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1.
Microbiol Res ; 227: 126297, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421711

RESUMO

Many plant growth promoting rhizobacteria such as Bacillus velezensis GJ11 can produce acetoin to trigger induced systemic resistance (ISR) in plants. For improving acetoin production, the mutant strains were respectively constructed by knockout of the gene of bdh (2,3-butanediol dehydrogenase) and gdh (glycerol dehydrogenase) in GJ11, but only GJ11Δbdh produced a high level of acetoin triggering strong ISR against Pseudomonas syringae infection in plants. GJ11Δbdh could induce H2O2 accumulation in plants by producing a high level of acetoin. H2O2 was necessary for triggering ISR against the pathogen infection because after scavenging H2O2 with ascorbic acid or catalase, the inhibition role to pathogen infection induced by acetoin almost disappeared in plants. Further investigation found the plants treated with GJ11Δbdh in an obvious "priming" state, in which the mild immune response was observed such as a slight increase of H2O2 production, callose deposition, and enzymes activity related with defence response (e.g. POD, PAL and PPO). The plants in "priming" could rapidly respond to the pathogen infection accompanying with a significant increase of H2O2 production, callose deposition, and enzymes activity. Collectively, this study provides new insight into the role of acetoin as a strong elicitor of defense response, and ascribes a new approach to construct the mutant strains with high production of acetoin for triggering stronger ISR against pathogens infection in plants.


Assuntos
Acetoína/metabolismo , Arabidopsis/genética , Bacillus/genética , Bacillus/metabolismo , Resistência à Doença/genética , Imunidade Vegetal/genética , Oxirredutases do Álcool/genética , Arabidopsis/imunologia , Arabidopsis/microbiologia , Ácido Ascórbico/metabolismo , Catalase/metabolismo , Resistência à Doença/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Genes de Plantas/genética , Peróxido de Hidrogênio/metabolismo , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Imunidade Vegetal/fisiologia , Pseudomonas syringae/patogenicidade , Desidrogenase do Álcool de Açúcar/genética
2.
Food Chem ; 299: 125110, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31284244

RESUMO

This study was undertaken in order to estimate the effect of in vitro propagation on antioxidant activity in strawberry. Results of this research exhibited differences between conventionally and in vitro propagated plants in respect of all traits analyzed. In spite of the decrease in range and mean content of vitamin C and polyphenols as well as antioxidant activity, the genetic gain expressed as percent of mean was higher in microplants regarding phenolics, flavonoids and antioxidant activity in contrast to conventional plants (22.39-20.83, 21.79-15.61, 9.52-3.39; resp.). Correlation and path coefficients showed changes of antioxidants inter-relations between micropropagated and conventional plants. Phenolics and vitamin C correlated positively with antioxidant activity in all genotypes. The highest positive direct effect on antioxidant activity was observed via vitamin C in microplants (0.705), while in conventional plants via phenolics (0.834). Flavonoids affected directly and positively antioxidant activity in microplants (0.103) and negatively in conventional plants (-0.143).


Assuntos
Antioxidantes/metabolismo , Flavonoides/metabolismo , Fragaria/crescimento & desenvolvimento , Fragaria/genética , Ácido Ascórbico/genética , Ácido Ascórbico/metabolismo , Flavonoides/genética , Fragaria/metabolismo , Genótipo , Fenóis/metabolismo , Polifenóis/genética , Polifenóis/metabolismo
3.
Food Chem ; 299: 125116, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31295637

RESUMO

The effects of exogenous melatonin treatment on the enzymatic browning and nutritional quality of fresh-cut pear fruit were investigated. Fresh-cut fruit soaked with 0, 0.05, 0.1 and 0.5 mM melatonin were stored at 4 °C. Our results showed that 0.1 mM melatonin treatment was optimal for reducing the surface browning and maintaining the titratable acidity of the fresh-cut fruit, which significantly decreased MDA and H2O2 contents and the growth of microorganism, enhanced total phenolic content and antioxidant capacity, and delayed the reduction of ascorbic acid. Furthermore, melatonin treatment at 0.1 mM decreased the expression of genes involving in enzymatic browning pathway including POD, PPO1, PPO5 and LOX1, and reduced PPO activity. Moreover, this treatment increased the expression of PAL and CHS, and enhanced PAL and CHS activities. These results showed that melatonin treatment might be a promising strategy to alleviate browning and improve the nutritional quality of fresh-cut pear fruit.


