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The moisture with salt ions adsorbed on the mineral soil surface is crucial to the cohesion process when the media is exposed to marine or coastal environments. However, the impact of salinity on the cohesion of soils is not well studied at the nanoscale. In this study, the salinity effect was investigated by studying the wettability and capillary force of NaCl solutions on quartz substrates via a molecular dynamics-based approach. Besides, a new visualization method was proposed to measure the contact angle of liquid droplets from the aspect of nanoscale. The results indicated that salt ions can weaken the wettability of the liquid on the quartz surface and inhibit the capillary force. Compared with water, the liquid with a 10% NaCl solution can achieve a capillary force reduction of around 70%, resulting in a detrimental effect on the cohesion of soils. Overall, this study enhanced the understanding of the nanoscale salinity effect on the cohesion process and provided insights into the modification of the mechanical properties of soils from the aspect of nanoscale. [ABSTRACT FROM AUTHOR]

Populations consuming saline drinking water are at greater risk of high blood pressure and potentially other adverse health outcomes. We modelled data and used available datasets to identify countries of higher vulnerability to future saltwater intrusion associated with climate change in 2050 under Representative Concentration Pathways (RCP)4.5 and RCP8.5. We developed three vulnerability criteria to capture geographies with: (1) any coastal areas with projected inland saltwater intrusion of ≥ 1 km inland, (2) > 50% of the population in coastal secondary administrative areas with reliance on groundwater for drinking water, and 3) high national average sodium urinary excretion (i.e., > 3 g/day). We identified 41 nations across all continents (except Antarctica) with ≥ 1 km of inland saltwater intrusion by 2050. Seven low- and middle-income countries of higher vulnerability were all concentrated in South/Southeast Asia. Based on these initial findings, future research should study geological nuances at the local level in higher-risk areas and co-produce with local communities contextually appropriate solutions to secure equitable access to clean drinking water.

Soil salinity is a major nutritional challenge with poor agriculture production characterized by high sodium (Na+) ions in the soil. Zinc oxide nanoparticles (ZnO NPs) and biochar have received attention as a sustainable strategy to reduce biotic and abiotic stress. However, there is a lack of information regarding the incorporation of ZnO NPs with biochar to ameliorate the salinity stress (0, 50,100 mM). Therefore, the current study aimed to investigate the potentials of ZnO NPs application (priming and foliar) alone and with a combination of biochar on the growth and nutrient availability of spinach plants under salinity stress. Results demonstrated that salinity stress at a higher rate (100 mM) showed maximum growth retardation by inducing oxidative stress, resulted in reduced photosynthetic rate and nutrient availability. ZnO NPs (priming and foliar) alone enhanced growth, chlorophyll contents and gas exchange parameters by improving the antioxidant enzymes activity of spinach under salinity stress. While, a significant and more pronounced effect was observed at combined treatments of ZnO NPs with biochar amendment. More importantly, ZnO NPs foliar application with biochar significantly reduced the Na+ contents in root 57.69%, and leaves 61.27% of spinach as compared to the respective control. Furthermore, higher nutrient contents were also found at the combined treatment of ZnO NPs foliar application with biochar. Overall, ZnO NPs combined application with biochar proved to be an efficient and sustainable strategy to alleviate salinity stress and improve crop nutritional quality under salinity stress. We inferred that ZnO NPs foliar application with a combination of biochar is more effectual in improving crop nutritional status and salinity mitigation than priming treatments with a combination of biochar.

Most of the available data on diffusion in natural clayey rocks consider tracer diffusion in the absence of a salinity gradient despite the fact that such gradients are frequently found in natural and engineered subsurface environments. To assess the role of such gradients on the diffusion properties of clayey materials, through-diffusion experiments were carried out in the presence and absence of a salinity gradient using salt-diffusion and radioisotope tracer techniques. The experiments were carried out with vermiculite samples that contained equal proportions of interparticle and interlayer porosities so as to assess also the role played by the two types of porosities on the diffusion of water and ions. Data were interpreted using both a classical Fickian diffusion model and with a reactive transport code, CrunchClay that can handle multi-porosity diffusion processes in the presence of charged surfaces. By combining experimental and simulated data, we demonstrated that (i) the flux of water diffusing through vermiculite interlayer porosity was minor compared to that diffusing through the interparticle porosity, and (ii) a model considering at least three types of porous volumes (interlayer, interparticle diffuse layer, and bulk interparticle) was necessary to reproduce consistently the variations of neutral and charged species diffusion as a function of salinity gradient conditions.

Mutants lacking functional HYD2 homoeologs showed improved seedling growth, but comparable or increased susceptibility to salt stress in tillering plants, suggesting a developmentally restricted role of HYD2 in salt response. Salinity stress threatens global food security by reducing the yield of staple crops such as wheat (Triticum ssp.). Understanding how wheat responds to salinity stress is crucial for developing climate resilient varieties. In this study, we examined the interplay between carotenoid metabolism and the response to salt (NaCl) stress, a specific form of salinity stress, in tetraploid wheat plants with mutations in carotenoid β-hydroxylase 1 (HYD1) and HYD2. Our investigation encompassed both the vulnerable seedling stage and the more developed tillering stage of wheat plant growth. Mutant combinations lacking functional HYD2 homoeologs, including hyd-A2 hyd-B2, hyd-A1 hyd-A2 hyd-B2, hyd-B1 hyd-A2 hyd-B2, and hyd-A1 hyd-B1 hyd-A2 hyd-B2, had longer first true leaves and slightly enhanced root growth during germination under salt stress compared to the segregate wild-type (control) plants. Interestingly, these mutant seedlings also showed decreased levels of neoxanthin and violaxanthin (xanthophylls derived from β-carotene) and an increase in β-carotene in roots. However, tillering hyd mutant and segregate wild-type plants generally did not differ in their height, tiller count, and biomass production under acute or prolonged salt stress, except for decreases in these parameters observed in the hyd-A1 hyd-B1 hyd-A2 hyd-B2 mutant that indicate its heightened susceptibility to salt stress. Taken together, these findings suggest a significant, yet developmentally restricted role of HYD2 homoeologs in salt-stress response in tetraploid wheat. They also show that hyd-A2 hyd-B2 mutant plants, previously demonstrated for possessing enriched nutritional (β-carotene) content, maintain an unimpaired ability to withstand salt stress.

Salinity is one of the substantial threats to plant productivity and could be escorted by other stresses such as heat and drought. It impairs critical biological processes, such as photosynthesis, energy, and water/nutrient acquisition, ultimately leading to cell death when stress intensity becomes uncured. Therefore, plants deploy several proper processes to overcome such hostile circumstances. Grapevine is one of the most important crops worldwide that is relatively salt-tolerant and preferentially cultivated in hot and semi-arid areas. One of the most applicable strategies for sustainable viticulture is using salt-tolerant rootstock such as Ruggeri (RUG). The rootstock showed efficient capacity of photosynthesis, ROS detoxification, and carbohydrate accumulation under salinity. The current study utilized the transcriptome profiling approach to identify the molecular events of RUG throughout a regime of salt stress followed by a recovery procedure. The data showed progressive changes in the transcriptome profiling throughout salinity, underpinning the involvement of a large number of genes in transcriptional reprogramming during stress. Our results established a considerable enrichment of the biological process GO-terms related to salinity adaptation, such as signaling, hormones, photosynthesis, carbohydrates, and ROS homeostasis. Among the battery of molecular/cellular responses launched upon salinity, ROS homeostasis plays the central role of salt adaptation.

