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1.
Nat Commun ; 11(1): 4368, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868758

RESUMO

Increased extracellular sodium activates Th17 cells, which provide protection from bacterial and fungal infections. Whilst high salt diets have been shown to worsen autoimmune disease, the immunological consequences of clinical salt depletion are unknown. Here, we investigate immunity in patients with inherited salt-losing tubulopathies (SLT). Forty-seven genotyped SLT patients (with Bartter, Gitelman or EAST Syndromes) are recruited. Clinical features of dysregulated immunity are recorded with a standardised questionnaire and immunological investigations of IL-17 responsiveness undertaken. The effects of altering extracellular ionic concentrations on immune responses are then assessed. Patients are hypokalaemic and hypomagnesaemic, with reduced interstitial sodium stores determined by 23Na-magnetic resonance imaging. SLT patients report increased mucosal infections and allergic disease compared to age-matched controls. Aligned with their clinical phenotype, SLT patients have an increased ratio of Th2:Th17 cells. SLT Th17 and Tc17 polarisation is reduced in vitro, yet STAT1 and STAT3 phosphorylation and calcium flux following T cell activation are unaffected. In control cells, the addition of extracellular sodium (+40 mM), potassium (+2 mM), or magnesium (+1 mM) reduces Th2:Th17 ratio and augments Th17 polarisation. Our results thus show that the ionic environment typical in SLT impairs IL-17 immunity, but the intracellular pathways that mediate salt-driven Th17 polarisation are intact and in vitro IL-17 responses can be reinvigorated by increasing extracellular sodium concentration. Whether better correction of extracellular ions can rescue the immunophenotype in vivo in SLT patients remains unknown.


Assuntos
Síndromes de Imunodeficiência/etiologia , Interleucina-17/metabolismo , Túbulos Renais Distais/patologia , Adolescente , Adulto , Idoso de 80 Anos ou mais , Animais , Pré-Escolar , Doença Crônica , Estudos de Coortes , Feminino , Doenças Genéticas Inatas , Humanos , Magnésio/metabolismo , Masculino , Pessoa de Meia-Idade , Potássio/metabolismo , Sais/metabolismo , Sais/uso terapêutico , Sódio/metabolismo , Cloreto de Sódio/metabolismo , Cloreto de Sódio na Dieta/uso terapêutico , Células Th17/metabolismo , Células Th2/metabolismo , Adulto Jovem
2.
Gene ; 761: 145043, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32777530

RESUMO

Tonoplast Intrinsic Proteins (TIPs) constitute a significant class of the aquaporins. The TIPs control water trade among cytosolic and vacuolar compartments and can also transport glycerol, ammonia, urea, hydrogen peroxide, metals/metalloids, and so forth. Additionally, TIPs are engaged with different abiotic stress responses and developmental processes like leaf expansion, root elongation and seed germination. In this study, ten TIP genes in the rice genome were identified from Oryza sativa ssp indica. Among these, representative groups of TIP genes were cloned and sequenced whilst some TIP sequences showed stop codons in the coding region. The secondary structure analysis represented six conserved transmembrane helices along with the inter-helical regions having conserved motifs. The representative three-dimensional tetrameric design of protein sequence of TIP1;1 displayed key features like NPA motifs, aromatic/arginine (ar/R) selectivity filters, and Froger's residues. The vacuolar localization, transmembrane topological properties, and conserved motif analysis of the cloned genes altogether supported their identity as TIPs. An unrooted phylogenetic tree delineated the relatedness of TIPs from Oryza with different species and bunched them into five clades. The promoter analysis uncovered key regulons associated with administering abiotic stress responses. Gene expression studies showed thatTIPsare differentially regulated under salt and drought stress at various time points in shoots and roots of rice. Also, the pattern of expression was found to be significantly variable in five different rice tissues. The heat-map based tissue and stress- specific expression analysis supported the experimental findings. In conclusion, the identification and transcript-level expression studies of TIPs significantly contribute towards the comprehension of their utilitarian significance in the abiotic stress response.


Assuntos
Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Aquaporinas/genética , Aquaporinas/metabolismo , Clonagem Molecular/métodos , Secas , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Oryza/metabolismo , Filogenia , Folhas de Planta/metabolismo , Cloreto de Sódio/metabolismo , Estresse Fisiológico/genética , Vacúolos/genética , Água/metabolismo
3.
PLoS One ; 15(7): e0236349, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32701993

RESUMO

Peptide signalling is an integral part of cell-to-cell communication which helps to relay the information responsible for coordinating cell proliferation and differentiation. Phytosulfokine Receptor (PSKR) is a transmembrane LRR-RLK family protein with a binding site for small signalling peptide, phytosulfokine (PSK). PSK signalling through PSKR promotes normal growth and development and also plays a role in defense responses. Like other RLKs, these PSKRs might have a role in signal transduction pathways related to abiotic stress responses. Genome-wide analysis of phytosulfokine receptor gene family has led to the identification of fifteen putative members in the Oryza sativa genome. The expression analysis of OsPSKR genes done using RNA-seq data, showed that these genes were differentially expressed in different tissues and responded specifically to heat, salt, drought and cold stress. Furthermore, the real-time quantitative PCR for fifteen OsPSKR genes revealed temporally and spatially regulated gene expression corresponding to salinity and drought stress. Our results provide useful information for a better understanding of OsPSKR genes and provide the foundation for additional functional exploration of the rice PSKR gene family in development and stress response.