Assuntos
Frutas/efeitos dos fármacos , Melatonina/farmacologia , Valor Nutritivo , Pyrus/efeitos dos fármacos , Antioxidantes/análise , Antioxidantes/metabolismo , Ácido Ascórbico/análise , Ácido Ascórbico/metabolismo , Armazenamento de Alimentos , Frutas/química , Frutas/metabolismo , Frutas/microbiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/metabolismo , Malondialdeído/análise , Malondialdeído/metabolismo , Fenóis/análise , Pyrus/química , Pyrus/genética , Pyrus/metabolismo
4.
Aquat Toxicol ; 213: 105228, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31229888

RESUMO

The present work was conducted to study how restoration of perturbed oxidant and antioxidant homeostasis is achieved in the UV-C radiation exposed cells of cyanobacterium Nostoc muscorum Meg1. Exposure to varying doses of UV-C radiation (6, 12, 18 and 24 mJ/cm2) showed damage to ultrastructures especially cytoplasmic membrane, cell wall and organisation of thylakoid membranes of the cyanobacterium under transmission electron microscope (TEM). All doses of UV-C exposure significantly induced most of the enzymatic antioxidant {catalase, superoxide dismutase (SOD) and glutathione reductase (GR)} activities, their protein levels (western blot analysis) and mRNA levels (real time PCR analysis) within the first hour of post UV-C radiation incubation period. In the same way, contents of many non-enzymatic antioxidants such as ascorbic acid, reduced glutathione, proline, phenol and flavonoids were also augmented in response to such UV-C radiation exposure. Although notable increase in ROS level was only seen in cultures treated with 24 mJ/cm2 UV-C exposure which also registered increase in protein oxidation (22%) and lipid peroxidation (20%), this boost in both enzymatic and non-enzymatic antioxidants was significant in all radiation exposed cells indicating cell's preparation to combat rise in oxidants. Further, albeit all antioxidants increased considerably, their levels were restored back to control values by day seventh re-establishing physiological redox state for normal metabolic function. The combined efficiency of the enzymatic and non-enzymatic antioxidants were so effective that they were able to bring down the increase levels of ROS, lipid peroxidation and protein oxidation to the physiological levels within 1 h of radiation exposure signifying their importance in the defensive roles in protecting the organism from oxidative toxicity induced by UV-C radiation exposure.


Assuntos
Antioxidantes/metabolismo , Homeostase , Nostoc muscorum/fisiologia , Nostoc muscorum/efeitos da radiação , Oxidantes/metabolismo , Estresse Fisiológico/efeitos da radiação , Raios Ultravioleta , Ácido Ascórbico/metabolismo , Catalase/metabolismo , Cisteína/metabolismo , Flavonoides/metabolismo , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos da radiação , Nostoc muscorum/ultraestrutura , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Prolina/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/toxicidade
5.
Br Poult Sci ; 60(3): 279-287, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31146535

RESUMO

1. This study analysed whether in ovo injection of ascorbic acid before incubation and at high incubation temperature influenced blood characteristics and performance in broilers reared in different temperature conditions. 2. A total of 3,000 fertile eggs from broiler breeders (Cobb®) were randomly divided into three incubation treatments: no ascorbic acid injection and egg incubation at 37.5°C (control); no ascorbic acid injection and egg incubation at 39°C; in ovo ascorbic acid injection prior to incubation (6 µg AA/100 µl water) and egg incubation at 39°C. 3. Male chicks hatched from the three incubation treatments were submitted to three distinct rearing temperatures (control, cold and hot) from the third week of age onwards (540 chicks were divided into 6 treatments with 5 replicates per treatment). 4. Measurements at 42 d showed that, after egg incubation at 39°C, the haematocrit, haemoglobin values, ionised calcium and glucose concentrations were increased and base excess values were reduced. However, in ovo injection of ascorbic acid normalised all these parameters. 5. Partial CO2 and O2 pressure were higher with increased rearing temperature. Blood pH was lower when eggs were incubated at 39°C and injected with ascorbic acid. In ovo injection of ascorbic acid induced leucocytosis due to lymphocytosis and heterophilia, restored basophils rate and led to monocytopoenia. Leucocytosis was triggered by hot rearing temperature due to lymphocytosis, eosinophilia and heterophilia. 6. The results obtained in this study showed that in ovo injection of ascorbic acid before incubation may serve as a long-term stimulator and modulator of the broiler immune system, and that high incubation temperatures induce adaptations in the electrolytic balance, minimising or avoiding the occurrence of respiratory alkalosis under hot rearing temperature.


