SUPPLEMENTAL DEXTROSE IN THE INFUSION FLUID DURING DIABETIC VITRECTOMY.

PURPOSE: Historically, supplemental dextrose to infusion fluid has been used to reduce the need for intraoperative lensectomies to maintain visualization during diabetic vitrectomy. Valved, small-gauge vitrectomy has reduced surgical time and decreased intraoperative fluid flow. Assessment of supplemental dextrose in modern vitrectomy is presented in this study. METHODS: A retrospective cohort study of diabetic patients undergoing vitrectomy was conducted. The dextrose group received supplemental dextrose in the infusion fluid, while the nondextrose group used a standard balanced salt solution (BSS Plus). Group assignment was per surgeons' typical practice patterns. Eyes with tractional retinal detachments were also evaluated as a subgroup. RESULTS: Three hundred thirty phakic eyes were included. Supplemental dextrose was used in 199 eyes (60.3%). One unplanned lensectomy was performed in this series, in the nondextrose group, not statistically different from the dextrose group, with zero lensectomies (P = 0.4). Cataract survival curves overlapped for all eyes and for the tractional retinal detachment subgroup. CONCLUSION: In modern vitrectomy, unplanned lensectomy is rare. No difference was observed in the rate of intraoperative lensectomies or overall postoperative cataract course with or without dextrose supplementation to the infusion fluid. Standard solutions appear to be adequate for infusion, even for diabetics.

Normal Saline Versus Hypertonic Saline for Airway STENT Maintenance: SALTY STENT Study.

BACKGROUND: Mucus plugging is a common complication of airway stenting. There is no data or guidance on the best airway hygiene regimen and consequently wide practice variation exists. METHODS: This single-center, nonblinded, randomized, pilot study aims to evaluate the effectiveness and safety of nebulized 3% saline (3%S) versus normal saline (NS) in reducing the incidence of mucus plugging in adult patients that undergo central airway stent placement. Patients were enrolled immediately after stent placement and randomized to nebulized 3%S or NS (3 mL) 3 times a day. Patients were scheduled for surveillance bronchoscopy in 4 to 6 weeks. Unscheduled bronchoscopies due to symptomatic mucus plugging were recorded. RESULTS: From December 2022 to March 2024, 37 patients were screened, and 35 were enrolled. Four in the 3%S and 8 in the NS group did not undergo a surveillance bronchoscopy and were excluded from the final analysis. During surveillance bronchoscopy for the 3%S (n=13) and NS (n=10) groups, obstructive mucus plugging was noted in 7.7% versus 40%, granulation requiring intervention in 7.7% versus 10%, and >25% circumferential biofilm in 0% versus 30%, respectively. In the 3%S versus NS groups, 0% versus 20% of patients required an unscheduled bronchoscopy due to mucus plugging. There were no side effects reported with the daily use of 3%S or NS. CONCLUSION: Nebulized 3%S is safe and may be equally or more effective than NS in preventing obstructive mucus plugging in patients who undergo airway stenting. A larger blinded randomized controlled trial is necessary to confirm this finding.

Effects of drinking saline water on carcass traits and meat quality of growing and mature Blackhead Ogaden sheep and Somali goats.

Water salinity has a significant impact on water quality, posing challenges for livestock production and productivity, particularly in arid regions where climate change affects freshwater availability. This study aimed to determine the effect of drinking saline water on the carcass and meat quality traits of sheep and goats in Ethiopia. A total of 100 males with an average initial body weight of growing (18.17 ± 0.51) and mature (22.22 ± 0.52 kg) Blackhead Ogaden sheep and growing (17.99 ± 0.50) and mature (21.99 ± 0.54) kg) Somali goats were used. The design of the experiment was a three-way factorial RCBD with three-factor combinations (5 treatment levels, 2 species, and 2 age groups).Water treatments were natural water (Lake Basaka water (control), low saline water (L-SW), moderate saline water (M-SW), high saline water (H-SW), and very high saline water (VH-SW); that is, NaCl was added to natural water at concentrations of 7.95, 11.93, 15.90, and 19.88 g TDS/L, respectively. The finding showed that increasing salinity levels in drinking water reduced slaughter body weight (SBW), carcass weight (CW), dressing percentage (DP), rib eye area (RAE), total edible components (TEC), and increased total non-edible components (TNEC) (P < 0.05). Similarly, sheep and mature animals had higher (P < 0.001) SBW, CW, DP, RAE, and TEC than goats and growing animals. Sensory evaluation, shear force, and proximate analysis were affected by water salinity, species, and age groups (P < 0.05). Overall, the study revealed that consuming saline water above 11 g TDS/L affected carcass traits and meat quality in Somali goats and Blackhead Ogaden sheep.

