mM Of NaCl Research Articles

Pseudoalteromonas agarivorans-derived Novel Ulvan Lyase of Polysaccharide Lyase Family 40: Potential Application of Ulvan and Partially Hydrolyzed products in Cosmetic Industry.

Ulvan is a complex sulfated polysaccharide in the cell walls of green algae with extensive applications in food, pharmaceutical, and agricultural industries, prompting extensive studies on ulvan, its oligosaccharides, monosaccharides, and cost-effective depolymerization methods. Our primary objectives were to investigate novel ulvan-utilizing marine bacteria, perform recombinant engineering of genes responsible for ulvan depolymerization, and determine their potential industrial applications. Samples were collected from Jeju Island, which is a South Korean region with significant excessive green algal growth, especially that of Ulva species. The marine bacterium Pseudoalteromonas agarivorans efficiently uses ulvan as its primary carbon source, indicating its potential for ulvan degradation. Thorough whole genome sequencing the paul40 gene, which is a polysaccharide lyase family 40 (PL40) member, was identified and subsequently engineered into the pET-16b vector for expression as a His-tagged 95kDa fusion protein. The ulvan depolymerization process was evaluated and confirmed using various analytical techniques including dinitrosalicylic acid assay, thin-layer chromatography, and gel permeation chromatography. Optimal enzyme activity occurred at 35°C, pH 8.0 in phosphate buffer, and 2.5mM of NaCl. Furthermore, enzyme characterization and specific activity measurements were performed. This study is the first to report hyaluronidase and elastase inhibition by ulvan and its derivatives along with the characterization of an ulvan lyase enzyme from the PL40 family.

Enhancing the interactions of ion-tagged oligonucleotides and magnetic ionic liquid supports for the sequence-specific extraction of hepatitis B virus DNA.

Infections from the hepatitis B virus (HBV) are a major risk factor for hepatocellular carcinoma, one of the most common types of liver cancer. Circulating cell-free DNA (ccfDNA) in human plasma can be used as a non-invasive biomarker for diagnosing HBV-related liver diseases. The isolation of target ccfDNA sequences is often challenging due to the co-extraction of highly abundant non-target DNA from samples. Ion-tagged oligonucleotide (ITO) probes coupled with magnetic ionic liquids (MIL) support have emerged as a promising methodology for sequence-specific DNA extractions to address challenges associated with solid supports such as streptavidin-coated magnetic bead. ITOs, disubstituted ion-tagged oligonucleotide (DTO), and ion-tagged disubstituted oligonucleotide (ITDO) probes featuring various substituents including linear alkyl, branched alkyl, and perfluoroalkyl moieties were examined to enhance hydrophobic and fluorophilic interactions between the probes and a trihexyl(tetradecyl)phosphonium manganese(II) hexafluoroacetylacetonate ([P66614+][Mn(hfacac)3-]) MIL support. The ITO-MIL approach was optimized by adjusting the annealing temperature (45°C), molar ratio of target DNA to ITO probe (1:100), and ionic strength (200mM NaCl) to maximize the extraction of target DNA. The 3-allyl-1-(23-bis(pentylthio)propyl)imidazolium bromide ([AI(C5S)2+][Br-])-ITO probe featuring a branched alkyl substituent yielded a higher loading efficiency (48.05±6.72%) due to increased hydrophobic ITO-MIL interactions, compared to that of 24.57±4.40% for the 3-allyl-1-(3-(pentylthio)propyl)imidazolium bromide ([AIC5S+][Br-])-ITO probe with a linear alkyl substituent. The high affinity of ITO-MILinteractions minimized the loss of probe during successive wash steps, yielding an approximate 10-fold greater amount of extracted target DNA using the [AI(C5S)2+][Br-])-ITO probe compared to [AIC5S+][Br-])-ITO probe. This study provides novel synthetic approaches for tailoring probe substituents using thiol-ene and thiol-yne "click" chemistry. Hydrophobic and fluorophilic ITO-MIL interactions were systematically investigated. Optimal conditions for the ITO-MIL method significantly improved the amount of extracted DNA. The ITO-MIL method using the [AI(C5S)2+][Br-]-HBV-ITO probe demonstrated selective extraction of target HBV DNA in both DI water and diluted human plasma containing a high abundance of background DNA.

