Salt Treatment Research Articles

Medicago truncatula β-glucosidase 17 contributes to drought and salt tolerance through antioxidant flavonoid accumulation.

Flavonoids are usually present in forms of glucosides in plants, which could be catabolized by β-glucosidase (BGLU) to form their corresponding flavonoid aglycones. In this study, we isolated three abiotic-responsive BGLU genes (MtBGLU17, MtBGLU21and MtBGLU22) from Medicago truncatula, and found only the recombinant MtBGLU17 protein could catalyse the hydrolysis of flavonoid glycosides. The recombinant MtBGLU17 protein is active towards a variety of flavonoid glucosides, including glucosides of flavones (apigenin and luteolin), flavonols (kaempferol and quercetin), isoflavones (genistein and daidzein)and flavanone (naringenin). In particular, the recombinant MtBGLU17 protein preferentially hydrolyses flavonoid-7-O-glucosides over their corresponding 3-O-glucosides. The content of luteoin-7-O-glucoside was reduced in the MtBGLU17 overexpression plants but increased in the Tnt-1 insertional mutant lines, whereas luteoin content was increased in the MtBGLU17 overexpression plants but reduced in the Tnt-1 insertional mutant lines. Under drought and salt (NaCl) treatment, the MtBGLU17 overexpression lines showed relatively higher DPPH content, and higher CAT and SOD activity than the wild type control. These results indicated that overexpression lines of MtBGLU17 possess higher antioxidant activity and thus confer drought and salt tolerance, implying MtBGLU17 could be potentially used as a candidate gene to improve plant abiotic stress tolerance.

GhCLCc-1, a Chloride Channel Gene from Upland Cotton, Positively Regulates Salt Tolerance by Modulating the Accumulation of Chloride Ions.

The ionic toxicity induced by salinization has adverse effects on the growth and development of crops. However, researches on ionic toxicity and salt tolerance in plants have focused primarily on cations such as sodium ions (Na+), with very limited studies on chloride ions (Cl-). Here, we cloned the homologous genes of Arabidopsis thaliana AtCLCc, GhCLCc-1A/D, from upland cotton (Gossypium hirsutum), which were significantly induced by NaCl or KCl treatments. Subcellular localization showed that GhCLCc-1A/D were both localized to the tonoplast. Complementation of Arabidopsis atclcc mutant with GhCLCc-1 rescued its salt-sensitive phenotype. In addition, the silencing of the GhCLCc-1 gene led to an increased accumulation of Cl- in the roots, stems, and leaves of cotton seedlings under salt treatments, resulting in compromised salt tolerance. And ectopic expression of the GhCLCc-1 gene in Arabidopsis reduced the accumulation of Cl- in transgenic lines under salt treatments, thereby enhancing salt tolerance. These findings elucidate that GhCLCc-1 positively regulates salt tolerance by modulating Cl- accumulation and could be a potential target gene for improving salt tolerance in plants.

The PbbHLH62/PbVHA-B1 module confers salt tolerance through modulating intracellular Na+/K+ homeostasis and reactive oxygen species removal in pear

The vacuolar H+-ATPase (V-ATPase) is a multi-subunit membrane protein complex, which plays pivotal roles in building up an electrochemical H+-gradient across tonoplast, energizing Na+ sequestration into the central vacuole, and enhancing salt stress tolerance in plants. In this study, a B subunit of V-ATPase gene, PbVHA-B1 was discovered and isolated from stress-induced P. betulaefolia combining with RT-PCR method. The RT-qPCR analysis revealed that the expression level of PbVHA-B1 was upregulated by salt, drought, cold, and exogenous ABA treatment. Subcellular localization analyses showed that PbVHA-B1 was located in the cytoplasm and nucleus. Moreover, overexpression of PbVHA-B1 gene noticeably increased the ATPase activity and the tolerance to salt in transgenic Arabidopsis plants. In contrast, knockdown of PbVHA-B1 gene in P.betulaefolia by virus-induced gene silencing had reduced resistance to salt stress. In addition, using yeast one-hybride (Y1H) and yeast two-hybride (Y2H) screens, PbbHLH62, a bHLH transcription factor, was identified as a partner of the PbVHA-B1 promoter and protein. Then, we also found that PbbHLH62 positively regulate the expression of PbVHA-B1 and the ATPase activity after salt stress treatment. These findings provide evidence that PbbHLH62 played a critical role in the salt response. Collectively, our results demonstrate that a PbbHLH62/PbVHA-B1 module plays a positive role in salt tolerance by maintain intracellular ion and ROS homeostasis in pear.