Assuntos
Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Galinhas/metabolismo , Temperatura Alta , Óvulo/química , Animais , Antioxidantes/administração & dosagem , Ácido Ascórbico/administração & dosagem , Análise Química do Sangue , Galinhas/sangue , Testes Hematológicos , Injeções/veterinária , Masculino
6.
BMC Evol Biol ; 19(1): 126, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31215418

RESUMO

BACKGROUND: L-ascorbate (Vitamin C) is an important antioxidant and co-factor in eukaryotic cells, and in mammals it is indispensable for brain development and cognitive function. Vertebrates usually become L-ascorbate auxothrophs when the last enzyme of the synthetic pathway, an L-gulonolactone oxidase (GULO), is lost. Since Protostomes were until recently thought not to have a GULO gene, they were considered to be auxothrophs for Vitamin C. RESULTS: By performing phylogenetic analyses with tens of non-Bilateria and Protostomian genomes, it is shown, that a GULO gene is present in the non-Bilateria Placozoa, Myxozoa (here reported for the first time) and Anthozoa groups, and in Protostomians, in the Araneae family, the Gastropoda class, the Acari subclass (here reported for the first time), and the Priapulida, Annelida (here reported for the first time) and Brachiopoda phyla lineages. GULO is an old gene that predates the separation of Animals and Fungi, although it could be much older. We also show that within Protostomes, GULO has been lost multiple times in large taxonomic groups, namely the Pancrustacea, Nematoda, Platyhelminthes and Bivalvia groups, a pattern similar to that reported for Vertebrate species. Nevertheless, we show that Drosophila melanogaster seems to be capable of synthesizing L-ascorbate, likely through an alternative pathway, as recently reported for Caenorhabditis elegans. CONCLUSIONS: Non-Bilaterian and Protostomians seem to be able to synthesize Vitamin C either through the conventional animal pathway or an alternative pathway, but in this animal group, not being able to synthesize L-ascorbate seems to be the exception rather than the rule.


Assuntos
Ácido Ascórbico/metabolismo , Eucariotos/enzimologia , Eucariotos/genética , Evolução Molecular , L-Gulonolactona Oxidase/genética , Animais , Drosophila melanogaster/genética , Eucariotos/classificação , Eucariotos/metabolismo , Genoma , L-Gulonolactona Oxidase/química , L-Gulonolactona Oxidase/metabolismo , Modelos Moleculares , Filogenia , Vertebrados/classificação , Vertebrados/genética
7.
Environ Pollut ; 251: 961-969, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31234263

RESUMO

Phycoremediation technologies significantly contribute to solving serious problems induced by heavy metals accumulation in the aquatic systems. Here we studied the mechanisms underlying Al stress tolerance in two diazotrophic cyanobacterial species, to identify suitable species for Al phycoremediation. Al uptake as well as the physiological and biochemical responses of Anabaena laxa and Nostoc muscorum to 7 days Al exposure at two different concentrations i.e., mild (100 µM) and high dose (200 µM), were investigated. Our results revealed that A. laxa accumulated more Al, and it could acclimatize to long-term exposure of Al stress. Al induced a dose-dependent decrease in photosynthesis and its related parameters e.g., chlorophyll content (Chl a), phosphoenolpyruvate carboxylase (PEPC) and Ribulose‒1,5‒bisphosphate carboxylase/oxygenase (RuBisCo) activities. The affect was less pronounced in A. laxa than N. muscorum. Moreover, Al stress significantly increased cellular membrane damage as indicated by induced H2O2, lipid peroxidation, protein oxidation, and NADPH oxidase activity. However, these increases were lower in A. laxa compared to N. muscorum. To mitigate the impact of Al stress, A. laxa induced its antioxidant defense system by increasing polyphenols, flavonoids, tocopherols and glutathione levels as well as peroxidase (POX), catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GPX) enzymes activities. On the other hand, the antioxidant increases in N. muscorum were only limited to ascorbate (ASC) cycle. Overall, high biosorption/uptake capacity and efficient antioxidant defense system of A. laxa recommend its feasibility in the treatment of Al contaminated waters/soils.


Assuntos
Alumínio/metabolismo , Anabaena/metabolismo , Antioxidantes/metabolismo , Biodegradação Ambiental , Nostoc muscorum/metabolismo , Fotossíntese/efeitos dos fármacos , Ácido Ascórbico/metabolismo , Catalase/metabolismo , Clorofila/metabolismo , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Peroxidação de Lipídeos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Peroxidases/metabolismo , Fosfoenolpiruvato Carboxilase/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo
8.
Ecotoxicol Environ Saf ; 181: 248-254, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31200197

