Long-term Salt Research Articles

Dietary Sodium Intake and Risk of Incident Type 2 Diabetes

ObjectiveTo fill the knowledge gap of the relation between long-term dietary sodium intake and type 2 diabetes (T2D), we evaluate the association between the frequency of adding salt to foods, a surrogate marker for evaluating the long-term sodium intake, and incident T2D risk. MethodsA total of 402,982 participants from UK Biobank (March 13, 2006 – October 10, 2010) who were free of diabetes, chronic kidney disease, cancer, or cardiovascular disease at baseline, and had completed information on adding salt were analyzed in this study. ResultsDuring a median of 11.9 years of follow-up, 13,120 incident cases of T2D were documented. Compared with participants who “never/rarely” added salt to foods, the adjusted HRs were 1.11 (95% CI, 1.06 to 1.15), 1.18 (95% CI, 1.12 to 1.24), and 1.28 (95% CI, 1.20 to 1.37) across the groups of “sometimes,” “usually,” and “always,” respectively (P-trend<.001). We did not find significant interactions between the frequency of adding salt to foods and baseline hypertension status and other covariates on the risk of incident T2D. The observed positive association was partly mediated by body mass index, waist to hip ratio, and C-reactive protein, with a significant mediation effect of 33.8%, 39.9%, and 8.6%, respectively. The significant mediation effect of body mass index was largely driven by the body fat mass rather than the body fat-free mass. ConclusionOur findings for the first time indicate that higher frequency of adding salt to foods, a surrogate marker for a person’s long-term salt taste preference and intake, is associated with a higher T2D risk.

PHT1;5 Repressed by ANT Mediates Pi Acquisition andDistribution under Low Pi andSalinity inSalt Cress.

Salinity and phosphate (Pi) starvation are the most common abiotic stresses that threaten crop productivity. Salt cress (Eutrema salsugineum) displays good tolerance to both salinity and Pi limitation. Previously, we found several Phosphate Transporter (PHT) genes in salt cress upregulated under salinity. Here, EsPHT1;5 induced by both low Pi (LP) and salinity was further characterized. Overexpression of EsPHT1;5 in salt cress enhanced plant tolerance to LP and salinity, while the knock-down lines exhibited growth retardation. The analysis of phosphorus (P) content and shoot/root ratio of total P in EsPHT1;5-overexpressing salt cress seedlings and the knock-down lines as well as arsenate uptake assays suggested the role of EsPHT1;5 in Pi acquisition and root-shoot translocation under Pi limitation. In addition, overexpression of EsPHT1;5 driven by the native promoter in salt cress enhanced Pi mobilization from rosettes to siliques upon a long-term salt treatment. Particularly, the promoter of EsPHT1;5 outperformed that of AtPHT1;5 in driving gene expression under salinity. We further identified a transcription factor EsANT, which negatively regulated EsPHT1;5 expression and plant tolerance to LP and salinity. Taken together, EsPHT1;5 plays an integral role in Pi acquisition and distribution in plant response to LP and salt stress. Further, EsANT may be involved in the cross-talk between Pi starvation and salinity signaling pathways. This work provides further insight into the mechanism underlying high P use efficiency in salt cress in its natural habitat, and evidence for a link between Pi and salt signaling.

Expression of the plastocyanin gene PETE2 in Camelina sativa improves seed yield and salt tolerance

Plastocyanin functions as an electron carrier in the photosynthetic electron transport chain, located at the thylakoid membrane. In several species, endogenous plastocyanin levels are correlated with the photosynthetic electron transport rate. Overexpression of plastocyanin genes in Arabidopsis thaliana increases plant size, but this phenomenon has not been observed in crop species. Here, we investigated the effects of heterologous expression of a gene encoding a plastocyanin isoform from Arabidopsis, AtPETE2, in the oil seed crop Camelina sativa under standard growth conditions and under salt stress. AtPETE2 heterologous expression enhanced photosynthetic activity in Camelina, accelerating plant development and improving seed yield under standard growth conditions. Additionally, CsPETE2 from Camelina was induced by salt stress and AtPETE2 expression lines had larger primary roots and more lateral roots than the wild type. AtPETE2 expression lines also had larger seeds and higher total seed yield under long-term salt stress compared with non-transgenic Camelina. Our results demonstrate that increased plastocyanin levels in Camelina can enhance photosynthesis and productivity, as well as tolerance to osmotic and salt stresses. Heterologous expression of plastocyanin may be a useful strategy to mitigate crop stress in saline soils.

