Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “salinity tolerance”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources
PubMed1991

Reproducibility of osmotic and nonosmotic tests of vasopressin secretion in men.

We have studied the reproducibility of the thirst and arginine vasopressin (AVP) responses to osmotic and hypoglycemic stimulation in healthy volunteers undergoing repeat hypertonic (855 mmol/l) saline infusion and insulin tolerance tests (ITTs). Hypertonic saline infusion caused similar mean rises in plasma osmolality, AVP, and thirst on each occasion. Linear-regression analysis defined close relationships between the slopes (r = +0.72, P less than 0.05) and the abscissal intercepts (r = +0.89, P less than 0.001) of the regression lines relating plasma osmolality (Posmol) and plasma AVP (PAVP), and the group intraindividual component of the variance for the slopes and intercepts was 7 and 0.6%, respectively. There were close correlations between the slopes (r = +0.79, P less than 0.02) and the intercepts (r = +0.84, P less than 0.01) of the regression lines relating Posmol and thirst, and group intraindividual component of the variance was 14 and 0.7%, respectively. Hypertonic saline infusion was infused on four occasions in four subjects, and the results showed that the linear regression lines relating PAVP and Posmol and thirst and Posmol were reproducible within an individual. There were similar falls in blood glucose and elevations in PAVP in both ITTs. No relationship was defined between the fall in blood glucose and either the rise in PAVP or the area under the AVP curve (AUC). The intraindividual component of the variance for the rise in AVP and the AUC was 77 and 22.5%, respectively. The AVP and thirst responses to osmotic stimulation are highly reproducible, but there is considerable intraindividual variation in the AVP response to hypoglycemia.

Adult↗
PubMed2001

Sodium and chloride regulation in freshwater and osmoconforming larvae of Culex mosquitoes.

In this study, we examined aspects of Na(+) and Cl(-) regulation in mosquito larvae of the genus Culex, a group that includes species that tolerate high salinity as well as other forms that are restricted to fresh water. When the euryhaline osmoconformer C. tarsalis was acutely transferred from 30 % to 50 % sea water, the patterns of hemolymph Na(+) and Cl(-) regulation were similar. The underlying regulatory mechanisms for these two ions have very different characteristics. In C. tarsalis, Na(+) efflux was significantly elevated compared with the rates measured in the freshwater-restricted C. quinquefasciatus, while Cl(-) influx was relatively lower. The modulation of Na(+) efflux and Cl(-) influx allowed C. tarsalis to avoid a potential salt load and ionic disturbance in the hemolymph during an acute increase ( )in salinity. The observed adjustment of NaCl regulation departs from that determined for other euryhaline organisms and is integral to the osmoconforming response. At the other extreme of the salinity spectrum, we observed that C. tarsalis faces difficulties in ion regulation in habitats with low NaCl levels because of its inability to reduce ion efflux and adjust ion absorption rates to maintain hemolymph ion balance. In contrast, C. quinquefasciatus exhibited a reduced ion efflux and the ability to upregulate Na(+) uptake, traits necessary to extend its lower salinity limit.

Animals↗
PubMed2000

[Effect of magnetic field on peroxidase activation and isozyme in Leymus chinensis].

This paper studied the effect of extra magnetic field and saline-alkali stress on the seedling growth of Leymus chinensis. The results showed that magnetic field treatment not only improved the seedling growth of L. chinensis, but also enhanced its saline-alkali tolerance. This treatment also increased its peroxidase(POD) activity, and induced an extra POD isozymic band on electropherogram. According to a comprehensive analysis, 300 mT and 200 mT for 10 minutes were determined as the optimum magnetic field intensity on L. chinensis seeds.

Enzyme Activation↗
PubMed1995

Cultured cells from a severe combined immunodeficient mouse have a slower than normal rate of repair of potentially lethal damage sensitive to hypertonic treatment.