Identification of QTNs, QTN-by-environment interactions, and their candidate genes for salt tolerance related traits in soybean

BackgroundSalt stress significantly reduces soybean yield. To improve salt tolerance in soybean, it is important to mine the genes associated with salt tolerance traits.ResultsSalt tolerance traits of 286 soybean accessions were measured four times between 2009 and 2015. The results were associated with 740,754 single nucleotide polymorphisms (SNPs) to identify quantitative trait nucleotides (QTNs) and QTN-by-environment interactions (QEIs) using three-variance-component multi-locus random-SNP-effect mixed linear model (3VmrMLM). As a result, eight salt tolerance genes (GmCHX1, GsPRX9, Gm5PTase8, GmWRKY, GmCHX20a, GmNHX1, GmSK1, and GmLEA2-1) near 179 significant and 79 suggested QTNs and two salt tolerance genes (GmWRKY49 and GmSK1) near 45 significant and 14 suggested QEIs were associated with salt tolerance index traits in previous studies. Six candidate genes and three gene-by-environment interactions (GEIs) were predicted to be associated with these index traits. Analysis of four salt tolerance related traits under control and salt treatments revealed six genes associated with salt tolerance (GmHDA13, GmPHO1, GmERF5, GmNAC06, GmbZIP132, and GmHsp90s) around 166 QEIs were verified in previous studies. Five candidate GEIs were confirmed to be associated with salt stress by at least one haplotype analysis. The elite molecular modules of seven candidate genes with selection signs were extracted from wild soybean, and these genes could be applied to soybean molecular breeding. Two of these genes, Glyma06g04840 and Glyma07g18150, were confirmed by qRT-PCR and are expected to be key players in responding to salt stress.ConclusionsAround the QTNs and QEIs identified in this study, 16 known genes, 6 candidate genes, and 8 candidate GEIs were found to be associated with soybean salt tolerance, of which Glyma07g18150 was further confirmed by qRT-PCR.

Exploring the impact of endophytic bacteria on mitigating salinity stress in Solanum lycopersicum L.

In the era of climate change, plants are being compelled to adapt and endure progressively in unfavorable environments. Applying biostimulants to plants can improve their growth and resilience by mitigating the adverse effects of abiotic stresses. Endophytes are well-known for promoting plant growth and producing natural compounds. The current study focuses on the ability of endophytic bacteria to increase plant growth and reduce salt stress in tomato plants. Nine isolates from the stems of Fagonia indica and Ajuga bracteosa showed a variety of salt stress tolerances as well as solubilizing phosphate, indole acetic acid, ammonia production, siderophore production, and extracellular enzymes like protease, cellulase, and chitinase. Four Endophytic bacteria Enterobacter hormaechei (MOSEL-FLS1), Stenotrophomonas maltophilia (MOSEL-FLS2), Bacillus subtilis (MOSEL-S8), and Staphylococcus epidermidis (MOSEL-S9) were selected based on plant growth promoting traits and halotolerant assay. These endophytic bacteria were subjected to ex-situ activities to figure out their capacity to stimulate the growth of the tomato plant in the growth room under different concentrations of NaCl (50–200 mM). All bacterial strains stimulated tomato plant growth under salinity stress compared to uninoculated controls. Antioxidant enzymes (SOD and POD), chlorophyll, and proline level in the plants was increased after salt treatment. Moreover, the activity of antioxidant enzymes and their relative transcript levels were dependent on the concentration of salinity stress. These findings highlight the varied microbial community linked to medicinal plants and their capacity to promote plant growth, potentially mitigating salt stress through the regulation of osmolytes and antioxidant enzymes. This makes them promising contenders for biofertilizers.

