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2.
J Rheumatol ; 50(2): 166-174, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36319020

RESUMO

OBJECTIVE: Morbidity and mortality in rheumatoid arthritis (RA) is partly mitigated by maintaining immune and hematologic homeostasis. Identification of those at risk is challenging. Red cell distribution width (RDW) and absolute lymphocyte count (ALC) associate with cardiovascular disease (CVD) and mortality in the general population, and with disease activity in RA. How these variables relate to inflammation and mortality in RA was investigated. METHODS: In a retrospective single Veterans Affairs (VA) Rheumatology Clinic cohort of 327 patients with RA treated with methotrexate (MTX)+/- a tumor necrosis factor (TNF) inhibitor (TNFi), we evaluated RDW and ALC before and during therapy and in relation to subsequent mortality. Findings were validated in a national VA cohort (n = 13,914). In a subset of patients and controls, we evaluated inflammatory markers. RESULTS: In the local cohort, high RDW and low ALC prior to MTX treatment was associated with subsequent mortality over 10 years (both P < 0.001). The highest mortality was observed in those with both high RDW and low ALC. This remained after adjusting for age and comorbidities and was validated in the national RA cohort. In the immunology cohort, soluble and cellular inflammatory markers were higher in patients with RA than in controls. ALC correlated with age, plasma TNF receptor II, natural killer HLA-DR mean fluorescence intensity, and CD4CM/CD8CM HLA-DR/CD38%, whereas RDW associated with age and ALC. MTX initiation was followed by an increase in RDW and a decrease in ALC. TNFi therapy added to MTX resulted in an increase in ALC. CONCLUSION: RDW and ALC before disease-modifying antirheumatic drug therapy are associated with biomarkers of monocyte/macrophage inflammation and subsequent mortality. The mechanistic linkage between TNF signaling and lymphopenia found here warrants further investigation.


Assuntos
Antirreumáticos , Artrite Reumatoide , Humanos , Índices de Eritrócitos , Estudos Retrospectivos , Inflamação/tratamento farmacológico , Metotrexato/uso terapêutico , Antirreumáticos/uso terapêutico , Biomarcadores , Contagem de Linfócitos
3.
Ecotoxicol Environ Saf ; 213: 112020, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33592373

RESUMO

The contribution of nanoparticles (NPs) in physiology of the plants became the new area of interest for the physiologists; as it is very much cost effective compared to the phytohormones. Our present investigation was also based on this interest in which the same doses (50 mg/L) of four different NPs were sprayed on stressed and non-stressed foliage. The experiment was conducted to assess the impact of four NPs viz., zinc oxide (ZnO), silicon dioxide (SiO2), titanium dioxide (TiO2), and ferric oxide (Fe2O3) on the morphology and physiology of linseed in the presence of sodium chloride (NaCl). Plants responded positively to all the treated NPs and improved the growth, carbon and nutrient assimilation, while salt stress increased the content of proline, hydrogen peroxide and superoxide anion. Application of NPs over the stressed plants further increased the antioxidant enzymatic system and other physiochemical reactions. Results indicate that application of NPs increased the growth and physiology of the plant and also increased the salt tolerance capacity of the plant.


Assuntos
Antioxidantes/metabolismo , Linho/fisiologia , Nanopartículas/toxicidade , Peróxido de Hidrogênio/farmacologia , Nanopartículas/química , Oxirredução , Fotossíntese/efeitos dos fármacos , Prolina/metabolismo , Salinidade , Estresse Salino , Tolerância ao Sal , Dióxido de Silício/toxicidade , Titânio , Óxido de Zinco
4.
Protoplasma ; 258(3): 601-620, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33392740

RESUMO

In plants, glucose (Glc) acts as a crucial signaling molecule in mediating metabolism, growth, stress tolerance mechanism, etc. However, little is known about Glc supplementation in salinity tolerance. This experiment was designed to study the ameliorative effect of Glc in mustard under salt stress. The seeds were soaked in three concentrations of NaCl (0, 50, or 100 mM) for 8 h and then treated with four concentrations of Glc (0, 2, 4, or 8%) as foliar spray for 5 days at 25-day stage. The plants were harvested at three growth stages (30, 45, and 60) for examining morpho-physiological and proteomic studies. Glc application as foliar spray increases growth, photosynthesis, and antioxidative enzyme activities in NaCl-treated plants. Glc applied in plants also showed reduction in superoxide anion, hydrogen peroxide, and malondialdehyde content under salt stress. Amongst all doses of Glc, spray of 4% Glc proved best in alleviating the harmful effects of salinity.