Estuarine wetlands harbor considerable carbon stocks, but rising sea levels could affect their ability to sequester soil carbon as well as their potential to emit methane (CH4). While sulfate loading from seawater intrusion may reduce CH4 production due to the higher energy yield of microbial sulfate reduction, existing studies suggest other factors are likely at play. Our study of 11 wetland complexes spanning a natural salinity and productivity gradient across the San Francisco Bay and Delta found that while CH4 fluxes generally declined with salinity, they were highest in oligohaline wetlands (ca. 3-ppt salinity). Methanogens and methanogenesis genes were weakly correlated with CH4 fluxes but alone did not explain the highest rates observed. Taxonomic and functional gene data suggested that other microbial guilds that influence carbon and nitrogen cycling need to be accounted for to better predict CH4 fluxes at landscape scales. Higher methane production occurring near the freshwater boundary with slight salinization (and sulfate incursion) might result from increased sulfate-reducing fermenter and syntrophic populations, which can produce substrates used by methanogens. Moreover, higher salinities can solubilize ionically bound ammonium abundant in the lower salinity wetland soils examined here, which could inhibit methanotrophs and potentially contribute to greater CH4 fluxes observed in oligohaline sediments.IMPORTANCELow-level salinity intrusion could increase CH4 flux in tidal freshwater wetlands, while higher levels of salinization might instead decrease CH4 fluxes. High CH4 emissions in oligohaline sites are concerning because seawater intrusion will cause tidal freshwater wetlands to become oligohaline. Methanogenesis genes alone did not account for landscape patterns of CH4 fluxes, suggesting mechanisms altering methanogenesis, methanotrophy, nitrogen cycling, and ammonium release, and increasing decomposition and syntrophic bacterial populations could contribute to increases in net CH4 flux at oligohaline salinities. Improved understanding of these influences on net CH4 emissions could improve restoration efforts and accounting of carbon sequestration in estuarine wetlands. More pristine reference sites may have older and more abundant organic matter with higher carbon:nitrogen compared to wetlands impacted by agricultural activity and may present different interactions between salinity and CH4. This distinction might be critical for modeling efforts to scale up biogeochemical process interactions in estuarine wetlands.

The San Francisco Estuary (estuary) and the Sacramento–San Joaquin Delta (the Delta) in California face significant challenges in managing water resources during extended droughts. Zooplankton are a vital trophic link between phytoplankton producers and higher-level consumers such as predatory zooplankton and fish. However, there is still much to be learned about what drives zooplankton abundance and how they respond to drastic changes in environmental conditions, such as droughts. We found that during drought years zooplankton abundance and distribution changes varied for examined taxa. Significant declines in the abundance of Daphnia spp. and the copepod Pseudodiaptomus forbesi occurred in the Suisun Marsh and Suisun Bay regions. In contrast, abundance of the non-native copepod Limnoithona tetraspina increased in Suisun Marsh and the South-Central Delta during those same drought conditions. Salinity is a strong determinant of the presence and abundance of the studied taxa, and we showed that changes in the distribution of salinity as a result of low outflow conditions were an important factor in the regional abundance of zooplankton. Because of the expected increase in the frequency and severity of regional droughts, understanding how these conditions affect zooplankton in the estuary will benefit scientists and resource managers who aim to improve conditions for native fishes.

Droughts have major effects on estuaries because freshwater entry is one of the defining features of an estuary, and freshwater flow is an important variable that determines the interannual change in the environment. In the upper San Francisco Estuary (the Sacramento–San Joaquin Delta, Suisun Bay, and Suisun Marsh), the Mediterranean climate includes frequent multi-year droughts. To assess ecosystem responses to droughts in the upper estuary, the Interagency Ecological Program Drought Synthesis Team assembled a set of flow, water quality, chlorophyll, zooplankton, and fish data from 1975 to 2021 to test for differences between multi-year droughts and multi-year wet periods and tested for linear relationships between each variable and the Sacramento Valley Hydrologic Index (see definitions and relationships as outlined in Appendix A). Our models showed droughts decreased Delta outflow, project exports, zooplankton in Suisun Bay, and some fish species. We also found that droughts increased water clarity, salinity, nutrients, chlorophyll in the South Delta, zooplankton in the South Delta, and water residence time. Although our analyses only tested correlations, we hypothesized that most of the food-web responses could be traced to increased residence time, decreased transport rates, or both. However, some responses may have been caused by secondary effects, including shifts in salinity gradients, regional changes in water quality, or differences in top-down effects of increased predation and grazing rates. With increased frequency of droughts in the future, this increasingly low-outflow, warming, clearing estuary—which is invaded by non-native species and has low pelagic fish production—is rapidly becoming the new “normal.”

Low salinity Waterflooding (LSWF) is a proven EOR technique which has emerged in the last few decades. In this, the salinity of the injected water is reduced. Studies have unveiled that the LSWF can improve about 5–38% of oil recovery. This work aims to study the effectiveness of LSWF by modeling Sea waterflooding (SWF) and LSWF using a commercial reservoir simulator and justifying the proposed mechanisms responsible for the incremental oil recovery due to LSWF. A critical parametric study has been undertaken, which led us to conclude that LSWF is a cost-effective, and environment-friendly method that results in additional oil recovery for sandstone reservoirs. [ABSTRACT FROM AUTHOR]

Zinc (Zn) deficiency and salt stress are well-known soil problems and often happen parallelly in cultivated soils. In this study, Zn-amino acid complexes (Zn-AAc) were used as a source of Zn to determine their effects on salt-induced damage in wheat plants. The bread wheat (Triticum aestivum L. cvs. Kavir) was supplied with Zn-glycine (Zn-Gly), Zn-alanine (Zn-Ala), and ZnSO4 as Zn sources at three salinity levels (EC 2, 4 and 6 dS m-). Salinity caused a significant decrease in shoot dry matter and grain yield of wheat, but this negative effect was significantly improved by the application of Zn-AAc. Salt stress decreased shoot and grain Zn concentration, but this reduction was lower in plants supplied by Zn-AAc. Calcium (Ca) and potassium (K) concentrations were increased in a shoot by salinity stress while decreased in grain. Sodium (Na) concentration decreased in shoot and grain by using Zn-AAc. At all of the salinity levels, wheat supplied with Zn-AAc had lower lipid peroxidation compared to those grown under the ZnSO4 source. Application of Zn-AAc increased the activities of catalase (CAT) and superoxide dismutase (SOD) in the roots of wheat plants in saline conditions. Based on the results, the adverse effects of salinity stress on wheat plants can moderately improve with Zn-AAc application. [ABSTRACT FROM AUTHOR]

In this study, freshwater microalga (Tetradesmus obliquus GEEL-11) was cultured in municipal wastewater supplemented with various NaCl concentrations (0–150 mM). The microalgal growth kinetics, morphological changes, nutrient removals, salinity change, fatty acids (FAs) composition, and biodiesel quality were investigated. Maximum microalgal growth was observed upon 75 mM salt addition, while the increase in salt hindered the growth of T. obliquus GEEL-11. T. obliquus GEEL-11 exhibited high nutrient removal N (87–99%) and P (94–100%) from municipal wastewater under various salt stress. The cell size of T. obliquus GEEL-11 increased and intracellular vesicular structures proliferated. The salinity dramatically decreased, indicating that T. obliquus GEEL-11 might be able to remediate saline wastewater. The palmitic acid (C16:0) and stearic acid (C18:0) accounted for 28.90–34.02% and 43.61–62.09% of T. obliquus GEEL-11, respectively. T. obliquus GEEL-11 exhibited significant quantities of fatty acids, representing its potential for biodiesel production. This study demonstrated that T. obliquus GEEL-11 could effectively remove N and P from wastewater embedded with high salt concentrations for biomass production. [ABSTRACT FROM AUTHOR]

The production of chitin generates wastewater containing high content of organic compounds, nutrients, and salinity, thus a biofilm system including anaerobic–anoxic–aerobic bioreactors was employed. This study aims to evaluate the performance of Stick-bed Biofix and Swim-bed Biofringe added to bioreactors as a biomass carrier in order to enhance biomass concentration. The results indicated that the organic removal has been insignificantly affected by high salinity, the removal efficiency was obtained at 95 ± 2% corresponding to a rate of 5.78 ± 1.10 kg COD/m3/d. Otherwise, the nitrogen removal rate was achieved at around 0.45 ± 0.17 kg N/m3/d and strongly decreased to 0.24 ± 0.10 kg N/m3/d under high salinity of 18,000 mg/L and a high loading rate of 1.03 ± 0.10 kg N/m3/d. Phosphorus removal was obtained at 0.032–0.057 kg P/m3/d and decreased by 1.5 times when the salinity is over 10,000 mg/L although the influent load was strongly reduced by pre-treatment. Besides, the biofilm system can also remove around 50% of calcium ions which causes high salinity in chitin production wastewater. [ABSTRACT FROM AUTHOR]