Assuntos
Genoma de Planta/genética , Oryza/genética , Hormônios Peptídicos/genética , Peptídeos/genética , Proteínas de Plantas/genética , Secas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Peptídeos/classificação , Filogenia , Salinidade , Transdução de Sinais/genética , Cloreto de Sódio/metabolismo , Estresse Fisiológico/genética
4.
J Food Sci ; 85(7): 2171-2176, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32476148

RESUMO

L. lactis is known as industrial starter in the fermentation of dairy and meat products, and it plays an important role in human health as an edible probiotic. During industrial production, L. lactis often experiences different stresses that delay the growth and decrease the survival in some serious conditions. In this study, the protective effects of hydroxypropyl ß-cyclodextrin (HP ß-CD) on L. lactis under multiple stresses were investigated. The microbial cells were treated with different stresses including heat, NaCl, cold, and H2 O2 stresses, and the results were showed by measuring the OD600 or spot plating method. The growth and tolerance were improved when HP ß-CD was added during different stress conditions, better than that of trehalose. Besides, the scanning electron microscopic and fluorescence spectrum studies showed that HP ß-CD could combine with L. lactis to protect the cell structure, suggesting that HP ß-CD may act as a protective agent of L. lactis. Therefore, HP ß-CD could be considered as a potential protective agent to be applied in food industry, and its protective mechanism on L. lactis still needs further investigation.


Assuntos
Lactococcus lactis/fisiologia , beta-Ciclodextrinas/metabolismo , Meios de Cultura/metabolismo , Fermentação , Temperatura Alta , Lactococcus lactis/crescimento & desenvolvimento , Cloreto de Sódio/metabolismo
5.
Plant Mol Biol ; 103(4-5): 561-580, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32405802

RESUMO

KEY MESSAGE: CmHKT1;1 selectively exports Na+ from plant cells. Upon NaCl stress, its expression increased in a salt-tolerant melon cultivar. Overexpression of CmHKT1;1 increased transgenic Arabidopsis salt tolerance through improved K+/Na+ balance. High-affinity K+ transporters (HKTs) are thought to be involved in reducing Na+ in plant shoots under salt stress and modulating salt tolerance, but their function in a moderately salt-tolerant species of melon (Cucumis melo L.) remains unclear. In this study, a Na+ transporter gene, CmHKT1;1 (GenBank accession number: MK986658), was isolated from melons based on genome data. The transcript of CmHKT1;1 was relatively more abundant in roots than in stems or leaves from melon seedlings. The tobacco transient expression system showed that CmHKT1;1 was plasma-membrane localized. Upon salt stress, CmHKT1;1 expression was more strongly upregulated in a salt-tolerant melon cultivar, 'Bingxuecui' (BXC) compared with a salt-sensitive cultivar, 'Yulu' (YL). Electrophysiological evidence demonstrated that CmHKT1;1 only transported Na+, rather than K+, when expressed in Xenopus laevis oocytes. Overexpression of CmHKT1;1 increased salt sensitivity in Saccharomyces cerevisiae and salt tolerance in Arabidopsis thaliana. Under NaCl treatments, transgenic Arabidopsis plants accumulated significantly lower concentrations of Na+ in shoots than wild type plants and showed a better K+/Na+ balance, leading to better Fv/Fm, root length, biomass, and enhanced plant growth. The CmHKT1;1 gene may serve as a useful candidate for improving crop salt tolerance.


Assuntos
Arabidopsis/metabolismo , Cucumis melo/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Arabidopsis/genética , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Clorofila/análise , Clonagem Molecular , Cucumis melo/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Membrana Transportadoras/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Brotos de Planta/genética , Saccharomyces cerevisiae/genética , Tolerância ao Sal , Plântula/genética , Plântula/metabolismo , Alinhamento de Sequência , Análise de Sequência de Proteína , Cloreto de Sódio/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Simportadores/genética , Simportadores/metabolismo , Tabaco/genética , Tabaco/metabolismo
6.
Gene ; 753: 144797, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32454180