Determination of germination characteristics and salinity and drought tolerances of Mountain Swan (Atriplex nitens Schkuhr)

In this study, it was aimed to determine the appropriate seed germination temperature, salt tolerance, salinity and drought tolerance of seedlings in Mountain swan (Atriplex nitens). For this purpose, an experiment was established in 2021 in laboratory conditions according to the factorial experiment design in random plots and in greenhouse conditions according to the random plots experiment design with three replications. Firstly, 4 constant (10, 15, 20, 25, 30°C) and 2 variable (20/15, 25/15°C) temperatures were used in the refrigerated incubator. Total germination rates and average germination times of seeds with and without pericarp were determined. Secondly, 6 different salt concentrations (0, 100, 200, 300, 400 and 500 mM NaCl) were studied considering the optimum germination temperatures (25°C and 20/15°C). At the end of the study, germination rates (%), average germination times (days) and sensitivity indices (SI) were determined. In the last two stages, seedlings were subjected to 4 different salinity (0, 100, 200, 300, 400 and 500 mM NaCl) and 5 different drought (control, low, moderate, high and severe) tests under greenhouse conditions. At this stage, plant and root length, stem thickness, leaf area index (LAI), plant and root dry weight, root/plant ratio and tolerance percentage values were measured. As a result of the laboratory study, it was determined that seeds without pericarp had a better germination percentage than seeds with pericarp. The highest total and normal germination rates were obtained from 200 mM NaCl treatment at 20/15°C. Germination rate was determined from 0, 100 and 200 mM salt treatments at 25°C. These results showed that Atriplex nitens seeds could germinate in high salt concentrations and that their seedlings had high tolerance to drought and salinity.

Combined Transcriptome and Proteome Analysis Reveals the Molecular Mechanism by Which ZmPDI Improves Salt Resistance in Rice (Oryza sativa)

As one of the most salt-tolerant grasses, characterizing salt-tolerance genes of Zoysia matrella [L.] Merr. not only broaden the theoretical information of salt tolerance, but also provide new salt-resistant genetic resources for crop breeding. The salt-inducible protein disulfide isomerase (ZmPDI) of Zoysia matrella [L.] Merr. was proved to enhance salt tolerance in homologous overexpression transgenic plants. In order to evaluate its potential application in crops, we conducted the salt tolerance evaluation in heterologous overexpression transgenic rice (OX-ZmPDI), Wild-type (WT) rice, and LOC_Os11g09280 (OsPDI, homologous gene of ZmPDI in rice) knock-out rice generated by CRISPR-Cas9 system (CR-OsPDI). Our findings revealed that OX-ZmPDI rice was higher and exhibited longer main root length, more proline (Pro) and malondialdehyde (MDA) and peroxidase (POD) activity than WT control after salt treatment, while CR-OsPDI resulted in contrary phenotypes. These results indicated that ZmPDI can significantly enhance the salt tolerance in rice, whereas loss-of-function of OsPDI reduces the salt tolerance. To further investigate these differences at the molecular level, we collected roots from OX-ZmPDI transgenic, CR-OsPDI transgenic, and wild-type (WT) plants at 0 and 24 h after salt treatment for RNA-seq and data-independent acquisition (DIA) proteome sequencing. Combined analysis of the transcriptome and proteome revealed that ZmPDI has the potential to enhance the salt tolerance of rice by modulating the expression of laccase-6, zingipain-2, WIP3, FKBP65, AKR4C10, GBSSII, Pho1, and TRXf1. Those results provided new information for the molecular regulation mechanism by which ZmPDI improves salt tolerance, and prove the potential of ZmPDI for application in crop breeding.

Unraveling wheat’s response to salt stress during early growth stages through transcriptomic analysis and co-expression network profiling

BackgroundSoil salinization is one of the vital factors threatening the world’s food security. To reveal the biological mechanism of response to salt stress in wheat, this study was conducted to resolve the transcription level difference to salt stress between CM6005 (salt-tolerant) and KN9204 (salt-sensitive) at the germination and seedling stage.ResultsTo investigate the molecular mechanism underlying salt tolerance in wheat, we conducted comprehensive transcriptome analyses at the seedling and germination stages. Two wheat cultivars, CM6005 (salt-tolerant) and KN9204 (salt-sensitive) were subjected to salt treatment, resulting in a total of 24 transcriptomes. Through expression-network analysis, we identified 17 modules, 16 and 13 of which highly correlate with salt tolerance-related phenotypes in the germination and seedling stages, respectively. Moreover, we identified candidate Hub genes associated with specific modules and explored their regulatory relationships using co-expression data. Enrichment analysis revealed specific enrichment of gibberellin-related terms and pathways in CM6005, highlighting the potential importance of gibberellin regulation in enhancing salt tolerance. In contrast, KN9204 exhibited specific enrichment in glutathione-related terms and activities, suggesting the involvement of glutathione-mediated antioxidant mechanisms in conferring resistance to salt stress. Additionally, glucose transport was found to be a fundamental mechanism for salt tolerance during wheat seedling and germination stages, indicating its potential universality in wheat. Wheat plants improve their resilience and productivity by utilizing adaptive mechanisms like adjusting osmotic balance, bolstering antioxidant defenses, accumulating compatible solutes, altering root morphology, and regulating hormones, enabling them to better withstand extended periods of salt stress.ConclusionThrough utilizing transcriptome-level analysis employing WGCNA, we have revealed a potential regulatory mechanism that governs the response to salt stress and recovery in wheat cultivars. Furthermore, we have identified key candidate central genes that play a crucial role in this mechanism. These central genes are likely to be vital components within the gene expression network associated with salt tolerance. The findings of this study strongly support the molecular breeding of salt-tolerant wheat, particularly by utilizing the genetic advancements based on CM6005 and KN9204.

