NaCl Conditions Research Articles

Enhanced lipid productivity of Chlamydomonas reinhardtii with combination of NaCl and CaCl2 stresses.

Salinity (NaCl) stress treatment is a strategy to induce lipid accumulation in microalgae. This study aimed to investigate the effect of a combination of two salts (NaCl/CaCl2) on lipid productivity of Chlamydomonas reinhardtii. C. reinhardtii was cultured in a two-stage culture comprising 9-day active growth in C medium followed by 3-day salt stress in C medium with various concentrations of NaCl (50‒200mM)/CaCl2 (100mM). In salt stress stage, NaCl (200mM), CaCl2 (100mM), and the NaCl/CaCl2 mixture inhibited growth but increased the lipid content in C. reinhardtii in comparison with NaCl (0, 50, and 100mM) conditions. Combinatorial treatment with 100mM NaCl/100mM CaCl2 resulted in the highest lipid content (73.4%) and lipid productivity (10.9mg/L/days), being 3.5- and 2.1-fold, respectively, in salt-free control conditions, and 1.8- and 1.5-folds, respectively, with 200mM NaCl. Furthermore, 100mM NaCl/100mM CaCl2 treatment markedly upregulated glycerol-3-phosphate dehydrogenase (GPDH), lysophosphatidic acid acyltransferase (LPAAT), and diacylglycerol acyltransferase (DAGAT), which are involved in lipid accumulation in C. reinhardtii. The upregulation of these genes with 100mM NaCl/100mM CaCl2 resulted in the highest lipid content in C. reinhardtii. Therefore, stress treatment using two salts, 100mM NaCl/100mM CaCl2, is a potentially promising strategy to enhance lipid productivity in microalgae.

Laboratory investigation of co-precipitation of CaCO3/BaCO3mineral scale solids at oilfield operating conditions: Impact of brine chemistry

Oilfield mineral scale deposition can become severe flow assurance challenge especially for offshore deepwater productions. Hazards arising from scale formation and subsequent deposition include production system throughput reduction and eventually blockage. Among various types of scales, carbonates are among the most frequently observed scales in oilfield operations. Similar to many natural and industrial processes, co-precipitation of multiple scales can commonly be observed in oilfield operations. Although extensive research efforts have been made in the domain of understanding the thermodynamics of scale formation, there are limited studies to investigate the kinetic aspect of scale formation, particularly the kinetics of co-precipitation of multiple scales. In this study, the kinetic characteristics of CaCO3/BaCO3co-precipitation have been experimentally investigated at representative oilfield conditions of 80 °C and 1 M NaCl condition. The focus was given to the investigation of the impact of different brine chemistry conditions such as mineral saturation level and Ca to Ba molar ratio. The experimental results suggest that CaCO3saturation level, substrate material and molar ratio can impact the nature and morphology of the carbonate scales formed. An elevation of CaCO3saturation index from 0.6 to 2 will change the formed carbonate solids from calcite to aragonite. In addition, at a Ca:Ba molar ratio of 1:15 with an excessive aqueous Ba species available, Ba species can partition into CaCO3crystal lattice to distort CaCO3lattice, resulting in almost 2-fold increase in aqueous Ca concentration. The results and conclusions from this study have the potential to benefit oilfield scale control strategy development, particularly the one related to carbonate scale formation control.

Endophytic fungi induce salt stress tolerance in greenhouse-grown basil

In many irrigated regions of Mediterranean areas, vegetable farmers are forced to use low quality water (often with elevated salinity) for their crops with important losses in productivity. Sweet basil (Ocimum basilicum L.) is one of the most important aromatic herbs cultivated in Italy under both open-field and protected conditions. The application of endophytic fungi such as mycorrhizal fungi and Trichoderma could be an efficient tool to mitigate the detrimental effect of salinity. A greenhouse experiment was carried out to assess the influence of co-inoculation of endophytic fungi and plant growth promoting rhizobacteria on yield and quality traits under non-saline (1 mM NaCl) and saline (40 mM NaCl) conditions. Increasing the NaCl concentration in the nutrient solution in both inoculated and non-inoculated plants decreased the yield and growth parameters but increased the quality traits in particular the hydrophilic and lipophilic antioxidant activities and total phenols. The microbial-based biostimulant markedly enhanced the marketable fresh yield by 17.0% compared to control plants. The better crop performance of inoculated basil has been attributed to a better pigment biosynthesis (i.e., higher SPAD index). On the other hand, the nitrate content in microbial biostimulant basil plants was significantly reduced by 16.1%, whereas the total phenols increased by 7.7% compared to untreated plants. Overall, the use of beneficial microorganisms could be adopted as a sustainable tool in vegetable cropping systems to mitigate the detrimental effect of saline water.