RESUMO

Although the North Delta region in Egypt is one of the most densely populated areas in the world, it suffers from a severe shortage of fresh water needed to irrigate crops. So usually farmers resort to the use of low-quality water, such as agricultural drainage water, which could pose a threat to the quality of crops and then human health. Two field experiments were carried out during two consecutive summer seasons of 2014 and 2015 aimed at delivering more information about the pros and cons of alternative irrigation for tomato using fresh and agricultural drainage water with or without applying of magnetic field. The twelve surface irrigations, which tomato needs during its whole growing season, were applied alternatively between fresh and agricultural drainage water, respectively, at the following percentages (100 + 0), (75 + 25), (50 + 50), (25 + 75) and (0 + 100). Magnetic field was applied using iron fillings at a rate of 150 kg ha-1. The results revealed that growth parameters, early, total and relative yield, marketable yield and total chlorophyll and NPK content of leaves were gradually decreased with increasing the irrigation using agricultural drainage water. However, irrigating tomato by 100% fresh water had the highest values, while using of 100% agricultural drainage water displayed the lowest values. Contrarily, vitamin C, total soluble solids (TSS) and fruit firmness where at their highest values when tomato irrigated by 100% of agricultural drainage water. Applying of magnetic field not only enhances the growth, yield and quality of tomato under irrigation using agricultural water but also under fresh water. These results are of importance in areas where the use of agricultural drainage water irrigating crops is inevitable for enhancing yield and its quality and consequently ensuring food safety.


Assuntos
Irrigação Agrícola , Lycopersicon esculentum/crescimento & desenvolvimento , Campos Magnéticos , Agricultura , Ácido Ascórbico/metabolismo , Egito , Água Doce , Frutas , Humanos , Lycopersicon esculentum/metabolismo , Folhas de Planta/metabolismo , Estações do Ano , Água
9.
Food Chem ; 295: 172-179, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174747

RESUMO

The effects of 10 and 20 days of fermentation followed by freeze-drying on the vitamin C and fatty acids contents, chemical conversions and overall chemical composition of Jerusalem artichoke were studied. Fermentation between the 10th and 20th days increased content of all saturated fatty acids and two of the four unsaturated fatty acids. The only fatty acid content that decreased was that of C18:1 cis 9 acid, which was suggested to be converted to other fatty acids. The experimental data, which were supported by energetical feasibility, suggested the reaction pathways of the mutual conversions of fatty acids and confirmed the decreased vitamin C content during fermentation. Discriminant modelling of the spectral data successfully distinguished the fresh, 10 days and 20 days fermented samples. The correlation of the spectral and reference data allowed to construct reference models for predicting the content of vitamin C and C18:1 cis 9 fatty acid.


Assuntos
Ácido Ascórbico/metabolismo , Ácidos Graxos/metabolismo , Helianthus/química , Silagem , Ácido Ascórbico/análise , Ácidos Graxos/análise , Fermentação , Análise de Alimentos/estatística & dados numéricos , Liofilização , Helianthus/metabolismo , Modelos Estatísticos , Silagem/análise , Espectrofotometria Infravermelho/estatística & dados numéricos
10.
Plant Physiol Biochem ; 141: 466-476, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31252252

RESUMO

The present study was aimed to investigate adaptation in physiology and biochemistry of Solanum lycopersicum seedlings under NaCl (NaCl0; 0.0 g NaCl kg-1 sand, NaCl1; 0.3 g NaCl/kg sand and NaCl2; 0.5 g NaCl/kg sand) stress, simultaneously supplemented with different (deprived; 0 mg/kg sand, LN; 105 mg/kg sand, MN; 210 mg/kg sand and HN; 270 mg/kg sand) levels of nitrogen (N). NaCl at both doses caused significant loss in growth, K+ content, K+/Na+ ratio, total chlorophyll and photosynthetic oxygen evolution. Further, N supplementation influences growth of test seedlings, that attained maximum growth in HN followed by MN, LN and deprived N conditions. N at HN level significantly declined Na+ accumulation in the cell and enhanced level of K+. NaCl treatment enhanced level of oxidative stress biomarkers: superoxide radical (O2•-), hydrogen peroxide (H2O2), MDA equivalents contents and electrolyte leakage in leaf as well as root despite enhanced activity of SOD, POD, CAT and GST, and enzymes participating in the ascorbate-glutathione cycle (AsA-GSH cycle) viz. APX, DHAR and GR. At the same time, higher contents of total AsA (AsA + DHA) and total GSH (GSH + GSSG), and maintained ratios of AsA/DHA and GSH/GSSG in HN fed seedlings were observed. Overall, the results suggest that HN supplementation was able in alleviating NaCl induced toxicity in test seedlings which was mainly due to the up-regulation of the AsA-GSH cycle, K+ and K+/Na+ ratio, which resulted into better growth performance of HN fed seedlings under NaCl stress while reverse was noticed for LN and deprive N conditions.