Investigation into the mechanisms of photosynthetic regulation and adaptation under salt stress in lavender.

Salinity stress is a major threat to agricultural productivity and sustainability, often causing irreversible damage to photosynthesis. Lavender, a valuable aromatic plant, experiences growth impacts under salt stress. However, the regulatory mechanisms of photosynthesis related to its adaptation to salt stress remain unclear. In this study, lavender was exposed to 0, 100, 200, and 300mM NaCl for 28 days. It was observed that lavender effectively maintained chlorophyll stability when salt concentrations were below 200mM and stress duration was under 21 days. The most effective model for lavender under salt stress was identified as a right-angled hyperbolic modified model. Under moderate salt stress (100mM, 200mM), genes such as LaPSB28, LaPSBS, and LaPSBR contributed to PSII core stability, enhanced photosynthetic pigment levels, and sustained high electron transfer rates to improve salt-tolerance. Additionally, LaLHCB4-1 and LaPSAK-1 regulated stomatal size, thereby facilitating gas exchange and supporting the photosynthetic process. Conversely, under high salt stress (300mM), LaPSBW-1, -2, and LaPSAB were found to reduce photosynthetic pigment levels and inhibit photosynthetic activity. However, genes such as LaCHLG-2, LaGLG-3, LaBAM1-1 and -3, and LaCHLP-3 aided in starch synthesis by increasing pigment content, thus promoting energy balance and enhancing salt tolerance. This regulation involved photosynthesis-antenna proteins and pathways related to starch, sucrose, and chlorophyll metabolism. These findings may support the cultivation of salt-tolerant lavender varieties and maximize saline soil usage.

The relationships between photochemical reflectance index (PRI) and photosynthetic status in radish species differing in salinity tolerance.

Since photosynthesis is highly sensitive to salinity stress, remote sensing of photosynthetic status is useful for detecting salinity stress during the selection and breeding of salinity-tolerant plants. To do so, photochemical reflectance index (PRI) is a potential measure to detect conversion of the xanthophyll cycle in photosystem II. Raphanus sativus var. raphanistroides is a wild radish species closely related to domesticated radish, and is distributed throughout the coastal regions of Japan, where it is thought to be salt tolerant. In this study, we raised wild and domesticated radishes under various salt conditions and assessed growth, photosynthetic status, and PRI. When grown at mild salt stress (50mM NaCl), wild radish leaves showed photosynthetic activity levels comparable to control plants, whereas the photosynthetic activity of domesticated radish was suppressed. This result suggests that wild radishes are more salt-tolerant than domesticated radishes. Although photosynthetic rate and the photochemical quantum yield were significantly correlated with PRI in both species, the PRI resolution was insufficient to distinguish differences in salt tolerance between wild and domesticated radish. Wild radish had a lower maximum quantum yield (Fv/Fm) when grown under moderate salt stress (200mM NaCl), suggesting chronic photoinhibition. The relationship between non-photochemical quenching (NPQ) and PRI was significant when leaves with chronic photoinhibition were eliminated but this relationship was not significant when they were included. In contrast, the relationship between photosynthesis and PRI was significant regardless of whether leaves displayed chronic photoinhibition or not. We conclude that PRI is useful to detect relatively large reductions in photosynthetic rate under salinity stress, and that care should be taken to evaluate NPQ from PRI.

Characterization of PHT Genes in ‘duli’ (Pyrus betulifolia Bunge) and Expression Analysis of PbPHTs in Response to Plant Growth Regulators, P, and Salt Stress