Efficacy of oral sodium chloride in reducing the incidence of hyponatremia in children with epilepsy receiving oxcarbazepine monotherapy: A randomized controlled trial (SCHO Trial).

INTRODUCTION: Hyponatremia is a well-documented adverse effect of oxcarbazepine treatment, but no clinical trial has yet been conducted to explore any intervention for reducing the incidence of hyponatremia. MATERIALS AND METHODS: This open-label trial evaluated the efficacy of add-on daily oral sodium chloride supplementation of 1-2 g/day for 12 weeks in reducing the incidence of hyponatremia in children receiving oxcarbazepine monotherapy aged 1-18 years. Apart from comparing the incidence of symptomatic and severe hyponatremia, serum and urine sodium levels, serum and urine osmolality, changes in behavior and cognition, and the number of participants with recurrence of seizures and requiring additional antiseizure medication (ASM) were also compared. RESULTS: A total of 120 children (60 in each group) were enrolled. The serum sodium level at 12 weeks in the intervention group was higher than that of the control group (136.5 ± 2.6 vs 135.4 ± 2.5 mEq/L, p = 0.01). The number of patients with hyponatremia was significantly lower in the intervention group (4/60vs14/60, p = 0.01). However, the incidence of symptomatic and severe hyponatremia (0/60vs1/60, p = 0.67 for both), changes in social quotient and child behavior checklist total score (0.6 ± 0.8 vs 0.7 ± 0.5, p = 0.41 and 0.9 ± 1.2 vs 1.1 ± 0.9, p = 0.30 respectively), the number of patients with breakthrough seizures (9/60vs10/60, p = 0.89), and the number of patients requiring additional ASMs (8/60vs10/60, p = 0.79) were comparable in both groups. CONCLUSIONS: Daily oral sodium chloride supplementation is safe and efficacious in reducing the incidence of hyponatremia in children with epilepsy receiving oxcarbazepine monotherapy. However, sodium chloride supplementation does not significantly reduce more clinically meaningful outcome measures like symptomatic and severe hyponatremia. Trial registry No. CTRI/2021/12/038388.

Effects of sodium chloride intake on urea-N recycling and renal urea-N kinetics in lactating Holstein cows.

