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Low salinity water flooding (LSWF) was initially considered using water with a low concentration of dissolved salts and was later extended to include modifying the ionic content of injected brines. This work investigates the effects of changing water salinity and composition along with the concentration of sulfate and iodide ions on oil recovery in carbonate reservoirs during the tertiary recovery stage. An experimental study was carried out using crude oil of 29°API, 8 core samples extracted from the Eocene carbonate reservoir (Egypt), and 6 different water salinities. The results showed additional oil recovery up to 5% of the original oil in place (OOIP) in the tertiary recovery stage with changing water salinity and water composition. Injection of high salinity (HS) and low salinity (LS) brines with high sulfate concentrations increased the incremental oil recovery by a value ranging from 1.7 to 3.8% of the OOIP. On the contrary, injection of HS and LS brines with low sulfate concentrations showed insignificant incremental oil recovery (less than 1% of the OOIP). Furthermore, injection of water with potassium iodide (KI) after injection of water with high sulfate brines showed additional oil recovery of about 1.7% of the OOIP. On the other hand, injection of water with KI after injection of water with low sulfate concentration showed insignificant incremental oil recovery (less than 0.4% of the OOIP). The concentration of sulfate in the injected water appeared to be key parameter to achieve effective waterflooding (WF) projects in carbonate reservoirs. Moreover, the results revealed that the multi-component ion exchange (MIE) mechanism seems to be the primary recovery mechanism for LSWF in carbonate reservoirs. The results and conclusions of this study can be used to develop guidelines for designing waterflooding projects in carbonate reservoirs with optimum salinity.

Crystallization of sodium sulfate into mirabilite in sulfate saline soil harms the soil potential and intensifies the reparative expenses for subgrade. However, the effects of pore relative humidity (PRH) on the salt swelling behavior have not been thoroughly explored. The multiple-humidity cycles experiments, in this paper, were performed to investigate salt swelling behavior in sulfate saline soil. The effects of different salinity, temperatures, and PRH values on salt swelling displacement (SSD) and salt swelling rate (SSR) of sulfate saline soil were analyzed. The X-ray Diffraction (XRD) technique was employed to investigate the mineral composition of post-experiment soil samples. All test results show that the SSD and SSR of soil samples increase with the increase of PRH and salinity and decreases as the increasing temperature. The enhancement of salt swelling in the presence of PRH was 80-90-80%. Besides, XRD results denote that the existence of mirabilite in the test soil samples verified for the salt swelling to be closely related to PRH in terms of microstructure. All the results further improve the mechanism of salt swelling in sulfate saline soil in the presence of PRH, which is of great significance to analysis and remediation of salt swelling behavior.

Soil salinity, whether natural or induced, is one of the most serious environmental stresses limiting crop production in the world. In this study, the impacts of foliar application of jasmonic acid and soil amendment with humic acid on growth parameters, forage yield, chlorophyll content, and physiological characteristics of forage sorghum were studied to mitigate salinity in combination with different concentrations under greenhouse conditions. The plants were subjected to salinity at 0.26 (S0), 2.3 (S1), and 4.7 dS m−1 (S2), different rates of humic acid at 0, 373.21, and 746.42 kg HA ha−1, were designed as HA0, HA1, and HA3 respectively, and jasmonic acid at 0 (JA0), 5 (JA1) and 10 mM (JA2) as a foliar application. Salinity stress had detrimental effects on all the parameters and they were gradually reduced with increased salinity. Applications of humic acid and jasmonic acid mitigated the inhibitory effects of salt stress on these variables at all salinity levels. The rate of HA1 increased fresh weight, chlorophyll a and b, transpiration rate, relative humidity, stomatal conductance to CO2 and stomatal conductance by 14.2%, 45.6%, 41.8%, 50.2%, 11.2%, 32.1% and 18.5% respectively, under S2. In addition, jasmonic acid at JA1 treatment increased plant height, elongation percentage, fresh and dry weight, chlorophyll a and b, relative humidity, and stomatal conductance to CO2 under S2. Interaction between JA2 and HA1 improved all the traits except plant height, elongation percentage, and leaf area, suggesting that JA and HA can reduce the negative effects of salinity on the sorghum. In conclusion, jasmonic acid and humic acid treatments improved the forage sorghum performance under salinity conditions through anthesis stages, better photosynthetic and growth parameters, which reduced the impacts of salinity, and resulted in better plant growth and biomass production, and help the plant to improved salt tolerance.

Turmeric (Curcuma longa L.) is of great importance due to its medicinal properties and industrial uses. However, as in most plants, physiological and biochemical changes occur in turmeric plants subjected to saline conditions. This study aimed to evaluate the growth and antioxidant response of turmeric plants, and the yield and composition of turmeric essential oil under saline stress. The study was greenhouse-based, and 180 days old turmeric plants were treated with 50, 100, and 150 mM NaCl solutions for 130 days. Plants grown under high NaCl concentrations showed significantly reduced shoot length and shoot and rhizome biomass accumulation. Large amounts of proline accumulated in the leaves at 150 mM NaCl. Lipid peroxidation and malondialdehyde content increased with salinity in both leaves and rhizomes. Antioxidant enzymes showed greater activity in the leaves of plants exposed to high NaCl concentrations. Salinity altered the yield and chemical composition of the essential oil in the rhizomes. A total of 114 compounds were identified in the essential oil, with the main compounds from the sesquiterpenes class. Sesquiterpenes can constitute a secondary antioxidant system which can assist the primary antioxidant defense system to maintain the levels of hydrogen peroxide in cells at concentrations sub-lethal to turmeric plants. In addition, the presence of rhizomes has a mitigating effect on salt stress in this species due to the antioxidant activity of the essential oil present in the rhizomes.

Drought and salinity are major environmental stresses that impair crop growth and productivity worldwide. Improving drought and salt tolerance of crops with microbial mutualists is an effective and environmentally sound strategy to meet the demands of the ever-growing world population. In the present study, we found that the Streptomyces albidoflavus OsiLf-2, a moderately salt-tolerant endophytic actinomycete, produced abundant osmolytes, including proline, polysaccharides, and ectoine. Inoculation with OsiLf-2 increased the osmotic-adjustment ability of the rice host by increasing the proline content (by 250.3% and 49.4%) and soluble sugar (by 20.9% and 49.4%) in rice under drought and salt conditions, relative to the uninoculated control. OsiLf-2 increased stress responses in the rice host at the physiological and biochemical levels (photosynthesis efficiency, osmolytes and antioxidant content), and the gene level (osmolytes synthesis, stress-responsive and ion-transport related genes), raising rice yields under both greenhouse and saline–alkaline soil conditions. The use of endophytic actinomycetes offers a promising biotechnological approach to developing stress-tolerant plants.

Saline–alkaline (SA) stress is characterized by high salinity and high alkalinity (high pH), which severely inhibit plant growth and cause huge losses in crop yields worldwide. Here we show that a moderate elevation of endogenous abscisic acid (ABA) levels by RNAi-mediated suppression of OsABA8ox1 (OsABA8ox1-kd), a key ABA catabolic gene, significantly increased tolerance to SA stress in rice plants. We produced OsABA8ox1-kd lines in two different japonica cultivars, Dongdao 4 and Nipponbare. Compared with non-transgenic control plants (WT), the OsABA8ox1-kd seedlings accumulated 25.9%–55.7% higher levels of endogenous ABA and exhibited reduced plasmalemma injury, ROS accumulation and Na+/K+ ratio, and higher survival rates, under hydroponic alkaline conditions simulated by 10, 15, and 20 mmol L−1 of Na2CO3. In pot trials using SA field soils of different alkali levels (pH 7.59, 8.86, and 9.29), OsABA8ox1–kd plants showed markedly higher seedling survival rates and more vigorous plant growth, resulting in significantly higher yield components including panicle number (85.7%–128.6%), spikelets per panicle (36.9%–61.9%), branches (153.9%–236.7%), 1000–kernel weight (20.0%–28.6%), and percentage of filled spikelets (96.6%–1340.8%) at harvest time. Under severe SA soil conditions (pH = 9.29, EC = 834.4 μS cm−1), OsABA8ox1-kd lines showed an 194.5%–1090.8% increase in grain yield per plant relative to WT plants. These results suggest that suppression of OsABA8ox1 to increase endogenous ABA levels provides a new molecular approach for improving rice yield in SA paddies.