The effects of hypertonic 0.5 M NaCl treatment after irradiation on the repair of DNA damage were examined in fibroblasts of the severe combined immunodeficient (scid) mouse. These cells are hypersensitive to ionizing radiation because of a deficiency in the repair of double-strand breaks. Hypertonic treatment caused radiosensitization due to a fixation of potentially lethal damage (PLD) in scid cells, demonstrating that scid cells normally repair PLD. To assess the kinetics of the repair of PLD, hypertonic treatment was delayed for various times after irradiation. Potentially lethal damage was repaired during these times in isotonic medium at 37 degrees C. It was found that the rate of repair of PLD was much slower in scid cells than in BALB/c 3T3 cells, which have a "wild-type" level of radiosensitivity. This fact indicates that the scid mutation affects the type of repair of PLD that is sensitive to 0.5 M NaCl treatment. In scid hybrid cells containing fragments of human chromosome 8, which complements the radiosensitivity of the scid cells, the rate of repair was restored to a normal level. An enzyme encoded by a gene on chromosome 8 may also be connected with PLD which is sensitive to hypertonic treatment.

3T3 Cells↗
PubMed1993

[Studies of radiosensitization of hyperthermia and hypertonic treatment in HEp-2 cells].

This paper presents the effects of hyperthermia, irradiation and post-irradiation treated by hypertonic solution on HEp-2 cells, alone or combined in vitro. The results showed that when the radiation treatment with hyperthermia at 44 degrees C 15', the latter had no directly killing effect on cells, a significant radiosensitization was found. The dose response curve showed that the Dq which represents sublethal damage was decreased to 4-5 times (1.49 Gy/0.31 Gy). However, the dose of D(o) which represents potentially lethal damage had almost not changed. When cells were treated with hypertonic solution (0.3 mol/L NaCl) postirradiation, or treated by combination of hyperthermia, irradiation, and hypertonic solution, the results were near the same, as compared with combination with hyperthermia alone. It is concluded that the radiosensitization is induced by hyperthermia which can inhibit the repair of the radio-induced DNA damage by heating.

Cell Survival↗
PubMed2025

The 13-lipoxygenase GmLOX6 is involved in JA biosynthesis and serves as a positive regulator of salt stress tolerance in soybean.

Salinity represents a major abiotic stressor that significantly impairs soybean growth and yield. Although jasmonic acid (JA) has been firmly established as a key regulator of plant defense against salt stress, the precise functions of lipoxygenase (LOX) genes responsible for initiating JA biosynthesis remain poorly defined. Here, a comprehensive genome-wide analysis of the soybean LOX gene family was performed, and a detailed functional characterization of GmLOX6 was carried out. Subcellular localization confirmed that GmLOX6 is targeted to chloroplasts, while enzymatic assays demonstrated that it acts as a 13-LOX enzyme with a strong preference for α-linolenic acid as substrate. To clarify its role under salt stress, we generated both overexpression and CRISPR/Cas9-mediated knockout lines of soybean. Phenotypic and molecular evaluations revealed that GmLOX6 facilitates JA production under salt stress, thereby contributing to enhanced JA accumulation. This elevation in JA levels was associated with improved salt tolerance through multiple physiological adaptations, including the activation of antioxidant enzymes for the detoxification of reactive oxygen species (ROS), enhanced Na+ extrusion to preserve ionic balance, and reinforced membrane stability. Moreover, GmRWP-RK11 was identified as a transcriptional repressor of GmLOX6. Functional disruption of GmRWP-RK11 via CRISPR/Cas9 conferred greater salt tolerance, further supporting its negative regulatory role. Collectively, these findings uncover a novel regulatory axis in which GmLOX6-mediated JA biosynthesis enhances soybean resistance to salinity through modulation of ROS homeostasis and Na+ transport. These insights provide an expanded understanding of the transcriptional and biochemical mechanisms underpinning JA-driven stress adaptation in soybean.