The effects of high (2.5% of DM) versus normal dietary sodium chloride (NaCl) intake on renal urea-N kinetics and urea-N metabolism were investigated in 9 rumen-cannulated and multicatheterized lactating dairy cows in a crossover design with 21-d periods. It was hypothesized that urinary urea-N excretion would be greater, and BUN concentration lower in response to greater diuresis induced by high NaCl intake. Also, urea-N transport across ruminal and portal-drained viscera (PDV) tissues was hypothesized to be affected by dietary sodium intake. A second experiment was conducted using 8 lactating cows in a crossover design with 14-d periods to test high NaCl (2.5% of DM) versus high KCl (3.2% of DM) intake on milk yield and MUN concentrations. Experiment 1 showed that despite greater diuresis, high NaCl intake had no effect on urinary urea-N excretion or BUN concentration. The high NaCl intake did not affect rumen ammonia concentrations, total rumen VFA concentrations, ruminal venous - arterial concentration differences for ammonia, or ammonia absorption indicating that high NaCl did not adversely affect ruminal fermentation and microbial protein synthesis. High NaCl intake did not affect the total amount of urea-N transport from blood to gut, but ruminal venous - arterial concentration differences for urea-N were lower with high NaCl and ruminal extraction of arterial urea-N was numerically smaller, indicating that the ruminal epithelial urea-N transport was lower with high NaCl. Energy-corrected milk yield was greater with high NaCl (3.2 ± 1.5 kg/d); however, MUN concentrations were not affected by treatment. In experiment 2, ECM was greater with NaCl (1.4 ± 0.31 kg/d) compared with KCl (30.2 and 28.8 ± 0.91 kg ECM/d, respectively). Milk urea-N concentration was lower with KCl, suggesting a urea-N lowering effect in milk not evident with high NaCl intake. In conclusion, the present data show that dietary Na intake of 12 to 13 g/kg DM was followed by greater diuresis but did not affect urea-N excretion or BUN concentration. High NaCl intake did not affect the total amount of urea-N transfer across PDV tissues. Energy-corrected milk yield was greater with high NaCl compared with both control and feeding KCl; however, with KCl, MUN decreased.

Acute hypernatremia increases functional connectivity of NaCl sensing regions in the human brain: An fMRI pilot study.

Rodent studies demonstrated specialized sodium chloride (NaCl) sensing neurons in the circumventricular organs, which mediate changes in sympathetic nerve activity, arginine vasopressin, thirst, and blood pressure. However, the neural pathways involved in NaCl sensing in the human brain are incompletely understood. The purpose of this pilot study was to determine if acute hypernatremia alters the functional connectivity of NaCl-sensing regions of the brain in healthy young adults. Resting-state fMRI scans were acquired in 13 participants at baseline and during a 30 min hypertonic saline infusion (HSI). We used a seed-based approach to analyze the data, focusing on the subfornical organ (SFO) and the organum vasculosum of the lamina terminalis (OVLT) as regions of interest (ROIs). Blood chemistry and perceived thirst were assessed pre- and post-infusion. As expected, serum sodium increased from pre- to post-infusion in the HSI group. The primary finding of this pilot study was that the functional connectivity between the SFO and a cluster within the OVLT increased from baseline to the late-phase of the HSI. Bidirectional connectivity changes were found with cortical regions, with some regions showing increased connectivity with sodium-sensing regions while others showed decreased connectivity. Furthermore, the functional connectivity between the SFO and the posterior cingulate cortex (a control ROI) did not change from baseline to the late-phase of the HSI. This finding indicates a distinct response within the NaCl sensing network in the human brain specifically related to acute hypernatremia that will need to be replicated in large-scale studies.

AM-301, a barrier-forming nasal spray, versus saline spray in seasonal allergic rhinitis: A randomized clinical trial.

RATIONALE: Saline nasal sprays are frequently used in the management of seasonal allergic rhinitis (SAR) for the cleansing and clearing of aeroallergens from the nasal cavity. Also using a drug-free approach, AM-301 nasal spray is forming a thin film barrier on the nasal mucosa to prevent contact with allergens, trap them, and facilitate their discharge. A clinical trial compared the efficacy, safety, and tolerability of AM-301 and saline spray in SAR. METHODS: A total of 100 patients were randomized 1:1 to self-administer AM-301 or saline 3 × daily for 2 weeks. Primary efficacy endpoint: reduction in mean daily reflective Total Nasal Symptom Score (rTNSS). Secondary efficacy endpoints: reduction in mean instantaneous TNSS and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), global impression of efficacy. Safety and tolerability: adverse events, relief medication use, symptom-free days, global impression of tolerability. RESULTS: AM-301-treated patients achieved a significantly lower rTNSS than the saline group (LS square means difference -1.1, 95% CI -1.959 to -0.241, p = .013) with improvement observed across all individual nasal symptoms. Likewise, all secondary endpoints showed statistical significance in favor of AM-301; for example, quality of life was significantly improved overall (p < .001) as well as for each individual RQLQ domain. Both treatments showed similarly good safety and tolerability. With AM-301, fewer patients used relief medication and more enjoyed symptom-free days compared to saline treatment. CONCLUSIONS: AM-301 was more effective than saline in improving SAR nasal symptoms and related quality of life while offering similar tolerability, demonstrating the benefits of a barrier approach.