The phosphate transporter (PHT) family plays an important role in the uptake and transport of P elements in plants. A total of 158 PbPHTs were identified from the genome of ‘duli’ (Pyrus betulifolia Bunge) in this study, including 70 PbPHT1s, 2 PbPHT2s, 70 PbPHT3s, 12 PbPHT4s, and 4 PbPHT5s. Among the 158 PHT genes, 150 were localized to 17 ‘duli’ chromosomes. Gene duplication analysis identified 18 tandemly duplicated gene pairs. The promoter analysis showed that there were a large number of cis-acting elements related to phytohormones, growth, development, stress, and light response in PbPHTs. qRT-PCR analysis revealed that most PHT genes in ‘duli’ were highly expressed in the fruits, flowers, leaves, stems, and roots, and 15 PbPHT genes were responsive to 5 μM, 0.5 mM, 5 mM H2PO4, NaCl, GR24 (synthetic SL analog), GA3 (gibberellin 3), ABA (abscisic acid), and IAA (indole-3-acetic acid). GR24, GA3, IAA, and 5 mM KH2PO4 treatments could increase the concentration, absorption, transport, and distribution of P elements in the rhizomes and leaves of ‘duli’, but 5 μM KH2PO4, NaCl, and ABA had the opposite effect. This study therefore provides a list of PbPHT genes with substantial roles in abiotic stress response, as well as important information to understand the functional characteristics of PbPHT during ‘duli’ abiotic stress tolerance, and explores the function of PbPHTs in exogenous hormones, phosphorus, and salt stress in the future.

Luminal flow in the connecting tubule induces afferent arteriole vasodilation.

Renal autoregulatory mechanisms modulate renal blood flow. Connecting tubule glomerular feedback (CNTGF) is a vasodilator mechanism in the connecting tubule (CNT), triggered paracrinally when high sodium levels are detected via the epithelial sodium channel (ENaC). The primary activation factor of CNTGF-whether NaCl concentration, independent luminal flow, or the combined total sodium delivery-is still unclear. We hypothesized that increasing luminal flow in the CNT induces CNTGF via O2- generation and ENaC activation. Rabbit afferent arterioles (Af-Arts) with adjacent CNTs were microperfused ex-vivo with variable flow rates and sodium concentrations ranging from < 1 to 80mM and from 5 to 40 nL/min flow rates. Perfusion of the CNT with 5mM NaCl and increasing flow rates from 5 to 10, 20, and 40 nL/min caused a flow-rate-dependent dilation of the Af-Art (P < 0.001). Adding the ENaC blocker benzamil inhibited flow-induced Af-Art dilation, indicating a CNTGF response. In contrast, perfusion of the CNT with < 1mM NaCl did not result in flow-induced CNTGF vasodilation (P > 0.05). Multiple linear regression modeling (R2 = 0.51; P < 0.001) demonstrated that tubular flow (β = 0.163 ± 0.04; P < 0.001) and sodium concentration (β = 0.14 ± 0.03; P < 0.001) are independent variables that induce afferent arteriole vasodilation. Tempol reduced flow-induced CNTGF, and L-NAME did not influence this effect. Increased luminal flow in the CNT induces CNTGF activation via ENaC, partially due to flow-stimulated O2- production and independent of nitric oxide synthase (NOS) activity.

Nano‐Porous Melt‐Blown Poly(Lactic Acid) Fiber Mat Air Filters for High Efficiency Particulate Capture

AbstractThis study introduces a two‐step technique for developing nano‐porous, compostable melt‐blown nonwovens with high porosity, specifically engineered for high‐performance particulate capture in air filter applications. The first step entails creating a high melt flow index material by melt‐blending low‐viscosity polylactic acid (PLA) with a sacrificial additive, polyethylene glycol (PEG), of varying molecular weights. Rheological, compatibility, and thermal analyses are conducted on the sample blends. The MFI of the resulting blends ranges from 56 g/10 min (baseline PLA) to 238 g/10 min (PLA/PEG 400–10%), confirming their suitability for the melt‐blowing process. These blends are then formed into nonwoven mats using a twin‐screw extruder, producing microfibers with diameters between 1.05 and 2.64 µm. The second step involves boiling water etching to remove PEG, creating nanopores within the fibers. This etching process leaves a network of nanopores (50–200 nm in size), distributed throughout the microfiber structure. The PLA/PEG 2000 sample exhibits optimal properties, achieving ≈72% particulate capture efficiency for 0.3 µm NaCl particulates during air filtration testing. This study represents an innovative and eco‐friendly approach for creating nano‐porous nonwoven mats with potential applications in air filtration, water filtration, and battery separators, where high porosity is beneficial.