Significant strides have been made in understanding El Niño-Southern Oscillation (ENSO) dynamics, yet its long-lead prediction remains challenging, especially for the El Niño events after 2000. Sea surface salinity (SSS) is known to affect ENSO development and intensity by influencing ocean stratification and heat redistribution and therefore, when combined with sea surface temperature (SST) data, can potentially enhance ENSO forecast skill. In this study, we develop a deep learning (DL) model that incorporates a multiscale-pyramid structure and spatiotemporal feature extraction blocks, and the model successfully extends effective ENSO forecast lead time to 24 months for 2000–2021 with reduced effect of the spring predictability barrier (SPB). Interpretable methods are then applied to reveal the time-dependent roles of SST and SSS in ENSO forecast. More specifically, SST is critical for short-medium lead forecasts (<1 year), while SSS is important for medium-long lead forecasts (>6 months). Furthermore, we track global SST and SSS spatiotemporal shifts related to subsequent ENSO development, highlighting the importance of ocean inter-basin and tropics-extratropics interactions. With increasing availability of satellite SSS observations, our findings unveil unprecedented potential for advancing ENSO long-lead forecast skills. [ABSTRACT FROM AUTHOR]

Marine microbes that have for eons been adapted to stable salinity regimes are confronted with sudden decreases in salinity in the Arctic Ocean. The episodic freshening is increasing due to climate change with melting multi-year sea-ice and glaciers, greater inflows from rivers, and increased precipitation. To investigate algal responses to lowered salinity, we analyzed the responses and acclimatation over 24 h in a non-model Arctic marine alga (pelagophyte CCMP2097) following transfer to realistic lower salinities. Using RNA-seq transcriptomics, here we show rapid differentially expressed genes related to stress oxidative responses, proteins involved in the photosystem and circadian clock, and those affecting lipids and inorganic ions. After 24 h the pelagophyte adjusted to the lower salinity seen in the overexpression of genes associated with freezing resistance, cold adaptation, and salt tolerance. Overall, a suite of ancient widespread pathways is recruited enabling the species to adjust to the stress of rapid salinity change. The authors analyzed the response of an Arctic pelagophyte to lowered salinity. They observed that several ancient and widespread pathways were activated, allowing the species to adjust to the stress of rapid salinity change. [ABSTRACT FROM AUTHOR]

Studies are being conducted to develop strategies to reduce the adverse effects of salinity stress. In the present study, it was aimed to determine the interactive effects of salinity stress with biochar on plant growth-the physiological and biochemical attributes of forage peas (Pisum sativum ssp. arvense L.). Salt applications were carried out with irrigation water at concentrations of 0, 25, 50, 75, and 100 mM NaCl. The experiment was conducted using a randomized complete block design with three applications [control: 0 (B0), 2.5% biochar (B1), and 5% biochar (B2)], five salt doses [0 (S0), 25 (S1), 50 (S2), 75 (S3), and 100 (S4) mM NaCl], and three replications, arranged in a 3 × 5 factorial arrangement. In the salt-stressed environment, the highest plant height (18.75 cm) and stem diameter (1.71 mm) in forage pea seedlings were obtained with the application of B1. The root fresh (0.59 g/plant) and dry weight (0.36 g/plant) were determined to be the highest in the B1 application, both in non-saline and saline environments. A decrease in plant chlorophyll content in forage pea plants was observed parallel to the increasing salt levels. Specifically, lower H2O2, MDA, and proline content were determined at all salt levels with biochar applications, while in the B0 application these values were recorded at the highest levels. Furthermore, in the study, it was observed that the CAT, POD, and SOD enzyme activities were at their lowest levels at all salt levels with the biochar application, while in the B0 application, these values were determined to be at the highest levels. There was a significant decrease in plant mineral content, excluding Cl and Na, parallel to the increasing salt levels. The findings of the study indicate that biochar amendment can enhance forage peas' growth by modulating the plant physiology and biochemistry under salt stress. Considering the plant growth parameters, no significant difference was detected between 2.5% and 5% biochar application. Therefore, application of 2.5 biochar may be recommended. [ABSTRACT FROM AUTHOR]

Salinity is an abiotic factor limiting plant fitness and therefore forest crop productivity, and salt-affected areas have been expanding throughout the world. Ectomycorrhizal (ECM) fungi can improve the salt tolerance of woody plants, including Eucalyptus species To screen for salt-resistant Pisolithus albus (PA) isolates, 16 PA isolates were cultivated on modified Melin-Norkrans agar containing NaCl at concentrations of 0, 10, 20, and 30 dS m−1. The P. albus isolate PA33 had the greatest salt resistance under 10 and 20 dS m−1 NaCl, which are soil salinity levels in salt-affected areas of Thailand. We studied the effect of PA33 on Eucalyptus camaldulensis × E. pellita cuttings under salt stress (0 and 16 dS m−1) for 1 month. PA enhanced the growth of the Eucalyptus seedlings, as indicated by higher relative growth rates in height and root collar diameter of inoculated seedlings compared with non-inoculated seedlings. Moreover, the inoculated seedlings had less cell damage from NaCl, as indicated by significantly lesser leaf thickness and electrolyte leakage than the controls. These findings could lead to practices conferring socioeconomic and environmental benefits, as abandoned salt-affected areas could be reclaimed using such Eucalyptus seedlings inoculated with salt-tolerant ECM fungi. [ABSTRACT FROM AUTHOR]

Durant, D. and Kernéïs, E., 2024. Investigating the farm resilience of polder environments after seawater flooding: Results from Storm Xynthia (2010). Journal of Coastal Research, 40(5), 887–900. Charlotte (North Carolina), ISSN 0749-0208. Climate forecasts predict that global warming will cause sea-levels to rise and will increase the frequency of storms in the future, thus also increasing the risk of submersion of coastal agricultural areas. Yet very few studies examine the consequences of seawater flooding, from either an agricultural or an environmental point of view. This study therefore investigates the resilience of coastal farming systems through the case study of the Saint Laurent de la Prée research farm hit by the Storm Xynthia in 2010. Two aspects of resilience are analysed here: (i) the soil characteristics of the system (indicators: salinity, sodicity and structural stability) after the submersion, and the system's ability to recover its productive capacity on croplands (crop yields) and on permanent grasslands (fodder production); and (ii) the ecological resilience of permanent grasslands (indicators: species richness and diversity). Results showed that the system recovered its productive capacity in 2012, so after two years, when the research farm engineers recorded a return of the crops and grasslands to a production level that they considered satisfactory. For crop soils, there was a quick recovery of salinity levels, but the structural stability after the storm was largely degraded and had not totally recovered by 2012. On grasslands, the farm suffered two successive years of low grassland productivity, partially due to a temporary shift in plant species' composition. Finally, two dimensions of resilience are discussed here: (i) the speed of recovery; and (ii) the ability to learn from the storm, in view of the increasing risks of coastal submersion in the future. As it appears that flood protection policy must consider local and long-term impacts of seawater flooding on agricultural lands, this study can provide useful information for further research on the foresight scenarios and adaptive strategies required. [ABSTRACT FROM AUTHOR]

High-frequency recordings of valve opening behavior (VOB) in bivalves are often used to detect changes in environmental conditions. However, generally a single variable such as temperature or the presence of toxicants in the water is the focus. A description of routine VOB under non-stressful conditions is also important for interpreting responses to environmental changes. Here we present the first detailed quantitative investigation of the in-situ VOB of eastern oysters (Crassostrea virginica) to environmental variables typically not considered stressful. The VOB of eight individuals was monitored for seven weeks in a Louisiana estuary. We examined the relationships between VOB metrics (variance in mean % max opening among oysters, the probability of an oyster being closed, and the rate of valve closure), and temperature, salinity, chlorophyll-a (chl-a) concentration, the rate of change in those environmental variables, and the rate of change in water depth. Relationships were analyzed through statistical models including rates of change over 0, 0.25, 1-, 6-, 12-, and 24-hours. All the responses were best explained by the 12-hour time step model. The interaction effect between salinity and the rate of change of salinity had the greatest impact on variance in oysters' behavior. Oysters closed faster at higher salinities and were more likely to be closed at lower chl-a concentrations. Significant interactions were found between many environmental variables, indicating a high level of complexity of oyster behavior in the natural environment. This study contributes to a better understanding of the impact of environmental conditions on oyster behavior and can help inform predictive tools for restoration initiatives and fisheries practices. [ABSTRACT FROM AUTHOR]