Assuntos
Antioxidantes/fisiologia , Carboidratos/fisiologia , Homeostase/fisiologia , Mostardeira/química , Estresse Oxidativo/fisiologia , Fotossíntese/fisiologia , Espécies Reativas de Oxigênio
5.
Plant Physiol Biochem ; 156: 64-77, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32906023

RESUMO

Salinity is one of the major threats to sustainable agriculture that globally decreases plant production by impairing various physiological, biochemical, and molecular function. In particular, salinity hampers germination, growth, photosynthesis, transpiration, and stomatal conductance. Salinity decreases leaf water potential and turgor pressure and generates osmotic stress. Salinity enhances reactive oxygen species (ROS) content in the plant cell as a result of ion toxicity and disturbs ion homeostasis. Thus, it imbalances nutrient uptake, disintegrates membrane, and various ultrastructure. Consequently, salinity leads to osmotic and ionic stress. Plants respond to salinity by modulating various morpho-physiological, anatomical, and biochemical traits by regulating ion homeostasis and compartmentalization, antioxidant machinery, and biosynthesis of osmoprotectants and phytohormones, i. e, auxins, abscisic acid, brassinosteroids, cytokinins, ethylene, gibberellins, salicylic acid, jasmonic acid, and polyamines. Thus, this further modulates plant osmoticum, decreases ion toxicity, and scavenges ROS. Plants upregulate various genes and proteins that participate in salinity tolerance. They also promote the production of various phytohormones and metabolites that mitigate the toxic effect of salinity. Based on recent papers, the deleterious effect of salinity on plant physiology is discussed. Furthermore, it evaluates the physiological and biochemical responses of the plant to salinity along with phytohormone response. This review paper also highlights omics (genomics, transcriptomics, proteomics, and metabolomics) approach to understand salt stress tolerance.


Assuntos
Fenômenos Fisiológicos Vegetais , Plantas/química , Salinidade , Tolerância ao Sal , Estresse Fisiológico , Fotossíntese , Reguladores de Crescimento de Plantas/química
6.
Protoplasma ; 257(6): 1685-1700, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32778964

RESUMO

Melatonin (MEL) is an antioxidant molecule, present throughout plant kingdom, animals, and microbes. It is a well-known free radical scavenger and modulates growth and development in plants against various abiotic and biotic stresses. The present study was done to investigate the role of MEL as a foliar spray on the morphological, physiological, and biochemical parameters in Brassica juncea cv. Varuna. Five different doses (10, 20, 30, 40, or 50 µM) of MEL were applied as foliar spray to the leaf of plant at 25 days after sowing (DAS) and continued up to 30 DAS once in a day. The plants were sampled at 30, 45, and 60 DAS to assess various parameters. The present results indicate that most of the parameters, i.e., growth, photosynthetic, nutrients, and enzyme activities increased in a concentration dependent manner. MEL application reduced the accumulation of reactive oxygen species (ROS) by enhancing the antioxidant enzyme activities. Microscopic examinations further revealed a significant increase in the size of the stomatal aperture in the presence of MEL. Out of the various concentrations tested, 40 µM of MEL proved best and can be used for further studies.


Assuntos
Antioxidantes/uso terapêutico , Melatonina/uso terapêutico , Mostardeira/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/farmacologia , Melatonina/farmacologia
7.
Bull Environ Contam Toxicol ; 105(3): 411-421, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32725326