Effect of Severe Salt Stress on Respiratory and Biochemical Parameters in Legumes With Differential Nodulation Form

ABSTRACTLegumes are among the most utilised agronomic plant species due to their symbiotic association with N2‐fixing bacteria. Since N2 fixation entails high ATP cost, salt stress disrupts N2 fixation in the symbiont, but increases the production of osmolytes and antioxidant systems in the host plant. This results in competition for C allocation between osmoprotection in the host and continued supply to the symbiont for N acquisition, which may result in different plant responses to salinity. Two‐nodule types of plant species with contrasting carbon requirements for organic N2 fixation can be found within legume species; determinate and indeterminate. In this study, we tested responses of respiratory carbon metabolism, nitrogen assimilation and antioxidant machinery in leaves and roots of Phaseolus vulgaris (determinate nodules) and Pisum sativum (indeterminate nodules) 24 and 72 h after salt treatment (300 mM of NaCl). In P. sativum, we observed that nitrogenase activity was maintained at 24 h, but showed a strong decrease at 72 h together with cytochrome activity. On contrast, in P. vulgaris, respiration rates were maintained by an enhanced antioxidant activity under salinity although at the expense of nodule metabolism. Despite of the severity of the salt stress for N2 fixation, both species showed similar mechanisms to cope with salinity, like the maintenance of alternative respiration and increased antioxidant defence, that are worthy to be tested in the long term under field conditions.

Rational Design of a Novel DNA Polymerase From Clostridium thermocellum to Improve LAMP Detection Performance.

Loop-mediated isothermal amplification (LAMP) is a detection method widely used in pathogen detection and clinical diagnosis. Nevertheless, it is highly constrained by thermal stability, catalytic activity, and resistance to inhibitors of Bst DNA polymerase. In this study, a novel DNA polymerase was characterized from Clostridium thermocellum, exhibiting potential in LAMP detection. Through bioinformatics analysis, the enzyme and the DNA-binding domain (DBD) from Pyrococcus abyssi were mutated for enhanced interaction between proteins and DNA. A chimeric mutant DBDE146K-S738R reaches the detection threshold 13 min earlier than wild-type Cth DNA polymerase in real-time LAMP detection with a template concentration of 1.58 × 105 fg/µL. It also showed the highest enzymatic activity at pH 9.0 and 65°C. The chimeric enzyme DBDE146K-S738R exhibits good thermal stability, capable of performing LAMP reactions after treatment at 73°C or 70°C for 8 h. Moreover, it maintains high activity even under the inhibitory conditions of 50 U/mL heparin, 1.6mM EDTA, 200mM NaCl, 10% ethanol, 1.2M urea, or 0.8% phenol. Notably, it was able to detect 1.58 × 102 ag/µL of the genome and 1.03 CFU/mL of the colony in Salmonella typhimurium detection. The enzyme's performance is superior to commercial Bst 2.0 and comparable to commercial Bst 3.0. The results suggest that DBDE146K-S738R in LAMP exhibits great potential for molecular biological studies and clinical diagnostic analysis.

Biopriming of Maize with their endophyte Aspergillus fumigatus reinforces their resistance to salinity stress and improves their physiological traits

Zea mays L. (Maize) is one of the most crucial world’s crops, for their nutritional values, however, the water scarcity and consequent soil salinization are the major challenges that limit the growth and productivity of this plant, particularly in the semi-arid regions in Egypt. Recently, biopriming has been recognized as one of the most efficient natural-ecofriendly approaches to mitigate the abiotic salt stress on plants. The haploid (128) and triploid (368) seeds of maize were selected as model verities for assessing their resistance to salt stress and mitigating their effect by fungal-biopriming. Overall, the haploid and triploid plants viabilities were drastically affected by salt concentration, at 500 mM of NaCl. At 500 mM NaCl, the fresh weights of the triploid and haploid seedlings were reduced by ~ 5 and 6.1 folds, compared to the controls, ensuring slightly higher salt resistance of the triploid than haploid ones. The pattern of the endophytic fugal isolates was plausibly changed with the salt concentration for both plant types, Aspergillus fumigatus isolate was emerged with the higher NaCl concentration (400–500 mM), and their morphological identity was molecularly confirmed and deposited into Genbank with accession # PQ200673. The fungal bioprimed seeds of the haploid and triploid plants were irrigated with 400 mM NaCl. The fungal-bioprimed plants displayed a significant improvement on the shoot density, fibrous roots, root length, shoot length, and leaves numbers and areas of the stressed-plants by ~ 1.7 folds, compared to control, ensures the triggering of different salt resistance machineries in plants upon fungal biopriming. The total antioxidant enzymes activities “catalase, peroxidase, superoxide dismutase” of the salt-stressed bioprimed maize plants were increased by ~ 4.7–5.3%, compared to control, confirming the mitigating effect of the salinity stress on plants upon fungal biopriming. The chlorophyll and carotenoids contents were significantly increased of the salt stressed maize upon biopriming with A. fumigatus. The expression of the sod, apx2, nhx11, hkt1, H + -PPase, nced of the plant salt stressed was strongly increased in response to A. fumigatus biopriming, normalized to β-actin gene. The expression of apx2 was dramatically increased by about 30 and 43 folds, in response to fungal biopriming. The nhx1 was significantly up-regulated by 18.9 fold in response to fungal biopriming, compared to control.