Long-term salt spray corrosion behaviors of HVOF-sprayed WC-Cr3C2-Ni coatings before and after vacuum sealing with silicone resin

The application of thermal sprayed WC based cermet coatings is restricted by their structure defects including pores and cracks during thermal spraying. This article fabricated a corrosion-resistant WC-Cr3C2-Ni coating by high velocity oxy-fuel (HVOF) spraying and vacuum sealing with silicone resin. Experiment outcomes show that silicone resin fills into the defects of the WC-Cr3C2-Ni coating. Benefiting from the block of silicone resin in pores and cracks, the sealed coating shows less corrosion pits than the unsealed coating after long-term salt spray corrosion. The sealed coating shows surface without grooves, corrosion pits with smaller size and cracks with decreased amount in comparison with the as-sprayed coating. The vacuum sealing with silicone resin is a strategy with high potential for expanding the application range of thermal sprayed coatings.

1379-P: Adding Salt to Foods and Risk of Severe Nonalcoholic Fatty Liver

Background: High sodium intake is associated with insulin resistance, obesity, and metabolic syndrome, whereas very few studies have assessed the association of sodium intake with risk of nonalcoholic fatty liver disease (NAFLD). We recently found that the frequency of adding salt to foods could reflect a person’s long-term salt taste preference and sodium intake and was significantly related to life expectancy and cardiovascular disease risk. In this study, we aimed to evaluate the association between the frequency of adding salt to foods and liver proton density fat fraction (PDFF, a magnetic resonance imaging-based measure to assess liver fat content) and severe NAFLD risk. Methods: A total of 494,240 participants from UK biobank, who were free of NAFLD at baseline (2006-2010) were analyzed in this study. Of the above participants, 9816 participants have MRI-PDFF data, measured in 2014. Generalized linear models were used to evaluated association between the frequency of adding salt to foods with liver-PDFF; Cox proportional hazards models were used to estimate the association between the frequency of adding salt to foods and severe NAFLD risk. Results: During a median of 11 years of follow-up, 5,294 severe NAFLD cases were documented. Compared with participants who Never/Rarely added salt to foods, the adjusted Hazard Ratios (95% confidence interval) were 1.11 (1.04, 1.18), 1.27 (1.17, 1.37), and 1.45 (1.30, 1.62) across the groups of Sometimes, Usually, and Always, respectively (P-trend&amp;lt;0.001). The liver-PDFF values were 4.7 % (95% CI, 3.9, 5.5), 5.1% (4.3, 5.9), 5.2% (4.4, 6.0) and 5.5% (4.5-6.4) in the groups of Never/Rarely, Sometimes, Usually, and Always added salt to foods, respectively (P-trend&amp;lt;0.001). In sensitivity analyses, we replaced the frequency of adding salt to foods with estimated 24-hour urinary sodium extraction and found similar significant associations. Conclusions: Our findings indicate that high sodium intake is associated with higher risk of severe NAFLD. Disclosure H. Ma: None. X. Wang: None. X. Li: None. Y. Heianza: None. L. Qi: None.