Salicylic acid (SA) and melatonin (MEL) are affordable and effective phytohormones that help mitigate environmental stress. However, the combined benefits of SA and MEL in managing salt and drought stress in lettuce have not been evaluated. Therefore, this study was designed to evaluate the effectiveness of foliar spraying with 1.0 mM SA and 100 µM MEL, either alone or in combination, to enhance lettuce yield, growth, photosynthetic pigments, mineral status, quality, and antioxidant response under four different irrigation regimes. The irrigation practices used were: full irrigation (FI, irrigated with 0.18 dS m −1 at 100 % field capacity [FC]), deficit irrigation (DI, irrigated with 0.18 dS m −1 at 75 % FC), saline irrigation (SW, irrigated with 2.5 dS m −1 at 100 % FC), and deficit saline irrigation (DSW, irrigated with 2.5 dS m −1 at 75 % FC). Additionally, a control treatment (CK) was carried out with foliar application of distilled water and irrigation at 0.18 dS m −1. Compared to the CK, the application of SA, MEL, and SA+MEL increased evapotranspiration by 4.3 %, 8.6 %, and 15.1 %, and yield by 10.2 %, 16.4 %, and 23.8 %, respectively, under FI conditions. Furthermore, the joint application of SA and MEL at FI showed 25.3 % and 20.2 % higher K +/Na+ and Ca2+/Na+ ratios, respectively, compared to the CK. Additionally, the co-application of SA+MEL improved chlorophyll a, b, and carotenoid levels by 19.2 %, 17.2 %, and 20.4 %, respectively, under FI conditions, compared to the CK. Exogenous application of SA, MEL, and SA+MEL also improved total soluble solids by 17.3 %, 18.5 %, and 11.1 % and reduced nitrate content by 9.7 %, 10.4 %, and 13.5 % in lettuce under FI conditions, compared to the CK. The application of SA+MEL together resulted in a more pronounced increase in vitamin C content compared to supplying SA and MEL individually. Moreover, under DSW conditions, exogenous application of SA, MEL, and SA+MEL decreased the membrane stability index by 13.7 %, 9.4 %, and 6.3 %, increased malondialdehyde by 65.4 %, 40.8 %, and 36.6 %, and increased proline content by 68.4 %, 65.4 %, and 96.4 %, respectively, compared to the CK. Moreover, exogenous SA+MEL significantly increased the activities of superoxide dismutase, catalase, peroxidase enzymes under both SW and DSW conditions compared to the SA or MEL. Conversely, the activity of ascorbate peroxidase enzyme showed a gradual decrease in DI, SW, and DSW conditions, relative to the FI conditions. In conclusion, the integrated application of SA+MEL is an optimal strategy to enhance yield, morpho-physiological traits, nutrient homeostasis, antioxidant capacity, and quality in lettuce and mitigate the adverse effects of drought, salinity, and drought-salinity stress. [Display omitted] • Deficit saline irrigation has the most adverse effect on lettuce yield. • SA and MEL enhanced lettuce tolerance to drought and salinity stress. • Joint use of SA (1.0 mM) and MEL (100 µM) more effectively alleviates stress in lettuce. • SA+MEL improved the nutrient homeostasis and antioxidant capacity of lettuce. • SA+MEL combination increased vitamin C and decreased the nitrate content of lettuce. [ABSTRACT FROM AUTHOR]

Salinity tolerance requires coordinated responses encompassing salt exclusion in roots and tissue/cellular compartmentation of salt in leaves. We investigated the possible control points for salt ions transport in roots and tissue tolerance to Na+ and Cl– in leaves of two contrasting mungbean genotypes, salt‐tolerant Jade AU and salt‐sensitive BARI Mung‐6, grown in nonsaline and saline (75 mM NaCl) soil. Cryo‐SEM X‐ray microanalysis was used to determine concentrations of Na, Cl, K, Ca, Mg, P, and S in various cell types in roots related to the development of apoplastic barriers, and in leaves related to photosynthetic performance. Jade AU exhibited superior salt exclusion by accumulating higher [Na] in the inner cortex, endodermis, and pericycle with reduced [Na] in xylem vessels and accumulating [Cl] in cortical cell vacuoles compared to BARI Mung‐6. Jade AU maintained higher [K] in root cells than BARI Mung‐6. In leaves, Jade AU maintained lower [Na] and [Cl] in chloroplasts and preferentially accumulated [K] in mesophyll cells than BARI Mung‐6, resulting in higher photosynthetic efficiency. Salinity tolerance in Jade AU was associated with shoot Na and Cl exclusion, effective regulation of Na and Cl accumulation in chloroplasts, and maintenance of high K in root and leaf mesophyll cells. Summary statement: Salinity tolerance in mungbean is related to its ability to intercept Na and Cl in roots, thereby reducing Na and Cl transport to shoot, effectively regulate Na and Cl accumulation in chloroplasts, and maintain high K in root and leaf mesophyll cells. [ABSTRACT FROM AUTHOR]

Agricultural land, water, and fertilizer utilization significantly impact the nutrient and water balances and greenhouse gas (GHG) emissions. This study explores the impacts of agricultural water, land, and fertilizer management on the trade-offs between economic benefit, GHG emissions, and water, salinity, nitrate, and phosphate balances by employing crop growth, flow, and solute simulation models, linked with an optimization algorithm. The coupled models can simulate flow, crop growth, and nutrient transport, and capture the water and solutes interaction between the farmland soil zone and saturated groundwater zone, while considering spatial heterogeneity of soil, crop, fertilizer, and irrigation. The optimization model was used to find the trade-offs between the conflicting objectives of maximizing the net economic benefit and minimizing GHG emissions. The optimal water and land allocation schemes, fertilizer application, and crop type were obtained under wet, normal, and dry hydrological years. Then a simple rule was introduced based on the optimum results of the wet, normal and dry years. The proposed methodology was applied to the Dashteabbas irrigation network in southwest Iran. The results showed that the mass loading of salt, nitrate and phosphate decreases to water bodies by 7%, 37%, and 37%, respectively, and less land (−19%), water (−16%), and fertilizer (−35%) are exploited. Also, despite the lower net benefit of the optimum solution (12% lower than the current situation), the GHG emissions (28% lower than the current situation) would decrease, indicating that the introduced rule can help decision-makers to promote coordinated economic and environmental development in the agricultural irrigation systems. [ABSTRACT FROM AUTHOR]

Creeping savory is a wild plant that is used for comestible consumption, preparation of beverages, and production of sanitary ware and herbal drugs. To investigate the effects of salinity stress and salicylic acid on antioxidant enzymes, photosynthetic pigments, relative water content, proline, and soluble protein content in S. spicigera a factorial experiment was conducted based on a Completely Randomized Design (CRD) and three replications. The experiment was implemented at the greenhouse of Agriculture and Natural Resources Research and Education Center of Kermanshah, Iran (2019). Experimental treatments were four levels of salinity (0-50-100-150 mM NaCl) and two levels of salicylic acid (0 and 2 mM). Results showed that increasing salinity levels caused a significant reduction in relative water content, leaf fresh weight, leaf dry weight, chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid content. Salinity drastically enhanced the antioxidant activities (SOD, POD, and CAT), and cell proline content. Salicylic acid considerably decreased proline content under salt stress conditions, but improved antioxidant activities of SOD, POD, and CAT, and enhanced chlorophyll a, chlorophyll b, total chlorophyll, carotenoid content, protein content, relative water content, and leaf fresh weight under salt stress. Salicylic acid reduced the destructive effect of salinity on some morphological, physiological, and biochemical characteristics in creeping savory. [ABSTRACT FROM AUTHOR]

SUMMARY: Mangroves grow in tropical/subtropical intertidal habitats with extremely high salt tolerance. Trehalose and trehalose‐6‐phosphate (T6P) have an alleviating function against abiotic stress. However, the roles of trehalose in the salt tolerance of salt‐secreting mangrove Avicennia marina is not documented. Here, we found that trehalose was significantly accumulated in A. marina under salt treatment. Furthermore, exogenous trehalose can enhance salt tolerance by promoting the Na+ efflux from leaf salt gland and root to reduce the Na+ content in root and leaf. Subsequently, eighteen trehalose‐6‐phosphate synthase (AmTPS) and 11 trehalose‐6‐phosphate phosphatase (AmTPP) genes were identified from A. marina genome. Abscisic acid (ABA) responsive elements were predicted in AmTPS and AmTPP promoters by cis‐acting elements analysis. We further identified AmTPS9A, as an important positive regulator, that increased the salt tolerance of AmTPS9A‐overexpressing Arabidopsis thaliana by altering the expressions of ion transport genes and mediating Na+ efflux from the roots of transgenic A. thaliana under NaCl treatments. In addition, we also found that ABA could promote the accumulation of trehalose, and the application of exogenous trehalose significantly promoted the biosynthesis of ABA in both roots and leaves of A. marina. Ultimately, we confirmed that AmABF2 directly binds to the AmTPS9A promoter in vitro and in vivo. Taken together, we speculated that there was a positive feedback loop between trehalose and ABA in regulating the salt tolerance of A. marina. These findings provide new understanding to the salt tolerance of A. marina in adapting to high saline environment at trehalose and ABA aspects. Significance Statement: We identified an important salt‐tolerant gene (AmTPS9A) in mangrove Avicennia marina and proposed a hypothesized model in which ABA and trehalose synergistically regulate salt tolerance in A. marina. Our study provides new insights into the salt tolerance of mangrove A. marina at the aspect of the trehalose pathway. [ABSTRACT FROM AUTHOR]