The effect of elevated muscle pain on neuromuscular fatigue during exercise.

PURPOSE: Muscle pain can impair exercise performance but the mechanisms for this are unknown. This study examined the effects of muscle pain on neuromuscular fatigue during an endurance task. METHODS: On separate visits, twelve participants completed an isometric time-to-task failure (TTF) exercise of the right knee extensors at ~ 20% of maximum force following an intramuscular injection of isotonic saline (CTRL) or hypertonic saline (HYP) into the vastus lateralis. Measures of neuromuscular fatigue were taken before, during and after the TTF using transcranial magnetic stimulation (TMS) and peripheral nerve stimulation. RESULTS: The mean pain intensity was 57 ± 10 in HYP compared to 38 ± 18 in CTRL (P < 0.001). TTF was reduced in HYP (4.36 ± 0.88 min) compared to CTRL (5.20 ± 0.39 min) (P = 0.003). Maximum voluntary force was 12% lower at minute 1 (P = 0.003) and 11% lower at minute 2 in HYP (P = 0.013) compared to CTRL. Voluntary activation was 4% lower at minute 1 in HYP compared to CTRL (P = 0.006) but not at any other time point (all P > 0.05). The TMS silent period was 9% longer at 100 s during the TTF in HYP compared to CTRL (P = 0.026). CONCLUSION: Muscle pain reduces exercise performance through the excacerbation of neuromuscular fatigue that is central in origin. This appears to be from inhibitory feedback from group III/IV nociceptors which acts to reduce central motor output.

Carbohydrate hastens hypervolemia achieved through ingestion of aqueous sodium solution in resting euhydrated humans.

PURPOSE: Ingesting beverages containing a high concentration of sodium under euhydrated conditions induces hypervolemia. Because carbohydrate can enhance interstitial fluid absorption via the sodium-glucose cotransporter and insulin-dependent renal sodium reabsorption, adding carbohydrate to high-sodium beverages may augment the hypervolemic response. METHODS: To test this hypothesis, we had nine healthy young males ingest 1087 ± 82 mL (16-17 mL per kg body weight) of water or aqueous solution containing 0.7% NaCl, 0.7% NaCl + 6% dextrin, 0.9% NaCl, or 0.9% NaCl + 6% dextrin under euhydrated conditions. Each drink was divided into six equal volumes and ingested at 10-min intervals. During each trial, participants remained resting for 150 min. Measurements were made at baseline and every 30 min thereafter. RESULTS: Plasma osmolality decreased with water ingestion (P ≤ 0.023), which increased urine volume such that there was no elevation in plasma volume from baseline (P ≥ 0.059). The reduction in plasma osmolality did not occur with ingestion of solution containing 0.7% or 0.9% NaCl (P ≥ 0.051). Consequently, urine volume was 176-288 mL smaller than after water ingestion and resulted in plasma volume expansion at 60 min and later times (P ≤ 0.042). In addition, net fluid balance was 211-329 mL greater than after water ingestion (P ≤ 0.028). Adding 6% dextrin to 0.7% or 0.9% NaCl solution resulted in plasma volume expansion within as little as 30 min (P ≤ 0.026), though the magnitudes of the increases in plasma volume were unaffected (P ≥ 0.148). CONCLUSION: Dextrin mediates an earlier hypervolemic response associated with ingestion of high-sodium solution in resting euhydrated young men. (247/250 words).

Barriers and Facilitators to Implementing Reduced-Sodium Salts as a Population-Level Intervention: A Qualitative Study.