Assuntos
Lycopersicon esculentum/metabolismo , Nitrogênio/química , Espécies Reativas de Oxigênio/metabolismo , Salinidade , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Biomarcadores/metabolismo , Clorofila/metabolismo , Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos , Malondialdeído/metabolismo , Estresse Oxidativo , Oxigênio/metabolismo , Fotossíntese , Pigmentação , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Potássio/química , Plântula/metabolismo , Cloreto de Sódio/química
11.
Food Chem ; 295: 607-612, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174802

RESUMO

The purpose of this study is to investigate the effects of sodium nitroprusside (SNP) treatment after harvest on the activity of antioxidative enzymes and the phenylpropanoid pathway of blueberries. Blueberry fruits were dipped in 1.0 mmol/L SNP solution for 10 min and stored at 4 °C. Fruits treated with distilled water were used as the control. The results indicated that SNP significantly inhibited the increase of weight loss and enhanced the ascorbic acid content of blueberry fruit. Moreover, SNP increased the activity of phenylalanine ammonia-lyase, 4-coumarate-CoA ligase, polyphenol oxidase, superoxide dismutase, glutathione reductase, ascorbate peroxidase, peroxidase, and hydrogen peroxide in blueberry fruit. The accumulation of lignin and anthocyanin in the fruit was also stimulated by the SNP treatment. These results demonstrate that SNP treatment could maintain the antioxidant ability of blueberries by regulating the phenylpropanoid pathway and antioxidant enzymes.


Assuntos
Antioxidantes/metabolismo , Mirtilos Azuis (Planta)/efeitos dos fármacos , Nitroprussiato/farmacologia , Antocianinas/metabolismo , Antioxidantes/química , Ascorbato Peroxidases/metabolismo , Ácido Ascórbico/metabolismo , Mirtilos Azuis (Planta)/química , Mirtilos Azuis (Planta)/metabolismo , Frutas/química , Frutas/efeitos dos fármacos , Frutas/metabolismo , Glutationa Redutase/metabolismo , Peróxido de Hidrogênio/metabolismo , Lignina/metabolismo , Peroxidase/metabolismo , Superóxido Dismutase/metabolismo
12.
Ecotoxicol Environ Saf ; 179: 212-221, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31048217

RESUMO

Aluminum (Al) toxicity is a major limiting factor for plant productivity. Boron (B) could mitigate Al toxicity in many plant species. However, information about the mechanisms of B alleviating Al toxicity in citrus is lacking. Trifoliate orange rootstock (Poncirus trifoliate L. Raf.) seedlings were irrigated with a nutrient solution containing two B and two Al levels. Results showed that exposure to Al severely impeded plant growth-related parameters. However, B supply improved plant biomass, root activity and relative root elongation under Al stress. Furthermore, B reduced the Al-induced H2O2 accumulation in roots as evidenced by lower fluorescence intensity of H2O2 staining. Boron decreased the Al-stimulated ascorbate (AsA) synthesis by down-regulated AsA synthesis-related metabolites in the L-galactose pathway. Boron alleviated some of the toxic effects of Al by decreasing redox states of AsA and enzyme activities involved in ascorbate-glutathione (AsA-GSH) cycle, ascorbate peroxidase, dehydroascorbate reductase, glutathione reductase and glutathione peroxidase while increased glutathione (GSH) content and γ-glutamylcysteine synthetase (γ-GCS) activity. Overall, our results suggest that B protects roots against Al-induced oxidative stress possibly by reducing metabolites accumulation in the L-galactose pathway of AsA synthesis and regulating AsA-GSH cycle.


Assuntos
Alumínio/toxicidade , Boro/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Poncirus/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Poluentes do Solo/toxicidade , Irrigação Agrícola , Ascorbato Peroxidases/metabolismo , Ácido Ascórbico/metabolismo , China , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Peróxido de Hidrogênio/metabolismo
13.
Environ Sci Pollut Res Int ; 26(19): 19261-19271, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31065988

RESUMO

Cadmium (Cd) contamination in agricultural soils is a prevalent environmental issue and poses potential threats to food security. Foliar ascorbic acid might prove a potent tool to alleviate toxicity of Cd toxicity in maize. An experiment was conducted with objectives to study exogenous ascorbic acid-modulated improvements in physiochemical attributes of maize under Cd toxicity. The experiment was conducted under completely randomized design. Treatments were comprised of varying concentrations of foliar ascorbic acid viz. 0.0, 0.1, 0.3, and 0.5 mM of AsA. Toxicity of Cd decreased the maize growth, increased lipid peroxidation, disturbed protein metabolism, and reduced the antioxidant defense capabilities compared with the control. However, foliar AsA significantly improved maize growth and development, photosynthetic capabilities, and protein concentrations in Cd-stressed maize plants. Meanwhile, the malondialdehyde contents and hydrogen peroxide accumulation levels in Cd-stressed maize plants decreased remarkably with increasing AsA concentrations. Furthermore, the combined treatments conspicuously boosted activities of superoxide dismutase, peroxidase, catalase, and glutathione reductase under the Cd stress alone. In addition, the application of AsA reduced the Cd uptake by 10.3-12.3% in grains. Conclusively, foliar ascorbic acid alleviated the negative effects of Cd stress in maize and improved photosynthetic processes, osmolytes, and antioxidant defense systems.