Glycine max↗
PubMed1997

Tolerance of the nematode Caenorhabditis elegans to pH, salinity, and hardness in aquatic media.

The toxicity of many chemicals depends on the physical conditions of the test environment, and any change or adjustment made to the tests can alter the results. Therefore it is important to establish the sensitivity of the test organism over a range of test conditions to determine when it is necessary to make adjustment and to what extent. In this study, we established the tolerance range of the nematode Caenorhabditis elegans for pH, salinity and hardness using 24- (without food source) and 96-h (with food source) aquatic toxicity tests. The tests were performed in two media: K-medium and moderately hard reconstituted water (MHRW). C.elegans has high tolerance under these test conditions. In K-medium worms survived a pH range of 3.1 to 11.9 for 24 h and 3.2 to 11.8 for 96 h without significant (p > 0.05) lethality. In MHRW the pH range was 3. 4 to 11.9 for 24 h and 3.4 to 11.7 for 96 h. Salinity tolerance tests were approximated with NaCl and KCl individually. Up to 15.46 g/L NaCl and 11.51 g/L KCl were tolerated by C. elegans in K-medium without significant lethality (p> 0.05). In MHRW higher salt concentrations were tolerated; about 20.5 g/L NaCl and 18.85 g/L KCl did not show any adverse effect compared to control. Hardness tolerance was tested by adding NaHCO3. The nematode could tolerate 0. 236 to 0.246 g/L of NaHCO3. The high tolerance of C. elegans to these test conditions (pH, salinity, and hardness) allows more versatility than other organisms commonly used in aquatic toxicity tests. It also allows the monitoring of effluents and receiving waters from freshwater or estuarine sources without dilution or adjustment.

Animals↗
PubMed2005

Transgenic cotton (Gossypium hirsutum L.) seedlings expressing a tobacco glutathione S-transferase fail to provide improved stress tolerance.

Transgenic cotton (Gossypium hirsutum L.) lines expressing the tobacco glutathione S-transferase (GST) Nt107 were evaluated for tolerance to chilling, salinity, and herbicides, antioxidant enzyme activity, antioxidant compound levels, and lipid peroxidation. Although transgenic seedlings exhibited ten-fold and five-fold higher GST activity under normal and salt-stress conditions, respectively, germinating seedlings did not show improved tolerance to salinity, chilling conditions, or herbicides. Glutathione peroxidase (GPX) activity in transgenic seedlings was 30% to 60% higher under normal conditions, but was not different than GPX activity in wild-type seedlings under salt-stress conditions. Glutathione reductase, superoxide dismutase, ascorbate peroxidase, and monodehydroascorbate reductase activities were not increased in transgenic seedlings under salt-stress conditions, while dehydroascorbate reductase activity was decreased in transgenic seedlings under salt-stress conditions. Transgenic seedlings had 50% more oxidized glutathione when exposed to salt stress. Ascorbate levels were not increased in transgenic seedlings under salt-stress conditions. Malondialdehyde content in transgenic seedlings was nearly double that of wild-type seedlings under normal conditions and did not increase under salt-stress conditions. These results show that expression of Nt107 in cotton does not provide adequate protection against oxidative stress and suggests that the endogenous antioxidant system in cotton may be disrupted by the expression of the tobacco GST.

Antioxidants↗
PubMed2006

XVSAP1 from Xerophyta viscosa improves osmotic-, salinity- and high-temperature-stress tolerance in Arabidopsis.

XVSAP1, a gene isolated from a dehydrated Xerophyta viscosa cDNA library, was transformed into Arabidopsis thaliana by Ti plasmid-mediated transformation under the control of a cauliflower mosaic virus 35S promoter, a nos terminator and bar gene selection. Expression of XVSAP1 in Arabidopsis led to constitutive accumulation of the corresponding protein in the leaves. Transgenic Arabidopsis grown in tissue culture maintained higher growth rates during osmotic, high-salinity and high temperature stress, respectively. Non-transgenic plants had shorter roots, leaf expansion was inhibited and leaves were more chlorotic than those of the transgenic plants. This study demonstrates that XVSAP1 has a significant impact on dehydration, salinity and high-temperature stress tolerance in Arabidopsis.