Salinity impairs plant growth, limiting agricultural development. It is desirable to identify genes responding to salt stress and their mechanism of action. We identified a function of the Zea mays WRKY transcription factor, ZmWRKY104, in salt stress response. ZmWRKY104 was localized in the nucleus and showed transcriptional activation activity. Phenotypic and physiological analysis showed that overexpression of ZmWRKY104 in maize increased the tolerance of maize to salt stress and alleviated salt-induced increases in O2− accumulation, malondialdehyde (MDA) content, and percent of electrolyte leakage. Further investigation showed that ZmWRKY104 increased SOD activity by regulating ZmSOD4 expression. Yeast one-hybrid, electrophoretic mobility shift test, and chromatin immunoprecipitation–quantitative PCR assay showed that ZmWRKY104 bound directly to the promoter of ZmSOD4 by recognizing the W-box motif in vivo and in vitro. Phenotypic, physiological, and biochemical analysis showed that ZmSOD4 increased salt tolerance by alleviating salt-induced increases in O2− accumulation, MDA content, and percent of electrolyte leakage under salt stress. Taken together, our results indicate that ZmWRKY104 positively regulates ZmSOD4 expression to modulate salt-induced O2− accumulation, MDA content, and percent of electrolyte leakage, thus affecting salt stress response in maize.

Lacustrine non‐skeletal carbonates exhibit a diversity of petrographies due to interactions between physico‐chemical and biologically influenced mechanisms. Despite the suggestion that evaporative concentration was involved in the formation of spherulite and shrubby‐bearing carbonate successions in the Pre‐Salt Cretaceous alkaline lakes of the South Atlantic, no consensus exists about the water chemistries promoting these exotic mineral textures. In this work, an experimental approach was developed to evaluate how changes in salinity (NaCl) and biopolymer concentrations (alginic acid) impact calcite growth dynamics from saline and alkaline synthetic solutions. Hydrochemical and petrographical data from selected modern saline/alkaline environments were compared with experimental datasets to further estimate how the underlying (bio)chemical conditions and lake locations probably converge to allow the formation of calcite spherulite grains in evaporitic settings. Spherulitic calcite from Recent saline lakes and experiments arise from waters with moderate to high [Calcium]/[Alkalinity] ratios ([Ca]/[Alk]) rather than in calcium‐depleted and alkaline‐rich environments which tend to produce single‐crystal calcites during abiotic water mixing or lake evaporation. This observation is consistent with the assembly of polycrystalline textures being a kinetically controlled feature, forced by remarkably high rates of nucleation. Also, the data analysed do not support a causative relationship between evaporite‐driven salinity fluctuations and the preferential formation of spherulites, shrubs or their intermediate textures. Ubiquitous in saline lakes, organic substances can lower the kinetic thresholds for spherulitic calcite aggregation while microbial photosynthesis can also raise pH, altogether enhancing calcite supersaturation and promoting spherulite formation in waters with moderate‐high [Ca]/[Alk] ratios and high salinities. Localised observations of abiotic spherulites in Recent soda lakes can occur in restricted mixing zones where [Ca]/[Alk] ratios are enhanced. This work highlights the roles of concentration regimes associated with biopolymers and microbial metabolism against the background salinity fluctuations in determining the morphological and textural transitions in lacustrine carbonate minerals.

ugarcane (Saccharum spp. hybrids) is moderately sensitive to salinity and the effects on plant performance vary according to stress level and genotype. This study aimed to evaluate the effect of salt stress induced by application of different NaCl levels in the irrigation solution on plant height, indirect index of chlorophylls (SPAD), and macronutrients concentration (N, P, K, Ca, Mg, and S) and Na in leaves of two sugarcane varieties: CP 72-2086 and Mex 69-290. The experiment was set in a completely randomized design with a 2×5 factorial arrangement. The study factors were sugarcane variety (CP 72-2086 and Mex 69-290) and NaCl concentration (0.0, 71.8, 143.6, 215.4, and 282.7 mM NaCl). Salinity as a single factor negatively affected plant height, SPAD units and N and P concentration in leaves; Ca concentrations increased, while K, Mg and S remained unaffected by the tested NaCl levels. Mex 69-290 grew higher and concentrated greater levels of N and K. Interactions of factors showed that salinity reduced growth in both varieties, but this reduction was more pronounced in CP 72-2086. SPAD units were also significantly reduced by salinity in both varieties. Concentrations of N and P in leaves decreased in both varieties in response to NaCl, while those of K and Ca increased in Mex 69-290. Concentration of Na was higher in Mex 69-290 which exhibited better performance than CP 72-2086. Sodium concentrations in leaves increased in direct relation to the tested NaCl concentrations. Mex 69-290 reached higher concentrations of Na in leave tissues but displayed better health than CP 72-2086. Thus, the variety Mex 69-290 showed more efficient Na-tolerance mechanisms related to Ca and K concentrations, and an indirect chlorophyll index better than CP 72-2086.

Individually selenium and α-tocopherol showed a pivotal role in combating abiotic stresses in plants. However, there is no report on how selenium behaves in the presence or absence of α-tocopherol under salt stress in crop plants. With this view, the present study was undertaken to dissect the interaction between selenium and α-tocopherol on growth performance, carbon metabolism, and uptake of different ions in maize plants grown under salt stress. This study was conducted with surface-sterilized seeds of maize that were soaked in deionized water (control), selenium (0.5 µM), and/or α-tocopherol (200 ppm) for 12 h before sowing and different salt levels (0, 100, 150, and 200 mM) in the form of NaCl was created in soil. A sample of maize plants from each treatment was collected 40 days after sowing. The results revealed that salinity lowered the growth performance, chlorophyll content, insoluble sugar, carbohydrate, phenolic, flavonoid content, and different ions uptake in concentration dependent manner whereas, soluble sugar, α-amylase activity, and sodium ion increased in comparison to control plants. Moreover, selenium and/or α-tocopherol treated plants without stress significantly amplified the growth performance, chlorophyll and carotenoid content, carbohydrate, phenolic, and flavonoid content, and improved the uptake of different concentrations ions (K+, Ca+2, K+/Na+, Ca+2/Na+, and Mg+2) over the control plants. Interestingly, treatment of combined selenium and α-tocopherol to the salt-stressed plants successfully recover the loss caused by increasing salt levels in maize plants through altered carbon metabolism and ions uptake reflected in improved growth performance and bigger growth leaf area of maize plants under salt stress. Selenium and α-tocopherol in combination also enhance the antioxidative defensive mechanism through the production of phenolics and flavonoids content in maize plants under salt stress. This approach could be an effective measure to lower salt stress and enhance the crop productivity of maize plants.

The comparison between salt stress protectants in terms of their ability to increase growth and yield under salinity is of great importance in crop production. Melatonin (MT) and cobalt (Co) have been suggested to promote the plant's salt tolerance by mediating physiological mechanisms. To explore the difference between these protectants in increasing salt tolerance, cucumber plants (Cucumis sativus L., cv. Barracuda F1) were submitted to different levels of salt stress (control = 0.25, 2, 3 and 4 dS m−1) with pretreatment of MT (100 and 200 μM) or Co (15 and 20 mg L−1). The results indicated that the increasing level of salt reduced the growth and productivity of cucumber plants, which may result from ions toxicity (Na+ and Cl− accumulation), oxidative stress (hydrogen peroxide, H2O2 and malondialdehyde, MDA accumulation), and the reduction of essential nutrients content. The concentration used, whether from MT or Co, was instrumental in determining the level of salt tolerance in the cucumber plants. Foliar application with 15 mg L−1 Co and 100 μM MT mitigated, at a similar level, the NaCl- induced inhibition of cucumber growth, fruit number and weight. At the physiological levels, both treatments increased protein content, essential nutrients (N, P, K+, and Ca2+) content, and catalase (CAT) activity of stressed plants. The mitigation was also observed in the reduced levels of H2O2 and MDA. However, Co (15 mg L−1) showed superiority compared to MT in reducing the content of toxic ions (Na+ and Cl−) and increasing the total yield, especially under the high salt stress (4 dS m−1). These results suggest that Co and MT can improve the salt tolerance of the cucumber plants, but the level of improvement may differ in some aspects, and this may be due to the difference in salt tolerance mechanisms among those protectants.