1376-P: Dietary Sodium Intake and Risk of Incident Type 2 Diabetes

Background: Type 2 Diabetes (T2D) and hypertension often coexist and share many common risk factors. High dietary sodium intake is a well-established risk factor for hypertension, whereas few studies have assessed the relation between dietary sodium intake and type 2 diabetes (T2D). In this study, we aimed to evaluate the association between the frequency of adding salt to foods, a surrogate marker for evaluating the long-term sodium intake, and incident T2D risk. Methods: A total of 402,982 participants from UK biobank, who were free of diabetes, chronic kidney disease, cancer, or cardiovascular disease at baseline, and had completed information on adding salt were analyzed in this study. Cox proportional hazards models were used to estimate the association between the frequency of adding salt to foods and incident T2D. Results: During a median of 11.8 years of follow-up, 13,120 incident T2D were documented. Compared with participants who Never/Rarely added salt to foods, the adjusted Hazard Ratios (95% confidence interval) were 1.13 (1.08, 1.17), 1.20 (1.14, 1.26), and 1.39 (1.30, 1.49) across the groups of Sometimes, Usually, and Always, respectively (P-trend&amp;lt;0.001). We did not find significant interactions between the frequency of adding salt to foods and baseline hypertension status and other covariates on the risk of incident T2D. The observed positive association was partly mediated by body mass index (BMI), waist to hip ratio, and C-reactive protein, with a significant mediation effect of 32.9%, 36.6% and 7.0%, respectively. The significant mediation effect of BMI was largely driven by the body fat mass rather than the body fat-free mass. Conclusions: Our findings for the first time indicate that higher frequency of adding salt to foods, a surrogate marker for a person’s long-term salt taste preference and intake, is associated with a higher T2D risk. Disclosure X.Wang: None. H.Ma: None. R.Tang: None. Q.Xue: None. X.Li: None. Y.Heianza: None. L.Qi: None.

3D-printed tripodal porous wood-mimetic cellulosic composite evaporator for salt-free water desalination

Solar desalination based on interfacial evaporation has been proven promising in producing clean water. However, so far, the lack of a facile preparation strategy and effective salt rejection has profoundly limited its potential for practical applications. Herein, inspired by the unique liquid transportation of natural wood, we report on a three-dimensional (3D) printed tripodal porous wood-mimetic cellulosic composite evaporator for long-term salt rejection, starting from cost-effective materials such as cellulose and carbon black. The printed evaporator displays a broadband solar absorption (>97%) and an extremely low thermal conductivity (0.075 W m−1 K−1), indicating its high photothermal conversion efficiency and outstanding thermal management. The printed tripodal porous evaporator contains large-sized channels (∼1 mm in diameter) that function as salt regenerating pathways, micropores (∼30 μm) and submicron pores (∼1 μm) for rapid water transport and efficient supply. Fluidic simulation reveals that large channels with high water flux lead to the salt concentration gradient between large and small channels via submicropores, meanwhile, the concentrated water at the top layer transports downward by diffusion and convection, further making the spontaneous horizontal and vertical salt exchange. Such a tripodal porous structure endows the evaporator with a high efficiency of ∼75% in a highly concentrated salt solution (15 wt% NaCl) under 1 sun irradiation, as well as superior salt-rejection property (100 h continuous evaporation in 15 wt% NaCl). This strategy, starting with sustainable cellulose-based composite materials and being able to balance the evaporation performance and long-term stability, opens up new doors toward clean water production.

Water Skin Effect and Arched Double‐Sided Evaporation for Boosting All‐Weather High Salinity Desalination (Adv. Energy Mater. 21/2023)

Solar-Driven Desalination In article number 2300134, Chengbing Wang, Dan Wei, and co-workers propose a synergistic strategy of water skin effect and double-sided evaporation for boosting all-weather high salinity desalination. An all-in-one arched double-sided evaporator with long-term salt rejection, and water-electricity generation is constructed. The synergistic strategy effectively enhances solar desalination performance.

The effects of cinnamon, ginger and sesame oils on in-situ solvothermal reduction of multi-layered graphene oxide in epoxy to improve hydrophobicity and corrosion resistance

An effective and green method including in-situ solvothermal reduction of multi-layered graphene oxide (MLGO) using a mixture of acetonitrile and sesame, ginger and cinnamon oils, was investigated for preparing a hydrophobic and corrosion-resistant epoxy coating. The efficiencies of the oils as green reducing agents with synergistic effect by acetonitrile in the solvothermal reduction of MLGO at a temperature of 70 °C were compared with each other. FT-IR, TGA, Raman, and Mapping-EDAX analysis showed that the solvothermal reduction process of MLGO in acetonitrile/cinnamon oil mixture was successfully performed. The results of long-term salt spray and electrochemical impedance tests showed that epoxy-RMLGO (acetonitrile/cinnamon oil) nano-coating had a significant improvement in corrosion resistance (after10 months, the impedance value was 8.1 × 108 Ω cm2) compared with the other coatings. Also, the value of the water contact angle for the nano-coating was 102.80° and based on Mapping-EDAX analysis, the C/O ratio was 54.45.