RESUMO

Phospholipase C proteins are phospholipid hydrolysing enzymes and crucial components of abiotic stress triggered lipid signaling in plants. PLCs are implicated in plant reaction to drought, salinity, and cold stress responses, however, characterization of the PLC family in the legume crop chickpea is missing. Here, we identify and describe nine PLC encoding genes in the chickpea genome. Phylogenetic analysis showed that the chickpea PLC family has evolved through a common path in dicots. Subcellular localization of fluorescence tagged proteins confirmed cytoplasmic and plasma membrane bound forms of PLCs in chickpea. The promoters of all the PLC genes are comprised of several hormone response related, development and abiotic stress related cis-regulatory elements. Expression analysis in five developmental stages (germination, seedling, vegetative, reproductive and senescence) showed significant expression of multiple PLCs in germination, vegetative and reproductive stages, suggesting their diverse role in various developmental processes. qRT-PCR expression analysis of the entire PLC gene family under drought, salt and cold stresses revealed that most PLC genes are differentially expressed in multiple abiotic stresses. These observations indicate the involvement of PLC gene family in abiotic stress signaling and responses in important legume crop. The present study opens new avenues for utilizing PLC- related information in biotechnological programs for abiotic stress tolerance and legume crop improvement.


Assuntos
Cicer/genética , Estresse Fisiológico/genética , Fosfolipases Tipo C/genética , Resposta ao Choque Frio , Secas , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas , Genômica , Germinação , Filogenia , Proteínas de Plantas/genética , Salinidade , Cloreto de Sódio/metabolismo , Transcriptoma/genética , Fosfolipases Tipo C/metabolismo
7.
Medicina (B Aires) ; 80(2): 157-161, 2020.
Artigo em Espanhol | MEDLINE | ID: mdl-32282322

RESUMO

Female sex hormones participate in the regulation of blood pressure and renal epithelial proliferation, effects not related to their reproductive function. About one-third of the world's population has abnormally high levels of blood pressure, hypertension, which is responsible for almost 50% of deaths from stroke and coronary heart disease. Salt sensitivity is a risk factor for cardiovascular morbidity and mortality and other diseases as well. We reported a model of salt sensitive hypertension in adult ovariectomized (oVx) Wistar rats. oVx rats are normotensive under normal salt intake (NS, 0.24% NaCl), but upon a high salt intake (HS, 1% NaCl) oVx rats developed a blood pressure profile of salt-sensitive hypertension. Our studies on kidney molecules related to sodium balance found that the circuit dopamine D1-like receptor, cytochrome P450 4A and Na+, K+-ATPase is altered by the absence of ovary hormones which is accompanied by a reduced ability to excrete sodium. In oVx rats HS intake also promotes changes in the expression of proteins related to sodium transport in peripheral blood mononuclear cells, mainly peripheral lymphocytes. Therefore, sodium transport is modified at several levels of normal physiology. Lately, we described that estradiol increases the rate of renal epithelial cell proliferation in primary cultures developed from human renal cortex. Thus, salt sensitivity, adaptive immunity, blood pressure and renal cell proliferation are complex biological responses regulated by female sex hormones.


Assuntos
Estradiol/metabolismo , Hipertensão/metabolismo , Rim/metabolismo , Cloreto de Sódio/metabolismo , Animais , Pressão Sanguínea , Proliferação de Células , Feminino , Humanos , Hipertensão/fisiopatologia , Ratos , Ratos Wistar , Cloreto de Sódio/efeitos adversos , ATPase Trocadora de Sódio-Potássio
8.
J Food Sci ; 85(5): 1565-1575, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32282071

RESUMO

We evaluated the temporal profile of the flavor enhancers monosodium glutamate (MSG), disodium inosinate (IMP), disodium guanylate (GMP), and monoammonium glutamate (MAG). We also evaluated the ability of these flavor enhancers to enhance salty taste in solutions containing different reductions of sodium chloride. Four experiments were conducted using Central Composite Rotational Design (CCRD) with focus on two objectives: concentration of flavor enhancers (0% to 1%) and reduction of sodium chloride content (0% to 100%). A 0.75% saline solution of NaCl was used as a control. In each experiment, the treatments were evaluated by the intensity of salty and umami tastes using an intensity scale. Treatments, selected according to the results of CCRD, were analyzed using time-intensity (TI) and temporal dominance of sensations (TDS) analyses. Glutamates (MSG/MAG) showed greater capacity to enhance salty taste than treatments containing nucleotides (IMP/GMP). The intensity of umami taste, using all the examined flavor enhancers, showed a similar sensory profile. Temporal perception curves (TI and TDS) of salty and umami tastes also showed a similar temporal profile. The glutamic acid amino acids were better able to improve salty taste than nucleotides in any range of sodium chloride reduction. Flavor enhancers showed greater ability to increase salty taste in smaller reductions in sodium chloride content. PRACTICAL APPLICATION: This research expand the knowledge about the ability to enhance the salty taste of flavor enhancers in different reductions in sodium content, Beside that, will provide information about the time profile of flavor enhancers. This study provides scientific technical information on the ability to intensify the salty taste of flavor enhancers and can assist the industry to develop new low sodium products and encourage the scientific community to conduct future research on this subject.