Abscisic acid (ABA) plays an important role in seed germination, stomatal closure, and seedling growth inhibition in plants. Among downstream genes whose expression levels are regulated by AFA1 (Arabidopsis F-box Protein Hypersensitive to ABA 1), one gene, AtHAD1 upregulated by ABA was selected from Arabidopsis. AtHAD1 was induced by drought and salt stresses as well as by ABA and was found in dry seeds. Its loss-of-function mutants exhibited increased ABA-sensitivity in germination, seedling growth, and stomatal closure. In addition, the mutants displayed a lower water loss rate and higher survival rate under drought stress than the wild-type plants, indicating that a loss of AtHAD1 leads to enhanced drought tolerance. These results show that AtHAD1 has an inhibitory role in ABA response and ABA-mediated drought tolerance. The expression levels of several ABA-responsive genes in athad1 were higher than those in the wild-type under the ABA treatment, suggesting that AtHAD1, as a negative regulator in ABA response, could be associated with the downregulation of the ABA-responsive genes. The phosphatase assay showed that AtHAD1 exhibits phosphatase activity. Monitoring of the subcellular localization of GFP-fused AtHAD1 proteins indicated that AtHAD1 exists in the nucleus and cytoplasm. Overall, this study shows that Arabidopsis HAD1 as an intracellular phosphatase negatively functions in the ABA-mediated cellular responses. This research could serve as a research basis to understand the functional link between ABA signaling and the regulation process of the cellular phosphate level.

Murray-Darling Freshwater Research CentreMDFRC item.The presence of sulfidic sediments (potential acid sulfate soils) is an emerging problem in the management of inland wetlands. Using data from 81 wetlands in the Murray-Darling Basin, a simple protocol was developed to assess whether a wetland will contain sulfidic sediments at levels that could cause ecological damage. Risk factors include whether or not the wetland receives municipal waste or irrigation return water, elevated salinity in the overlying water (>1750 µS/cm) or sediment (400 µS/cm in a 1:5 soil : water extract) and high levels of sulfate in the water column (>10 mg/L). Neutral or basic sediment pH indicates that, even if the sediment does contain sulfidic sediments, there is a reduced likelihood of acidification if the sediments are oxidized.

Carbon monoxide (CO), nitric oxide (NO) and hydrogen sulfide (H2S) are gasotransmitters known for their roles in plant response to (a)biotic stresses. The crosstalk between these gasotransmitters and potassium ions (K+) has received considerable attention in recent years, particularly due to the dual role of K+ as an essential mineral nutrient and a promoter of plant tolerance to abiotic stress. This review brings together what it is known about the interplay among NO, CO, H2S and K+ in plants with focus on the response to high salinity. Some findings obtained for plants under water deficit and metal stress are also presented and discussed since both abiotic stresses share similarities with salt stress. The molecular targets of the gasotransmitters NO, CO and H2S in root and guard cells that drive plant tolerance to salt stress are highlighted as well.

Salinity stress is one of the most important global problems that afflicts and limits the growth and development of turfgrass in arid and semi-arid areas. Therefore, this experiment was conducted to evaluate the effects of the interaction between gamma-aminobutyric acid (GABA) and salinity (NaCl) on perennial ryegrass (Lolium perenne L.). Perennial ryegrass plants were treated with three concentrations of GABA (0, 50, and 100 mM) and NaCl (0, 50, and 100 mM) for two months. Multivariate analysis of variance revealed that GABA, salinity, and their interaction had significant effects on the majority of measured traits. In shoots and roots, the application of salinity increased the Na+/K+ ratio, as well as proline, total soluble carbohydrates and protein (TSP), malondialdehyde (MDA), and hydrogen peroxide (H2O2) content, but reduced relative water content, membrane stability index (MSI), total chlorophyll content, and shoot and root growth. When GABA was applied in saline conditions, Na+ did not accumulate, the Na+/K+ ratio decreased, and the amount of K+ content increased significantly in shoots and roots, thereby allowing plant growth to resume. Peroxidase (POD) and superoxide dismutase (SOD) activities increased significantly (51.83% and 322%, respectively), whereas H2O2 and MDA contents decreased significantly (34.4% and 67%, respectively). In addition, the construction of a biplot, heatmap, and correlation plot fortified the positive effects of GABA on perennial ryegrass growth in saline conditions. GABA may help to alleviate salinity damage through its involvement in osmotic adjustment (proline and TSP), reducing the Na+/K+ ratio and limiting oxidative damage in cells with a dramatic increase in POD and SOD activity. Therefore, the application of GABA is an alternative technique for improving turfgrass tolerance to salinity.

The linear gel is prepared by treating bio-diesel with various water samples collected from different water bodies. The new biodiesel based linear gel was employed in the recovery of oil wells through hydrofracturing and pilot tests were conducted for the first time. The viscosity of gel was measured at various bottom hole-circulating temperatures and it was found to vary from 32 to zero dial reading in the range of 45ºC to 60ºC. The gel was observed to break at 45ºC and 60ºC in 120 min. So the final temperature was selected as 60ºC for the application of gel for coal bed methane (CBM) wells. It was observed that higher levels of salinity in water helped in optimum utilization of gel in real-time application.

Saffron is one of the highly prized spices in the world. This spice is dark-red owing to the accumulation of crocins. Crocins are a group of carotenoid derivatives termed apocarotenoids with various health-promoting properties, especially anticancer and antidepressant ones. The present study aims to investigate the changes in the total crocin content in Crocus sativus stigma under salt stress. Additionally, plant resistance was evaluated by measuring the amounts of proline, soluble and insoluble sugars, potassium, and sodium in leaves. The corms about 80 g were planted in planting boxes under 6 levels of salinity (0, 2, 4, 6, 10 dS/m) in a completely random design with four replications. Results showed that after a relative decrease under electrical conductivities (EC) from 2 to 4 dS/m (49.62 mg/g DW), a sudden increase occurred in the total crocin content at the EC of 6 dS/m (63.07 mg/g DW). The amount of proline significantly increased at the EC of 4 dS/m (18.1 µg/g DW). With increasing levels of salinity, the amount of glucose, calcium, potassium, and sodium gradually increased in the leaves. Therefore, one of the advantages of saffron cultivation in saline areas or with saline water can be an increase in crocin. This not only brings huge economic benefits but also has a beneficial effect on human health.

Globally, one of the key restrictions on agricultural production is salinity and its impact is expected to increase. As a result, it is necessary to improve crop salinity tolerance. One promising approach is the use of plant nutrition technologies such as the application of zinc sulfate (Zn) and Azotobacter chroococcum (Az) which may improve plant survival under environmental stresses. A greenhouse experiment was conducted with three replications and included four levels of salinity (0, 40, 60 and 80 mM NaCl) in combination with four treatments [control, 2 mM zinc sulfate foliar application (Zn), inoculation with Azotobacter chroococcum (Az) and co-application of Az and Zn (Az+Zn)]. The results indicate that exposure to salinity increased soybean contents of anthocyanin, malondialdehyde (MDA), osmolytes, sodium ion (Na+), and the activities of antioxidant enzymes However, the amount of chlorophyll and carotenoid, relative water content (RWC), maximum quantum yield of photosystem II (PSII; Fv/Fm), membrane stability index (MSI), and ion contents decreased. Application of Zn and inoculation with Az enhanced the chlorophyll (a, b and a+b), carotenoid, RWC, Fv/Fm, MSI, anthocyanin, osmolytes, N, K+, P contents, and K+/Na+; the activities of CAT, SOD, POX, and APX as well as MDA and Na+ contents were reduced. Overall our results reveal that combined Zn and Az application was the most effective treatment for alleviating the negative effects of salinity stress in soybean.