Abrasion-resistant superhydrophilic objects with anisotropic water transport capacities prepared by a selective laser sintering 3D printing strategy

Liquid directional manipulation has been widely used in the fields of microfluidic, microreactor, liquid separation and collection, sewage treatment. Most studies based on the construction of gradient structures on the substrate surface realized liquid directional transportation, but their fragile surfaces are vulnerable to external forces and can only transport thin water film according to the array thickness. Here, we report that abrasion-resistant superhydrophilic objects with anisotropic water transport capacities can be one-step constructed by selective laser sintering (SLS) the composites of hydrophilic glass beads (GBs) and thermoplastic phenol–formaldehyde resin (PF) grains. The long interlayer micro-slits between the adjacent printing layers cooperated with the inserted hydrophilic GBs formed long capillary channels, resulting in anisotropic water transport abilities on different printing surfaces. In addition, the abrasion-resistant ability endowed superhydrophilic mechanical stability. Furthermore, water could climb about ∼26 cm along the horizontal printed sample, showing excellent anti-gravity water transport ability. Finally, we demonstrated that the printed evaporators with diverse salt-resistant structures not only maintain long-term salt resistance, but also possess high evaporation efficiency. The superhydrophilic materials proposed in this study will lead the design and preparation of liquid directional transport materials and provide advanced inspiration for 3D printing functional materials.

The role of cyanoalanine synthase and alternative oxidase in promoting salt stress tolerance in Arabidopsis thaliana

BackgroundCyanide is a toxic chemical that inhibits cellular respiration. In plants, cyanide can be produced by themselves, especially under stressful conditions. Cyanoalanine synthase (CAS) is a key enzyme involved in plant cyanide detoxification. There are three genes encoding CAS in Arabidopsis thaliana, but the roles of these genes in the plant’s response to stress are less studied. In addition, it is known that alternative oxidase (AOX) mediates cyanide-resistant respiration, but the relationship between CAS and AOX in regulating the plant stress response remains largely unknown.ResultsHere, the effects of the overexpression or mutation of these three CAS genes on salt stress tolerance were investigated. The results showed that under normal conditions, the overexpression or mutation of the CAS genes had no significant effect on the seed germination and growth of Arabidopsis thaliana compared with wild type (WT). However, under 50, 100, and 200 mM NaCl conditions, the seeds overexpressing CAS genes showed stronger salt stress resistance, i.e., higher germination speed than WT seeds, especially those that overexpressed the CYS-C1 and CYS-D1 genes. In contrast, the seeds with CAS gene mutations exhibited salt sensitivity, and their germination ability and growth were significantly damaged by 100 and 200 mM NaCl. Importantly, this difference in salt stress resistance became more pronounced in CAS-OE, WT, and mutant seeds with increasing salt concentration. The CAS-OE seeds maintained higher respiration rates than the WT and CAS mutant seeds under salt stress conditions. The cyanide contents in CAS mutant seeds were approximately 3 times higher than those in WT seeds and more than 5 times higher than those in CAS-OE seeds. In comparison, plants overexpressing CYS-C1 had the fastest detoxification of cyanide and the best salt tolerance, followed by those overexpressing CYS-D1 and CYS-D2. Furthermore, less hydrogen sulfide (H2S) was observed in CAS-OE seedlings than in WT seedlings under long-term salt stress conditions. Nonetheless, the lack of AOX impaired CAS-OE-mediated plant salt stress resistance, suggesting that CAS and AOX interact to improve salt tolerance is essential. The results also showed that CAS and AOX contributed to the reduction in oxidative damage by helping maintain relatively high levels of antioxidant enzyme activity.ConclusionIn summary, the findings of the present study suggest that overexpression of Arabidopsis CAS family genes plays a positive role in salt stress tolerance and highlights the contribution of AOX to CAS-mediated plant salt resistance, mainly by reducing cyanide and H2S toxicity.