Assuntos
Aromatizantes/metabolismo , Inosina Monofosfato/metabolismo , Cloreto de Sódio/metabolismo , Glutamato de Sódio/metabolismo , Aromatizantes/análise , Humanos , Inosina Monofosfato/análise , Cloreto de Sódio/análise , Glutamato de Sódio/análise , Paladar
9.
PLoS One ; 15(3): e0229897, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32142525

RESUMO

Physiology and nutritional quality of a facultative CAM plant Mesembryanthemum crystallinum under drought stress alone are poorly understood. To induce drought, M. crystallinum was cultured aeroponically with different nutrient spraying intervals such as 5, 30, 60 and 240 min. The long spraying interval such as 240 min resulted in lower mass of root and shoot, shorter total root length with less tips and smaller surface area, compared to short interval of 5 min. Grown under the longest spraying interval of 240 min, M. crystallinumalso had significantly higher leaf dry matter content but lower leaf succulence. However, CAM acidity was undetectable for any plants. Although M. crystallinum grown under extended spraying intervals had higher photosynthetic pigments, they utilized lesser light energy and did not dissipate heat as effectively as those grown under 5 min. Compare to other shorter spraying intervals, photosynthetic gas exchange rates were significantly reduced under 240 min spraying interval, indicating signs of water deficit stress. Shoot nitrate, total reduced nitrogen, total soluble protein and Rubisco concentrations were similar for all plants. For phytochemicals and dietary minerals, plants grown under 240 min spraying interval had significantly higher values than the other plants. Therefore, drought does not result in the induction of CAM but regulates photosynthetic performance and enhances nutritional quality of M. crystallinum.


Assuntos
Secas , Fotossíntese/genética , Folhas de Planta/crescimento & desenvolvimento , Ribulose-Bifosfato Carboxilase/genética , Mesembryanthemum/química , Mesembryanthemum/metabolismo , Valor Nutritivo , Folhas de Planta/genética , Cloreto de Sódio/metabolismo
10.
Arch Microbiol ; 202(6): 1469-1476, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32193578

RESUMO

A novel Gram-stain-positive, motile, moderate halophile, strain L9T, was isolated from hides of white goat in China. The isolate grew optimally at 30 °C, at pH 7 and with 5-10% (w/v) NaCl. The predominant menaquinone was MK-7, and the major cellular fatty acids were identified as iso-C15:0 and anteiso-C15:0. The peptidoglycan amino acid type was determined to be A4ß, containing L-ornithine and D-aspartic as diagnostic amino acids. The phospholipids were dominated by diphosphatidylglycerol, phosphatidylglycerol, one unidentified aminophospholipid and two unidentified phospholipids. Genome sequencing resulted in a genome size of 4.0 Mbp and a DNA G + C content of 35.9 mol%. Phylogenetic trees based on the 16S rRNA gene sequences showed the isolate to be closely related to Oceanobacillus limi H9BT (98.2% similarity) and Ornithinibacillus halophilus G8BT (97.5% similarity). The ANI and dDDH values between strain L9T and the closely related species were 69.8-76.1% and 13.0-20.5%, respectively. On the basis of the data presented, strain L9T represents a novel species of the genus Ornithinibacillus, for which the name Ornithinibacillus caprae sp. nov. is proposed. The type strain is L9T (= KCTC 43176T = CGMCC 1.17659T).


Assuntos
Bacillaceae/classificação , Bacillaceae/isolamento & purificação , Cabras/microbiologia , Aminoácidos/análise , Animais , Bacillaceae/genética , Técnicas de Tipagem Bacteriana , Composição de Bases/genética , DNA Bacteriano/genética , Ácidos Graxos/análise , Peptidoglicano/química , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio/metabolismo
11.
Plant Mol Biol ; 102(6): 645-657, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32040759

RESUMO

KEY MESSAGE: RNA-seq was used to analyze the transcriptional changes in sugar beet (Beta vulgaris L.) triggered by alkaline solution to elucidate the molecular mechanism underlying alkaline tolerance in sugar beet. Several differentially expressed genes related to stress tolerance were identified. Our results provide a valuable resource for the breeding of new germplasms with high alkaline tolerance. Alkalinity is a highly stressful environmental factor that limits plant growth and production. Sugar beet own the ability to acclimate to various abiotic stresses, especially salt and alkaline stress. Although substantial previous studies on response of sugar beet to saline stress has been conducted, the expressions of alkali-responsive genes in sugar beet have not been comprehensively investigated. In this study, we conducted transcriptome analysis of leaves in sugar beet seedlings treated with alkaline solutions for 0 day (control, C), 3 days (short-term alkaline treatment, ST) and 7 days (long-term alkaline treatment, LT). The clean reads were obtained and assembled into 25,507 unigenes. Among them, 975 and 383 differentially expressed genes (DEGs) were identified in the comparison groups ST_vs_C and LT_vs_C, respectively. Gene ontology (GO) analysis revealed that oxidation-reduction process and lipid metabolic process were the most enriched GO term among the DEGs in ST_vs_C and LT_vs_C, respectively. According to Kyoto Encyclopedia of Genes and Genomes pathway, carbon fixation in photosynthetic organisms pathway were significantly enriched under alkaline stress. Besides, expression level of genes encoding D-3-phosphoglycerate dehydrogenase 1, glutamyl-tRNA reductase 1, fatty acid hydroperoxide lyase, ethylene-insensitive protein 2, metal tolerance protein 11 and magnesium-chelatase subunit ChlI, etc., were significantly altered under alkaline stress. Additionally, among the DEGs, 136 were non-annotated genes and 24 occurred with differential alternative splicing. Our results provide a valuable resource on alkali-responsive genes and should benefit the improvement of alkaline stress tolerance in sugar beet.