This study was conducted to examine cement kiln dust (CKD) efficiency for wastewater treatment. We analyzed the physicochemical characteristics of wastewater before and after treatment and then we determined its removal potential. The optimum factors of the treatment process were determined using a jar test technique. It was pH (8.1), dosage (1.9 g) and grain size (0.1 mm) with contact time of 30 min at 150 rpm. CKD pollutant removal efficiency reached 85.3, 81.6, 97.1, 86.8, 36, 74, 61.2, and 94.6% for BOD, COD, TP, TN, TDS, salinity, conductivity and turbidity, respectively, with an increase in the concentration of DO of 84%. On the other hand, removal percent of heavy metals achieved were 88.4, 90.9, 88.5, 97.2, 94.2, 70, and 79.9% for Pb, Cd, Zn, Fe, Co, Ni, and Cu, respectively. These results were compared with alum removal potential of wastewater treatment for confirmation. Alum pollutant removal efficiency reached 86.6, 79.6, 96.6, 59.9, 39.7, 65, 59 and 95.2% for BOD, COD, TP, TN, TDS, salinity, conductivity and turbidity, respectively, with an increase in the concentration of DO of 85.3%. On the other hand, removal percent of heavy metals achieved were 82.1, 90.6, 89.1, 96.8, 93.2, 72.8, and 84.1% for Pb, Cd, Zn, Fe, Co, Ni, and Cu, respectively. The methodology carried out in this study indicated that CKD can be used as a good environmental alternative coagulant for low to moderate wasted water as it achieved removal percent similar to that achieved by the common coagulant alum.

This study was carried out with the objective of evaluating the water relations, photosynthetic pigments and growth of passion fruit cv. BRS Rubi do Cerrado, as a function of the cationic nature of irrigation water and exogenous application of hydrogen peroxide. The experiment was carried out under greenhouse conditions in Pombal – PB, Brazil. The experimental design was randomized blocks, in a 6 × 4 factorial scheme, corresponding to six cationic nature of water - CNW (S1 - Control; S2 - Na+; S3 - Ca2+; S4 - Na++Ca2+; S5 - Mg2+ and S6 - Na++Ca2++Mg2+) and four concentrations of hydrogen peroxide - H2O2 (0, 20, 40 and 60 μM), distributed in a randomized block design with four replicates. Plants in the control treatment (S1) were irrigated using water with electrical conductivity (ECw) of 0.3 dS m-1, while those of the other treatments (S2; S3; S4; S5 and S6) were subjected to ECw of 3.0 dS m-1, prepared with different cation(s). Application of 60 μM of H2O2 reduced the percentage of intercellular electrolyte leakage in plants irrigated with water of calcic composition. Salinity of water composed of sodium, sodium+calcium and sodium+calcium+magnesium, and H2O2 concentrations of 40 and 60 μM resulted in lower leaf water potential. The biomass accumulation of passion fruit was more sensitive to the variation of the electrical conductivity of the water. Regardless of the cationic nature, the use of water with electrical conductivity of 3.0 dS m-1 produced passion fruit seedlings with a Dickson quality index higher than 0.2, considered acceptable. RESUMO Realizou-se esta pesquisa com o objetivo de avaliar as relações hídricas, os pigmentos fotossintéticos e o crescimento do maracujazeiro cv. BRS Rubi do Cerrado, em função da natureza catiônica da água de irrigação e aplicação exógena de peróxido de hidrogênio. O experimento foi desenvolvido em condições de casa de vegetação em Pombal - PB. O delineamento experimental foi o de blocos casualizados, em esquema fatorial 6 × 4 , sendo seis natureza catiônica da água - NCA (S1 -Testemunha; S2 - Na+; S3 - Ca2+; S4 - Na++Ca2+; S5 - Mg2+ e S6 - Na++Ca2++Mg2+) e quatro concentrações de peróxido de hidrogênio – H2O2 (0, 20, 40 e 60 µM), distribuídos em delineamento de blocos ao acaso com quatro repetições. As plantas do tratamento testemunha (S1) foram irrigadas com água de condutividade elétrica (CEa) de 0,3 dS m-1, e os demais tratamentos (S2; S3; S4; S5 e S6) foram submetidos à CEa de 3,0 dS m-1, preparada com diferente(s) cátion(s). Aplicação de 60 µM de H2O2 diminuiu a percentagem de extravasamento de eletrólitos nas plantas irrigadas com água de composição cálcica. A salinidade da água constituída de sódio, sódio+cálcio e sódio+cálcio+magnésio e concentrações de 40 e 60 µM de H2O2 resultou em menor potencial hídrico foliar. O acúmulo de fitomassas do maracujazeiro foi mais sensível à variação da condutividade elétrica da água. Independente da natureza catiônica, o uso de água com condutividade elétrica de 3,0 dS m-1 produziu mudas de maracujazeiro com índice de qualidade de Dickson superior a 0,2 considerado aceitável.

Forest degradation is a worldwide problem, although its causes vary due to geographical and climatic differences and man-made causes. In recent years, the Robinia pseudoacacia forest in the Yellow River Delta has suffered severe degradation. The causative mechanisms were investigated in the field over two years, and the results show that increased forest degradation was reflected by increased tree mortality, high leaf and soil sodium salt levels and groundwater depth. Average tree diameters decreased, and leaf chlorophyll and soil microbial contents decreased. Redundancy discriminate analysis (RDA) showed that degradation of the forest was correlated positively with soil salt content, but negatively with groundwater depth. Correlation analysis showed that 0.79%–0.95% soil salt content and above 1.20 m groundwater depth caused the death of R. pseudoacacia trees due to localized anthropogenic economic activities, such as rice farming, that disrupted the original water–salt balance. Measures are recommended to prevent further degradation and restore degraded forests.

The integration of taxonomic and ecological traits is a more balanced approach in the systematic identification of living organisms. We isolated ten strains of Dunaliella from different geographical regions of Iran, including six terrestrial and four aquatic taxa. All strains belonged to the section Dunaliella based on the morphological and molecular investigation. First, optimal salinity was determined for bio-pigment accumulation. Each alga had its own optimum salinity, and the range of 1.5 to 2.5 M NaCl was further studied. Dunaliella parva YzS produced the maximum biomass density (231.92 mg L−1), while Dunaliella salina MrL accumulated the highest value of total carotenoid (1.72%AFDW). At the early stationary growth phase, the algae had a 11.7 to 41.7% lipid content. FAMEs varied from C10 to C24 with one or more double bonds. The results showed highly significant levels of palmitic (C16) and α-linolenic (C18:3n3) acids. According to the fatty acid profiles, the clustering pattern aligns with the sample origin. Compared to aquatic strains, terrestrials were more resistant to harsh conditions, e.g., dry conditions due to the synthesis of very long chain fatty acids. Lipid compositions may therefore be attributable to the environmental origins of taxa. The fatty acid composition was affected by the environmental conditions, while the accumulation of carotenoid was dependent on the biological and genetic entity of algal taxa. Examination of habitat parameters revealed that aquatic strains were well adapted to maintain homeostasis in higher salinity and conductivity; terrestrial strains were much better able to tolerate high concentrations of nitrate and phosphate.

The focus of the present study was to explore how and to what extent ultrahigh salinity affects the adsorption of cadmium and hydrocarbon pollutants onto aluminum hydroxide adsorbents formed in an electrocoagulation process. The changes in the nature and structure of the electro-generated aluminum particles and the possible removal mechanisms due to high salt content were investigated by using FE-SEM/EDS, FTIR, BET, and XRD analyses. The pseudo-second order and Freundlich models proved to fit the data for cadmium adsorption onto the aluminum hydroxides best. It was demonstrated that the adsorption capacities were significantly affected by the high salinity. With the rise of the salinity from 2 to 170 g/L, the cadmium and COD removal yields dropped from 81 to 60% and from 90 to 72%. The increase of the oil content led to the enhanced cadmium adsorption capacity due to surface complexation and ion exchange mechanisms. It was proved that Lagergren pseudo-first-order kinetic model could justify COD abatement trends. FTIR spectra depicted that the negative impact of high salinities on the adsorption was due to causing the formation of less stable adsorbents. According to BET analysis, the occurrence of much wider pore size distribution and smaller specific surface area in high salinity case was the main reason for the decreased adsorption capacity. Based on XRD analysis, the higher crystallinity of the produced aluminum hydroxide particles and their consequential smaller surface areas resulted in the lower adsorption capacity in the hypersaline environment. It was concluded that adsorption via inner-sphere and outer-sphere complexation and sweep flocculation were the possible removal mechanisms. Total treatment cost of 8.75 and 3.49 €/m3 were estimated for low and ultrahigh salinity conditions.