RESUMO

Phytoremediation is an ecologically and economically feasible technique to remove heavy metal from soil. The aim of the study was to examine cadmium (Cd) toxicity and phytoremediation aptitude of Brassica juncea. In the present study, plants survived when exposed to different levels of Cd (0, 25, 50 and 100 mg/kg soil) and accumulated a large amount of Cd in its root and shoot. Translocation factor (TF) of Cd from root to shoot was > 1 at both 45 and 60-day stage of growth suggesting that B. juncea is a hyperaccumulator and strong candidate for phytoextraction of Cd. Alongside, Cd impaired photolysis of water, PSII activity, nutrient uptake, photosynthesis and sugar accumulation in the plant. Cd-generated oxidative stress restricts the growth of B. juncea. The toxic effect of Cd was more pronounced at 45-day stage of growth signifying the drifting of plant towards acquirement of exclusion strategy.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Mostardeira/metabolismo , Poluentes do Solo/metabolismo , Cádmio/análise , Metabolismo dos Carboidratos , Gases , Metais Pesados/metabolismo , Mostardeira/efeitos dos fármacos , Mostardeira/crescimento & desenvolvimento , Oxirredução , Solo , Poluentes do Solo/análise
8.
Open Life Sci ; 15: 217-228, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33987478

RESUMO

Plant hormones play important roles in controlling how plants grow and develop. While metabolism provides the energy needed for plant survival, hormones regulate the pace of plant growth. Strigolactones (SLs) were recently defined as new phytohormones that regulate plant metabolism and, in turn, plant growth and development. This group of phytohormones is derived from carotenoids and has been implicated in a wide range of physiological functions including regulation of plant architecture (inhibition of bud outgrowth and shoot branching), photomorphogenesis, seed germination, nodulation, and physiological reactions to abiotic factors. SLs also induce hyphal branching in germinating spores of arbuscular mycorrhizal fungi (AMF), a process that is important for initiating the connection between host plant roots and AMF. This review outlines the physiological roles of SLs and discusses the significance of interactions between SLs and other phytohormones to plant metabolic responses.

9.
Physiol Mol Biol Plants ; 26(12): 2503-2520, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33424161

RESUMO

Auxins (Aux) are primary growth regulators that regulate almost every aspect of growth and development in plants. It plays a vital role in various plant processes besides controlling the key aspects of cell division, cell expansion, and cell differentiation. Considering the significance of Aux, and its potential applications, a study was conducted to observe the impact of indole acetic acid (IAA), a most active and abundant form of Aux on Brassica juncea plants growing under natural environmental conditions. Different concentrations (0, 10-10, 10-8, 10-6 M) of IAA were applied once in a day at 25-day stage of growth for 5 days, consecutively. Various parameters (growth, photosynthetic, biochemical, oxidative biomarkers and nutrient composition) were assessed at different days after sowing (DAS). Scanning electron microscopy (SEM) of leaf stomata, reactive oxygen species (ROS) localization in leaf and roots, and confocal microscopy were also conducted. The results revealed that all the IAA concentrations were effective in growth promotion and ROS reduction, however, the 10-8 M of IAA exhibited the maximum improvement in all the above mentioned parameters as compared to the control.

10.
Carbohydr Res ; 487: 107884, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31811968

RESUMO

Sugars are metabolic substrates playing a part in modulating various processes in plants during different phases of development. Thus, modulating the sugar metabolism can have intense effects on the plant metabolism. Glucose is a soluble sugar, found throughout the plant kingdom. Apart from being a universal carbon source, glucose also operates as a signaling molecule modulating various metabolic processes in plants. From germination to senescence, wide range of processes in plants is regulated by glucose. The effect of glucose is found to be concentration dependent. Photosynthesis and its related attributes, respiration and nitrogen metabolism are influenced by glucose application. Endogenous content of glucose increases upon exposure of plant to various abiotic stresses and also when glucose is supplied exogenously. Glucose accumulation alleviates the damaging effects of stress by enhancing production of antioxidants and compounds similar to that of photosynthetic CO2 fixation which act as an osmoticum by maintaining osmotic pressure inside the cell, pH homeostasis regulator and reduce membrane permeability during stress. Glucose interaction with various phytohormones has also been discussed in this review.


Assuntos
Glucose/metabolismo , Plantas/química , Metabolismo dos Carboidratos , Glucose/química , Pressão Osmótica , Fotossíntese , Plantas/metabolismo , Estresse Fisiológico
11.
Int J Biol Macromol ; 145: 372-389, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31862372