Salinity drastically hampers the germination and growth of legumes including mungbean which jeopardizes the food and nutritional security of the rising human population. An experiment entailing varying salinity levels (0, 50, and 150 Mm NaCl) was conducted to investigate the response of salinity on germination and seedling growth of four mungbean genotypes (BARI Mung-7, BARI Mung-8, BU Mug-2, and BU Mug-4). The germination indices such as percentage and rate of germination along with the coefficient of velocity (GP) of all mungbean genotypes were significantly reduced by the salt stress, especially of Binamoog-5 at 150 mM NaCl. Contrarily, BARI Mung-8 remained superior by recording better germination indices under all salinity levels. The same cultivar outperformed the rest of the cultivars based on the greatest weights (fresh and dry) and length of roots and shoots, while BU Mug-2 could not perform at par under a saline environment. Thus, it might be inferred that mungbean genotypes differ in their potential for salt endurance due to the germination vigor and seedling growth robustness and screening of salt-tolerant cultivars could mitigate the detrimental effects of saline environment. [ABSTRACT FROM AUTHOR]

Salinity, a significant abiotic stressor, imperils vegetable growth, yield, and quality. Moreover, elevated salinity levels, driven by climate change, jeopardize vegetable nutritional quality. In particular, protected cultivation systems, responsible for 60% of the global vegetable industry's economic value, encounter notable challenges in managing salinity due to water runoff and drainage mechanism limitations. Therefore, it is crucial to understand the intricate mechanisms that control salinity and use this knowledge to improve plant tolerance to these conditions. In this study, we explore strategies to effectively mitigate the detrimental impacts of salinity on vegetable crops cultivated within protected environments. Additionally, we investigate the benefits of controlled moderate salinity adjustments in protected cultivation to enhance their nutritional content. Moderate salinity or nutrient solution increases typically raise total soluble solids, sugar, vitamin C, phenols, lycopene, and antioxidants in most fruit vegetables. Though generally applicable to leafy vegetables, exceptions like lettuce and wild rocket may show inconsistencies, potentially reducing some quality traits. Interdisciplinary approaches are essential to developing sustainable solutions for managing salinity in protected cultivation systems, thereby ensuring the resilience of vegetable production in the face of changing environmental conditions. Given the impracticality of desalinating all areas, future research should also investigate synergies between moderate salinity stress, cultivars used, and environmental factors from physiological and molecular perspectives to enhance vegetable nutritional quality. [ABSTRACT FROM AUTHOR]

The research aimed to examine the enhancement effect of Spirulina platensis (blue–green microalga or Cyanobacterium) and Chlorella vulgaris (green microalga) water extracts as biological stimulant in improving growth parameters, chlorophyll content, yield, and fruit quality of tomato plants under salinity stress. Tomato seeds (Solanum lycopersicum L of cv. Agyad) were soaked in three microalgae water extracts at a 10% concentration (Chlorella vulgaris, Spirulina platensis, and Chlorella: Spirulina at a ratio of 1:1). Chemical and biochemical analyses for the used materials and products were achieved. After germination, tomato transplants were irrigated with saline water at three levels of saline water (2, 4, and 7 dS/m) using sea salt. Successive grown tomato transplant at 7.0 dS/cm were infused in clayey soil. The grown plants were prayed by algal extract and irrigated by the same solution. Vegetative growth, yield, shelf life, and chlorophylls (a and b) were determined. It was found that the highest vegetative growth, yield, and chlorophyll content were measured in tomato transplants with the Spirulina: Chlorella mixture, followed by Spirulina platensis and Chlorella vulgaris water extracts, all of these measurements increased significantly in response to microalgae treatments. Experimental tomato fruits of Chlorella and mixture treatments can stay for 45 days at room temperature. Both algal extracts and their mixture enhanced the bioaccumulation of micronutrients (Fe, Zn, Mn, and Cu) compared with the control, while Chlorella extract surpassed Spirulina and mixture extracts. Concerning the used dried algae and their water extract, Spirulina platensis surpasses Chlorella vulgaris for protein and ash content. [ABSTRACT FROM AUTHOR]

Soil acidity and salinity stress significantly affect nutrient availability and uptake, as well as the growth, development, and yield of maize plants. This research aimed to screen, characterize, and assess the ability of selected indigenous biofilm-forming rhizophosphate bacteria (BFRB) to produce growth factor and promote maize growth. Soil samples were collected from both acid ecosystems (AE) and saline ecosystems (SE). Thirty isolates of rhizophosphate bacteria were obtained based on the clear zone around colonies on selective Pikovskaya agar media. Subsequently, a qualitative biofilm test was conducted, resulting in the identification of 9 isolates of biofilm-forming rhizophosphate bacteria. Biochemical test was performed to asses phosphate solubility index (PSI) and production of indole acetic acid (IAA) and biological assays was performed to measure the effect of selected BFRB on maize growth characteristics. The experiment was arranged in a randomized block design with 10 treatments (control and 9 isolates of BFRB) and 3 replications. The findings revealed that all isolate has avaibility to membentuk biofilm dan mampu melarutkan P. three potential isolates of BFRB from both AE and SE significantly enhanced maize growth. Isolates PS-03, PN-05, and PC-04 from saline soils, as well as isolates NA-01, NG-04, and NF-04 from acid land, exhibited notable increases in root length, plant height, and dry weight compared to the control. For instance, isolates PS-03, PN-05, and PC-04 from saline soils increased maize height by 2160.87% and root length by 392.64%, and they also increased the dry weight of the plants by 20.50%. Similarly, isolates NA-01, NG-04, and NF-04 from acid soil increased maize height by 673.82% and root length by 220.29%, and they increased the dry weight of the plants by 12.57%. These findings suggest that these BFRB isolates hold significant potential for developing rhizophosphate biofilm biofertilizers to enhance maize productivity in marginal soils. Additionally, each of these bacteria produced IPF and IAA, which contributed to the significant increases in plant height and root length, and formed biofilms that were present on the roots of the maize plants. Therefore, field trials are necessary to utilize these biophosphate fertilizers to improve fertilization efficiency and maize productivity in saline and acidic ecosystems. [ABSTRACT FROM AUTHOR]

Azadirachta indica or neem is recognized for its unique properties, both against insects and in improving human health. However, proteomics studies of this plant's response to abiotic stresses have yet to be reported. Application of this technique highly depends on efficient and optimized sample preparation, in deriving highly reproducible proteomics data. The present study highlights the comparison of protein extraction method which effectively recovers proteins from recalcitrant phenolic-rich tissues of neem callus. Four protocols based on TCA-acetone or/and phenol extraction methods were compared. The TCA-acetone complemented with PVPP method was the most effective approach and generated the greatest total protein yields, spot number, good resolution, and spot intensities. Subsequently, the differential proteomics performed revealed that proteins associated with oxidoreduction, energy, transcriptional, stress response, respiration, and cell division were differentially regulated in salinity stress treatment. Meanwhile, the expression of proteins classified in the group of energy, photosynthesis, protein synthesis, oxidoreduction, and post-transcriptional regulation was altered in the JA-stressed callus. The accumulation of AZA was also noticeably reduced in salinity- and JA-treated callus, suggesting these tested stress parameters were not effective in improving AZA production in the neem callus. Overall, this analysis provides valuable information on the application of plant tissue culture as an alternative for sustainable production of major bioactive constituents in A. indica. Together, the proteomics results brought forward a possible fundamental representation of the mechanism associated with salinity and JA tolerance in the neem callus. [ABSTRACT FROM AUTHOR]