This study investigated: (1) the effects of various concentrations of melatonin (MT) and Ca2+; and (2) the impact of crosstalk between these signal molecules on photosynthesis and salt tolerance of Dracocephalum kotschyi Boiss. Results indicated that 5 mM CaCl2, as well as 100 μM MT were the best concentrations for increasing shoot dry weight, leaf area, SPAD index, maximum quantum efficiency of photosystem II (Fv/Fm), and decreasing malondialdehyde content under salinity stress. The impact of MT on growth and photosynthesis was closely linked to its effect on enhancing antioxidant enzyme activities in leaves. Application of p-chlorophenylalanine, as an inhibitor of MT biosynthesis, negated the impacts of MT on the aforementioned attributes. Salinity and MT boosted cytosolic Ca2+ concentration. Exogenous MT, as well as Ca2+, enhanced tolerance index, membrane stability, leaf area, the content of chlorophyll (Chl) a, Chl b, and carotenoids (Car), Fv/Fm, and stomatal conductance under salinity stress. These impacts of MT were eliminated by applying a calmodulin antagonist, a Ca2+ chelator and a Ca2+ channel blocker. These novel findings indicate that the MT-induced effects on photosynthetic parameters and salt-evoked oxidative stress were mediated through calcium/calmodulin (Ca2+/CaM) signalling.

Biodiesel production from the microalgal oil of the estuarine diatom Halamphora coffeaeformis has proven to be technically viable. However, a fuller understanding of the environmental factors that regulate its tolerance and neutral lipid accumulation is required for improved mass cultivation in seawater-based outdoor raceway ponds. Meteorological conditions and evaporation processes can significantly influence factors such as the salt levels, water temperature and nutrient and light availability in these systems. Laboratory experiments with H. coffeaeformis growing in f/2 medium were therefore carried out in order to evaluate the effect of temperature and salinity on its growth and tolerance ranges and the effect of salinity on its total lipid and lipid fraction content and fatty acid methyl ester profile. Results indicate that the temperature and salinity ranges of the species were 5 °C to 30 °C and 5‰ to 95‰, respectively. The optimum temperature was between 20 and 25 °C, and the optimum salinity was 20‰. Neutral lipid accumulation increased in cells adapted at 45‰ with respect to those growing at 20‰. Total lipid composition at 45 ‰ was characterized by 85.5% neutral lipids, 2.5% phospholipids and a high percentage of C16.1 (36.4% of total fatty acids). These properties are important for an adequate quality of biodiesel. The eurytolerant behaviour of H. coffeaeformis and the effect of salinity stress on its growth and neutral lipid accumulation are demonstrated. The findings indicate the beneficial attributes of this strain for the development and feasibility of seawater-based outdoor raceway ponds for biodiesel production.

Abiotic stresses, such as iron deficiency and high salinity, affect apple growth and development. WRKY transcription factors (TFs) are widely involved in the responses of plants to adverse stresses. In the present study, a new WRKY gene was isolated from Malus xiaojinensis and designated as MxWRKY53. Subcellular localization showed that MxWRKY53 was localized to the nucleus. The expression level of MxWRKY53 was highly affected by salt, low Fe, and high Fe stresses in M. xiaojinensis seedlings. When MxWRKY53 was introduced into Arabidopsis thaliana, it greatly enhanced the salt and Fe tolerance. When dealt with high and low Fe stresses, the overexpression of MxWRKY53 in transgenic A. thaliana resulted in higher levels of root length, fresh weight, and contents of chlorophyll and Fe than wild type (WT). Increased expression of MxWRKY53 in transformed A. thaliana also contributed to higher contents of chlorophyll and proline, and higher activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), while malondialdehyde (MDA) content was lower, especially in response to salt stress. Therefore, these results show that MxWRKY53 plays a positive role in the process of plant resistance to salt, low Fe, and high Fe stresses.

A major stress factor that can seriously limit plant growth and productivity is the soil degradation caused by salinity. Arbuscular mycorrhizal fungi (AMF) establish symbioses with most agricultural plants and improve growth under soil stress. In this study, tea plants with and without AMF inoculation under salt stress were investigated with the RNA-seq and the genome sequencing of tea plant, obtaining a positive insight into AMF-colonized involved in the improvement of growth and quality affected by lignin and cellulose synthesis under salt stress. Totals of 1402 and 1915 differentially expressed genes (DEGs) were identified in tea leaf with and without AMF under salt stress. Functional annotation analysis revealed that these DEGs were mainly involved in metabolic process, membrane and cell part and catalytic activity function. The Kyoto Encyclopedia of Genes and Genomes pathways analysis showed that the DEGs were enriched on the cellulose synthesis with AMF or enriched on the lignin and cellulose synthesis without AMF under salt stress. Further experiments verified that the more lignin deposited on the xylem vascular and the sclerenchyma of tea plants after salt stress, and lignin autofluorescence in tea plants with AMF was weaker than that without AMF. AMF inoculation could alleviate the salt stress, which showed in the decrease of lignin and cellulose accumulation. Moreover, the tea plants inoculated AMF increased tolerance by osmotic regulation and protective enzymes. In general, our results provide a more comprehensive insight into the role of AMF in adapting the adverse condition and keep the quality of fresh tea leaves in the northern Tea Area.

Melatonin (MEL) is a ubiquitous molecule with pleiotropic roles in plant adaption to stress. In this study, we investigated the effects of foliar spray of 100 and 200 μM MEL on the biochemical and physiological traits linked with the growth performance of olive seedlings exposed to moderate (45 mM NaCl) and severe (90 mM NaCl) salinity. Both salt stress conditions caused a considerable reduction in leaf relative water content and the contents of photosynthetic pigments (carotenoids, chlorophylls a and b and total chlorophylls), K+ and Ca+2 , while the contents of Na+ and the activities of antioxidant enzymes increased. In addition, salt-stressed olive seedlings showed high accumulations of hydrogen peroxide (H2 O2 ), malondialdehyde (MDA) and electrolyte leakage (EL), indicating that olive seedlings suffered from salinity-induced oxidative damage. In contrast, MEL application revived the growth of olive seedlings, including shoot height, root length and biomass under salt stress conditions. MEL protected the photosynthetic pigments and decreased the Na+ /K+ ratio under both moderate and severe salt stresses. Furthermore, MEL induced the accumulations of proline, total soluble sugars, glycine betaine, abscisic acid and indole acetic acid in salt-stressed olive seedlings, which showed a positive correlation with improved leaf water status and biomass. MEL application also increased the activities of catalase, superoxide dismutase, ascorbate peroxidase and peroxidase in salt-stressed seedlings, resulting in lower levels of H2 O2 , MDA and EL in these plants. Taken together, MEL mitigates salinity through its roles in various biochemical and physiological processes, thereby representing a promising agent for application in crop protection. This article is protected by copyright. All rights reserved.