RESUMO

Oligomers derived through irradiation of marine polysaccharides have generated a lot of interest of plant biologists as the application of these molecules has yielded positive results regarding various plant processes. To comprehend the previously established growth-promoting activity of irradiated chitosan (ICH) and to gain insight of the structure-property relationship, gamma rays induced structural changes were analyzed using techniques such as Fourier Transform Infrared (FT-IR) spectroscopy, Ultraviolet-visible (UV-Vis) spectroscopy, 13C-Nuclear Magnetic Resonance (NMR) spectroscopy and Scanning Electron Microscopy (SEM). Moreover, to study the bioactivity of ICH samples a pot experiment was conducted on citronella grass (Cymbopogon winterianus) to access its response to foliar application of various levels (40, 60, 80 and 100 mg L-1) of ICH in terms of growth, physiological attributes and essential oil (EO) production. The application of ICH at 80 mg L-1(ICH-80) resulted in the maximum values of most of the attributes studied. Due to this treatment, the maximum improvement in the content (29.58%) and yield (90.81%) of EO in Cymbopogon winterianus were achieved. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that ICH-80 also increased the content of citronellal (14.81%) and geraniol (18.15%) of the EO as compared to the control.


Assuntos
Quitosana/efeitos da radiação , Clorofila/agonistas , Cymbopogon/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Reguladores de Crescimento de Plantas/efeitos da radiação , Folhas de Planta/efeitos dos fármacos , Monoterpenos Acíclicos/isolamento & purificação , Monoterpenos Acíclicos/metabolismo , Aldeídos/isolamento & purificação , Aldeídos/metabolismo , Carotenoides/agonistas , Carotenoides/metabolismo , Quitosana/farmacologia , Clorofila/biossíntese , Cymbopogon/crescimento & desenvolvimento , Cymbopogon/metabolismo , Raios gama , Óleos Voláteis/química , Óleos Voláteis/metabolismo , Fotossíntese/fisiologia , Reguladores de Crescimento de Plantas/farmacologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo
12.
Carbohydr Polym ; 227: 115331, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590878

RESUMO

Chitosan in both native and degraded form (oligosaccharides) acts as a growth promoter and generate responses associated with both primary and secondary metabolism in plants. Chitosan and its oligosaccharides enhance photosynthesis by amplifying the activities of various enzymes of carbon and nitrogen metabolism as well as light and dark reaction of photosynthesis. They play a vital role in stimulating photosynthetic machinery by regulating primary photochemistry. They also overcome the limitations of stomata and amplify the carbon fixation efficiency in dark reactions and promote carbohydrate synthesis. Chitosan and its oligosaccharides stimulate the enzymes and content of secondary metabolites. A plausible explanation is that chitosan and its oligosaccharides acted as the suitable ligand for the induction of available receptors and thus elicit various signaling pathways viz, GPCR and PLC/PKC, MAPK, H2O2 burst, stimulation of transcription factors in the plant generating a maximum possible response. Chitosan and its oligosaccharides also exhibit antimicrobial activities and act as biopestiside, preventing proliferation of pathogens and preserve crop yield and quality.


Assuntos
Quitosana/metabolismo , Produção Agrícola , Oligossacarídeos/metabolismo , Plantas/metabolismo , Metabolismo Secundário
13.
IET Nanobiotechnol ; 13(4): 345-352, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31171737

RESUMO

Nanotechnology is an emerging field of science that applies particles between 1 and 100 nm in size for a range of practical uses. Nano-technological discoveries have opened novel applications in biotechnology and agriculture. Many reactions involving nanoparticles (NPs) are more efficient compared to those of their respective bulk materials. NPs obtained from plant material, denoted as biogenic or phytosynthesised NPs, are preferred over chemically synthesised NPs due to their low toxicity, rapid reactions and cost-effective production. NPs impart both positive and negative impacts on plant growth and development. NPs exhibit their unique actions as a function of their size, reactivity, surface area and concentration. An insight into NP biosynthesis and translocation within the plant system will shed some light on the roles and mechanisms of NP-mediated regulation of plant metabolism. This review is a step towards that goal.


Assuntos
Biotecnologia , Nanopartículas , Nanotecnologia , Plantas/metabolismo , Fenômenos Fisiológicos Vegetais
14.
Plant Physiol Biochem ; 135: 119-126, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30529977

RESUMO

Energy acts as a primary prerequisite for plant growth like all the other organisms. Soluble sugars function in providing enough supply of nutrients which further helps in building macromolecules and energy to carry out specific and coordinated development. Sugars functions as nutrient as well as signaling molecule to promote cell division and differentiation in plants. Intriguingly, glucose has emerged as a crucial signaling molecule where hexokinase1 acts as the conserved glucose sensor. On the molecular scale, an extensive crosstalk between glucose and phytohormone signaling has been observed where glucose signals trigger multiple hexokinase1-dependent as well as hexokinase1-independent pathways to mediate diverse developmental, physiological and molecular mechanisms. Taken together, these findings this review focused on the glucose crosstalk with several classical plant hormonal-signaling pathways and the crucial role of hexokinase1 in modulating plant physiological processes.