Impact of Salt-tolerant Rootstock on the Enhancement of Sensitive Tomato Plant Responses to Salinity

In the present study, salt-tolerant (Tom 174) and sensitive (Tom 121) tomato genotypes were grafted onto their own roots (174/174 and 121/121), and a susceptible genotype was also grafted onto tolerant genotype 121/174. The grafted plants were grown under 50 mm NaCl and control conditions in a greenhouse. Plant physiological parameters, fruit yield, and physical measurements of fruit (e.g., weight, height, diameter, volume), and chemical analysis of fruit (e.g., vitamin C, pH, and total dry matter content) were investigated. When the sensitive genotype was grafted onto tolerant genotype 121/174, the tolerant genotype Tom 174 reduced the yield loss of susceptible genotype from 44% to 3%. Also, fruit size, total dry matter content, and vitamin C increased, while pH decreased under saline conditions. The rootstock Tom 174 seemed to be able to control sensitive scions’ stomatal openness and closure for transpiration and CO2 transition on photosynthesis because dry matter content was increased. It was found that the tolerant genotype played a role in ameliorating leaf osmotic adjustment of the sensitive genotype in grafting under salt stress. The combination 121/174 had the lowest Na+ concentration in young leaves. Thus, the tolerant rootstock Tom 174 decreased the transport of accumulation of Na+ ions to young leaves in this grafting combination.

Combined Effects of Phosphate Solubilizing Bacteria and Nanosilica on the Growth of Land Cress Plant

The present study was done to isolate and characterize two strains of phosphate solubilizing bacteria from rhizospheres of acacia, sugar beet, and wheat, then determine synergic effects of nanosilica and these strains on the vegetative growth of land cress plant. Isolates identification was performed using physiological, morphological, biochemical tests, and 16S ribosomal ribonucleic acid sequencing. Nanosilica was extracted from Equisetum telmateia and characterized via X-ray diffraction, scanning electron microscopy, dynamic light scattering, Brunauer–Emmett–Teller, and X-ray fluorescence techniques. The size and the purity of extracted silica powder were about 30 nm, 97.5 %, respectively. Two strains, namely, Pseudomonas stutzeri and Mesorhizobium sp. were the most efficient strains to grow and solubilize phosphorus in the presence of 860 mM NaCl and various pH conditions. The highest growth of these two strains was observed at 0.05 and 0.07 ppm of nanosilica. The highest amount of dry weight of shoot and root of land cress plant was recorded with the simultaneous application of these strains in combination with nanosilica. The combination of nanosilica and these strains enhanced the soil nitrogen and phosphorus content and the vegetative growth of land cress plant.

Differential Salt Sensitivity of Two Flax Cultivars Coincides with Differential Sodium Accumulation, Biosynthesis of Osmolytes and Antioxidant Enzyme Activities

The present study was conducted in order to determine the response of two Egyptian flax cultivars (Sakha 102 and Sakha 105) to salt stress. To this end, seedlings of both cultivars were subjected to 150 mM NaCl condition, and the growth, Na+ and K+ concentrations, proline and hydrogen peroxide concentrations, and antioxidant enzyme activities were measured and compared with plants grown under non-stressed conditions. The results showed that salt stress reduced the overall growth of Sakha 102 by 38% as opposed to almost 50% reduction in Sakha 105. H2O2 significantly increased in Sakha 105, but remained unchanged in Sakha 102. The Na+ concentration in the leaf of Sakha 102 was 30% more than in the leaf of Sakha 105. The K+ concentrations were reduced by the same degree in all tissues of both plants and the Na+/K+ ratios were similar in both cultivars (generally > 1). The proline concentration was significantly more elevated in leaf, stem, and root of Sakha 102 (5.4, 2.5, and ten-fold, respectively) than in Sakha 105 (2.3, 2.3, and 4.0-folds). CAT activity markedly increased in the root of Sakha 102 (3.5-fold), but remained unchanged in Sakha 105. Taken together, these results suggest that Sakha 102 is more salt tolerant than Sakha 105, and that differences in proline concentration and ROS production under stress may account to a greater degree in the differential tolerance.