Exogenous application of salicylic acid ameliorates salinity stress in barley (Hordeum vulgare L.)

Barley (Hordeum vulgare L.) is a significant cereal crop belonging to Poaceae that is essential for human food and animal feeding. The production of barley grains was around 142.37 million tons in 2017/2018. However, the growth of barley was influenced by salinity which was enhanced by applying a foliar spray of salicylic acid. The current study investigated to evaluated the potential effect of SA on the barley (Hordeum vulgare L.) plants under salinity stress and its possible effects on physiological, biochemical, and growth responses. The experiment was conducted at Postgraduate Research Station (PARS), University of Agriculture; Faisalabad to assess the influence of salicylic acid on barley (Hordeum vulgare L.) under highly saline conditions. The experiment was conducted in a Completely Randomized Design (CRD) with 3 replicates. In plastic pots containing 8 kg of properly cleaned sand, two different types of barley (Sultan and Jau-17) were planted. The plants were then watered with a half-strength solution of Hoagland’s nutritional solution. After the establishment of seedlings, two salt treatments (0 mM and 120 mM NaCl) were applied in combining three levels of exogenously applied salicylic acid (SA) (0, 0.5, and 1 mg L-1). Data about morphological, physiological, and biochemical attributes was recorded using standard procedure after three weeks of treatment. The morpho-physiological fresh weight of the shoot and root (48%), the dry mass of the shoot and root (66%), the plant height (18%), the chlorophyll a (30%), the chlorophyll b (22%), and the carotenoids (22%), all showed significant decreases. Salinity also decreased yield parameters and the chl. ratio (both at 29% and 26% of the total chl. leaf area index). Compared to the control parameters, the following data was recorded under salt stress: spike length, number of spikes, number of spikelets, number of tillers, biological yield, and harvest index. Salicylic acid was used as a foliar spray to lessen the effects of salinity stress, and 1 mg L-1 of salicylic acid proved more effective than 0.5 mg L-1. Both varieties show better growth by applying salicylic acid (0 mg L-1) as a control, showing normal growth. By increasing its level to (0.5 mg L-1), it shows better growth but maximized growth occurred at a higher level (1 mg L-1). Barley sultan (Hordeum vulgare L.) is the best variety as compared to Jau-17 performs more growth to mitigate salt stress (0mM and 120mM NaCl) by improving morpho-physiological parameters by enhancing plan height, Root and shoot fresh and dry weights, as well as root and shoot lengths, photosynthetic pigments, area of the leaves and their index, and yield attributes and reduce sodium ions.

Integrative physiology and transcriptome reveal salt-tolerance differences between two licorice species: Ion transport, Casparian strip formation and flavonoids biosynthesis