Arabidopsis↗
PubMed2002

A comparison of outpatient hysteroscopy with saline infusion hysterosonography.

OBJECTIVES: To establish the accuracy of saline infusion hysterosonography in diagnosing uterine pathology when compared with outpatient hysteroscopy. DESIGN: Prospective, parallel, blinded comparative study. SETTING: Outpatient hysteroscopy clinic in a large university teaching hospital. POPULATION: All women referred for outpatient hysteroscopy in a 15-month period. INTERVENTIONS: Women underwent saline infusion hysterosonography followed by flexible hysteroscopy. The ultrasonographer was blinded to the hysteroscopy result and the gynaecologist was blinded to the saline infusion hysterosonography result. MAIN OUTCOME MEASURES: The relative success rates and pain scores for each procedure. The validity of saline infusion hysterosonography as a diagnostic test. RESULTS: One hundred and seventeen women entered the study; 70 women were premenopausal and 47 postmenopausal. In 27 women, one or both procedures could not be performed. Saline infusion hysterosonography failed in 20 women, on one occasion hysteroscopy failed and both investigations failed in six women. Ninety cases remained for direct comparison, with 78 cases of agreement on the uterine findings in both investigations. Twelve cases disagreed; in one case, an adhesion was seen, two cases with polyps and five with fibroids seen on ultrasound but not seen on hysteroscopy. There were four cases where polyps were identified on hysteroscopy but not on saline infusion hysterosonography. The median pain scores were 1.6 for saline infusion hysterosonography and 3.2 for hysteroscopy. CONCLUSIONS: Both saline infusion hysterosonography and hysteroscopy are well tolerated by women. Saline infusion hysterosonography has a high failure rate but has a lower pain score than hysteroscopy.

Adult↗
PubMed2006

Acquisition and extinction of conditioned nicotine analgesic tolerance.

These studies demonstrated the acquisition and extinction of conditioned tolerance to the analgesic effect of nicotine in rats. In Experiment 1, distinctive environmental cues were either paired or unpaired with nicotine. Following acquisition, the paired group was more tolerant to nicotine than the unpaired and saline groups. Conditioned tolerance was extinguished in the paired group after placebo sessions in the distinctive environment. Experiment 2 examined whether the distinctive environment functioned as a CS or as an occasion setter for injection cues. After acquisition, exposure to the distinctive environment, with or without placebo injections, resulted in extinction. This demonstrates that the distinctive environment served as a CS, not as an occasion setter for injection cues.

Analgesics↗
PubMed1999

Salinity as a constraint on growth of oligohaline marsh macrophytes. I. Species variation in stress tolerance.

The effects of increased salinity on plant growth were examined in a greenhouse experiment with four species common to oligohaline marshes of the northern Gulf of Mexico: Eleocharis palustris, Panicum hemitomon, Sagittaria lancifolia, and Scirpus americanus. Effects of final salinity reached (6 or 12 g/L), salinity influx rate (3 d or 3 wk), and duration of exposure (1, 2, or 3 mo) were investigated. Sagittaria lancifolia was the first species to show visible signs of stress, with browning and curling of older leaf edges. The salt effect was delayed for 6-8 wk in P. hemitomon, but this species had the highest aboveground tissue mortality rate at 12 g/L as exposure continued. Final salt concentration affected all species to a greater degree than did salinity influx rate. No aboveground mortality occurred at 6 g/L, but growth suppression was apparent and varied with species. The magnitude of growth suppression in response to salinity increased for all species as the duration of exposure increased. Overall, we ranked the species as follows, in order from least to most salt tolerant: Panicum hemitomon < Sagittaria lancifolia < Eleocharis palustris < Scirpus americanus. This ranking reflects the field occurrence of these species along a gradient of increasing salinity in northern Gulf of Mexico coastal habitats from freshwater wetlands through oligohaline areas to mesohaline wetlands.