Salinity tolerance of wild barley Hordeum vulgare ssp. spontaneum

AbstractSalinity tolerance of 47 wild barley genotypes and six barley cultivars was evaluated under control and salinity stress (300 mM NaCl) conditions. Shoot and root dry weight (DW), plant height, membrane stability index (MSI), relative water content, survival rate, leaf malondialdehyde (MDA) and proline contents, root and leaf Na, K, Ca and K/Na ratio, and chlorophyll a fluorescence were measured. Salinity stress caused significant increase in the MDA, proline content, Na and Ca concentrations of the roots and leaves, but resulted in a decrease in the other traits. H. spontaneum genotypes were considerably less affected by the salinity than the genotypes of H. vulgare. Plant survivability was negatively correlated with the Na concentration (r =−.66) but positively correlated with the leaf K/Na ratio (r = .67) and MSI (r = .68). Tolerance mechanisms such as ion exclusion (Na) were likely to be present in the wild barley causing K/Na homeostasis as well as the much lower root and shoot Na, resulting in the higher survival rate.

Jasmonic acid enhances the resistance of potato plants in vitro to salt stress

The protective effect of jasmonic acid (JA) was evaluated under stress (100 mM NaCl) condition. The investigations were carried on potato plants (Solanum tuberosum L.) of the mid-season variety Lugovskoy. Plant-regenerants were grafted and cultured in test tubes on modified Murashige-Skoog agar medium in the absence (control) or in the presence of JA at concentrations of 0.001; 0.1 and 10 M under optimal growing conditions or with the addition of NaCl. After 28 days of cultivation, growth (length of stem and root, number of tiers and leaves, plant mass) and physiological (proline content and photosynthetic pigments, determination of the osmotic potential of cell exudate) of the plants were assessed. For the first time it has been shown that jasmonic acid (0.1 and 10 M) manifests a pronounced protective effect on potato plants under salt stress condition. The protective effect based on the partial removal of the salt negative effect on the main photosynthetic pigments and the maintenance of the osmotic status of cell contents during salinization.

A Genome-Wide Association Study Revealed Key SNPs/Genes Associated With Salinity Stress Tolerance In Upland Cotton.

Millions of hectares of land are too saline to produce economically valuable crop yields. Salt tolerance in cotton is an imperative approach for improvement in response to ever-increasing soil salinization. Little is known about the genetic basis of salt tolerance in cotton at the seedling stage. To address this issue, a genome-wide association study (GWAS) was conducted on a core collection of a genetically diverse population of upland cotton (Gossypium hirsutum L.) comprising of 419 accessions, representing various geographic origins, including China, USA, Pakistan, the former Soviet Union, Chad, Australia, Brazil, Mexico, Sudan, and Uganda. Phenotypic evaluation of 7 traits under control (0 mM) and treatment (150 mM) NaCl conditions depicted the presence of broad natural variation in the studied population. The association study was carried out with the efficient mixed-model association eXpedited software package. A total of 17,264 single-nucleotide polymorphisms (SNPs) associated with different salinity stress tolerance related traits were found. Twenty-three candidate SNPs related to salinity stress-related traits were selected. Final key SNPs were selected based on the r2 value with nearby SNPs in a linkage disequilibrium (LD) block. Twenty putative candidate genes surrounding SNPs, A10_95330133 and D10_61258588, associated with leaf relative water content, RWC_150, and leaf fresh weight, FW_150, were identified, respectively. We further validated the expression patterns of twelve candidate genes with qRT-PCR, which revealed different expression levels in salt-tolerant and salt-sensitive genotypes. The results of our GWAS provide useful knowledge about the genetic control of salt tolerance at the seedling stage, which could assist in elucidating the genetic and molecular mechanisms of salinity stress tolerance in cotton plants.