BackgroundGlycyrrhiza inflata Bat. and Glycyrrhiza uralensis Fisch. are both original plants of ‘Gan Cao’ in the Chinese Pharmacopoeia, and G. uralensis is currently the mainstream variety of licorice and has a long history of use in traditional Chinese medicine. Both of these species have shown some degree of tolerance to salinity, G. inflata exhibits higher salt tolerance than G. uralensis and can grow on saline meadow soils and crusty saline soils. However, the regulatory mechanism responsible for the differences in salt tolerance between different licorice species is unclear. Due to land area-related limitations, the excavation and cultivation of licorice varieties in saline-alkaline areas that both exhibit tolerance to salt and contain highly efficient active substances are needed. The systematic identification of the key genes and pathways associated with the differences in salt tolerance between these two licorice species will be beneficial for cultivating high-quality salt-tolerant licorice G. uralensis plant varieties and for the long-term development of the licorice industry. In this research, the differences in growth response indicators, ion accumulation, and transcription expression between the two licorice species were analyzed.ResultsThis research included a comprehensive comparison of growth response indicators, including biomass, malondialdehyde (MDA) levels, and total flavonoids content, between two distinct licorice species and an analysis of their ion content and transcriptome expression. In contrast to the result found for G. uralensis, the salt treatment of G. inflata ensured the stable accumulation of biomass and total flavonoids at 0.5 d, 15 d, and 30 d and the restriction of Na+ to the roots while allowing for more K+ and Ca2+ accumulation. Notably, despite the increase in the Na+ concentration in the roots, the MDA concentration remained low. Transcriptome analysis revealed that the regulatory effects of growth and ion transport on the two licorice species were strongly correlated with the following pathways and relevant DEGs: the TCA cycle, the pentose phosphate pathway, and the photosynthetic carbon fixation pathway involved in carbon metabolism; Casparian strip formation (lignin oxidation and translocation, suberin formation) in response to Na+; K+ and Ca2+ translocation, organic solute synthesis (arginine, polyamines, GABA) in response to osmotic stresses; and the biosynthesis of the nonenzymatic antioxidants carotenoids and flavonoids in response to antioxidant stress. Furthermore, the differential expression of the DEGs related to ABA signaling in hormone transduction and the regulation of transcription factors such as the HSF and GRAS families may be associated with the remarkable salt tolerance of G. inflata.ConclusionCompared with G. uralensis, G. inflata exhibits greater salt tolerance, which is primarily attributable to factors related to carbon metabolism, endodermal barrier formation and development, K+ and Ca2+ transport, biosynthesis of carotenoids and flavonoids, and regulation of signal transduction pathways and salt-responsive transcription factors. The formation of the Casparian strip, especially the transport and oxidation of lignin precursors, is likely the primary reason for the markedly higher amount of Na+ in the roots of G. inflata than in those of G. uralensis. The tendency of G. inflata to maintain low MDA levels in its roots under such conditions is closely related to the biosynthesis of flavonoids and carotenoids and the maintenance of the osmotic balance in roots by the absorption of more K+ and Ca2+ to meet growth needs. These findings may provide new insights for developing and cultivating G. uralensis plant species selected for cultivation in saline environments or soils managed through agronomic practices that involve the use of water with a high salt content.

Halophytes and heavy metals: A multi-omics approach to understand the role of gene and genome duplication in the abiotic stress tolerance of Cakile maritima.

The origin of diversity is a fundamental biological question. Gene duplications are one mechanism that provides raw material for the emergence of novel traits, but evolutionary outcomes depend on which genes are retained and how they become functionalized. Yet, following different duplication types (polyploidy and tandem duplication), the events driving gene retention and functionalization remain poorly understood. Here we used Cakile maritima, a species that is tolerant to salt and heavy metals and shares an ancient whole-genome triplication with closely related salt-sensitive mustard crops (Brassica), as a model to explore the evolution of abiotic stress tolerance following polyploidy. Using a combination of ionomics, free amino acid profiling, and comparative genomics, we characterize aspects of salt stress response in C. maritima and identify retained duplicate genes that have likely enabled adaptation to salt and mild levels of cadmium. Cakile maritima is tolerant to both cadmium and salt treatments through uptake of cadmium in the roots. Proline constitutes greater than 30% of the free amino acid pool in C. maritima and likely contributes to abiotic stress tolerance. We find duplicated gene families are enriched in metabolic and transport processes and identify key transport genes that may be involved in C. maritima abiotic stress tolerance. These findings identify pathways and genes that could be used to enhance plant resilience and provide a putative understanding of the roles of duplication types and retention on the evolution of abiotic stress response.

Morita-Baylis-Hillman Spirannulation under Phosphine- and Anion-Binding Catalysis.

We introduce an advancement in Morita-Baylis-Hillman (MBH) chemistry that provides access to α-spirannulated enones. The treatment of enone-tethered azaarenium salts with catalytic amounts of organophosphines provides spiroindenyl dihydropyridines. It represents the α-spirannulation of enones via an intramolecular MBH (IMBH) reaction utilizing dual phosphine- and anion-binding catalysis. The IMBH adducts were subjected to several post-synthetic modifications to access highly functionalized molecules.

Genome-Wide Identification and Expression Analysis of TGA Family Genes Associated with Abiotic Stress in Sunflowers (Helianthus annuus L.).