Ionization Characteristics of Glycan Homologues in Various Modes of Electrospray.

Fluorescence labeled glycan homologous mixtures were quantified using fluorescence and then used to evaluate ionization performances in electrospray ionization at micro, nano, and femto flow modes. nanoESI produced higher (2+ and 3+) charged ions adducted with sodium and calcium. In comparison, femtoESI was found to favor the generation of [M + H]+ ions against metal adducts, even with nonvolatile salts up to 1 mM for NaCl and 100 μM for CaCl2. For labeled glucose homopolymer (GHP) glycans, nanoESI and femtoESI had 0.81 and 3 nM detection limits, respectively. With LC separation and a much higher flow rate, conventional microflow ESI detected all glycans with 10-fold lower concentrations. Overall, nanoESI had the optimum uniformity in the relative ionization efficiency (RIE). When summing up intensities of analyte ions formed with all charge carriers, the RIE of the midsized glycans (10 to 16 glucose units) appear to be uniform (RIE 95%-105%). For the smaller (1-5 glucose units) glycan components, femtoESI provided better uniformity than nanoESI and conventional ESI. For the labeled IgG N-glycans, the impact of chemical structure on the ionization efficiency was revealed by the strong correlation between their RIE trends in different ionization modes.

Role of biotin carboxyl carrier protein subunit 2 (BCCP2) in resistance to multiple stresses in Arabidopsis thaliana.

Abiotic stresses, including drought, salinity, and temperature extremes, are serious constraints to plant growth and agricultural development. These stresses that plants face in nature are often multiple and complex. Biotin carboxyl carrier protein subunit 2 (BCCP2) is one of the two subunits of biotin carboxyl carrier protein, which is a functional subunit of acetyl coenzyme A carboxylase, primarily studied for its role in fatty acid synthesis. In this study, we identified the expression pattern of AtBCCP2 under various stress conditions, including 4mM NaHCO₃, 2mM Na₂CO₃, 150mM NaCl, 300mM D-mannitol, 100μM ABA, 5mMH₂O₂, 4°C, and 37°C. It was determined that AtBCCP2 is positively regulated by NaHCO₃, Na₂CO₃, NaCl, and ABA, but negatively regulated by D-mannitol. Phenotypic experiment confirmed that the AtBCCP2 transgenic overexpression plants exhibited increased resistance to NaHCO₃, Na₂CO₃, NaCl, and ABA stresses, but more sensitive to drought stress simulated by D-mannitol. In contrast, mutant plants showed the opposite phenotypes. Additionally, AtBCCP2 transgenic overexpression plants demonstrated stronger antioxidant activity and lower MDA content under stresses such as NaHCO₃, Na₂CO₃, NaCl, and ABA, in contrast to the mutant plants. In response to D-mannitol simulated drought stress, AtBCCP2 transgenic overexpression plants showed lower antioxidant activity and higher MDA content, while mutant plants exhibited the opposite trend. In conclusion, this study provides a theoretical basis for understanding the role of AtBCCP2 in response to multiple stresses and contributes a new gene to the pool of those involved in abiotic stress responses.

Amorphous cassava starch/spirulina protein mixtures stabilized Pickering emulsions: Preparation and stability.