Assuntos
Antioxidantes/metabolismo , Ácido Ascórbico/farmacologia , Cádmio/toxicidade , Poluentes do Solo/toxicidade , Zea mays/efeitos dos fármacos , Ácido Ascórbico/metabolismo , Cádmio/metabolismo , Relação Dose-Resposta a Droga , Peroxidação de Lipídeos/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Distribuição Aleatória , Poluentes do Solo/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
14.
Ecotoxicol Environ Saf ; 180: 575-587, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31129436

RESUMO

The present study identified inverse relationships between nickel (Ni) levels and growth, photosynthesis and physio-biochemical attributes, but increasing levels of Ni stress enhanced methylglyoxal, electrolyte leakage, hydrogen peroxide, and lipid peroxidation content. Exogenous application of salicylic acid (SA) (10-5 M) ameliorated the ill-effects of Ni by restoring growth, photosynthesis and physio-biochemical attributes and increasing the activities of enzymes associated with antioxidant systems, especially the ascorbate-glutathione (AsA-GSH) cycle and glyoxalase system. In addition, SA application to Ni-stressed plants had an additive effect on the activities of the ascorbate and glutathione pools, and the AsA-GSH cycle enzymes (ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione reductase), superoxide dismutase, catalase, glutathione S-transferase, and osmolyte biosynthesis). This trend also follows in glyoxalase system viz. glyoxalase I and glyoxalase II enzymes. Nevertheless, exogenous SA supplementation restored mineral nutrient contents. Principal component analysis showed that growth, photosynthesis, and mineral nutrient parameters were positively correlated with each other and negatively correlated with antioxidant enzymes and oxidative stress biomarkers. Hence, SA is an alternative compound with potential application in the phytoremediation of Ni.


Assuntos
Níquel/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Ácido Salicílico/farmacologia , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Glutationa/metabolismo , Lactoilglutationa Liase/metabolismo , Peroxidação de Lipídeos , Mostardeira/efeitos dos fármacos , Mostardeira/enzimologia , Mostardeira/metabolismo , Fotossíntese/efeitos dos fármacos , Aldeído Pirúvico/metabolismo , Tioléster Hidrolases/metabolismo , Regulação para Cima/efeitos dos fármacos
15.
Plant Sci ; 284: 185-191, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31084871

RESUMO

Transcriptional activation of ascorbate biosynthesis-associated genes under illumination is one of the important steps in ascorbate pool size regulation in photosynthetic tissues. Several biological processes within chloroplasts such as photosynthesis are required for this activation, suggesting functional chloroplasts to play a key role. We herein found that when grown on agar plate, ascorbate content in Arabidopsis non-photosynthetic tissues, roots, are unexpectedly almost comparable to that in shoots. The high accumulation of ascorbate was particularly observed in root regions closer to the root-hypocotyl junction, in which chloroplast development occurred because of a direct exposure to light. When chloroplast development in roots were further stimulated by shoot removal, the expression of biosynthetic genes, especially VTC2 gene that encodes GDP-l-galactose phosphorylase, was activated, resulting in an increase in ascorbate pool size. These positive effects were canceled when the roots were treated with a photosynthetic inhibitor. A null mutation in the LONG HYPOCOTYL 5 (HY5) gene almost completely inhibited root greening as well as the VTC2 expression. Overall, these findings show that chloroplast development can trigger the expression of ascorbate biosynthesis-associated genes not only in leaves but also in roots.


Assuntos
Arabidopsis/metabolismo , Ácido Ascórbico/biossíntese , Cloroplastos/fisiologia , Raízes de Plantas/metabolismo , Arabidopsis/fisiologia , Ácido Ascórbico/metabolismo , Clorofila/metabolismo , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas/fisiologia , Redes e Vias Metabólicas , Raízes de Plantas/fisiologia , Reação em Cadeia da Polimerase em Tempo Real
16.
Talanta ; 201: 388-396, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122439

RESUMO

Ascorbic acid (AA) is an essential vitamin and plays an irreplaceable role in humans' daily life. Therefore, it is of profound significance to develop effective strategies for AA sensing. Herein, a novel bi-functional sensing strategy was developed by using carbon dots (CDs) and MnO2 nanosheet as the fluorometric/magnetic signal source. When AA was absence, the fluorescence of CDs was quenched by MnO2 nanosheet due to the inner filter effect. Neither the fluorescence nor magnetic signal of the nanoprobe can be detected. In the presence of AA, a redox reaction occurred between MnO2 nanosheet and AA resulting in the generation of magnetic resonance imaging (MRI) response Mn2+ and decomposing of MnO2 nanosheet structure, thus leading to the recovery of CDs fluorescence. The detection limit of the AA was determined to be 2.89 µM with a linear range of 0-80 µM in fluorescence mode, and detection limit of 0.776 µM with a linear range of 0-80 µM in MRI mode when used transverse relaxation rate as signal. Furthermore, the developed fluorometric/magnetic bi-functional nanoprobe showed good biocompatibility, high response rate, high selectivity towards AA and could be used to analyses AA in real samples. Moreover, in vivo imaging of AA in mice was achieved in magnetic mode. The fluorometric/magnetic bi-function sensor for AA detection was introduced, which provided a novel strategy for sensor design based on CDs.