Sunflower (Helianthus annuus L.) is an important, substantial global oil crop with robust resilience to drought and salt stresses. The TGA (TGACG motif-binding factor) transcription factors, belonging to the basic region leucine zipper (bZIP) family, have been implicated in orchestrating multiple biological processes. Despite their functional significance, a comprehensive investigation of the TGA family's abiotic stress tolerance in sunflowers remains elusive. In the present study, we identified 14 TGA proteins in the sunflower genome, which were unequally distributed across 17 chromosomes. Employing phylogenetic analysis encompassing 149 TGA members among 13 distinct species, we revealed the evolutionary conservation of TGA proteins across the plant kingdom. Collinearity analysis suggested that both HaTGA01 and HaTGA03 were generated due to HaTGA08 gene duplication. Notably, qRT-PCR analysis demonstrated that HaTGA04, HaTGA05, and HaTGA14 genes were remarkably upregulated under ABA, MeJA, and salt treatments, whereas HaTGA03, HaTGA06, and HaTGA07 were significantly repressed. This study contributes valuable perspectives on the potential roles of the HaTGA gene family under various stress conditions in sunflowers, thereby enhancing our understanding of TGA gene family dynamics and function within this agriculturally significant species.

Potassium Chloride as an Effective Alternative to Sodium Chloride in Delaying the Thermal Aggregation of Liquid Whole Egg.

The potential of potassium chloride (KCl) to be used as a substitute for sodium chloride (NaCl) was studied by monitoring the effects of salt treatment on thermal behavior, aggregation kinetics, rheological properties, and protein conformational changes. The results show that the addition of KCl can improve solubility, reduce turbidity and particle size, and positively influence rheological parameters such as apparent viscosity, consistency coefficient (K value), and fluidity index (n). These changes indicate delayed thermal denaturation. In addition, KCl decreased the content of β-sheet and random coil structures and increased the content of α-helix and β-turn structures. The optimal results were obtained with 2% KCl addition, leading to an increase in Tp up to 85.09 °C. The correlation results showed that Tp was positively correlated with solubility, α-helix and β-turn but negatively correlated with ΔH, turbidity, β-sheet and random coil. Overall, compared to NaCl, 2% KCl is more effective in delaying the thermal aggregation of LWE, and these findings lay a solid theoretical foundation for the study of sodium substitutes in heat-resistant liquid egg products.

Changes in Photosystem II Complex and Physiological Activities in Pea and Maize Plants in Response to Salt Stress.

Salt stress significantly impacts the functions of the photosynthetic apparatus, with varying degrees of damage to its components. Photosystem II (PSII) is more sensitive to environmental stresses, including salinity, than photosystem I (PSI). This study investigated the effects of different salinity levels (0 to 200 mM NaCl) on the PSII complex in isolated thylakoid membranes from hydroponically grown pea (Pisum sativum L.) and maize (Zea mays L.) plants treated with NaCl for 5 days. The data revealed that salt stress inhibits the photochemical activity of PSII (H2O → BQ), affecting the energy transfer between the pigment-protein complexes of PSII (as indicated by the fluorescence emission ratio F695/F685), QA reoxidation, and the function of the oxygen-evolving complex (OEC). These processes were more significantly affected in pea than in maize under salinity. Analysis of the oxygen evolution curves after flashes and continuous illumination showed a stronger influence on the PSIIα than PSIIβ centers. The inhibition of oxygen evolution was associated with an increase in misses (α), double hits (β), and blocked centers (SB) and a decrease in the rate constant of turnover of PSII reaction centers (KD). Salinity had different effects on the two pathways of QA reoxidation in maize and pea. In maize, the electron flow from QA- to plastoquinone was dominant after treatment with higher NaCl concentrations (150 mM and 200 mM), while in pea, the electron recombination on QAQB- with oxidized S2 (or S3) of the OEC was more pronounced. Analysis of the 77 K fluorescence emission spectra revealed changes in the ratio of the light-harvesting complex of PSII (LHCII) monomers and trimers to LHCII aggregates after salt treatment. There was also a decrease in pigment composition and an increase in oxidative stress markers, membrane injury index, antioxidant activity (FRAP assay), and antiradical activity (DPPH assay). These effects were more pronounced in pea than in maize after treatment with higher NaCl concentrations (150 mM-200 mM). This study provides insights into how salinity influences the processes in the donor and acceptor sides of PSII in plants with different salt sensitivity.