This study explored stabilized emulsions using cassava starch (CS) and spirulina protein (SP) mixtures, targeting microbial proteins as potential replacements for animal proteins in food stability applications. The final viscosity and enthalpy change of the CS/SP mixtures decreased from 3.78 to 1.58Pa·s and from 11 to 6.2J/g with increased SP content (from 0% to 40%). Hydrophobic interactions were predominant in mixtures. Optimal emulsion stability was achieved with 70% oil fraction and 40% SP content, where adjustments in CS/SP ratio enhanced the robustness of cross-linked network. Thermal treatment, pH, and ionic strength differently affect emulsion storage stability for 42days, with optimal performance at 70°C, pH3, and 50mM NaCl. Synergistic stabilization of CS and SP was achieved through interfacial structures providing steric barriers and electrostatic repulsion, preventing droplet coalescence. This research highlights the potential of emulsions as nutrient delivery systems with high resilience against environmental stresses.

Unveiling abiotic stress-induced cell death modalities in the heterocytous cyanobacterium Anabaena sp. PCC 7120

Regulated cell death (RCD) in cyanobacteria is a post-stress phenomenon necessary for stress adaptability and eco-physiology. However, the sequential modulations in cellular processes conferring regulated forms of death remained elusive. In this study, we evaluated morpho-physiological and biochemical determinants of cell death in a time-dependent manner to understand the sequential cellular events during the process. The death was instigated by exposing heterocytous cyanobacterium Anabaena sp. PCC 7120–1 mM H2O2, 250 mM NaCl and sulfur-starvation. A significant changes in the sequences of morpho-physiological and biochemical events were observed in different stress conditions. Upon H2O2 treatment rapid oxidation of cytosol and disintegration of cell envelop was observed prior to DNA fragmentation. On the other hand, salt-stress and sulfur-deprivation induced phosphatidylserine (PS) externalisation, gradual rise in redox potential, and DNA fragmentation prior to membrane disintegration. Furthermore, we analysed the time-dependent expression of five orthocaspases, the putative executioner of cyanobacterial cell death. Out of five, only two orthocaspases anaOC2 and anaOC6 exhibit expression pattern synergistic and coherent with DNA fragmentation in salt treated and sulfur-deficient cells. However, no orthocaspases expression was evident during H2O2 treatment. Considering these parameters, H2O2 induced death was regarded as accidental cell death (ACD), whereas in salt and sulfur stresses mediated two different RCD subroutines, which were orthocaspases-dependent. Overall for the first time, we demonstrated the existence of three death modalities in cyanobacteria based on sequential cellular events and relative expression of orthocaspases.

Plant Growth‐Promoting Bacteria Associated With Some Salt‐Tolerant Plants

ABSTRACTGiven the benefits of bacteria associated with the rhizosphere and phytoplane of halophytes, this research focused on examining the plant growth‐promoting characteristics of bacteria isolated from Cressa cretica, Suaeda aegyptiaca, and Alhagi graecorum. From the 33 isolates tested, 9 exhibited plant growth‐promoting traits. Bacillus rugosus strain CS5 and Bacillus sp. strain SS4 exhibited the notable growth inhibition of the pathogenic fungus Fusarium oxysporum, with values of 47% and 45%, respectively. Bacillus sp. strains SS4 and CS1 demonstrated impressive results in solubilizing phosphorus and zinc, respectively, achieving concentrations of 259 and 271 mg L−1. Additionally, Staphylococcus xylosus strain SR2, Bacillus sp. strain SS4, and Bacillus paralicheniformis strain CR1 thrived in nitrogen‐free media. The Priestia filamentosa strain AL4 showed the greatest HCN production, whereas B. paralicheniformis strain CR1 was notable for higher auxin production. The Bacillus sp. strains SS4 and CS1 exhibited greater tolerance than other isolates in a medium containing 600 mM of NaCl. Additionally, inoculating these isolates into soil significantly alleviated the salinity and drought stress on Zea mays seedlings. These findings suggest that further investigation into these strains as microbial inoculants could be beneficial for mitigating salt and drought stress in plants.

Arbuscular Mycorrhizae Confers Salinity Tolerance to Medicago sativa L.