Widespread use of reduced-sodium salts can potentially lower excessive population-level dietary sodium intake. This study aimed to identify key barriers and facilitators to implementing reduced-sodium salt as a population level intervention. Semi-structured interviews were conducted with key informants from academia, the salt manufacturing industry, and government. We used the reach, effectiveness, adoption, implementation, and maintenance (RE-AIM) framework to inform our interview guides and data analysis. Eighteen key informants from nine countries across five World Health Organization regions participated in the study from January 2020 to July 2020. Participants were concerned about the lack of robust evidence on safety for specific populations such as those with renal impairment. Taste and price compared to regular salt and an understanding of the potential health benefits of reduced-sodium salt were identified as critical factors influencing the adoption of reduced-sodium salts. Higher production costs, low profit return, and reduced market demand for reduced-sodium salts were key barriers for industry in implementation. Participants provided recommendations as potential strategies to enhance the uptake. There are presently substantial barriers to the widespread use of reduced-sodium salt but there are also clear opportunities to take actions that would increase uptake.

Serum Sodium Concentration and Mental Status in Children With Diabetic Ketoacidosis.

OBJECTIVES: Diabetic ketoacidosis (DKA) is typically characterized by low or low-normal serum sodium concentrations, which rise as hyperglycemia resolves. In retrospective studies, researchers found associations between declines in sodium concentrations during DKA and cerebral injury. We prospectively investigated determinants of sodium concentration changes and associations with mental status alterations during DKA. METHODS: Using data from the Pediatric Emergency Care Applied Research Network Fluid Therapies Under Investigation in Diabetic Ketoacidosis Trial, we compared children who had declines in glucose-corrected sodium concentrations with those who had rising or stable concentrations. Children were randomly assigned to 1 of 4 intravenous fluid protocols that differed in infusion rate and sodium content. Data from the first 4, 8, and 12 hours of treatment were analyzed for 1251, 1086, and 877 episodes, respectively. RESULTS: In multivariable analyses, declines in glucose-corrected sodium concentrations were associated with higher sodium and chloride concentrations at presentation and with previously diagnosed diabetes. Treatment with 0.45% (vs 0.9%) sodium chloride fluids was also associated with declines in sodium concentration; however, higher rates of fluid infusion were associated with declines in sodium concentration only at 12 hours. Frequencies of abnormal Glasgow Coma Scale scores and clinical diagnoses of cerebral injury were similar in patients with and without declines in glucose-corrected sodium concentrations. CONCLUSIONS: Changes in glucose-corrected sodium concentrations during DKA treatment are influenced by the balance of free-water loss versus sodium loss at presentation and the sodium content of intravenous fluids. Declines in glucose-corrected sodium concentrations are not associated with mental status changes during treatment.

Ibuprofen inhibits oral NaCl response through transmembrane channel-like 4.

Nonsteroidal anti-inflammatory drugs, such as ibuprofen, are known to modify salty taste perception in humans. However, the underlying molecular mechanisms remain unknown. We investigated the inhibitory effect of ibuprofen on the NaCl stimulation of epithelium sodium channel (ENaC) and transmembrane channel-like 4 (TMC4), which are involved in salty taste detection. Although ibuprofen only minimally inhibited the response of the ENaC to NaCl, it significantly inhibited the TMC4 response to NaCl with an IC50 at 1.45 mM. These results suggest that ibuprofen interferes with detection of salty taste via inhibition of TMC4.

Salt Reduction Initiatives in the Eastern Mediterranean Region and Evaluation of Progress towards the 2025 Global Target: A Systematic Review.

This study aims at identifying national salt reduction initiatives in countries of the Eastern Mediterranean Region and describing their progress towards the global salt reduction target. A systematic review of published and grey literature was conducted. Key characteristics of strategies were extracted and classified according to a pre-defined framework: salt intake assessments; leadership and strategic approach; implementation strategies; monitoring and evaluation of program impact. Salt intake levels were estimated in 15 out of the 22 countries (68%), while national salt reduction initiatives were identified in 13 (59%). The majority of countries were found to implement multifaceted reduction interventions, characterized by a combination of two or more implementation strategies. The least common implementation strategy was taxation, while the most common was reformulation (100%), followed by consumer education (77%), initiatives in specific settings (54%), and front of pack labelling (46%). Monitoring activities were conducted by few countries (27%), while impact evaluations were lacking. Despite the ongoing salt reduction efforts in several countries of the region, more action is needed to initiate reduction programs in countries that are lagging behind, and to ensure rigorous implementation and evaluations of ongoing programs. Such efforts are vital for the achievement of the targeted 30% reduction in salt intake.