Site-saturation mutagenesis at amino acid 329 of Klebsiella pneumoniae halophilic α-amylase affects enzymatic properties

Halophilic α-amylases possess optimal activity in high salt concentrations. Therefore, they can be used in many extreme conditions in industrialised production. In the present work, a halophilic α-amylase (KP) from Klebsiella pneumoniae was characterised, and it exhibited a high specific activity of 3512 U/mg under optimal conditions of 2M NaCl at 50°C and pH 6.5, but only 97 U/mg in the absence of salt. Furthermore, threonine at position 329 (Thr-329) was found to be related to the non-halophilic properties of KP according to PCR-based site-saturation mutagenesis. The activity of a mutant KP in which this threonine was replaced by aspartic acid was improved 14.6-fold compared with the native enzyme under salt-free conditions, and was increased by 14.8% in the absence of salt. Additionally, the optimal enzymatic properties of KP, including pH and temperature, were altered very little by the amino acid replacement. A further three halophilic α-amylases displayed similar mutational results. The findings provide a reference for bidirectional transformation of KP and similar halophilic enzymes.

A large-scale screening of quinoa accessions reveals an important role of epidermal bladder cells and stomatal patterning in salinity tolerance

The presence of epidermal bladder cells (EBCs) in halophytes allows considerable amount of Na+ being accumulated in these external structures, away from the metabolically active mesophile cells. Also, stomatal patterning may represent a primary mechanism by which plants can optimise its water-use efficiency under saline condition. This investigation was aimed to explore the varietal differences in a salinity tolerance of quinoa (Chenopodium quinoa) by evaluating a broad range of accessions and linking the overall salinity tolerance with changes in stomatal characteristics and EBC parameters. One hundred and fourteen accessions were grown under temperature-controlled glasshouse under non-saline and 400 mM NaCl conditions, and different physiological and anatomical characteristics were measured. Accessions were classified into three classes (sensitive, intermediate and tolerant) based on a relative dry weight defined as salinity tolerance index (STI). Results showed a large variability in STI indicating a strong genetic variation in salinity tolerance in quinoa. Bladders density was increased in a majority of accessions under saline condition while the bladder’s diameter remained unchanged; this resulted in a large variability in a bladder’s volume as a dependant variable. Stomata density remained unchanged between saline and non-saline conditions while the stomata length declined between 3% to 43% amongst accessions. Leaf Na+ concentration varied from 669 μmol/gDW to 3155 μmol/gDW under saline condition and, with an exception of a few accessions, leaf K+ concentration increased under saline conditions. Correlation analysis indicated a significant positive association between EBC diameter and STI on one hand and EBC volume and STI on the other hand, in a salt-tolerant group. These observations are consistent with the role of EBCs in sequestration of toxic Na+ in the external structures, away from the cytosol. A negative association was found between EBC density and diameter in salt-sensitive plants. A negative association between STI and stomata length was also found in a salt-tolerant group, suggesting that these plants were able to efficiently regulate stomatal patterning to balance water loss and CO2 assimilation under saline conditions. Both salt-sensitive and salt-tolerant groups had the same Na+ concentration in the shoot under saline conditions; however, a negative association between leaf Na+ concentration and STI in salt-sensitive plants indicated a more efficient Na+ sequestration process into the EBCs in salt-tolerant plants.