Assuntos
Beta vulgaris/genética , Beta vulgaris/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Estresse Fisiológico/genética , Transcriptoma/genética , Aclimatação , Álcalis , Beta vulgaris/enzimologia , Carbono/metabolismo , Ontologia Genética , Genes de Plantas/genética , Folhas de Planta/genética , Plântula/genética , Análise de Sequência de RNA , Cloreto de Sódio/metabolismo
12.
Ecotoxicol Environ Saf ; 193: 110322, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32109582

RESUMO

The γ-aminobutyric acid (GABA) shunt is closely associated with plant tolerance; however, little is known about its mechanism. This study aimed to decipher the responses of the GABA shunt and related carbon-nitrogen metabolism in poplar seedlings (Populus alba × Populus glandulosa) treated with different NaCl and CdCl2 concentrations for 30 h. The results showed that the activities of glutamate decarboxylase (GAD) and GABA-transaminase (GABA-T) were activated, as well as α-ketoglutarate dehydrogenase (α-KGDH) and succinate dehydrogenase (SDH) activities were enhanced by NaCl and CdCl2 stresses, except for SDH under CdCl2 stress. Meanwhile, the expression levels of GADs, GABA-Ts SDHs, succinyl-CoA ligases (SCSs), and succinic acid aldehyde dehydrogenases (SSADHs) were also increased. Notably, significant increases in the key components of GABA shunt, Glu and GABA, were observed under both stresses. Soluble sugars and free amino acids were enhanced, whereas citrate, malate and succinate were almost inhibited by both NaCl and CdCl2 stresses except that citrate was not changed or just increased by 50-mM NaCl stress. Thus, these results suggested that the carbon-nitrogen balance could be altered by activating the GABA shunt when main TCA-cycle intermediates were inhibited under NaCl and CdCl2 stresses. This study can enhance the understanding about the functions of the GABA shunt in woody plants under abiotic stresses and may be applied to the genetic improvement of trees for phytoremediation.


Assuntos
Cloreto de Cádmio/toxicidade , Carbono/metabolismo , Nitrogênio/metabolismo , Populus/efeitos dos fármacos , Cloreto de Sódio/toxicidade , Estresse Fisiológico/efeitos dos fármacos , Ácido gama-Aminobutírico/metabolismo , Aminoácidos/metabolismo , Cloreto de Cádmio/metabolismo , Ciclo do Ácido Cítrico/efeitos dos fármacos , Glutamato Descarboxilase/metabolismo , Populus/crescimento & desenvolvimento , Populus/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Cloreto de Sódio/metabolismo
13.
J Agric Food Chem ; 68(9): 2757-2764, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32026695

RESUMO

Aspergillus oryzae 3.042 was mutagenized using atmospheric and room-temperature plasma (ARTP) technology to enhance its salt-tolerant proteases activity. Compared to the starting strain, mutant H8 subjected to 180 s of ARTP treatment exhibited excellent genetic stability (15 generations), growth rate, and significantly increased activities of neutral proteases, alkaline proteases, and aspartyl aminopeptidase during fermentation. Mutant H8 significantly enhanced the contents of 1-5 kDa peptides, aspartic acid, serine, threonine, and cysteine in soy sauce by 16.61, 7.69, 17.30, 8.61, and 45.00%, respectively, but it had no effects on the contents of the other 14 free amino acids (FAAs) due to its slightly enhanced acidic proteases activity. Analyses of transcriptional expressions of salt-tolerant alkaline protease gene (AP, gi: 217809) and aspartyl aminopeptidase gene (AAP, gi: 6165646) indicated that their expression levels were increased by approximately 30 and 27%, respectively. But no mutation was found in the sequences of AP and AAP expression cassettes, suggesting that the increased activities of proteases in mutant H8 should be partially attributed to the increased expression of proteases. ARTP technology showed great potential in enhancing the activities of salt-tolerant proteases from A. oryzae.