Assuntos
Glucose/fisiologia , Reguladores de Crescimento de Plantas/fisiologia , Fenômenos Fisiológicos Vegetais , Transdução de Sinais/fisiologia , Glucose/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Plantas/metabolismo
15.
Plant Physiol Biochem ; 129: 198-212, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29894860

RESUMO

BRs are polyhydroxylated sterol derivatives, classified as phytohormones. Plants of Brassica juncea var. Varuna were grown in pots and an aqueous solution (10-8 M) of two brassinosteroid isomers 28-homobrassinolide (HBL) and 24-epibrassinolide (EBL) of same concentration (10-8 M) was applied to their leaves. The treatment up-regulated the photosynthetic machinery directly by enhancing water splitting activity, photochemical quenching, non-photochemical quenching, maximum PSII efficiency, actual PSII efficiency, electron transport rate, stomatal movement, stomatal conductance, internal CO2 concentration, transpiration rate, net photosynthetic rate and carbohydrate synthesis. Moreover, the level of biochemical enzymes (carbonic anhydrase and nitrate reductase), reactive oxygen species (superoxide and hydrogen peroxide) generation, antioxidant enzyme activity and mineral status (C, N, Mg, P, S, K), which indirectly influence the rate of photosynthesis, also improved in the treated plants. Out of the two BR analogues tested, EBL excelled in its effects over HBL.


Assuntos
Brassinosteroides/farmacologia , Colestanonas/farmacologia , Mostardeira/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Reguladores de Crescimento de Plantas/farmacologia , Folhas de Planta/efeitos dos fármacos , Esteroides Heterocíclicos/farmacologia , Antioxidantes/metabolismo , Peróxido de Hidrogênio/metabolismo , Microscopia Eletrônica de Varredura , Mostardeira/metabolismo , Complexo de Proteína do Fotossistema II/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/ultraestrutura , Raízes de Plantas/efeitos dos fármacos , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/ultraestrutura , Transpiração Vegetal/efeitos dos fármacos , Superóxidos/metabolismo
16.
Nitric Oxide ; 73: 22-38, 2018 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-29275195

RESUMO

Nitric oxide (NO) is a major signaling biomolecule associated with signal transduction in plants. The beneficial role of NO in plants, exposed to several abiotic stresses shifted our understanding as it being not only free radical, released from the toxic byproducts of oxidative metabolism but also helps in plant sustenance. An explosion of research in plant NO biology during the last two decades has revealed that NO is a key signal associated with plant growth, germination, photosynthesis, leaf senescence, pollen growth and reorientation. NO is beneficial as well as harmful to plants in a dose-dependent manner. Exogenous application of NO at lower concentrations promotes seed germination, hypocotyl elongation, pollen development, flowering and delays senescence but at higher concentrations it causes nitrosative damage to plants. However, this review concentrates on the beneficial impact of NO in lower concentrations in the plants and also highlights the NO crosstalk of NO with other plant hormones, such as auxins, gibberellins, abscisic acid, cytokinins, ethylene, salicylic acid and jasmonic acid, under diverse stresses. While concentrating on the multidimensional role of NO, an attempt has been made to cover the role of NO-mediated genes associated with plant developmental processes, metal uptake, and plant defense responses as well as stress-related genes. More recently, several NO-mediated post translational modifications, such as S-nitrosylation, N-end rule pathway operates under hypoxia and tyrosine nitration also occurs to modulate plant physiology.


Assuntos
Óxido Nítrico/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Estresse Fisiológico , Germinação/fisiologia , Ácidos Indolacéticos/metabolismo , Pressão Osmótica , Fotossíntese , Desenvolvimento Vegetal , Folhas de Planta/fisiologia , Fenômenos Fisiológicos Vegetais , Processamento de Proteína Pós-Traducional
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