Thromboxane A2 receptor antagonist (ONO-8809) attenuates renal disorders caused by salt overload in stroke-prone spontaneously hypertensive rats.

Epidemiological and clinical studies have demonstrated that excessive salt intake causes severe hypertension and exacerbates organ derangement, such as in chronic kidney disease (CKD). In this study, we focused on evaluating the histological and gene expression effects in the kidneys of stroke-prone spontaneously hypertensive rats (SHRSP) with a high salt intake and the thromboxane A2 / prostaglandin H2 receptor (TPR) blocker ONO-8809. Six-week-old SHRSPs were divided into three groups and were fed normal chow containing 0.4% NaCl, 2.0%NaCl or 2.0%NaCl + ONO-8809 (0.6 mg/kg p.o. daily). Histological analyses with immunohistochemistry and a gene expression assay with a DNA kidney microarray were performed after 8 weeks. The following changes were observed in SHRSPs with the high salt intake. Glomerular sclerotic changes were remarkably observed in the juxtamedullary cortex areas. The ED1, monocyte chemoattractant protein-1 (MCP-1), nitrotyrosine and hypoxia inducible factor 1α (HIF-1α) staining areas were increased in the glomeruli and interstitial portion of the kidneys. The genes Tbxa2r (that encodes TPR), Prcp and Car7 were significantly underexpressed in the kidneys. The plasma 8-isoprostane level was significantly elevated and was attenuated with the ONO-8809 treatment. Thromboxane A2 (TXA2 ) and oxidative stress exaggerated renal dysfunction in the salt-loaded SHRSPs, and ONO-8809 as a TPR blocker suppressed these changes. Therefore, ONO-8809 is a candidate drug to prevent CKD in hypertensive patients when CKD is associated with a high salt intake.

The effects of 0.9% saline versus Plasma-Lyte 148 on renal function as assessed by creatinine concentration in patients undergoing major surgery: A single-centre double-blinded cluster crossover trial.

OBJECTIVES: Saline and Plasma-Lyte have different physiochemical contents; consequently, they may differently affect patients' renal function. We compared the effects of fluid therapy with 0.9% saline and with Plasma-Lyte 148 on renal function as assessed by creatinine concentration among patients undergoing major surgery. METHODS: We conducted a prospective, double-blinded cluster crossover trial comparing the effects of the two fluids on major surgery patients. The primary aim was to establish the pilot feasibility, safety and preliminary efficacy evidence base for a large interventional trial to establish whether saline or Plasma-Lyte is the preferred crystalloid fluid for managing major surgery patients. The primary efficacy outcome was the proportion of patients with changes in renal function as assessed by creatinine concentration during their index hospital admission. We used changes in creatinine to define acute kidney injury (AKI) according to the RIFLE criteria. RESULTS: The study was feasible with 100% patient and clinician acceptance. There were no deviations from the trial protocol. After screening, we allocated 602 patients to saline and 458 to Plasma-Lyte. The median (IQR) volume of intraoperative fluid received was 2000 mL (1000:2000) in both groups. Forty-nine saline patients (8.1%) and 49 Plasma-Lyte patients (10.7%) developed a postoperative AKI (adjusted incidence rate ratio [aIRR]: 1.34; 95% CI: 0.93-1.95; p = 0.120). No differences were observed in the development of postoperative complications (aIRR: 0.98; 95% CI: 0.89-1.08) or the severity of the worst complication (aIRR: 1.00; 95% CI: 0.78-1.30). The median (IQR) length of hospital stay was six days (3:11) for the saline group and five days (3:10) for the Plasma-Lyte group (aIRR: 0.85; 95% CI: 0.73-0.98). There were no serious adverse events relating to the trial fluids, nor were there fluid crossover or contamination events. CONCLUSIONS: The study design was feasible to support a future follow-up larger clinical trial. Patients treated with saline did not demonstrate an increased incidence of postoperative AKI (defined as changes in creatinine) compared to those treated with Plasma-Lyte. Our findings imply that clinicians can reasonably use either solution intraoperatively for adult patients undergoing major surgery. TRIAL REGISTRATION: Registry: Australian New Zealand Clinical Trials Registry; ACTRN12613001042730; URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=364988.