Assuntos
Aspergillus oryzae/enzimologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/metabolismo , Cloreto de Sódio/metabolismo , Aspergillus oryzae/química , Aspergillus oryzae/genética , Aspergillus oryzae/metabolismo , Estabilidade Enzimática , Fermentação , Proteínas Fúngicas/química , Mutagênese , Peptídeo Hidrolases/química , Alimentos de Soja/análise , Alimentos de Soja/microbiologia
14.
J Neurosci ; 40(10): 2069-2079, 2020 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-32005766

RESUMO

The organum vasculosum of the lamina terminalis (OVLT) contains NaCl-sensitive neurons to regulate thirst, neuroendocrine function, and autonomic outflow. The OVLT also expresses the angiotensin II (AngII) type1 receptor, and AngII increases Fos expression in OVLT neurons. The present study tested whether individual OVLT neurons sensed both NaCl and AngII to regulate thirst and body fluid homeostasis. A multifaceted approach, including in vitro whole-cell patch recordings, in vivo single-unit recordings, and optogenetic manipulation of OVLT neurons, was used in adult, male Sprague Dawley rats. First, acute intravenous infusion of hypertonic NaCl or AngII produced anatomically distinct patterns of Fos-positive nuclei in the OVLT largely restricted to the dorsal cap versus vascular core, respectively. However, in vitro patch-clamp recordings indicate 66% (23 of 35) of OVLT neurons were excited by bath application of both hypertonic NaCl and AngII. Similarly, in vivo single-unit recordings revealed that 52% (23 of 44) of OVLT neurons displayed an increased discharge to intracarotid injection of both hypertonic NaCl and AngII. In marked contrast to Fos immunoreactivity, neuroanatomical mapping of Neurobiotin-filled cells from both in vitro and in vivo recordings revealed that NaCl- and AngII-responsive neurons were distributed throughout the OVLT. Next, optogenetic excitation of OVLT neurons stimulated thirst but not salt appetite. Conversely, optogenetic inhibition of OVLT neurons attenuated thirst stimulated by hypernatremia or elevated AngII but not hypovolemia. Collectively, these findings provide the first identification of individual OVLT neurons that respond to both elevated NaCl and AngII concentrations to regulate thirst and body fluid homeostasis.SIGNIFICANCE STATEMENT Body fluid homeostasis requires the integration of neurohumoral signals to coordinate behavior, neuroendocrine function, and autonomic function. Extracellular NaCl concentrations and the peptide hormone angiotensin II (AngII) are two major neurohumoral signals that regulate body fluid homeostasis. Herein, we present the first compelling evidence that individual neurons located in the organum vasculosum of the lamina terminalis detect both NaCl and AngII. Furthermore, optogenetic interrogations demonstrate that these neurons play a pivotal role in the regulation of thirst stimulated by NaCl and AngII. These novel observations lay the foundation for future investigations for how such inputs as well as others converge onto unique organum vasculosum of the lamina terminalis neurons to coordinate body fluid homeostasis and contribute to disorders of fluid balance.


Assuntos
Angiotensina II/metabolismo , Hipernatremia/metabolismo , Neurônios/fisiologia , Organum Vasculosum/fisiologia , Sede/fisiologia , Angiotensina II/farmacologia , Animais , Masculino , Ratos , Ratos Sprague-Dawley , Cloreto de Sódio/metabolismo , Cloreto de Sódio/farmacologia , Equilíbrio Hidroeletrolítico/fisiologia
15.
J Appl Microbiol ; 129(2): 367-377, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32027767

RESUMO

AIMS: Exposure of Listeria monocytogenes to osmotic stress can induce increased resistance to subsequent lethal exposure to cell envelope stressors, such as nisin and bile salts. We wanted to determine if similar cross-protection phenotypes could occur when L. monocytogenes strains were treated with osmotic stress and exposed to sublethal levels of the cell envelope stressor, bile. METHOD AND RESULTS: Growth phenotypes were measured for six L. monocytogenes strains exposed to 6% NaCl, 0·3 and 1% bile in BHI. To evaluate cross-protection, cells were pre-exposed to 6% NaCl, followed by exposure to BHI+1% bile for 26 h and vice versa. Significant increases in λ (lag phase) and doubling time were observed under salt and bile stresses compared with BHI alone. Average λ and Nmax (maximum cell density) in 0·3 and 1% bile for all strains were significantly lower than that in 6% NaCl. Pre-exposure to 6% NaCl followed by exposure to 1% bile significantly increased λ (P < 0·05), whereas pre-exposure to 1% bile followed by exposure to 6% NaCl led to formation of filamentous cells, with no changes in cell density over 26 h. CONCLUSIONS: Variation in growth characteristics was observed among strains exposed to bile. Exposure to osmotic stress did not lead to increased resistance to bile. Exposure to bile significantly impacted the ability of L. monocytogenes to adapt to grow under osmotic stress, where cells did not multiply but formed filamentous cells. SIGNIFICANCE AND IMPACT OF THE STUDY: Pre-exposure to a cell envelope stress and subsequent exposure to an osmotic stress appears to pose a significant stress to L. monocytogenes cells.