Alfalfa, a crop cultivated worldwide for use as livestock feed, exhibits great adaptability to various environmental conditions. This study evaluates the biomass production, lipid peroxidation, photosynthetic pigments and osmo-compatible response in Medicago sativa var CW660 mycorrhizae (AM) and non-mycorrhizae (NM) plants with Rhizophagus intraradices and when subjected to salinity (100 mM and 200 mM of NaCl). They were evaluated using the following morphological parameters: foliage fresh weight (FFW), foliage dry weight (FDW), root fresh weight (RFW), root dry weight (RDW), foliage length (FL) and root length (RL), chlorophylls a and b, proline and malondialdehyde (MDA) in AM and NM plants treated with different concentration of NaCl. The LFW and the LDW were higher in M plants. The RFW and the RDW increased in control AM plants, and under different saline treatments there were no differences between AM and NM in either parameter. FL increased in the control and at 100 mM of NaCl in M plants. Chlorophyll a decreased 27–30% and b decreased 1–50% in AM and NM plants at 200 mM NaCl. The proline level increased four times and promoted a defense in AM plants at 200 mM of NaCl. Lipid peroxidation decreased in AM plants by 10% at maximum salinity. M. sativa CW660 is sensitive to salinity stress, and inoculation with arbuscular mycorrhizal fungi (AMF) regulates its physiology and performance under such conditions, with osmotic protection and membrane protection.

Mixed matrix PVDF microfiltration membranes with in-situ synthesized polyethyleneimine particles as a platform for flow through, high capacity, weak base and salt tolerant anion exchange membrane adsorbers for downstream bioprocessing

The rapid growth of the monoclonal antibody (mAb) therapeutic market has led to a need for improved downstream bioprocessing, including mAb capture and release from bioreactor harvests followed by product purification and polishing. Membrane chromatography (MC) is poised to displace resin-based column chromatography in mAb product polishing. To remove negatively charged product impurities (e.g., host cell proteins, DNA, viruses, and endotoxins), anion exchange (AEX) membrane adsorbers offer higher process rates and eliminate the risks of cross contamination as they can be deployed as single use separation devices, which are increasingly being utilized in downstream bioprocessing to increase manufacturing speed and decrease production cost. Here, we describe a one-pot and single step phase inversion casting process for the preparation of a family of mixed matrix polyvinylidene fluoride (PVDF) microfiltration (MF) membranes with in-situ synthesized polyethyleneimine (PEI) microparticles that can serve as flow through, high capacity, and salt tolerant weak base AEX membrane adsorbers. These new membranes have a high content of weak base (WB) groups (primary and secondary amines) by virtue of the utilization of bis(2-chloroethyl)amine hydrochloride (BCAH) as crosslinker in the in-situ synthesis of PEI microparticles in the dope dispersions prior to membrane casting. By varying the concentration of PEI and BCAH in the casting dispersions, we successfully utilized nonsolvent induced phase separation (NIPS) with isopropyl alcohol as the nonsolvent in the membrane coagulation bath to prepare a mixed matrix PVDF-PEI MF membrane with (i) a relatively uniform and open microstructure in which the PEI particles completely cover the PVDF spherulites present at the membrane surface and cross section, (ii) high water flux (>1000 liters/m2/hr. at 2 bar) and (iii) a high loading of BCAH crosslinked PEI microparticles (51.0 wt%) containing weak base primary, secondary, and tertiary amine groups. The protein binding measurements show that this new mixed matrix PVDF-PEI MF membrane can serve as a flow through, high capacity, and salt tolerant WB AEX membrane adsorber with a bovine serum albumin (BSA) dynamic binding capacity of ∼60 mg BSA per mL of membrane in a 50 mM TRIS buffer containing 100 mM of NaCl (15 mS/cm) at 10 % breakthrough and flow rate of 10 MV/min. The overall results of this study indicate that our mixed matrix PVDF-PEI MF membranes with in-situ synthesized and BCAH crosslinked PEI microparticles have a promising potential to serve as a platform for the design, preparation, and scale up of a new generation of flow through, high capacity, salt tolerant, WB AEX membrane adsorber materials for downstream bioprocessing.

Heterologous expression of the durum wheat TdHKT1;4-1 partially complements the mutant athkt1 in Arabidopsis thaliana under severe salt stress.