Nanotechnology has been amplified in different areas of science as well as agriculture in the present era. So, the present work was designed to evaluate the result of nitrate mediated silver nanoparticles (Nit-AgNPs) and indole acetic acid (IAA) on physio-biochemical features of the selected maize variety (Pahari white) under 40 and 80 mM salinity induction. Seeds were propagated in triplicates in earthen pots (18 cm inferior and superior inside diameter, 20 cm stature, and 2 cm breadth) filled with silt and soil (1:2) having 3.09-5.12 Electrical conductivity (EC), 6.8-7.3 pH, and 4-16% moisture contents. Scanning electron microscopy results showed the average particle size around 90 nm indicating a high surface area suitable for adsorption properties, agglomerated, roughly spherical, and were uniformly dispersed. Elemental quantification of biosynthesized AgNPs analyzed via energy dispersive X-ray spectroscopy showed a strong peak at 3.0 KeV along with the presence of elements K, N, O, and C. Results of Thermo-gravimetric Analysis (TGA)/Differential Thermal Analysis (DTA) showed endothermic major decline at 150-300°C, while exothermic peak at 300-400°C. The growth responses at 40 mM salinity concentration have been reduced representing from the least boundary of chlorophyll "a," "b," and peroxidase content, whereas; this adverse effect has been reduced by operation of Nit-AgNPs as separate treatment and in combination with IAA. From the current study, it has been concluded that salinity concentration at 80 mM adversely affected the values of osmolytes, protein, and superoxide dismutase whereas the maximum amplitude of proline reduced by the application of Nit-AgNPs as distinct treatment indicating that the plant behaves normal with the combined application of nanoparticles and IAA.

During salinity stress, osmoregulatory processes in euryhaline fish need to modify for their survival, and glucose is the preferred mode of extra energy during such conditions. These organisms must have a proper mechanism to maintain glucose homeostasis during such modified osmoregulatory process across different body fluids. Hence, we studied high salinity effect on regulation of glucose homeostasis in Mozambique tilapia. The fish were induced to 15‰ salinity for 21 days. Glucose, glycogen, ion concentrations, Na+-K+-ATPase, pyruvate kinase, γ-amylase activities and GLUT mRNA expressions were investigated in liver, intestine, gill and white muscle tissues. At the end of experiment, Na+ ion concentrations, glucose content and activity of Na+-K+-ATPase especially in the gill and intestine were increased, while decrease in liver and gill glycogen content was seen. Lower concentration of glycogen decrease was observed in the intestine and white muscle of the treated group. High pyruvate kinase activity was noticed in liver and gill tissues that correlates with high Na+-K+-ATPase activity. Elevated γ-amylase activity was observed in the liver and intestine suggesting breakdown of glycogen; however, gill and white muscle did not show any increased activity. Increase in GLUT1 and GLUT4 mRNA expressions was observed especially in the gill and intestine, while increase in GLUT2 mRNA expressions was observed in the liver. Upregulations of GLUTs suggest higher influx of glucose into the cell for catabolism to provide energy and further to drive the enhanced osmoregulatory process. These findings suggest glucose homeostasis being regulated in Mozambique tilapia during salinity acclimation.

Salinity commonly affects photosynthesis and crop production worldwide. However, some studies have shown that hydrogen peroxide seed priming can increase the tolerance of plants to salt stress. In ...

Ion-engineered water injection (EWI) is one of the advantageous enhanced oil recovery (EOR) techniques that gained considerable attention in recent years. Many mechanisms have been proposed for additional oil recovery with modified seawater composition when injected into carbonate formations. However, the prediction of EWI is a big challenge due to complex rock/fluid interactions at pore level and related mechanisms. Thus, an efficient design method for water composition is required. This study investigates the optimization of EWI through the concentration of the active and non-active ions in injection water at laboratory scale for chalk core samples by considering the most dominant design parameters. Data from many imbibition tests of chalk core samples were selected. The Response Surface Methodology (RSM) was used to screen the significant contributing parameters. The sensitivity analysis showed that the four most important design parameters are crude oil acid number (TAN), crude oil base number (TBN), temperature, and injected water salinity. An optimum EWI design was suggested, and the predicted responses were validated using other experimental results that have not been used for model development with high accuracy. The model can be applied for experimental design and optimum water composition.

Salinity is a major global problem that threatens the agricultural sector, especially in areas that suffer from a shortage of water. It motivates ionic toxicity, osmotic and oxidative stresses, which greatly inhibits plant performances and crop productivites. However, micronutrients (MNs) or plant extracts, like germinated maize grain extract (gMGE), have been reported to minimize the effects of salt stress on plant growth and returns. Therefore, this study aimed at evaluating the influences of MNs or gMGE applied as foliar sprays on growth, physio-biochemical indices, and antioxidative system components in three genotypes of tomato plants stressed by 9 dS m−1 NaCl. This salinity level markedly increased Na+ content, lipid peroxidation, ion leakage, and markers related to oxidative stress (superoxide; O2 − and hydrogen peroxide; H2O2). Besides, marked increases in activities of enzymatic (especially different forms of superoxide dismutase; SODs) and non-enzymatic antioxidants and osmoprotectant compounds were also observed. In contrast, growth, photosynthetic capacity including hill reaction activity (HRA), K+/Na+ ratio, tissue cell integrity (e.g., cell water content and membrane stability), and K+ and MNs contents decreased significantly under stress. However, compared to MNs, gMGE significantly improved the activities of the antioxidative system components (particularly SODs) and osmoprotectants, which were reflected in reduced Na+ accumulation, lipid peroxidation, ion leakage, and oxidative stress. These results were coupled with remarkable elevations in photosynthetic capacity including HRA, K+/Na+ ratio, tissue cell integrity, K+ content, and MNs contents, all of which were reflected in the enhancement of plant growth. Compared to local tomato cultivars (e.g., Castle Rock and C10), the wild line “0043-1” had better results. The interaction of three factors; salt stress, promoters, and tomato genotypes was significant. The wild tomato line “0043-1” as the best salt-tolerant is a good candidate for implication in breeding programs for tolerance to salinity to produce salt-tolerant cultivars for use to maximize tomato growth and productivity in saline environments.

Salinity stress severely affects plant growth and crop productivity. FCS-like zinc finger family genes (FLZ) play important roles in plant growth and stress responses. But most information of this family obtained was involved in sucrose signaling, limited function has been known in response to salinity stress. In this study, a novel FLZ gene TaFLZ2D has been isolated and characterized in response to salinity stress in wheat. TaFLZ2D was induced by both salinity stress and exogenous abscisic acid (ABA). Its transcript level was substantially higher in the salt resistant wheat cultivar SR3 than in its closely related but salt sensitive cultivar JN177. Transient expression in Nicotiana benthamiana leaf epidermal cells demonstrated TaFLZ2D was localized both in the cytoplasm membrane and nucleus. Constitutive expression of TaFLZ2D in Arabidopsis thaliana improved salinity stress tolerance and ABA sensitivity. Phenotype analysis under KCl and mannitol treatment demonstrated TaFLZ2D increased salinity stress tolerance mainly due to the superior ability to cope with ionic stress. TaFLZ2D over-expressing lines increased abscisic acid synthesis, peroxidase activity and reduced rate of water loss. Transcriptomic analysis demonstrated over-expression of TaFLZ2D regulated ABA-dependent and independent signaling pathway related genes expression and activated antioxidant related genes expression under normal condition and Ca2+ signaling related genes expression under NaCl treatmemt. Taken together, TaFLZ2D is a positive regulator of salinity stress tolerance, which contributes to salinity stress mainly through superior ability for ionic stress tolerance and ROS detoxification.

Soil salinity is an environmental threat limiting rice productivity. Identification of salinity tolerance genes and exploitation of their mechanisms in plants are vital for crop breeding. In this study, the function of stress-activated protein kinase 7 (OsSAPK7), a SnRK2 family member, was characterized in response to salt stress in rice. Compared with variety 9804, OsSAPK7-overexpression plants had a greater survival rate, increased chlorophyll and proline contents, and superoxide dismutase and catalase activities at the seedling stage under salt-stress conditions, as well as decreased sodium potassium ratio (Na+/K+) and malondialdehyde contents. After salt stress, the OsSAPK7 knockout plants had lower survival rates, increased Na+/K+ ratios and malomdiadehyde contents, and decreased physiological parameters compared with 9804. These changes in transgenic lines suggested that OsSAPK7 increased the salt tolerance of rice by modulating ion homeostasis, redox reactions and photosynthesis. The results of RNA-Seq indicated that genes involved in redox-dependent signaling pathway, photosynthesis and zeatin synthesis pathways were significantly down-regulated in the OsSAPK7 knockout line compared with 9804 under salt-stress condition, which confirmed that OsSAPK7 positively regulated salt tolerance by modulating diverse stress-defensive responses in rice. These findings provided novel insights for the genetic improvement of rice and for understanding the regulatory mechanisms of salt-stress tolerance.