Susceptibility of dry-cured tuna to oxidation and biogenic amines generation related to microbial status and salting/curing technology

The present study evaluated the effect of salting/curing methods and raw tuna flesh microbial status on the lipid oxidation and the incidence of biogenic amines in “muxama”, a dry tuna product. After drying (T0), salted/cured and uncured “muxamas” processed in the air presented malondialdehyde (MDA) levels lower than those under vacuum (P < 0.05) with differences amounting to 53.18% and 50.84%, respectively. Regardless the salting method, MDA content tended to increase with storage, with lipid oxidation progressing faster in uncured samples. The microbial status of fresh muscles kept almost unchanged or slightly decreased after salting under vacuum, with Enterobacteriaceae counts falling below 10 cfu/g. T0 cured “muxamas” differed in the microbial status, with the initial total counts at 30 °C (1.6x104 cfu/g) remaining almost unchanged (4.9x104 cfu/g) or increasing from 5.9x103 cfu/g to 1.6x107 cfu/g, reflecting distinct microbial survival among the flora under the present NaCl and Aw conditions. Histamine in fresh tuna muscle varied between 4.19 and 2305 mg/kg (dry matter) without detectable spoilage signs between samples. After processing and storage, BA profiles also changed, expressing distinct microbiota evolutions, with histamine content keeping below legislated values or increasing from 26.39 mg/kg up to 208.21 mg/kg (T0), 1179.20 mg/kg (T1) and 1107.35 mg/kg (T3). Muxama is susceptible to lipid oxidation and BAs formation.

Control of pathogens in fresh pork sausage by inclusion of Lactobacillus sakei BAS0117

A pork sausage was produced with low sodium content (1.64%) to which Lactobacillus sakei was added with the aim of developing a meat pork sausage for cooking and having technological, organoleptic, and hygienic advantages. The lactic acid bacteria (LAB) L. sakei, Lactococcus sp., and Pediococcus pentosaceus were submitted to extreme pH, temperature, and NaCl conditions. Lactobacillus sakei was used in pork sausage because of its resistance to different culture conditions and its antimicrobial potential. The food-borne pathogens Listeria monocytogenes Scott A, Enterococcus faecalis, and Staphylococcus aureus were used as indicator microorganisms to evaluate the antimicrobial activity of selected LAB strains. Salmonella enterica serotype Choleraesuis is a common pathogen of pigs. To the raw sausage product containing L. sakei and nonpathogenic endogenous microbiota, we added about >104 and <105 CFU/g of S. enterica serotype Choleraesuis to evaluate the inhibitory potential of L. sakei towards this pathogen. Salmonella Choleraesuis was inhibited in the presence of L. sakei over 7 days of storage of the meat product (about 3.0 log cycles reduction). Lactobacillus sakei significantly increased inhibition when compared with the nonfermented sausage. Thus, L. sakei BAS0117 played an important role as an additional hurdle in the fermented meat pork sausage during storage.

The separation of gold and vanadium in carbonaceous gold ore by one-step roasting method

The separation of gold and vanadium in the refractory carbonaceous gold ore had been performed by one-step roasting method. The thermodynamic viability of the possible reactions in the process was analyzed based on thermodynamic data. And the effects of experimental parameters such as roasting temperature, roasting time and NaCl dosage on the recovery ratios of gold and vanadium were investigated. Under the optimal conditions of NaCl 10%, roasting temperature 800 °C, roasting time 4 h and air gas flow rate 1 L/min, the recovery ratios of gold and vanadium were 92% and 85.34%, respectively, realizing the effective separation of gold and vanadium. In addition, the reaction mechanism and phase transformation during the roasting process were revealed using SEM, EDS and XRD. Results demonstrated that it was beneficial to the chlorination reaction of gold in the presence of pyrite. In the low-temperature roasting, the chlorination reaction of gold was dominant in the roasting process. And in the high-temperature roasting, the chlorination reaction of gold and the sodium reaction of vanadium were dominant in the roasting process.

Analysis of pH and salt concentration on structural and model-drug delivery properties of polysaccharide-based multilayered films