Mangroves have unique adaptations that help them survive in highly saline and hypoxic environments. The present study examines how two mangrove species, namely Kandelia candel (L.) Druce and Rhizophora mucronata Lam., well known for their ultrafiltration capability, responded to different salinity levels. We have conducted histochemical, biochemical and gene expression analyses of lignin and cell wall components from the two non-salt-secreting mangrove species treated with different salinity gradients. Root length decreased at higher salinity treatments for K. candel (11.7–13.8 cm in freshwater; 5.7–6.7 cm at 20 ppt), while R. mucronata (4.9–6.4 cm in freshwater; 5.5–9.4 cm at 35 ppt) showed no significant change. The rate of lignin deposition near the vascular bundles varied from freshwater to salt treatments and between the species. Overall lignin content in the K. candel roots increased at higher salinity (40.6–70.6 µg/mg at freshwater to 53.9–145.1 µg/mg at 20 ppt). At the same time, R. mucronata showed comparatively higher lignin content (101.4–149.6 µg/mg) than K. candel (40.6–145.1 µg/mg). Total pectin concentration increased after 60 days in K. candel at freshwater (55.7–199.82 µg/mg) and salt treatments (90.0–210.5 µg/mg at 20 ppt). But pectin content decreased after 60 days of treatment in R. mucronata. A similar trend was observed for total carbohydrates and cellulose. Overall, hemicellulose concentration was low in R. mucronata compared to K. candel. Total polyphenol content was higher in R. mucronata (308.1–731.1 µg GAE/mg DW) than in K. candel (43.1–400.4 µg GAE/mg DW). Higher gene expression of lignin biosynthesis genes viz CAD, HCT, C3H, COMT and peroxidase was observed in R. mucronata at 5 ppt salinity 60 days after treatment. The results of this study will help explain the role of root lignification in mangrove salinity tolerance mechanisms. [ABSTRACT FROM AUTHOR]

Seagrasses have long been a focal point for management efforts aimed at restoring ecosystem health in estuaries worldwide. In Tampa Bay, Florida (USA), seagrass coverage has declined since 2016 by nearly a third (11,518 acres), despite sustained reductions of nitrogen loads supportive of light environments for growth. Changing physical water quality conditions related to climate change may be stressing seagrasses beyond their optimal growth ranges, requiring an assessment to determine if this decline can be linked to climate stress. Three ambient water quality datasets of varying sampling designs and coverage were evaluated to characterize physicochemical environments in Tampa Bay and the potential relationships with seagrass change. Tampa Bay has become hotter and fresher with water temperature increasing by 0.03–0.04 °C per year and salinity decreasing by 0.04–0.06 ppt per year, translating to an increase of 1.3 to 1.7 °C and a decrease of 1.6 to 2.6 ppt over the last 50 years. Additionally, the number of days when temperature was above 30 °C or salinity was below 25 ppt has increased on average across all bay segments by 48 and 37 days, respectively, since 1975. These changes varied spatially and seasonally, with the most dramatic changes observed in the upper bay. Generalized Additive Models provided a weight-of-evidence that recent seagrass declines are somewhat associated with hotter and fresher conditions. Trends in warming and increased precipitation in the region are likely to continue, further creating suboptimal conditions for seagrasses in Tampa Bay. These results should compel resource managers to consider the likelihood that reduced resilience of estuarine resources due to shifting ecological baselines driven by additional climate change drivers will complicate long-standing management paradigms. While conventional management approaches that focus on limiting nutrient loads should be continued, their future effectiveness may be confounded by climate change drivers and warrant additional, complementary interventions and continuous monitoring data to support ecosystem health into the future. [ABSTRACT FROM AUTHOR]

Identification of potential lands on the basis of their environmental benefits and constraints can greatly contribute to the stability of canola production in different parts of the world including Sistan-Baluchestan province, Iran. Accordingly, using GIS, the scores of environmental factors affecting canola production including temperature, rainfall, slope, altitude, organic matter, soil salinity, pH and soil nutrients (N, P, K, Fe and Zn) were integrated along with the weights of analytical hierarchical process (AHP) for the production of canola suitability maps. The zoning maps of climate, topography, and soil as well as the canola suitability maps and the current production maps of canola were prepared. According to the AHP results canola cultivation was affected the most by climate (rainfall and water sources) compared with topography and soil. ArcGIS results indicated southern lands of Zahedan had the highest organic matter, and excluding Hirmand, other parts of the area had appropriate salinity for canola production. The most appropriate areas in terms of acidity for canola production are Hirmand and the central part of Zahedan. In arable soil, the nitrogen level was not maximum in the region, and Nimrooz and Zabol had the highest phosphorus. Potassium was average in the research area, and Zabol, Zahak, Nimrooz and Hamoon had the highest Fe. The output maps obtained from the combination of various ecological factors indicated that the moderate and non-suitable classes of land for canola cultivation are located in the northern parts of Zahak, Hamon, Nimzoz and the total lands of Hirmand and Zabol. [ABSTRACT FROM AUTHOR]

Purpose: Environmental stresses are a main disturbing factor influencing horticultural productivity around the world. It will affect all plants including resistant or non-resistant cultivars. So, it is important to find the better cultivars and to check the response to adverse environmental conditions. Research method: Thus, the present research was conducted to evaluate responses of different bearing status of pistachio cultivars including Kalleh-Ghochi (K), Ohadi (O) and Ahmad-Aghaii (A), grafted on Badami-Rize-Zarand as rootstock, for six consecutive years to soil salinity. Findings: ONbearing trees of 'Ahmad-Aghaii' showed the highest yield, followed by 'Ohadi' and 'Kalleh-Ghochi'. In addition, the lowest leaf temperature was observed with this cultivar. Although the highest nitrogen, sodium, carbohydrate, peroxidase and leaf temperature was obtained in ON-bearing trees, however, the lowest potassium and total phenol content indicated in OFF-bearing status. It was found a negative correlation between leaf potassium content and ABI, between leaf peroxidase activity and ABI and between leaf temperature and ABI. On the other hand, leaf temperature increased as leaf sodium content increased. Research limitations: There was no limitation. Originality/Value: From data presented here, it is concluded that salinity and Na accumulation might be effective in changing the response of the pistachio cultivar under harsh environmental conditions which affects yield component and alternate bearing index. [ABSTRACT FROM AUTHOR]

Barley (Hordeum vulgare) is the fourth largest cereal crop in the world, with considerable nutritional value. Recently more studies on the toleration of barley to salt stress have been published, indicating an increased concern for food safety. Salt stress is an increasing threat to agricultural productivity; thus, an attempt was made to explore the growth-promoting capacities of an endophytic fungal strain Aspergillus niger CSR3 in H. vulgare. In the current study, we investigated various physiological and biochemical characteristics of two H. vulgare varieties, namely OM-80 and OM-82, under 300 mM NaCl and 100% seawater treatments with and without the inoculation of CSR3. Our results showed that biopriming of H. vulgare seeds with CSR3 enhanced germination ratio both in control and salt treated conditions. Under salt stress, the growth of H. vulgare plants was significantly reduced; however, CSR3 alleviated the salt stress and significantly increased root/shoot length and weight compared to their respective counterparts both under control and stress conditions. The fungal strain showed an ameliorated response to salt stress by improving the photosynthetic machinery. Results demonstrate that accumulation of reduced glutathione (GSH), catalase (CAT), and flavonoids decreased in inoculated plants as compared to non-inoculated under saline conditions indicating the potential of CSR3 in maintaining cellular homeostasis against salinity stress. Moreover, our finding also revealed that starch accumulation decreased with a gradual increase of salt treatment; however, CSR3 inoculation enhanced starch and decreased sugar level, indicating its potential to convert excess sugar to starch. In conclusion, CSR3 can improve plant performance significantly and can greatly improve sustainable agricultural production in saline marginal lands. [ABSTRACT FROM AUTHOR]

Abiotic stresses such as salinity, submergence, drought and extreme temperatures greatly affect rice production worldwide. Marker-assisted selection was effectively used to introgress QTLs for salinity tolerance (Saltol) and submergence tolerance (Sub1) into the background of elite rice variety Jyothi. Saltol introgressed BC1F2 lines of Jyothi with 79.3% of recipient parent genome was crossed with Sub1 introgressed BC2F2 lines of Jyothi showing 95.9% of parent genome recovery. F1 progenies were screened with Saltol and Sub1 linked foreground markers and recombinant markers. F1 heterozygous plants were selfed to produce F2 generation. F2 progenies homozygous for both the loci were selected. Phenotypic screening for salinity and submergence tolerance was performed to validate the introgressed genes. The plants able to tolerate both salinity and submergence stresses were selected for selfing to raise F3 progenies. The pyramided lines were also similar to recurrent parent in agro-morphological and grain quality traits. [ABSTRACT FROM AUTHOR]