Assuntos
Bile/metabolismo , Listeria monocytogenes/fisiologia , Cloreto de Sódio/metabolismo , Microbiologia de Alimentos , Cinética , Listeria monocytogenes/citologia , Listeria monocytogenes/crescimento & desenvolvimento , Listeria monocytogenes/metabolismo , Estresse Fisiológico
16.
Poult Sci ; 99(2): 966-973, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32036988

RESUMO

The objective of this study was to evaluate the effect of dietary chloride (Cl) levels on performance, eggshell mechanical quality, and ultrastructure in layers based on the substitution of sodium chloride (NaCl) by sodium sulfate (Na2SO4). Three hundred sixty Jing Brown laying hens aged 43 wk were randomly divided into 5 groups and fed with corn-soybean meal diets containing 0.06, 0.10, 0.15, 0.20, and 0.25% total Cl inclusion. Every group had 8 replicates of 9 birds each. The feeding trial lasted for 12 wk. The results showed dietary 0.06% Cl due to complete substitution of NaCl by Na2SO4, depressed performance (P < 0.05) from 45 to 54 wk of age, increased serum creatinine level (P < 0.05), and caused visible renal tubular atrophy. Dietary Cl levels quadratically affected breaking strength, thickness, and weight of eggshell (P < 0.05). Better eggshell quality could be obtained when NaCl was partly replaced by Na2SO4 in laying hen diets maintaining Cl level at 0.10 or 0.15%. Moreover, the eggshell ash content was affected by Cl levels in a quadratic (P < 0.001) manner, with higher values observed in the 0.10 and 0.15% Cl groups (P < 0.05). Besides, the eggshell ultrastructural data showed that the total thickness and effective thickness significantly increased (P < 0.05) and mammillary thickness decreased (P < 0.05) in the group of dietary 0.15% Cl compared with the groups of 0.06 and 0.25% Cl. In conclusion, the complete substitution of dietary NaCl by Na2SO4 may induce Cl deficiency and depress laying performance and eggshell quality. Na2SO4 could partly replace NaCl in diets for laying hens (43-54 wk of age) without adverse effects on performance at the dietary Cl level from 0.10 to 0.25%. Better eggshell quality could be obtained when NaCl was partly replaced by Na2SO4 in laying hen diets maintaining Cl level at âˆ¼0.15%.


Assuntos
Galinhas/fisiologia , Casca de Ovo/química , Cloreto de Sódio/metabolismo , Sulfatos/metabolismo , Ração Animal/análise , Animais , Dieta/veterinária , Relação Dose-Resposta a Droga , Casca de Ovo/efeitos dos fármacos , Feminino , Distribuição Aleatória , Cloreto de Sódio/administração & dosagem , Sulfatos/administração & dosagem
17.
Acta Crystallogr D Struct Biol ; 76(Pt 1): 73-84, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31909745

RESUMO

Thioredoxin (TRX) is an important antioxidant against oxidative stress. TRX from the extremely halophilic archaeon Halobacterium salinarum NRC-1 (HsTRX-A), which has the highest acidic residue content [(Asp + Glu)/(Arg + Lys + His) = 9.0] among known TRXs, was chosen to elucidate the catalytic mechanism and evolutionary characteristics associated with haloadaptation. X-ray crystallographic analysis revealed that the main-chain structure of HsTRX-A is similar to those of homologous TRXs; for example, the root-mean-square deviations on Cα atoms were <2.3 Šfor extant archaeal TRXs and <1.5 Šfor resurrected Precambrian TRXs. A unique water network was located near the active-site residues (Cys45 and Cys48) in HsTRX-A, which may enhance the proton transfer required for the reduction of substrates under a high-salt environment. The high density of negative charges on the molecular surface (3.6 × 10-3 e Å-2) should improve the solubility and haloadaptivity. Moreover, circular-dichroism measurements and enzymatic assays using a mutant HsTRX-A with deletion of the long flexible N-terminal region (Ala2-Pro17) revealed that Ala2-Pro17 improves the structural stability and the enzymatic activity of HsTRX-A under high-salt environments (>2 M NaCl). The elongation of the N-terminal region in HsTRX-A accompanies the increased hydrophilicity and acidic residue content but does not affect the structure of the active site. These observations offer insights into molecular evolution for haloadaptation and potential applications in halophilic protein-related biotechnology.