Assuntos
Ácido Ascórbico/análise , Corantes Fluorescentes/química , Imagem por Ressonância Magnética/métodos , Compostos de Manganês/química , Óxidos/química , Pontos Quânticos/química , Espectrometria de Fluorescência/métodos , Animais , Ácido Ascórbico/química , Ácido Ascórbico/metabolismo , Fluorescência , Corantes Fluorescentes/toxicidade , Limite de Detecção , Fenômenos Magnéticos , Masculino , Camundongos Endogâmicos BALB C , Oxirredução , Óxidos/toxicidade , Pontos Quânticos/toxicidade
17.
Plant Physiol Biochem ; 139: 681-690, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31054470

RESUMO

Arabinogalactan proteins (AGPs) are ubiquitous components of the amorphous plant extracellular matrix. They are characterized by a high proportion of sugar moieties, heterogeneity of their protein backbone and carbohydrate chains. It is known that AGPs form a complex network with other basic constituents in cell wall thus it may also play a role in softening process of fruit. The use of enzymatic degradation and cell wall polysaccharide directed probes are valid analytical tools for the study of developmental modification of the fruit structure. However, it is unknown whether pectolytic enzymes affect AGPs. Thus, the aim of the current work is to detect AGP epitopes in situ to understand the impact of selected degradation enzymes on various carbohydrate moieties of AGPs. Secondly, there are no data with clarification of the impact of vitamin C on fruit ripening processes at the cellular level; hence, we also focused on the effect of vitamin C on the arrangement of AGPs as important constituents of the polysaccharide-proteoglycan network in the fruit cell wall. The results indicate that the distribution of the examined AGP carbohydrate moieties differs, which are related to changes in tissue architecture. The absence of glycan chains causes disruption in establishment of correlations between cell wall constituents and rearrangement in the cell wall structure. The induced modifications of cell walls are not comparable to alterations occurring in naturally ripening fruit, which allows a conclusion that the synergistic action of a wide variety of factors influences ripening.


Assuntos
Ácido Ascórbico/metabolismo , Frutas/metabolismo , Lycopersicon esculentum/metabolismo , Mucoproteínas/metabolismo , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo
18.
Plant Mol Biol ; 100(4-5): 391-410, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30953278

RESUMO

KEY MESSAGE: Our results reveal both soil drought and PEG can enhance malate, glutathione and ascorbate metabolism, and proline biosynthesis, whereas soil drought induced these metabolic pathways to a greater degree than PEG. Polyethylene glycol (PEG) is widely used to simulate osmotic stress, but little is known about the different responses of wheat to PEG stress and soil drought. In this study, isobaric tags for relative quantification (iTRAQ)-based proteomic techniques were used to determine both the proteomic and physiological responses of wheat seedlings to soil drought and PEG. The results showed that photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, maximum potential efficiency of PS II, leaf water content, relative electrolyte leakage, MDA content, and free proline content exhibited similar responses to soil drought and PEG. Approximately 15.8% of differential proteins were induced both by soil drought and PEG. Moreover, both soil drought and PEG inhibited carbon metabolism and the biosynthesis of some amino acids by altering the accumulation of glyceraldehyde-3-phosphate dehydrogenase, ribulose-bisphosphate carboxylase, and phosphoglycerate kinase, but they both enhanced the metabolism of malate, proline, glutathione, and ascorbate by increasing the accumulation of key enzymes including malate dehydrogenase, monodehydroascorbate reductase, pyrroline-5-carboxylate dehydrogenase, pyrroline-5-carboxylate synthetase, ascorbate peroxidase, glutathione peroxidase, and glutathione S-transferase. Notably, the latter five of these enzymes were found to be more sensitive to soil drought. In addition, polyamine biosynthesis was specifically induced by increased gene expression and protein accumulation of polyamine oxidase and spermidine synthase under PEG stress, whereas fructose-bisphosphate aldolase and arginase were induced by soil drought. Therefore, present results suggest that PEG is an effective method to simulate drought stress, but the key proteins related to the metabolism of malate, glutathione, ascorbate, proline, and polyamine need to be confirmed under soil drought.