Does Potassium Modify the Response of Zinnia (Zinnia elegans Jacq.) to Long-Term Salinity?

Salinity is one of the major abiotic stress factors hindering crop production, including ornamental flowering plants. The present study examined the response to salt stress of Zinnia elegans 'Lilliput' supplemented with basic (150 mg·dm-3) and enhanced (300 mg·dm-3) potassium doses. Stress was imposed by adding 0.96 and 1.98 g of NaCl per dm-3 of the substrate. The substrate's electrical conductivity was 1.1 and 2.3 dS·m-1 for lower potassium levels and 1.2 and 2.4 dS·m-1 for higher potassium levels. Salt stress caused a significant and dose-dependent reduction in leaf RWC, increased foliar Na and Cl concentrations, and reduced K. About 15% and 25% of cell membrane injury at lower and higher NaCl doses, respectively, were accompanied by only slight chlorophyll reduction. Salt stress-induced proline increase was accompanied by increased P5CS activity and decreased PDH activity. More than a 25% reduction in most growth parameters at EC 1.1-1.2 dS·m-1 but only a slight decrease in chlorophyll and a 25% reduction in the decorative value (number of flowers produced, flower diameter) only at EC 2.3-2.4 dS·m-1 were found. Salt stress-induced leaf area reduction was accompanied by increased cell wall lignification. An enhanced potassium dose caused a reduction in leaf Na and Cl concentrations and a slight increase in K. It was also effective in membrane injury reduction and proline accumulation. Increasing the dose of potassium did not improve growth and flowering parameters but affected the lignification of the leaf cell walls, which may have resulted in growth retardation. Zinnia elegans 'Lilliput' may be considered sensitive to long-term salt stress.

Insights into Adaptive Regulation of the Leaf-Petiole System: Strategies for Survival of Water Lily Plants under Salt Stress.

The water lily (Nymphaea tetragona) is an ancient angiosperm that belongs to the Nymphaeaceae family. As a rooted floating-leaf plant, water lilies are generally cultivated in fresh water, therefore, little is known about their survival strategies under salt stress. Long-term salt stress causes morphological changes, such as the rapid regeneration of floating leaves and a significant decrease in leaf number and surface area. We demonstrate that salt stress induces toxicity soon after treatment, but plants can adapt by regenerating floating leaves that are photosynthetically active. Transcriptome profiling revealed that ion binding was one of the most-enriched GO terms in leaf-petiole systems under salt stress. Sodium-transporter-related genes were downregulated, whereas K+ transporter genes were both up- and downregulated. These results suggest that restricting intracellular Na+ importing while maintaining balanced K+ homeostasis is an adaptive strategy for tolerating long-term salt stress. ICP-MS analysis identified the petioles and leaves as Na-hyperaccumulators, with a maximum content of over 80 g kg-1 DW under salt stress. Mapping of the Na-hyperaccumulation trait onto the phylogenetic relationships revealed that water lily plants might have a long evolutionary history from ancient marine plants, or may have undergone historical ecological events from salt to fresh water. Ammonium transporter genes involved in nitrogen metabolism were downregulated, whereas NO3--related transporters were upregulated in both the leaves and petioles, suggesting a selective bias toward NO3- uptake under salt stress. The morphological changes we observed may be due to the reduced expression of genes related to auxin signal transduction. In conclusion, the floating leaves and submerged petioles of the water lily use a series of adaptive strategies to survive salt stress. These include the absorption and transport of ions and nutrients from the surrounding environments, and the ability to hyperaccumulate Na+. These adaptations may serve as the physiological basis for salt tolerance in water lily plants.