Salinity is one of the main factors influencing the early life stages of fish along an estuary, which shows great temporal and spatial changes. Recently, remote sensing has been widely applied to map salinity changes and fuzzy logic is identified as a suitable and strong tool for modeling complex systems. Based on collections of fish larvae and juveniles and water parameters in May, September, November, and December during 2019 along the Ba Lat estuary of the Red River, northern Vietnam, the present study attempts to predict the mapping and monitoring of the salinity using multispectral satellite imagery from Landsat 8 OLI satellite. The study determined that the NFS machine learning model, when improved by PCA, achieved a higher performance in displaying different salinity levels. The present study also confirms that using high spatial resolution or hyperspectral images would have increased the accuracy of spatial variation in similar modeling and mapping. Fuzzy rule–based modelling suggests that the occurrence of fish larvae and juveniles depended on salinity levels, with an R2 > 0.9, compared to the field surveys. This finding further confirms the accuracy data obtained by artificial neural network models. [ABSTRACT FROM AUTHOR]

Three different wheat varieties were the subject of an experiment to see how salt affected seed germination and seedling development. BARI Gom20 (Gourab) was employed as a salt sensitive variety, whereas BARI Gom28 and BARI Gom25 were utilized on salt tolerant types. Three replications, three salinity levels (0, 150, and 200 mM of NaCl), and a complete randomized design (CRD) were used to set up the experiment. All the wheat varieties had a noticeable growth loss due to salt stress. Wheat growth was inhibited more in salt-sensitive cultivars compared to salt-tolerant cultivars, BARI Gom28 showed overall stronger salt tolerance. When wheat was tested for salt tolerance, there were striking variations in the antioxidant enzymes (catalase, peroxidase, and ascorbate peroxidase) that were present. The effect of rising salt content, catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) activity varied between salt-sensitive and salt-tolerant cultivars. Intriguingly, TaAOX1a and TaAOX1c gene expression levels increased in BARI Gom28 as the degree of salt concentration increased. Additionally, the salt-tolerant BARI Gom28 had smaller accumulations of hydrogen peroxide, malondialdehyde, and higher activity of the antioxidant enzymes than the salt-sensitive Gourab, indicating that the latter had comparatively less oxidative damage. However, the contribution of antioxidant enzymes and AOX gene family to salinity stress response in wheat is further requisite to unlock the molecular functions. Exploring the molecular mechanism for lowering salt stress in wheat cultivars will require more research. [ABSTRACT FROM AUTHOR]

This study investigates the differential responses of two maize genotypes, SC180 and SC168, to salt stress, aiming to elucidate the mechanisms underlying salinity tolerance and identify traits associated with improved stress resilience. Salinity stress, imposed by 150 mM NaCl, adversely affected various growth parameters in both genotypes. SC180 exhibited a more pronounced reduction in shoot length (13.6%) and root length (13.6%) compared to SC168, which showed minimal reductions (3.0% and 2.3%, respectively). Additionally, dry weight losses in SC180's leaves, stems, and roots were significantly greater than those in SC168. Under salinity stress, both genotypes accumulated Na+ in all organs, with SC168 showing higher Na + concentrations. However, K+ levels decreased more significantly in SC180's leaves than in SC168's. The study also assessed physiological responses, noting that SC180 experienced a substantial reduction in relative water content (RWC) in leaves (22.7%), while SC168's RWC remained relatively stable (5.15%). Proline accumulation, a marker for osmotic adjustment, increased 2.3-fold in SC168 compared onefold in SC180. Oxidative stress indicators, such as electrolyte leakage and hydrogen peroxide levels, were elevated in both genotypes under salt stress, with SC180 showing higher increases (48.5% and 48.7%, respectively) than SC168 (35.25% and 22.0%). Moreover, antioxidant enzymes (APX, CAT, POD, SOD, GR) activities were significantly enhanced in SC168 under salinity stress, whereas SC180 showed no significant changes in these activities. Stress indices, used to quantify and compare salinity tolerance, consistently ranked SC168 as more tolerant (average rank = 1.08) compared to SC180 (average rank = 1.92). Correlation analyses further confirmed that SC168's superior tolerance was associated with better Na + regulation, maintenance of K+ levels, and a robust antioxidant defense system. In conclusion, SC168 demonstrated greater resilience to salinity stress, attributed to its efficient ion regulation, stable water status, enhanced osmotic adjustment, and strong antioxidant response. These findings provide valuable insights for breeding and developing salinity-tolerant maize varieties. [ABSTRACT FROM AUTHOR]

Massive salt accumulations, or salt giants, have formed in highly restricted marine basins throughout geological history, but their impact on biodiversity has been only patchily studied. The salt giant in the Mediterranean Sea formed as a result of the restriction of its gateway to the Atlantic during the Messinian Salinity Crisis (MSC) 5.97 to 5.33 million years ago. Here, we quantify the biodiversity changes associated with the MSC based on a compilation of the Mediterranean fossil record. We conclude that 86 endemic species of the 2006 pre-MSC marine species survived the crisis, and that the present eastward-decreasing richness gradient in the Mediterranean was established after the MSC. [ABSTRACT FROM AUTHOR]

Total alkalinity (TA) has increased in the Baltic Sea, with implications for atmospheric CO2‐induced acidification and CO2 uptake. We compiled extensive data of TA in surface waters of the Baltic Sea, aiming to (i) identify new tendencies in the relationship between TA and salinity (TA–S relationship), (ii) update the TA trend analysis, (iii) investigate spatial–temporal patterns, and (iv) discuss potential drivers and implications. We observed a progressive decrease in the slopes and increase in the intercepts of the TA–S overtime due to the persistent process of TA enhancement. A weak seasonal pattern was identified, with warmer months presenting lower salinity and TA. Lower rates of TA increase were observed in high salinities (Skagerrak–Kattegat; +1.00 to +2.20 μmol kg−1 yr−1), intermediate trends in low salinities (Gulf of Bothnia; +3.28 to +3.57 μmol kg−1 yr−1), and maximal trends in the Central Baltic Sea (+3.70 to +4.57 μmol kg−1 yr−1) and Bornholm Basin (+4.82 to +5.32 μmol kg−1 yr−1). The increase in the intercept of the TA–S in the Gulf of Bothnia suggests a progressive increase in the external supply of TA, although lower than previously thought. The maximum trend in the Bornholm Basin suggests an increase in external supply from the Southern catchment and/or the accumulation of internal production. The positive TA–phosphorus correlations underscore a significant internal source. The TA increase amplifies the CO2 uptake by 1.8–7.8% during spring/summer and reduces the CO2 outgassing by 3.4–7.7% in autumn/winter. The TA enhancement has the potential to buffer CO2‐induced acidification by 39–60% by 2050. [ABSTRACT FROM AUTHOR]

Transgenerational plasticity in plants enables rapid adaptation to environmental changes, allowing organisms and their offspring to adapt to the environment without altering their underlying DNA. In this study, we investigated the transgenerational plasticity in salinity tolerance of rice plants using a reciprocal transplant experimental strategy. Our aim was to assess whether non-genetic environment-induced phenotypic modifications and transgenerational salinity affect the salinity tolerance of progeny while excluding nuclear genomic factors for two generations. Using salt-tolerant and salt-sensitive rice genotypes, we observed that the parentally salt-stressed salt-sensitive genotype displayed greater growth performance, photosynthetic activity, yield performance, and transcriptional responses than the parentally non-stressed salt-sensitive plants under salt stress conditions. Surprisingly, salt stress-exposed salt-tolerant progeny did not exhibit as much salinity tolerance as salt stress-exposed salt-sensitive progeny under salt stress. Our findings indicate that the phenotypes of offspring plants differed based on the environment experienced by their ancestors, resulting in heritable transgenerational phenotypic modifications in salt-sensitive genotypes via maternal effects. These results elucidated the mechanisms underlying transgenerational plasticity in salinity tolerance, providing valuable insights into how plants respond to changing environmental conditions. [ABSTRACT FROM AUTHOR]