Journal Article↗
PubMed1976

Teleost chloride cell. I. Response of pupfish Cyprinodon variegatus gill Na,K-ATPase and chloride cell fine structure to various high salinity environments.

Certain euryhaline teleosts can tolerate media of very high salinity, i.e. greater than that of seawater itself. The osmotic gradient across the integument of these fish is very high and the key to their survival appears to be the enhanced ability of the gill to excrete excess NaCl. These fish provide an opportunity to study morphological and biochemical aspects of transepithelial salt secretion under conditions of vastly different transport rates. Since the cellular site of gill salt excretion is believed to be the "chloride cell" of the branchial epithelium and since the enzyme Na,K-ATPase has been implicated in salt transport in this and other secretory tissues, we have focused our attention on the differences in chloride cell structure and gill ATPase activity in the variegated pupfish Cyprinodon variegatus adapted to half-strength seawater (50% SW), seawater (100% SW), or double-stregth seawater (200% SW). The Na,K-ATPase activity in gill homogenates was 1.6 times greater in 100% SW. When 50% SW gills were compared to 100% SW gills, differences in chloride cell morphology were minimal. However, chloride cells from 200% SW displayed a marked hypertrophy and a striking increase in basal-lateral cell surface area. These results suggest that there are correlations among higher levels of osmotic stress, basal-lateral extensions of the cell surface, and the activity of the enzyme Na,K-ATPase.

Adenosine Triphosphatases↗
PubMed2004

Aquaporin functionality in roots of Zea mays in relation to the interactive effects of boron and salinity.

Zea mays L. cv. amylacea, a plant tolerant of B and salinity, was used to determine the involvement of aquaporin functionality in the interactive effects of B and salinity. Also, growth, chlorophyll concentration, and water relations were studied. While growth and chlorophyll concentration did not show noticeable changes under saline conditions, the decrease in leaf water potential and osmotic potential, together with the marked decrease of stomatal conductance and root hydraulic conductance, showed that the plants were adjusted osmotically. However, no effect of B was observed. The very weak response of the Lpc of salt-stressed roots to Hg suggested that water channels were greatly reduced in number or, if present, were non-functional. The evidence that substantial B movement can occur through diffusion and channel-mediated transport is compelling, and could account for B uptake under conditions of adequate or greater B supply. Therefore, the reduction in the functionality of aquaporins for NaCl-treated plants could be related to the reduction of B concentrations in roots and leaves in B + NaCl-treated plants, in comparison with plants treated only with B.

Aquaporins↗
PubMed1993

Effects of enteral infusion of hypertonic saline and nutrients on canine jejunal motor patterns.

The aim of the study was to clarify the effects of hypertonic solutions on jejunal motility. The study focused on differential effects of hypertonic saline and nutrients. Motility of the canine proximal jejunum was recorded with closely spaced strain-gauge transducers. During fasting, hyperosmotic solutions (up to 1520 mosmol/liter) of saline or nutrients (1 kcal/ml) were infused into the proximal jejunum (0.5-1.5 ml/min) up to 6 hr. The hyperosmotic solutions stimulated jejunal motility. With both increasing osmolarity of saline or increasing energy load of nutrients, jejunal motility linearly declined. The reduction of motility was associated with a change in motor pattern from a propulsive to a more segmenting one. Hypertonic glucose evoked a significantly smaller level of motor activity compared with both saline (at given osmolarities) and an elemental diet (at given energy loads). Motility parameters were not different between glucose and maltose, although osmolarity of maltose was less than half (760 vs 1520 mosmol/liter). In contrast, a mixture of glucose-fructose exerted a smaller inhibition of jejunal motility than glucose. The hypertonic solutions of saline or nutrients were tolerated over 2 hr; with hypertonic saline retrograde power contractions with or without vomiting occurred, whereas with hypertonic nutrients vomiting was preceded by strong inhibition of jejunal motility. Three conclusions can be derived from the present results: (1) The behavior of jejunal motility suggested that the motor activity was the result of both a local stimulation and an inhibitory feedback mechanism. (2) The different degree of inhibition between glucose and saline indicated that the nutrient itself played a major role in the inhibitory feedback regulation, whereas osmolarity was of minor importance. (3) Comparisons between different nutrients suggested a linkage between inhibitory control of motility and the absorptive capacity of the gut for the single nutrient.