Nitrogen removal from high-saline municipal wastewater via anammox-based process driven by both nitritation and denitratation

Nitrogen removal from saline municipal wastewater has recently attracted attention; thus, developing energy-efficient technology such as anaerobic ammonium oxidation (anammox) for advanced nitrogen removal of hypersaline wastewater is significant. In this study, the long-term salt adaptation and evolution mechanisms of an anammox-based process driven by both nitritation (NH4+→NO2—, PN) and denitratation (NO3—→NO2—, PD) were investigated under salinities ranging from 1.0% to 3.0% (10–30 g NaCl/L). At 1.0% salinity, PN evolved into the major nitrite production pathway with thorough suppression of nitrite oxidation. At 1.5% salinity, nitrite reduction was inhibited along with suspended sludge loss due to poor sludge settleability. Under 2.0% salinity with only-biofilm, the highest nitrogen removal efficiency (81.2%) was observed with influent and effluent total inorganic nitrogen concentrations of 44.5 and 8.2 mg N/L, respectively. Notably, results showed that anammox bacteria occupied up to 1.07% of the microbial community (qPCR: 1.14×1011 copies/(g dry sludge)) and has strong adaptability to salinity. With salinity increases, anammox contribution kept over 85% and Ca. Kuenenia (0.57%→0.22%) was more tolerant than Ca. Brocadia (0.46%→0.02%). Metagenomic sequencing revealed that the multiple nitrite substrates production by Nitrosomonas (amoA-enriched), Denitratisoma and Denitromonas (narG-enriched) guaranteed the high anammox contribution. This study provides a multifaceted understanding of the anammox-based process, which can enable improved application in real saline wastewater treatment.

Abstract P423: Adding Salt to Foods is Associated With the Risk of Incident Chronic Kidney Diseases

Introduction: We recently found the frequency of adding salt to foods could reflect a person’s long-term salt taste preference and intake and was related to the risk of cardiovascular diseases. Whether adding salt to foods is related to chronic kidney disease (CKD) remains unknown. Hypothesis: We assessed the hypothesis that the frequency of adding salt to foods was associated with incident CKD risk in a general population of adults. Methods: A total of 465,288 participants initially free of CKD at baseline from the UK Biobank cohort with completed information on adding salt were analyzed in this study. Incident CKD cases were identified by ICD-10 codes and OPCS-4 codes. Cox proportional hazard models were used to estimate the association between the frequency of adding salt to foods and incident CKD. Results: During a median follow-up of 11.8 years, we documented 22,031 incident events of CKD. A higher frequency of adding salt to foods was significantly related to a higher CKD risk after adjustment for sex, age, race, body mass index (BMI), Townsend deprivation index, smoking, drinking, regular physical activity, high cholesterol, cardiovascular diseases (CVD), diabetes at baseline. Compared with the “never/rarely” group, the adjusted HRs (95% CI) of “sometimes”, “usually”, and “always” groups were 1.03 (0.99, 1.07), 1.07 (1.02, 1.11), 1.12 (1.06, 1.19), respectively ( P -trend&lt;0.001). In addition, we found that estimated glomerular filtration rate (eGFR), BMI and physical activity significantly modified the associations, which were more pronounced in participants with higher level of eGFR, and lower level of BMI or physical activity (P-interaction=0.003, 0.004 and 0.02, respectively). Conclusion: Our findings for the first time indicate that a higher frequency of adding salt to foods is associated with a higher CKD risk in the general population.

Silicon Increased Sodium Transporter Gene Expressions in Apple Under Short- and Long-Term Salt Stress

Silicon Increased Sodium Transporter Gene Expressions in Apple Under Short- and Long-Term Salt Stress

In planta evidence that the HAK transporter OsHAK2 is involved in Na+ transport in rice.

HAK family transporters primarily function as K+ transporters and play major roles in K+ uptake and translocation in plants, whereas several HAK transporters exhibit Na+ transport activity. OsHAK2, a rice HAK transporter, was shown to mediate Na+ transport in Escherichia coli in a previous study. In this study, we investigated whether OsHAK2 is involved in Na+ transport in the rice plant. Overexpression of OsHAK2 increased Na+ translocation from the roots to the shoots of transgenic rice. It also increased both root and whole-plant Na+ content, and enhanced shoot length under low Na+ and K+ conditions. Meanwhile, OsHAK2 overexpression increased salt sensitivity under a long-term salt stress condition, indicating that OsHAK2 is not involved in salt tolerance, unlike in the case of ZmHAK4 in maize. These results suggest that OsHAK2 is permeable to Na+ and contributes to shoot growth in rice plants under low Na+ and K+ conditions.