The overflow of cold water through the Faroe Bank Channel (FBC) is the densest water crossing the Greenland‐Scotland Ridge and the densest source for the Atlantic Meridional Overturning Circulation (AMOC). Here, we show that the overflow volume transport remained stable from 1996 to 2022, but that the bottom water warmed at an average rate of 0.1°C per decade, mainly caused by warming of deep waters upstream. The salinity of the overflow water has increased as a lagged and reduced response to the salinity increase seen in the upper‐layer source waters. Therefore, the potential density of the bottom water over the FBC sill shows no statistically significant trend. After entrainment of warmer ambient waters downstream of the FBC, the nonlinear density dependence upon temperature implies, however, that the overflow contributed water of reduced density to the local overturning and the deep limb of the AMOC. Plain Language Summary: As part of the Atlantic Meridional Overturning Circulation—often called AMOC—dense water is formed north of the subsea ridge between Greenland and Scotland. On its route southward at depth, the dense water has to cross this subsea ridge called the Greenland‐Scotland Ridge. The densest water flows through the deepest trench, which is the Faroe Bank Channel with a sill depth of 840 m. Here, the strength of the flow has been monitored since 1995 together with its temperature and salinity characteristics. While the strength of the flow has been stable throughout the monitoring period, the dense water in the Faroe Bank Channel has warmed and also become more saline. Despite the warming, the density of the water, which is determined by the combination of temperature and salinity, has remained nearly unchanged. After leaving the Faroe Bank Channel, the dense water intensively entrains and mixes with warmer surrounding water and forms a larger volume of water, termed Iceland‐Scotland Overflow Water, that feeds the AMOC. The density of this large volume is sensitive to warming. The observed warming of the dense water may, therefore, have implications for the AMOC and thereby on the regional as well as global climate. Key Points: Observed Faroe Bank Channel overflow strength has been stable from 1996 to 2022, but the overflow waters warmed in the recent two decadesConcurrent salinity increase prevented the bottom water density from decreasing significantly from the effect of warmingAfter entrainment downstream, the overflow contributed water of reduced density to global overturning due to non‐linear effects of warming [ABSTRACT FROM AUTHOR]

Introduction: Salinity is a key variable in the dynamic and thermal balance of the entire climate system. To address the complexities of diverse terrains and fluctuating ocean waves, we commonly use free-surface models with quasistationary (e.g. height, pressure, or terrain following) coordinates for simulating salinity. In such models, the vertical grid dynamically adjusts with the undulation of seawater. However, this adjustment also occurs when freshwater enters or exits the ocean. Freshwater-induced salinity changes at the ocean's surface are artificially distributed to each vertical layer within a model time step. This means that the freshwater at the ocean surface instantaneously and directly affects the seafloor. This process is different from physical diffusion processes. The diffusion effects caused by the influx and outflow of freshwater have a very small impact on the seafloor. This error leads to salinity non-conservation and disrupts the vertical distribution structure of salinity. Previous studies have also addressed this issue with solutions such as the vertical Lagrangian-remap method. Method: This paper proposes a natural vertical distribution calculation scheme (NVDCS) which is different from the approaches of our predecessors. In the discrete formulation of the original ocean equations, freshwater flux is introduced to ensure salinity conservation. In each model time step, by calculating the seawater volume changes due to freshwater inflow or outflow, as well as the vertical grid changes caused by sea surface undulations, the aforementioned artificial error is eliminated from each vertical layer. Discussion: This scheme ensures that changes in the vertical coordinates of each layer result solely from internal oceanic dynamic processes, avoiding the instantaneous and directly impact of surface freshwater. Ultimately, the influence of freshwater is confined to the ocean surface. Results: This method is straightforward to implement and user-friendly. Sensitivity experiments indicate that in free-surface models, quasi-stationary coordinates introduce artificial errors. The proposed calculation scheme not only eliminates this error but also achieves a better vertical distribution structure than using virtual salt flux, while ensuring salinity conservation. [ABSTRACT FROM AUTHOR]

In-situ measurements of ocean temperature and salinity are critical to ocean-related studies but are limited in space and time. Satellite retrievals provide high-resolution, globally-covered sea surface temperature (SST), salinity (SSS) and cannot directly measure the subsurface information., and height (SSH), but are limited to the ocean surface and cannot directly measure the subsurface information. Here we design a physics-informed algorithm that can reconstruct the vertical distributions of upper ocean temperature and salinity based purely on satellite observations. The algorithm stresses the tight ocean surface-subsurface coupling and the co-variability of ocean temperature and salinity. It is firstly tested with climate model simulations and then validated with actual observations by Argo floats, moored buoys and multiple ocean reanalysis datasets. The resultant satellite-based upper ocean temperature and salinity dataset has a global coverage, a high spatial resolution, and resolves ocean thermohaline structure from surface to 400 m. This dataset complements existing ocean subsurface products as an independent satellite-based observational dataset. The success of our reconstruction algorithm highlights a pressing need to maintain and advance the satellite observations of SST, SSS, and SSH. The reconstructed ocean temperature and salinity dataset can be accessed at https://doi.org/10.5281/zenodo.13145129 (Liu, 2024) and be used by researchers to study mesoscale ocean phenomena, assess the ocean heat content in various sea areas and etc. [ABSTRACT FROM AUTHOR]

Soil salinity is a major abiotic stress that limits the growth and productivity of horticultural crops. Most fruit crops are glycophytes, and their production is adversely affected by salt stress. The key findings indicate that salinity reduces several plant growth parameters such as shoot and root length, number of leaves, plant biomass and relative water content as well as biochemical parameters such as photosynthetic pigments and proline. Physiological results show decreased water absorption, nutrient imbalances such as changes in ion concentrations and hormone levels and increased oxidative stress. Several mitigation strategies are recommended, such as the use of salt-tolerant rootstocks, application of growth regulators and soil amendments to enhance salt tolerance in tropical fruit crops. This review concludes that integrating physiological and agronomic strategies is essential for mitigating the adverse effects of salinity on tropical fruits. [ABSTRACT FROM AUTHOR]

Manufacturing a multilayer evaporator with a delicate structure and removing salt accumulation during prolonged operation are challenges in seawater desalination. A flexible single‐layer salt‐rejecting monolithic porous evaporator (SRMPE) is presented that floats on the near surface of seawater without any support structure. The hydrophilic component of this network polymer modulates the water association state in SRMPE, achieving a high evaporation rate of 3.47 kg m−2 h−1 and an efficiency of 94.3%. With a large capillary water flux (14.4 L m−2 h−1), the SRMPE exhibits superior and rapid self‐cleaning by removing sodium chloride (NaCl) powder (33% by weight) within 1.25 h in simulated seawater (salinity, 3.5%) under 1 sun radiation. Furthermore, even after continuous irradiation for 12 h in highly concentrated brine (25% salinity), no salt crystallizes on the evaporator surface. It may stimulate creative work by scientists and engineers in the design of simple, highly efficient salt‐rejecting, self‐cleaning interfacial solar evaporators. [ABSTRACT FROM AUTHOR]

A novel demodulation scheme for a point-type fiber sensor is designed for salinity concentration monitoring based on a Sagnac interferometer (SI) composed of a tapered polarization-maintaining fiber (TPMF) and optical time stretching technology. The SI, constructed using a PMF with a taper region of 5.92 μm and an overall length of 30 cm, demonstrated a notable enhancement in the evanescent field, which intensifies the interaction between the light field and external salinity. This enhancement allows for a direct assessment of salinity concentration changes by analyzing the variations in the SI reflection spectra and the experimental results indicate that the sensitivity of the sensor is 0.151 nm/‰. In contrast to traditional fiber optic sensors that depend on spectral demodulation with slower response rates, this work introduces a new approach where the spectral shift is translated to the time domain, utilizing a dispersion compensation fiber (DCF) with the demodulation rate reaching up to 50 MHz. The experimental outcomes reveal that the sensor exhibits a sensitivity of −0.15 ns/‰ in the time domain. The designed sensor is anticipated to play a pivotal role in remote, real-time monitoring of ocean salinity. [ABSTRACT FROM AUTHOR]

This article explores the impact of salinity on two different maize cultivars and their ability to tolerate salt stress. The study reveals that the more salt-tolerant cultivar is better at excluding sodium (Na+) and retaining potassium (K+), which are crucial for minimizing Na+ uptake. The researchers also discovered that the salt-tolerant cultivar experienced a net influx of hydrogen ions (H+) under severe salt stress, while the salt-sensitive cultivar did not. This suggests that net H+ influx is an important but often overlooked trait in salt tolerance. Additionally, the study found that K+ efflux and Na+ influx help maintain charge balance during H+ influx. [Extracted from the article]