Assuntos
Halobacterium salinarum/metabolismo , Tiorredoxinas/química , Evolução Molecular , Conformação Proteica , Tolerância ao Sal , Cloreto de Sódio/metabolismo
18.
Nat Commun ; 11(1): 186, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31924762

RESUMO

Sodium (Na+) toxicity is one of the major damages imposed on crops by saline-alkaline stress. Here we show that natural maize inbred lines display substantial variations in shoot Na+ contents and saline-alkaline (NaHCO3) tolerance, and reveal that ZmNSA1 (Na+ Content under Saline-Alkaline Condition) confers shoot Na+ variations under NaHCO3 condition by a genome-wide association study. Lacking of ZmNSA1 promotes shoot Na+ homeostasis by increasing root Na+ efflux. A naturally occurred 4-bp deletion decreases the translation efficiency of ZmNSA1 mRNA, thus promotes Na+ homeostasis. We further show that, under saline-alkaline condition, Ca2+ binds to the EF-hand domain of ZmNSA1 then triggers its degradation via 26S proteasome, which in turn increases the transcripts levels of PM-H+-ATPases (MHA2 and MHA4), and consequently enhances SOS1 Na+/H+ antiporter-mediated root Na+ efflux. Our studies reveal the mechanism of Ca2+-triggered saline-alkaline tolerance and provide an important gene target for breeding saline-alkaline tolerant maize varieties.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Tolerância ao Sal/fisiologia , Sódio/metabolismo , Zea mays/fisiologia , Proteínas de Ligação ao Cálcio/genética , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Homeostase , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Tolerância ao Sal/genética , Cloreto de Sódio/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Zea mays/genética
19.
J Agric Food Chem ; 68(5): 1480-1493, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31899641

RESUMO

Licorice (Glycyrrhiza uralensis Fisch) possesses a substantial share of the global markets for its unique sweet flavor and diverse pharmacological compounds. Cultivated licorice is widely distributed in northwest regions of China, covered with land with a broad range of salinities. A preliminary study indicated that suitable salt stress significantly increased the content of bioactive constituents in licorice. However, the molecular mechanisms underlying the influence of salinity on the accumulation of these constituents remain unclear, which hinders quality breeding of cultivated licorice. In our study, flavonoid-related structural genes were obtained, and most of them, such as phenylalanine ammonia-lyases, cinnamate 4-hydroxylases, 4-coumarate: CoA ligases, chalcone synthases, chalcone-flavanone isomerase, and flavonol synthase, showed high levels after salt treatment. In the biosynthesis of glycyrrhizin, three key enzymes (bAS, CYP88D6, and CYP72A154) were identified as differentially expressed proteins and remarkably upregulated in the salt-stressed group. Combining these results with the contents of 14 bioactive constituents, we also found that the expression patterns of those structural proteins were logically consistent with changes in bioactive constituent profiles. Thus, we believe that suitable salt stress increased the accumulation of bioactive constituents in licorice by upregulating proteins involved in the related biosynthesis pathways. This work provided valuable proteomic information for unraveling the molecular mechanism of flavonoid and glycyrrhizin metabolism and offered fundamental resources for quality breeding in licorice.


Assuntos
Glycyrrhiza uralensis/química , Extratos Vegetais/metabolismo , Proteínas de Plantas/metabolismo , Cloreto de Sódio/metabolismo , Flavonoides/metabolismo , Glycyrrhiza uralensis/genética , Glycyrrhiza uralensis/metabolismo , Ácido Glicirrízico/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Raízes de Plantas/química , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Proteômica , Estresse Salino
20.
Food Microbiol ; 87: 103351, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31948609

RESUMO

The objective of this work was to investigate the effect of stress conditions frequently encountered in food-associated environments on virulence-associated characteristics of eight strains of Listeria monocytogenes. Strains were grown at low (11 °C, cold stress) and optimal (37 °C) temperatures and in high NaCl concentrations (6% NaCl, 11 °C; cold-osmotic stress) and tested for their ability to invade the human intestinal epithelial Caco-2 cells. Results demonstrate that the correlation between exposure to cold stress and increased invasion phenotype is strain-dependent as strains investigated exhibited different behaviours, i.e. exposure to cold stress conditions resulted in a significant increase of invasion levels in five out of the eight strains tested, when compared to growth under optimal conditions. On the other hand, when these cold-adapted cells were subsequently submitted to high salt concentrations and low temperature, their enhanced ability to invade Caco-2 was lost. Surprisingly, saturated fatty acids (SFA) and branched chain fatty acids (BCFA) decreased when L. monocytogenes were exposed to stress conditions as opposed to what has been observed in other studies, therefore highlighting that further studies will need to deepen in the understanding of the lipid metabolism of these strains. The effect of stress conditions on the survival of three selected L. monocytogenes strains through an in vitro gastrointestinal (GI) tract digestion model was further investigated. The exposure to cold-osmotic stress increased the survival of one strain through the GI tract.


Assuntos
Listeria monocytogenes/fisiologia , Listeriose/microbiologia , Adaptação Fisiológica , Células CACO-2 , Temperatura Baixa , Contagem de Colônia Microbiana , Humanos , Listeria monocytogenes/química , Listeria monocytogenes/crescimento & desenvolvimento , Listeria monocytogenes/patogenicidade , Pressão Osmótica , Cloreto de Sódio/metabolismo , Estresse Fisiológico , Virulência
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