High-affinity K+ (HKT) transporters which mediate Na+-specific transport or Na+-K+ co-transport play a key role in plant salt tolerance. In our previous functional study in Xenopus oocytes, we demonstrated that the durum wheat TdHKT1;4-1 acts as a Na+-selective transporter. Here, we investigated the function of TdHKT1;4-1 and its contribution in salt stress tolerance in the Arabidopsis athkt1 mutant background. Our results revealed that TdHKT1;4-1 partially complements the salt sensitivity phenotype of the athkt1 transgenic lines. Comparative physiological analyses and oxidative stress status under moderate salt stress (50mM NaCl) showed that both transgenic lines SH3 and SH5 restored the salt stress tolerance comparable to the level observed in Wt plants. Whereas, under severe salt stress treatment (100mM NaCl), the athkt1 transgenic lines exhibited an intermediate salt stress tolerance between Wt and athkt1 mutant. Moreover, TdHKT1;4-1 was highly expressed in leaves under moderate and severe salt stress, while in roots, it was largely expressed only under severe salt stress. In addition, antioxidant enzymes such as catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) were significantly expressed in SH3 and SH5 lines compared to athkt1 and Wt under moderate stress. Therefore, TdHKT1;4-1 seems to differ from its Arabidopsis homologous counterpart, as it contributes to salt stress tolerance up to a specific threshold, above which the TdHKT1;4-1 expression may lead to higher root Na+ influx, hence increasing its toxicity during salt stress.

Investigation of the association between gene expression levels and phenolic compound content in the leaves of Sonchus arvensis plants under salinity stress

Sonchus arvensis is recognized for its high content of phenolic compounds and antioxidants, exhibiting various medicinal benefits, including anti-diabetic, anti-depressant, and anti-cancer properties. This has positioned the plant as a significant candidate for commercial food, medicinal, and antioxidant supplements. Salinity may enhance the level of chlorogenic and caffeic acid, which are key secondary metabolites in S. arvensis. To investigate this, a completely randomized design experiment with three replications was implemented in a greenhouse to examine the impact of salinity on the expression of six genes responsible for the biosynthesis of chlorogenic acid. Additionally, the study examined how salinity affects the accumulation of chlorogenic acid, caffeic acid, chicoric acid, and apigenin in the lower and middle leaves of plants. Salinity stress treatments were applied at four different levels: 0 (control), 50, 100, and 150 mM of NaCl. The results indicated that the expression levels of phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), 4-coumarate-CoA ligase (4CL), and p-coumaroyl ester 3′-hydroxylase (C3′H) were highest in the middle leaves at a concentration of 150 mM NaCl. Notably, there was an eight-fold increase in C4H expression in these leaves under the same salinity conditions. Conversely, the expression of shikimate/quinate O-hydroxycinnamoyl transferase (HCT) and quinate O-hydroxycinnamoyl transferase (HQT) genes decreased across all salinity treatments. Additionally, the levels of chlorogenic acid, caffeic acid, and chicoric acid were significantly elevated at 50 mM NaCl in both the lower and middle leaves, suggesting that cultivating S. arvensis in mildly saline environments could be beneficial. Furthermore, the findings from this study may serve as a preliminary step towards the cloning and full characterization of the genes examined in S. arvensis.

Lipid metabolism improves salt tolerance of Salicornia europaea.

Salicornia europaea L., a succulent euhalophyte plant, has been found to exhibit optimal reproductive capabilities under appropriate salinity concentrations. However, the underlying metabolic changes are not yet fully understood. This study conducted a comprehensive analysis combining transcriptomic and lipidomic techniques to investigate the molecular mechanisms of lipid metabolism in response to different NaCl concentrations (0 and 200mM). Transcriptomic data demonstrated that salt treatment mainly affected processes including lipid biosynthesis, phosphatidylinositol signaling, and glycerophospholipid metabolism. The expression levels of several key genes involved in salt tolerance, namely SeSOS1, SeNHX1, SeVHA-A, SeVP1, and SePSS, were found to be upregulated upon NaCl treatment. A total of 485 lipid compounds were identified, of which 27 changed in abundance under salt treatment, including the enrichment of phospholipids and sphingolipids. Moreover, the increase in the double-bond index (DBI) was mainly due to phospholipids and sphingolipids. Comparing the acyl chain length (ACL) showed that the ACL coefficient of S1P significantly decreased under 200mM NaCl. This study suggests that S. europaea adapt to saline environments through altering phospholipids and sphingolipids to improve salt tolerance. The salinity response of S. europaea can provide important insights into the action of lipids and their salt adaptation mechanisms.