyte with exceptional salt tolerance and vivid pigmentation, serves as an ideal model for salinity adaptation. This study integrates physiological and transcriptomic analyses to reveal how high salinity (400 mmolL(-)1 NaCl) upregulates 4,5-DOPA dioxygenase after 30 days of salt stress, promoting betacyanin accumulation to mitigate oxidative damage. Compared to the control, betacyanin content in the 200 mmolL(-)1 and 400 mmolL(-)1 NaCl groups increased to 1.975-fold and 3.675-fold, respectively, while chlorophyll a content decreased by 45.78% and 69.88%, chlorophyll b by 11.45% and 28.24%, and total chlorophyll by 30.28% and 53.06%. This trade-off in pigment allocation highlights the plant's adaptive strategy under salinity stress. The photosynthetic characteristics of S. salsa confirm that its photoprotective mechanisms are significantly enhanced under 400 mmolL(-)1 NaCl. At the molecular level, betacyanin biosynthesis alleviates oxidative stress, while transcriptional regulation of photosystem I (PSI) and photosystem II (PSII) genes-such as PsbY, PsaO, PsbM, and PsbW-partially restores photosynthetic activity. Stabilization of the electron transport chain by upregulated genes like PetA and PetH further enhances photosynthetic resilience. These findings highlight the synergy between betacyanin production and photosynthetic regulation in enhancing salinity resilience, providing insights for soil restoration and salt-tolerant crop breeding.