Morpho-Physiological and Transcriptional Regulation of Root System under Saline Conditions in Nymphaea Plants

Water lilies (Nymphaea L.) are ancient angiosperms that can be cultivated in both fresh and brackish water. Water lily plants have adapted morphologically and physiologically to the aqueous environment. Nonetheless, little is known about the regulatory mechanisms that enable water lily to acclimate to saline conditions, restricting its production and distribution. To illustrate the role of roots in water lily salinity tolerance, we investigated the adaptive regulation of the water lily root system under high salinity. Aspects of its root architecture, including root length, surface area, volume, and tip number, were significantly reduced by salt stress. Transcriptome sequencing showed that 120 genes were upregulated and 1214 genes were downregulated under salt stress. The differentially expressed genes were mainly enriched in oxidoreductase activity, structural molecule activity, and transmembrane transporter activity. Most ion transporter genes were downregulated, suggesting that water lily may partially close ion channels and/or transporters to avoid excessive ion accumulation or ion imbalance under long-term salt stress. Genes related to NO3− transport were both up- and downregulated, whereas genes related to ammonium transport were uniformly downregulated, suggesting that transcriptional changes may play a role in balancing nitrogen metabolism under long-term saline conditions. The roots showed relatively high concentrations of Na+ and had the ability to hyper-accumulate Na+ under salt stress. These findings provide insight into the regulatory mechanisms that enable water lily roots to tolerate salinity and lay a foundation for the breeding of salt-tolerant cultivars.

A wood-inspired bimodal solar-driven evaporator for highly efficient and durable purification of high-salinity wastewater

The designed WBE breaks the trade-off between water evaporation and salt resistance, achieving ultrahigh water evaporation capacity (3.02 kg m−2h−1) and long-term salt resistance (continuous 100 h in 20 wt% brine) under 1 sun irradiation.

PS-B08-11: SALT DIRECTLY REGULATES UMOD TRAFFICKING IN A NORMOTENSIVE BACKGROUND

Objective: Uromodulin (UMOD) is the most abundant protein secreted into urine of healthy individuals and is primarily produced by the renal thick ascending limb cells (TAL) of the loop of Henle. Genetic studies have demonstrated an association between UMOD risk variants, kidney diseases, and hypertension. We have previously demonstrated that salt induces a reduction in urinary UMOD excretion in normotensive rats after three weeks, which was exacerbated in a chronic hypertensive rat model. Our next objective was to determine the influence of salt on UMOD secretion independent of blood pressure effects. Here we investigate the underlying molecular differences in the effects of intermittent and chronic salt-loading on UMOD trafficking dynamics in the TAL. Design and Methods: Wistar-Kyoto (WKY) normotensive rats were maintained on 1% NaCl for three weeks in an intermittent pattern (one week on, one week off, one week on) or continuously (chronic) over three months. Urine was collected over a 24-hour period every experimental week. Total kidneys were harvested for lysate extraction, subcellular fractionation, and immunofluorescence analyses. UMOD levels were measured using ELISAs, qPCR, and Western blotting. Results: No abnormal changes in blood pressure, body weight, or renal parameters including albumin-creatinine-ratio and injury markers KIM-1 and NGAL were observed in either animal study group. During intermittent salt-loading, there was no significant difference in UMOD mRNA expression or total kidney UMOD protein levels. However, UMOD excretion significantly decreased after one week and remained lower than control levels even after salt removal. Similarly, chronic salt-loading did not alter UMOD mRNA levels, however total kidney UMOD protein levels were increased after three months. More specifically, analysis of subcellular fractions of the medulla from these salt-loaded animals showed higher levels of cytosolic UMOD compared to membrane-bound UMOD. Immunofluorescence analyses revealed a trend towards increased localisation of UMOD with endoplasmic reticulum (ER) marker calnexin. Conclusions: Our findings underline the effect of salt in molecular trafficking of UMOD in the kidney independent of blood pressure effects. Long-term salt exposure of TAL cells leads to intracellular accumulation of this abundant renal protein. The relationship between salt, UMOD accumulation, and renal end-organ damage in hypertension requires further research.