Analysis of Variance↗
PubMed1999

Halomonas campisalis sp. nov., a denitrifying, moderately haloalkaliphilic bacterium.

The isolation and characterization of a denitrifying bacterium that is both moderately halophilic and alkaliphilic is described. The organism was isolated for use in the development of a bioprocess that could potentially reduce the costs of ion exchange resin regenerant disposal. The process of ion exchange, after resin regeneration, produces a briny, alkaline waste that is difficult and expensive to dispose. The biological removal of nitrate and subsequent reuse of these brines can potentially provide a cost-saving alternative to disposing of this waste product. To achieve our objective, a moderately halophilic, alkaliphilic bacterium was isolated from sediment samples taken from the salt plain of Alkali Lake in Washington State (USA). The haloalkaliphilic bacterium, designated strain 4A, is motile with rod-shaped cells that are 3 to 5 microm long and 1 microm wide. Electron acceptors used include oxygen, nitrate, and nitrite. In addition, it has similar specific nitrate reduction rates and biomass yields as non-halophilic denitrifying bacteria. It is capable of using a variety of electron donors. This organism can grow at NaCl concentrations ranging from 0.2 to 4.5 M with optimum growth occurring at 1.5 M and pH values ranging from 6 to 12 with 9.5 being the optimum pH. The temperature range for growth of strain 4A is 4-50 degrees C with optimal growth occurring at 30 degrees C. The G + C content is 66 mol%. Phylogenetic analyses based upon 16S rDNA gene sequence placed isolate 4A in the genus Halomonas. In addition, DNA-DNA hybridization experiments clearly indicate that it is a unique species. Phenotypic and phylogenetic studies indicate that isolate 4A represents a new species. We propose the name Halomonas campisalis for this species and strain 4A (ATCC 700597) as the type strain. Due to its denitrification ability, broad carbon utilization range and its high salinity and pH tolerance this organism, and similar ones, hold promise for the treatment of saline, alkaline waste.

Biodegradation, Environmental↗
PubMed2003

Tolerance of citrus rootstock seedlings to saline stress based on their ability to regulate ion uptake and transport.

Forty-five-day-old seedlings of sour orange (Citrus aurantium L.) and Citrus macrophylla Wester, the most commonly used rootstocks in lemon orchards, were grown in nutrient solutions containing 1 (control), 10, 20, 30 or 60 mM NaCl for 14 days. The effects of salinity on growth, uptake, transport and accumulation of Cl- and Na+ ions in leaves, stem and four root segments were studied. The 60 mM NaCl treatment reduced leaf dry mass more in C. macrophylla (40%) than in sour orange (20%), whereas it reduced root dry mass more in sour orange (36%) than in C. macrophylla (20%). In C. macrophylla, Cl- and Na+ uptake rates were high at the beginning of the saline treatments, but low at the end of the 14-day experiment. In contrast, sour orange showed high uptake rates at the beginning and end of the experiment. In response to increasing salinity, root and shoot concentrations of Cl- and Na+ increased in sour orange, but not in C. macrophylla. Different loading characteristics of Cl- and Na+ were observed between young and old segments of the root system. In general, old root segments reached quasi-steady-states later than young root segments. These results suggest that sour orange and C. macrophylla have different regulatory mechanisms for uptake and transport of Cl- and Na+.

Biomass↗