Assuntos
Proteômica , Estresse Fisiológico , Triticum/fisiologia , Ácido Ascórbico/metabolismo , Secas , Glutationa/metabolismo , Malatos/metabolismo , Redes e Vias Metabólicas , Pressão Osmótica , Polietilenoglicóis/farmacologia , Prolina/biossíntese , Triticum/genética , Triticum/metabolismo , Água/metabolismo
19.
J Sci Food Agric ; 99(11): 5073-5082, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30980532

RESUMO

BACKGROUND: Pomegranate fruit is an excellent source of bioactive polyphenolics, known to contribute significantly to human health. India is the largest producer of pomegranate in the world and produces the finest quality fruit with highly desirable consumer traits such as soft seeds, low acidity, and attractive fruit and aril color. Knowledge of the extent of variation in key metabolites (sugars, organic acids, phenolics, and anthocyanins) is key to selecting superior genotypes for germplasm improvement. Relevant information with respect to Indian genotypes is scarce. The present study therefore aims to evaluate quantitatively important metabolites in some cultivars and elite germplasm of pomegranate in India. RESULTS: Identification and quantification of primary and secondary metabolites such as sugars, organic acids, vitamin C, polyphenolics, and anthocyanins were conducted using a liquid chromatography - mass spectrometry (LC-MS) platform. Fructose and citric acid were the predominant sugar and organic acid, respectively. Wild genotypes had significantly higher concentrations of organic acids, antioxidant activity, and phenolics, namely punicalagin, ellagic acid, sinapic, and ferulic acid. CONCLUSION: Cyanidin and delphinidin derivatives of anthocyanins were more abundant in red aril commercial genotypes. Results suggest that wild-sour accessions represent a rich source of polyphenolics that can be utilized in future breeding programs to breed healthier varieties, food supplements, and pharmaceutical products. © 2019 Society of Chemical Industry.


Assuntos
Células Germinativas Vegetais/classificação , Punicaceae/química , Punicaceae/metabolismo , Antocianinas/análise , Antocianinas/metabolismo , Ácido Ascórbico/análise , Ácido Ascórbico/metabolismo , Cromatografia Líquida de Alta Pressão , Cor , Frutas/química , Frutas/classificação , Frutas/genética , Frutas/metabolismo , Genótipo , Células Germinativas Vegetais/metabolismo , Índia , Espectrometria de Massas , Polifenóis/análise , Polifenóis/metabolismo , Punicaceae/classificação , Punicaceae/genética , Metabolismo Secundário , Sementes/química , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Açúcares/análise , Açúcares/metabolismo
20.
BMC Cancer ; 19(1): 307, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30943919

RESUMO

BACKGROUND: The transcription factor hypoxia inducible factor (HIF) -1 drives tumor growth and metastasis and is associated with poor prognosis in breast cancer. Ascorbate can moderate HIF-1 activity in vitro and is associated with HIF pathway activation in a number of cancer types, but whether tissue ascorbate levels influence the HIF pathway in breast cancer is unknown. In this study we investigated the association between tumor ascorbate levels and HIF-1 activation and patient survival in human breast cancer. METHODS: In a retrospective analysis of human breast cancer tissue, we analysed primary tumor and adjacent uninvolved tissue from 52 women with invasive ductal carcinoma. We measured HIF-1α, HIF-1 gene targets CAIX, BNIP-3 and VEGF, and ascorbate content. Patient clinical outcomes were evaluated against these parameters. RESULTS: HIF-1 pathway proteins were upregulated in tumor tissue and increased HIF-1 activation was associated with higher tumor grade and stage, with increased vascular invasion and necrosis, and with decreased disease-free and disease-specific survival. Grade 1 tumors had higher ascorbate levels than did grade 2 or 3 tumors. Higher ascorbate levels were associated with less tumor necrosis, with lower HIF-1 pathway activity and with increased disease-free and disease-specific survival. CONCLUSIONS: Our findings indicate that there is a direct correlation between intracellular ascorbate levels, activation of the HIF-1 pathway and patient survival in breast cancer. This is consistent with the known capacity of ascorbate to stimulate the activity of the regulatory HIF hydroxylases and suggests that optimisation of tumor ascorbate could have clinical benefit via modulation of the hypoxic response.


Assuntos
Antígenos de Neoplasias/metabolismo , Ácido Ascórbico/metabolismo , Neoplasias da Mama/patologia , Anidrase Carbônica IX/metabolismo , Carcinoma Ductal de Mama/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Antígenos de Neoplasias/genética , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Anidrase Carbônica IX/genética , Hipóxia Celular , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Proteínas Proto-Oncogênicas/genética , Estudos Retrospectivos , Análise de Sobrevida , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/genética
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