Pathophysiology of Hypertension: The Mosaic Theory and Beyond.

Dr Irvine Page proposed the Mosaic Theory of Hypertension in the 1940s advocating that hypertension is the result of many factors that interact to raise blood pressure and cause end-organ damage. Over the years, Dr Page modified his paradigm, and new concepts regarding oxidative stress, inflammation, genetics, sodium homeostasis, and the microbiome have arisen that allow further refinements of the Mosaic Theory. A constant feature of this approach to understanding hypertension is that the various nodes are interdependent and that these almost certainly vary between experimental models and between individuals with hypertension. This review discusses these new concepts and provides an introduction to other reviews in this compendium of Circulation Research.

Potato NAC Transcription Factor StNAC053 Enhances Salt and Drought Tolerance in Transgenic Arabidopsis.

The NAC (NAM, ATAF1/2, and CUC2) transcription factors comprise one of the largest transcription factor families in plants and play important roles in stress responses. However, little is known about the functions of potato NAC family members. Here we report the cloning of a potato NAC transcription factor gene StNAC053, which was significantly upregulated after salt, drought, and abscisic acid treatments. Furthermore, the StNAC053-GFP fusion protein was found to be located in the nucleus and had a C-terminal transactivation domain, implying that StNAC053 may function as a transcriptional activator in potato. Notably, Arabidopsis plants overexpressing StNAC053 displayed lower seed germination rates compared to wild-type under exogenous ABA treatment. In addition, the StNAC053 overexpression Arabidopsis lines displayed significantly increased tolerance to salt and drought stress treatments. Moreover, the StNAC053-OE lines were found to have higher activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) under multiple stress treatments. Interestingly, the expression levels of several stress-related genes including COR15A,DREB1A, ERD11, RAB18, ERF5, and KAT2, were significantly upregulated in these StNAC053-overexpressing lines. Taken together, overexpression of the stress-inducible StNAC053 gene could enhance the tolerances to both salt and drought stress treatments in Arabidopsis, likely by upregulating stress-related genes.

Thermal Analysis of Stomatal Response under Salinity and High Light.

A non-destructive thermal imaging method was used to study the stomatal response of salt-treated Arabidopsis thaliana plants to excessive light. The plants were exposed to different levels of salt concentrations (0, 75, 150, and 220 mM NaCl). Time-dependent thermograms showed the changes in the temperature distribution over the lamina and provided new insights into the acute light-induced temporary response of Arabidopsis under short-term salinity. The initial response of plants, which was associated with stomatal aperture, revealed an exponential growth in temperature kinetics. Using a single-exponential function, we estimated the time constants of thermal courses of plants exposed to acute high light. The saline-induced impairment in stomatal movement caused the reduced stomatal conductance and transpiration rate. Limited transpiration of NaCl-treated plants resulted in an increased rosette temperature and decreased thermal time constants as compared to the controls. The net CO2 assimilation rate decreased for plants exposed to 220 mM NaCl; in the case of 75 mM NaCl treatment, an increase was observed. A significant decline in the maximal quantum yield of photosystem II under excessive light was noticeable for the control and NaCl-treated plants. This study provides evidence that thermal imaging as a highly sensitive technique may be useful for analyzing the stomatal aperture and movement under dynamic environmental conditions.