Background NAC (NAM, ATAF and CUC) transcription factors (TFs) play vital roles in plant development and abiotic stress tolerance. Salt stress is one of the most limiting factors for rice growth and production. However, the mechanism underlying salt tolerance in rice is still poorly understood. Results In this study, we functionally characterized a rice NAC TF OsNAC3 for its involvement in ABA response and salt tolerance. ABA and NaCl treatment induced OsNAC3 expression in roots. Immunostaining showed that OsNAC3 was localized in all root cells. OsNAC3 knockout decreased rice plants’ sensitivity to ABA but increased salt stress sensitivity, while OsNAC3 overexpression showed an opposite effect. Loss of OsNAC3 also induced Na+ accumulation in the shoots. Furthermore, qRT-PCR and transcriptomic analysis were performed to identify the key OsNAC3 regulated genes related to ABA response and salt tolerance, such as OsHKT1;4, OsHKT1;5, OsLEA3–1, OsPM-1, OsPP2C68, and OsRAB-21. Conclusions This study shows that rice OsNAC3 is an important regulatory factor in ABA signal response and salt tolerance.

We investigated the effects of salinity stress and gamma radiation on salinity tolerance in wheat crops. To this end, mutant lines were generated by exposing Arg and Bam wheat varieties at the primordial state to 150 and 200 gamma radiation doses in the field. The top 15 mutant lines were specified for cultivation in the fifth-generation under two conditions, including non-stress and salinity stress. According to Fernandez's model, the three mutant lines had high yields under both conditions. The three mutant lines were selected with their two parents, and then, cultivated in a completely randomized factorial design in a greenhouse under non-stress and salinity conditions. The mutant lines showed significantly higher osmotic adjustment, leaf relative water content (RWC), potassium ion concentration, soluble sugar content and lower proline (Pro), and glycine betaine (GB) content than the parents at both the vegetative (VEG) and reproductive (REP) stages under salinity conditions. The expression of genes involved in the Pro biosynthesis pathway, P5CS and P5CR genes, in mutant lines were less than their parents, and conversely, P5CDH in mutant lines was more than their parents. The changes in the expression of CMO and BADH genes involved in the GB synthesis pathway indicated that the mutant lines had less gene expression compared to their parent genotypes of Arg and Bam. The results indicated an increase in antioxidant activity in the mutant lines compared to their parents. Consequently, irradiated plants have probably adapted to the salinity stress by increasing the osmotic adjustment, RWC, potassium ion concentration, and soluble sugar content, as well as activating antioxidant enzymes.

Water quality can affect the survival and growth of aquatic organisms considering water is a living medium for fish. This study aims to determine how the effect of different models of different ponds on water quality fluctuations for the growth of white shrimp ( L. vannamei ) intensive pattern. The method used in this study is a comparative descriptive method. The statistical test used is using T test two samples (independent). The main parameters in this study were the results of measuring the growth of white shrimp ( L. vannamei ) while the supporting parameters in this study were measurements of water quality and total bacteria. The results of this study can be seen that differences in cultivation models have a significant effect on temperature, pH (Power of Hydrogen), DO (Dissolved oxygen), nitrate and have no significant effect on salinity, ammonia and nitrite. The average Specific Growth Rate (SGR) of vaname shrimp in the indoor culture model is 4.5±0.003%/day and the average Growth Rate (GR) is 0.29±0.024 g/day. While the outdoor cultivation model is 3.9±0.003%/day and the average Growth Rate (GR) is 0.26±0.017 g/day.

Agro-waste management generates worries to most developing countries and the menace needs to be curbed to reduce pollution. This study investigated the Proximate and Physicochemical composition of Oil Palm Empty fruit bunch. Samples collected were oven dried, grinded and analytical methods were carried out adopting AOAC 2005 (Association of official Analytical Chemists) test methods. The proximate analysis of the EFB revealed it to be a poor source of lipid (3.75 ± 0.01) but with a high fibre content (67.0 ± 1.19). The results showed concentrations of ash (6.87 ± 0.11), carbohydrate (12.3 ± 0.95), moisture (5.13 ± 0.24) and protein (4.87 ± 0.01). The physicochemical characteristics of oil palm empty fruit bunch is reported that pH had mean of 5.81±0.22, while temperature, total suspended solid, electrical conductivity, total dissolved solid, salinity, nitrate and sulphate had mean of 28.14 ± 0.02, 5.09 ± 0.02, 53.15 ± 0.03, 26.61 ± 0.015, 19.97±0.03, 14.65 ± 0.05, and 4.94 ± 0.02 respectively. More so, phosphate had mean of 17.55 ± 0.04, while ammonia, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, magnesium and calcium had mean of 0.04 ± 0.01, 2.86 ± 0.01, 1.58 ± 0.02, 2.55 ± 0.02, 1.05 ± 0.01 and 3.77 ± 0.01 respectively. The Proximate and Physicochemical composition of the Oil Palm Empty Fruit Bunch in this study demonstrates the efficiency of utilizing and application of this byproduct in various processes to help combat waste management issues in the environment.

The objective of the present study was to degrade the herbicide atrazine in iron-containing media using several selected plant species under circumneutral conditions. The concentration of the root apoplastic H2O2 (CRAH) for 59 plant species was mainly measured using the potassium iodide-starch qualitative staining technique. Plant species with a range of CRAH values were used for the atrazine degradation. At pH 6.5, atrazine was immediately removed and most significantly by Asteraceae plants having high CRAH (≥ 1.5 mM) in the presence of Fe3+-nitrilotriacetate. Less biologically harmful degradation products (deethylatrazine and deisopropylatrazine) of the Fenton reaction were identified in the treated medium. Asteraceae plants were estimated to remove atrazine via a rhizosphere Fenton reaction which was more than twice that via plant uptake. This is the first report demonstrating direct and immediate degradation of atrazine in the medium by plant roots. The high CRAH of Asteraceae plants was connected with salinity/drought tolerance mechanisms and phylogenetic evolution. Roots of Asteraceae plants with high apoplastic H2O2 significantly degraded atrazine by transforming to less biologically harmful degradation products in the presence of iron under circumneutral conditions via the rhizosphere Fenton reaction.

In this study, striped catfish larvae were gradually exposed to the increase of different salinities, and then they reached the levels of 0, 5, 10, 15, and 20 psu after 10 days, followed by heat shock at 39 °C to determine stress tolerance. After the 10-day experiment, the survival rate of fish exposed to the 20 psu treatment was only 28.6 ± 4%, significantly lower than that of the other treatments. The results showed that the osmolality of the whole-body (WB) homogenate was gradually and significantly increased with salinity elevation, except in fish exposed to freshwater and 5 psu treatments, while there were no significant changes in WB Na+/K+-ATPase activity. Digestive enzymatic activities, i.e., pepsin, α-amylase, alkaline phosphatase, and leucine alanine peptidase (leu-ala) generally increased with salinity, but not aminopeptidase and trypsin. Lysozyme and peroxidase activities increased in fish larvae exposed to 15 and 20 psu. These increases proportionally improved growth performance, with the lowest and the highest final weights observed in fish reared at 0 psu (0.08 ± 0.03 g/larvae) and 20 psu (0.11 ± 0.02 g/larvae), respectively, although the average growth recorded at 20 psu could be biased by the high mortality in this group. Occurrence of skeleton deformities, such as in caudal vertebrae and branchiostegal rays, was significantly higher in fish exposed to the higher osmotic conditions (15.0 ± 1.2% and 10.3 ± 2.1% respectively at 0 psu vs. 31.0 ± 2.9% and 49.0 ± 5.6%, respectively at 15 psu). After the 12.5-h heat shock, survival rates significantly differed between treatments with the highest survival observed in fish submitted to 5 psu (68.9%), followed by those exposed to 0 (27%) and 10 (20%) while all fish died at 15 psu. These findings suggest that the striped catfish larvae could be reared in salinity up to 5 to 10 psu with a higher survival and tolerance to thermal stress when compared to fish maintained in freshwater.