Genome-wide identification of the monovalent cation/proton antiporter (CPA) superfamily and expression analysis in tomato

The cation/proton antiporter (CPA) superfamily, crucial for regulating Na+, K+, and pH equilibrium in plant cells, plays an essential role in plant growth and stress adaptation. However, limited research has been conducted on the CPA gene superfamily in tomatoes. In this study, a total of 31 SlCPA members were identified in the tomato genome, comprising 18 cation/H+ exchangers (SlCHXs), 7 Na+/H+ exchangers (SlNHXs), and 6 K+ efflux antiporters (SlKEAs). A comprehensive analysis encompassing their chromosomal locations, gene structures, phylogenetic relationships, collinearity, tissue-specific expression profiles, and responses to abiotic stress was undertaken. Collinearity and phylogenetic analyses unveiled two groups, represented by Solyc08g081810, Solyc01g008190, Solyc12g056160, and Solyc06g060630, Solyc08g078880, suggesting potential redundancy resulting from duplication events. Tissue-specific expression analysis revealed SlNHXs and SlKEAs expression at multiple developmental stages, while SlCHXs were predominantly expressed during early flower and fruit development, indicating their likely involvement in these processes. Salt treatment notably induced the expression of SlSOS1 (Solyc01g005020) and Solyc04g056600, implicating their role in responding to salt stress. Under drought stress, the expression of Solyc01g005020 and Solyc08g081820 was also significantly induced, supported by promoter element analyses indicating the presence of drought response-related cis-elements like ABRE and MYB binding sites. This study establishes a foundation for further elucidating the gene functions of individual members within the tomato SlCPA family.

Metabolic effects of a submaximal dose of pink salt and monosodium glutamate in experimental rats

Background & objectivesPink salt and monosodium glutamate (MSG) are two typical food additives used in cooking to enhance flavour. However, excessive use of them has been associated to a variety of metabolic problems, including weight gain and hyperglycemia. The current study aimed to assess the metabolic changes caused by submaximal dosages of MSG and pink salt in experimental rats. MethodsTwenty-four 120–150 g Wister rats of both sexes were divided into three groups: control, pink salt-treated (0.8 g/kg daily for three weeks), and MSG-treated (3.6 g/kg daily for three weeks). The body weight, amount of food and water consumed, and blood glucose levels of animals were measured and recorded as indicators of their metabolic changes. Furthermore, after salt treatments at intervals such as week 1, week 2, and week 3, the survival rate and general toxicity manifestations were determined. The results were statistically analysed using one-way ANOVA, with p < 0.05 being considered significant. ResultsThe study found that the group given a submaximal dose of MSG gained significantly more weight (p < 0.05), consumed more food and water, and had higher blood glucose levels than the control. Ninety percent of the MSG therapy group survived by the end of the third week, however, they suffered from negative effects like abdominal distention, respiratory problems, ptosis, and subcutaneous swelling. On the other hand, the consumption of food and drink was significantly (p < 0.05) increased upon the administration of pink salt. Only little changes were observed in the body weight, blood sugar levels, and general features (such as subcutaneous swelling, change in bowel colour, and loose stools). Additionally, it was shown that the survival rate remained unchanged, particularly after week 3. ConclusionAccording to study findings, MSG may induce metabolic issues, increasing the chance of death. While there was no discernible metabolic aberration linked to pink salt. Further research is required to fully understand the mechanism and consequences of these taste enhancers on the host system before pink salt can be deemed safe.

Seed morphology characterization and salinity effects on two popular rice (Oryza sativa L.) varieties of Nagaland

Salinity is one of the significant problems in rice production as it limits its growth and development. Salinity can occur through natural processes due to weathering and human intervention, such as irrigation. The present study reports two different rice varieties, 'Makrilha' and 'Thevur' which are categorized as very long (&lt; 7.50 mm) and slender in shape (&lt; 3.0 mm) and subjected to different salt treatments (0 mM, 100 mM, 200 mM, and 300 mM NaCl solutions) and their germination responses, such as germination percentage (GP), germination index (GI), mean germination time (MGT), vigor index (VI), root and shoot length. The study concluded that Makrilha has a higher GP (88.33%) as compared to Thevur (63%) at 200 mM NaCl solution. Both the rice showed 100% germination in the control 0 mM and 100 mM salt solutions, and no germination was recorded in the 300 mM NaCl solution. GI was recorded at its maximum in Makrilha as compared to Thevur. MGT and VI were more concentrated in Thevur than Makrilha. There was a significant difference in GI, VI, root, and shoot length (P &lt; 0.05) as salinity increased for both rices. There was no significant difference in GP (P = 0.122) and MGT (P = 0.088). The study also found a positive correlation between GI and GP. MGT is negatively correlated with GP and GI. VI is positively correlated with GP, and GI is negatively correlated with MGT. Root and shoot length are positively correlated with GP, GI, and VI but negatively correlated with MGT for both rice varieties. The rice root and shoot length are affected as salt concentration increases and are statistically significant (root P = 0.012, shoot P = 0.001). Salt is used to control weeds in almost every part of Nagaland. Thus, the effect of salt applications needs to be studied in rice. Based on the data obtained for germination parameters such as GP, GI, VI, MGT, root and shoot length, 'Makrilha' tends to show more tolerance towards salinity as compared to 'Thevur' under controlled environmental conditions. Thus, this study can provide insight into selecting rice with a higher salt tolerance for cultivation.