This paper explores the influence of pH and ionic strength of polyelectrolyte solutions as a simple and chemically amenable strategy for tuning the structure and drug delivery properties of polyelectrolyte multilayers produced via layer-by-layer technique. Carboxymethylcellulose/chitosan films were buildup under different pH (4.0 and 6.0) and salt concentrations (0 or 0.2 M NaCl) conditions. Systematic data analyses using Design of Experiments indicate that high ionic strength favors the formation of thinner and rougher films. Higher pH led to the formation of thinner and rougher films, attributed to the substantial decrease in the degree of ionization of carboxymethylcellulose and the random coil conformation of chitosan at the outermost layer, respectively. The random coiled conformation of chitosan near to neutral pH also seems to be the major factor to increase the surface film roughness under wet conditions. Drug delivery tests performed with Rose Bengal (model drug) indicate a predominant non-Fickian release mechanism for most of the buildup conditions tested. Densely packed multilayered films obtained at pH 6.0 and 0.2 M NaCl resulted in a faster, Fickian release mechanism, with minimal changes in surface morphology under wet conditions. The total amount of drug released shows a significative influence of only the polyelectrolyte solution pH, associated with the higher amount of free amino groups of chitosan at the film surface at higher pH conditions. These findings shed light on a strategy to develop functional coatings with tailored structural and drug delivery properties by simply controlling film depositions conditions.

Responses of Foreign GA3 Application on Seedling Growth of Castor Bean (Ricinus communis L.) under Salinity Stress Conditions

Castor bean (Ricinus communis L.), a promising bioenergy crop, is readily planted in marginal lands like saline soils. A controlled experiment was conducted to explore the possibility of using gibberellic acid (GA3) as a promoter for caster bean grown under NaCl conditions and to try to determine the most appropriate concentration of GA3 for seedling growth. The seeds of salt-tolerant cultivar Zibi 5 were firstly soaked with 0, 200, 250, and 300 µM GA3 for 12 h and then cultured with 1/2 Hoagland solution containing 0, 50, and 100 mM NaCl in pots filled with sand. Plant height, stem diameter, leaf area, dry mater of each organ, activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), soluble protein, and proline content in the leaves were examined. Plant height and stem diameter, SOD, and POD activity was significantly highest in the treatment of 250 µM GA3 under salt concentration of 50 mM NaCl among all the testing days; protein content was highest when GA3 concentration was 250 µM under 100 mM NaCl treatment. This indicated that caster bean seed soaking with 250 µM GA3 could be the most suitable concentration for promoting seedling growth of caster bean, improving their stress resistance.

Actividad proteolítica de frutos silvestres de Bromelia karatas L. de Yucatán, México

Introduction: Bromeliads are a source of proteases that have not been fully studied. Objectives: To evaluate the proteolytic activity of wild fruits of Bromelia karatas L. under different temperature, pH and NaCl conditions, and to estimate the thermal stability of their proteases. Materials and methods: The effect of pH (6, 7, 8, 9, 10 and 12), incubation temperatures (30, 40, 50, 60 and 70 °C) and NaCl concentrations (5, 10 and 20 %) on the proteolytic activity of the fruits was compared. The thermal stability of the proteases was assessed at 30, 50 and 70 °C for 240 minutes. The molecular weights and isoelectric points of the proteases were estimated by non-reducing two-dimensional zymography. The data were analyzed using a one-factor ANOVA and Tukey's test (α = 0.05). Results and discussion: The proteolytic activity of B. karatas fruit extract (8.59 U·mg-1) was greater than that of Ananas comosus [L.] Merr. variety comosus (3.42 U·mg-1). The activity was higher at pH 6 and 7 and in concentrations lower than 5 % NaCl. Proteases were stable at 30 and 50 °C for 210 minutes. The two-dimensional zymogram, under non-reducing conditions, showed at least 40 light zones with apparent molecular weights between 27.3 and 290 kDa, potentially representing proteases. Conclusion: The proteases of B. karatas have potential for application in the food industry.

Tolerance of two apple rootstocks to short-term salt stress: focus on chlorophyll degradation, photosynthesis, hormone and leaf ultrastructures