Silicon (Si) application to crops is a promising way for the deployment of sustainable agriculture. Here, the effects of Si on salt stress tolerance were investigated in alfalfa (Medicago sativa L.)-rhizobia symbioses. Two Moroccan, Ouad-Lmaleh (OL) and Demnate-201 (Dm), and one European, NS-Mediana-ZMS-V (NS-Med), alfalfa varieties were associated to Ensifer meliloti Rm41 rhizobial strain. One-month-old alfalfa plants were exposed to 120 mM NaCl for five weeks with or without 3 mM of Si. The plants subjected to salt stress showed reduced biomass, chlorophyll (Chl) contents and relative water content (RWC) in comparison to the controls. The alfalfa-rhizobia symbiosis was also impaired under stress as reflected by less root nodulation and lower nitrogen (N) content and nitrogen content index (NCI). Added Si significantly increased plant biomass, nodules number, N content, NCI, Chl contents and RWC under salt stress. Results showed that salt-stressed alfalfa increased malonyldialdehyde (MDA), hydrogen peroxide (H2O2) and electrolyte leakage (EL). However, Si incorporation in the cultured media reduced oxidative damages under salt-stress particularly in NS-Med variety by 26%, 70% and 70% for MDA, H2O2 and EL respectively. The lower amount of MDA, H2O2 and EL in the Si-treated plants seems to be related to its capacity to modulate superoxide dismutase and polyphenol oxidase activities and increase total polyphenol, flavonoid and carotenoid contents. Besides, compatible osmolytes, such as proline, glycine betaine and soluble sugars were found increased particularly in Si-treated OL plants by 46%, 33% and 26% respectively in comparison to Si-untreated plants. Alfalfa varieties reacted differently to Si treatment. Sodium concentration in alfalfa plants increased under salinity and reduced by Si treatment with an increase in the potassium content. Our findings showed that exogenous Si application could be a promising way to mitigate the toxic effect of salt and could improve alfalfa growth and its rhizobial symbiosis when grown in salt-affected soils.

Abiotic stresses, among which extreme temperatures, salinity, drought, UV radiation, heavy metal pollution, etc., adversely affect the growth and yield of cereals, the most important group of monocotyledonous plants that have met the nutritional and other needs of mankind for thousands of years. To cope with stress, plants deploy certain adaptive strategies that combine morphological, physiological, and biochemical responses, and on which growth and productivity depend. An important place in the formation of such strategies is occupied by phytohormones - signaling biomolecules of a different chemical structure and physicochemical properties, which act in nanomolar concentrations and regulate most physiological and metabolic processes of plants. In this review, the latest literature data concerning the growth and development regulation by exogenous phytohormones in cereals under abiotic stresses have been analyzed and summarized. The effects of priming and foliar treatment with abscisic acid, gibberellins, auxins, cytokinins, brassinosteroids, jasmonic and salicylic acids on the cultivated cereals tolerance to different abiotic stressors are discussed. Peculiarities of bilateral and multilateral hormonal signaling in the formation of responses of cultivated cereals to abiotic stressors after application of exogenous phytohormones are considered. The issue of exogenous phytohormones effects on molecular mechanisms controlling the synthesis of endogenous hormones, their signaling and activity are singled out. It is emphasized that phytohormonal engineering opens new opportunities to increase yields and is seen as an important promising approach to overcoming the cereal losses caused by adverse external factors.

Numerous fresh and saline-water tropical aquaculture ponds that often can be significant sources super-saturation of CO2 towards the atmosphere are gradually increasing throughout the world. The role of salinity in regulating the chlorophyll-a and dissolved pCO2 in a freshwater aquaculture pond, situated in East Kolkata Wetlands, Eastern India, was tested using a microcosm conducted during summer (April-May) and winter (December���January) months. The effects of enhanced salinity to microcosm sets of 5, 10 and 15 ppt were monitored for nine consecutive days. pH, dissolved oxygen (DO), pCO2(water), chlorophyll-a, and gross primary productivity (GPP) were measured in-situ and every day during the entire microcosm. Enhanced salinity was hypothesised to alter the pCO2(water) and chl-a dynamics of this system significantly. Increasing salinity to 5 ppt would enhance the photosynthetic potential of the existing primary producers and reduce the pCO2(water) significantly, thus boosting the CO2 sink strength. This enhanced CO2 sink strength, accompanied with increased GPP and DO, was also observed in 10 ppt, only during summer; however, low temperature was found to abate the photosynthetic response during winter. Finally, in 15 ppt treatments, drastic chlorophyll-a reduction and extreme CO2 super-saturation showed the existing phytoplankton community cannot cope with such high salinity.

Environmental context Atmospheric trace gases called volatile halocarbons (VHCs) significantly contribute to ozone depletion and global warming. The oceans are a primary source of VHCs, and concentrations and fluxes of selected VHCs in the Yellow Sea and East China Sea were measured. These data, and the influence of marine environmental factors on these parameters, provide information which will permit the assessment of the marine contribution of VHC behaviour and impact. Abstract Concentrations of five volatile halocarbons (VHCs), that is, chloroform (CHCl3), trichloroethylene (C2HCl3), tetrachloroethylene (C2Cl4), bromoform (CHBr3) and chlorodibromomethane (CHBr2Cl), were measured in the South Yellow Sea (SYS) and East China Sea (ECS) during autumn in 2011. The average (min–max) concentrations of CHCl3, C2HCl3, C2Cl4, CHBr2Cl and CHBr3 in surface seawater were 63.91 (24.63–361.23), 28.46 (1.82–85.77), 21.04 (9.85–89.31), 20.92 (7.98–59.89) and 75.91 (0.04–537.04) pmol L−1 respectively. The five VHCs exhibited a point distribution in autumn with clearly defined patterns in certain areas. In the vertical profiles, the highest concentrations of VHCs generally appeared in the upper mixing layer. Different VHCs were correlated with different environmental parameters, such as temperature, salinity, chlorophyll a (Chl-a), nutrient levels and bacteria. These results revealed that the sources of these VHCs were influenced by the Yangtze River effluent and Kuroshio waters as well as the biogenic release. Diurnal bimodal cycles were obvious in the concentrations of the five VHCs in the ECS. In general, concentrations peaked around noon, likely owing to biological production and photochemical mechanisms, and a secondary peak occurred around midnight, possibly resulting from a combination of respiration, zooplankton feeding and tidal action. The estimated sea-to-air fluxes showed that the study area was a net source of the five VHCs in the atmosphere during the study period.

The anthropogenic discharges of inorganic nutrients impact water quality, affecting the macroinvertebrate assemblage and food safety. The main objective of this study was to examine the seawater quality and macroinvertebrate dynamics in muddy habitats of Buenaventura Bay, Colombian Pacific. Macroinvertebrates were captured using artisanal trawl nets during different seasons and along four sampling sites. Multivariate analyses (canonical correspondence analysis and generalized additive model) were used to assess the effects of variations in nitrite, nitrates, phosphate concentrations, and physicochemical variables (salinity, pH, dissolved oxygen [DO], temperature, and total dissolved solids [TDS]) of water on the macroinvertebrate assemblage. Richness was the highest at sites with high salinity and temperature and low concentrations of nitrites and TDS. The densities of the commercial shrimp species Xiphopenaeus riveti and Rimapenaeus byrdi were the highest at sites with higher DO and alkalinity, and lower nitrate concentrations. The swimming crab Callinectes arcuatus was dominant at sites with low water quality. In summary, in the transitional season and at the inner sites of Buenaventura Bay, it was observed the lowest water quality due to high nitrate concentration. High nitrate concentration was highlighted as the main anthropogenic factor that could decrease the capture of target macroinvertebrate species for food and livelihoods of artisanal fishermen and their families. Thus, macroinvertebrate communities may be vulnerable to increased inorganic nutrient inputs, which could affect estuarine water quality and ecosystems services. Integr Environ Assess Manag 2022;18:796-812. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental ToxicologyChemistry (SETAC).