Effect of salting and dehydration treatments on the physicochemical and gel properties of hen and duck egg yolks, plasma and granules.

Salted hen egg yolks are less oily and less flavorful than salted duck egg yolks. However, hen eggs have a more adequate market supply and have a broader application prospect than duck eggs. In the present study, egg yolks, plasma, and granules were dehydrated by adding 1% NaCl to simulate traditional curing process of salted egg yolk. The changes in the pickling process of hen egg yolks (HEY) and duck egg yolks (DEY) plasma and granules were compared to reveal the gelation mechanism and the underlying causes of quality differences in salted HEY and DEY. Salted HEY can be compared with the changes in DEY during the pickling process to provide a theoretical basis for the quality improvement of salted HEY to salted DEY. The results showed that both plasma and granules were involved in gel formation, but exhibited different aggregation behaviors. Based on the intermolecular forces, the HEY proteins achieved aggregation mainly through hydrophobic interactions and DEY proteins mainly through covalent binding. According to spin-spin relaxation time, HEY gels immobilized a large amount of lipid and interacted strongly with lipids. DEY gels showed much free lipid and had weak interaction with lipid. The microstructure showed that HEY proteins were easily unfolded to form a homogeneous three-dimensional gel network structure after salting, whereas heterogeneous aggregates were formed to hinder the gel development in DEY. Changes in protein secondary structure content showed that pickling can promote the transformation of the α-helices to β-sheets structure in HEY gels, whereas more α-helices structure was formed in DEY gels. The present study has demonstrated that different gelation behaviors of hen and duck egg yolk proteins (especially in plasma) through salting treatment led to the difference in the quality of salted HEY and DEY. © 2024 Society of Chemical Industry.

Transcriptional Profiling of BpWRKY49 Reveals Its Role as a Master Regulator in Stress Signaling Pathways in Birch (Betula platyphylla)

The WRKY family of transcription factors (TFs) is one of the most diverse families in plants, playing crucial roles in various plant growth and stress response processes. Asian white birch (Betula platyphylla) is a globally distributed tree species that holds ecological, medical, and economic significance. However, the regulatory mechanisms of WRKY TFs in birch remain poorly understood. Herein, we cloned and characterized the BpWRKY49 gene from birch. Through bioinformatics analyses, we revealed the potential involvement of BpWRKY49 in both biotic and abiotic stress responses. In addition, BpWRKY49 was found to be localized in the nucleus and exhibited transcriptional activity in yeast. Transactivation assays further confirmed that BpWRKY49 exhibited transcriptional activity at its C-terminal end. Notably, our binding specificity assays demonstrated the specific interaction of BpWRKY49 with the W-box cis element in vitro. Furthermore, tissue-specific expression analysis demonstrated that BpWRKY49 exhibited the highest expression level in the roots. Real-time quantitative PCR (RT-qPCR) analysis of birch plants subjected to salt and drought treatments revealed that BpWRKY49 displayed significant 30-fold and 10-fold upregulations under salt and drought stress conditions, respectively. DAP-seq analysis of BpWRKY49 identified a total of 21,832 peaks, with 3477 occurring in the promoter region of genes. Gene ontology (GO) enrichment analysis highlighted prominent terms related to defense against biotic stress, followed by terms associated with abiotic stress and development. Y1H assays of three genes provided evidence for the binding ability of BpWRKY49 to the promoters of BpPUB21, BpBTL15, and BpHIP47 in vitro. Collectively, our findings strongly suggest that BpWRKY49 possesses diverse functions and may activate multiple genes to contribute to various biological processes, including salt stress tolerance, in birch.