To elucidate the salt tolerance of Malus halliana Koehne and Malus robusta Rehd., changes of photosynthetic parameters, hormone content and chlorophyll degradation enzymes of them were compared after treated with different concentration of NaCl. Salt stresses were simulated using 50, 100, 200 mM of NaCl solution, and 1/2 Hoagland nutrient solution was used instead of NaCl solution as control (CK). Except for the indole acetic acid (IAA) content, the changes of Chlorophyll (Chl) content, net photosynthetic rate (PN), stomatal conductance (gs), IAA/ABA ratio, intercellular CO2 concentration (Ci), transpiration rate, abscisic acid content (ABA), Pheophytinase (PPH) and Pheophorbide a monooxygenase (PaO) in Malus halliana were lower than those in Malus robusta under 100 and 200 mM NaCl condition. The values of Chlase, PPH and Pao in Malus robusta were significantly higher than that in Malus halliana. According to correlation analysis, the Chl was extremely positively correlated with Chla, Chlb, IAA/ABA, PN and gs, significantly negative correlation with Chla/b, ABA and PaO, and negative correlation with Ci, Chlase and PPH. The chloroplast ultrastructure of Malus robusta was greatly damaged resulting in chloroplasts disintegration and that of Malus halliana was maintained to be completed at 100 and 200 mM NaCl. In certain range of salt concentrations, Malus halliana could be better to adjust the levels of Chlorophyll content, Chlase, PPH, PaO and the number of starch grain and osmiophilic granules to relieve the damage of photosynthetic system due to salt stress. In a word, the Malus halliana could be better adapted to high salt concentration than Malus robusta.

The interplay between ambient temperature and salt intake affects oxidative status and immune responses in a ubiquitous Neotropical passerine, the rufous-collared sparrow

Physiological traits associated with maintenance, growth, and reproduction demand a large amount of energy and thus directly influence an animal's energy budget, which is also regulated by environmental conditions. In this study, we evaluated the interplay between ambient temperature and salinity of drinking water on energy budgets and physiological responses in adult Rufous-collared sparrow (Zonotrichia capensis), an omnivorous passerine that is ubiquitous in Chile and inhabits a wide range of environments. We acclimated birds to 30 days at two ambient temperatures (27 °C and 17 °C) and drinking water salinity (200 mM NaCl and fresh water) conditions. We evaluated: 1) the aerobic scope and the activities of mitochondrial metabolic enzymes, 2) osmoregulatory parameters, 3) the skin-swelling immune response to an antigen, 4) oxidative status, and 5) the length of telomeres of red blood cells. Our results confirm that Z. capensis tolerates the chronic consumption of moderate levels of salt, maintaining body mass but increasing their basal metabolic rates consistent with expected osmoregulatory costs. Additionally, the factorial aerobic scope was higher in birds acclimated to fresh (tap) water at both 17° and 27 °C. Drinking water salinity and low ambient temperatures negatively impacted inflammatory response, and we observed an increase in lipid peroxidation and high levels of circulating antioxidants at low temperatures. Finally, telomere length was not affected by osmo- and thermoregulatory stress. Our results did not support the existence of an interplay between environmental temperature and drinking water salinity on most physiological and biochemical traits in Z. capensis, but the negative effect of these two factors on the inflammatory immune response suggests the existence of an energetic trade-off between biological functions that act in parallel to control immune function.

Regulation of a plant aquaporin by a Casparian strip membrane domain protein-like.

The absorption of soil water by roots allows plants to maintain their water status. At the endodermis, water transport can be affected by initial formation of a Casparian strip and further deposition of suberin lamellas and regulated by the function of aquaporins. Four Casparian strip membrane domain protein-like (CASPL; CASPL1B1, CASPL1B2, CASPL1D1, and CASPL1D2) were previously shown to interact with PIP2;1. The present work shows that CASPL1B1, CASPL1B2, and CASPL1D2 are exclusively expressed in suberized endodermal cells, suggesting a cell-specific role in suberization and/or water transport regulation. When compared with wild-type plants, and by contrast to caspl1b1*caspl1b2 double loss of function, caspl1d1*caspl1d2 double mutants showed, in some control or NaCl stress experiments and not upon abscisic acid (ABA) treatment, a weak enlargement of the continuous suberization zone. None of the mutants showed root hydraulic conductivity (Lpr ) phenotype, whether in control, NaCl, or ABA treatment conditions. The data suggest a slight negative role for CASPL1D1 and CASPL1D2 in suberization under control or salt stress conditions, with no major impact on whole root transport functions. At the molecular level, CASPL1B1 was able to physically interact with PIP2;1 and potentially could influence the regulation of aquaporins by acting on their phosphorylated form.