Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.613
Filtrar
1.
Plant Mol Biol ; 101(1-2): 203-220, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31297725

RESUMO

KEY MESSAGE: Here, a functional characterization of a wheat MSR has been presented: this protein makes a contribution to the plant's tolerance of abiotic stress, acting through its catalytic capacity and its modulation of ROS and ABA pathways. The molecular mechanism and function of certain members of the methionine sulfoxide reductase (MSR) gene family have been defined, however, these analyses have not included the wheat equivalents. The wheat MSR gene TaMSRA4.1 is inducible by salinity and drought stress and in this study, we demonstrate that its activity is restricted to the Met-S-SO enantiomer, and its subcellular localization is in the chloroplast. Furthermore, constitutive expression of TaMSRA4.1 enhanced the salinity and drought tolerance of wheat and Arabidopsis thaliana. In these plants constitutively expressing TaMSRA4.1, the accumulation of reactive oxygen species (ROS) was found to be influenced through the modulation of genes encoding proteins involved in ROS signaling, generation and scavenging, while the level of endogenous abscisic acid (ABA), and the sensitivity of stomatal guard cells to exogenous ABA, was increased. A yeast two-hybrid screen, bimolecular fluorescence complementation and co-immunoprecipitation assays demonstrated that heme oxygenase 1 (HO1) interacted with TaMSRA4.1, and that this interaction depended on a TaHO1 C-terminal domain. In plants subjected to salinity or drought stress, TaMSRA4.1 reversed the oxidation of TaHO1, activating ROS and ABA signaling pathways, but not in the absence of HO1. The aforementioned properties advocate TaMSRA4.1 as a candidate for plant genetic enhancement.


Assuntos
Heme Oxigenase-1/metabolismo , Metionina Sulfóxido Redutases/metabolismo , Transdução de Sinais , Estresse Fisiológico , Triticum/enzimologia , Ácido Abscísico/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/fisiologia , Secas , Perfilação da Expressão Gênica , Heme Oxigenase-1/genética , Metionina Sulfóxido Redutases/genética , Oxirredução , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Salinidade , Tolerância ao Sal , Plântula/enzimologia , Plântula/genética , Plântula/fisiologia , Triticum/genética , Triticum/fisiologia , Técnicas do Sistema de Duplo-Híbrido
2.
Food Chem ; 299: 125038, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31284248

RESUMO

Wheat is one of the world's most widely consumed staple food. However, the number of people suffering from wheat-related disorders has increased drastically. Amylase-trypsin inhibitors (ATIs) have recently been identified as one of the main triggers of non-celiac wheat sensitivity (NCWS). In this study, an enzymatic assay for the determination of trypsin inhibition activity in hexaploid wheat was developed. This method was optimized with respect to several parameters, such as extraction and incubation procedures, and was validated according to international standards, concerning accuracy, precision and robustness of the method. Results revealed that linear inhibition and thus accuracy occurred only in a narrow concentration range. However, after optimization of settings the novel method was found to be satisfactory for accurate determination of trypsin inhibition in wheat. Purification of the wheat extract with immobilized trypsin beads led to the identification of CM inhibitors (chloroform/methanol soluble proteins) as main contributors of trypsin inhibition.


Assuntos
Amilases/farmacologia , Ensaios Enzimáticos/métodos , Triticum/enzimologia , Inibidores da Tripsina/farmacologia , Tripsina/metabolismo , Alérgenos/farmacologia , Humanos
3.
Ecotoxicol Environ Saf ; 181: 345-352, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202935

RESUMO

Nanomaterials are being used increasingly in various areas such as electronic devices manufacture, medicine, mechanical devices production, and even food industry. Therefore, the evaluation of their toxicity is mandatory. Graphene oxide (GO) has been shown to have both positive as well as negative impact on different crop plants, depending on species, dose, and duration of exposure. The current study evaluated the impact of GO sheets at different concentrations (500, 1000 and 2000 mg/L) on physiological, biochemical and genetic levels to determine the possible toxic action. Wheat caryopses were treated with GO for 48 h and 7 days. The germination rate and roots elongation decreased in a dose-response manner, except the sample treated with GO at a concentration of 1000 mg/L. Mitotic index has ascendant trend; its increase may be due to the accumulation of prophases GO induced significant accumulation of the cells with aberrations, their presence suggests a clastogenic/aneugenic effect of these carbon nanomaterials. Regarding enzymatic and non-enzymatic antioxidant system defence, the activity varied depending on the dose of GO. Thus, chlorophyll a pigments content decreased significantly at high dose (2000 mg/L), while the carotenoid pigments had lower content at 500 mg/L of GO, and no statistical difference encountered in case of chlorophyll b amount. The antioxidant enzyme activity (CAT, POD, and SOD) was higher at low dose of GO, indicating the presence of oxidative stress generated as a response to the GO treatment. Also, the free radical scavenging activity of the polyphenolic compounds was enhanced upon GO exposure. The GO accumulation has been identified by transmission electron microscopy only at plumules level, near the intercellular space.


Assuntos
Grafite/toxicidade , Nanoestruturas/toxicidade , Triticum/efeitos dos fármacos , Antioxidantes/metabolismo , Clorofila/metabolismo , Clorofila A/metabolismo , Germinação/efeitos dos fármacos , Estresse Oxidativo , Óxidos/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/metabolismo , Triticum/enzimologia , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
4.
Ecotoxicol Environ Saf ; 181: 49-59, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31170649

RESUMO

N-acetylcysteine (N-Acetyl L-cysteine, NAC) is a thiol compound derived from the addition of the acetyl group to cysteine amino acid. NAC has been used as an antioxidant, free radical scavenger, and chelating agent for reducing the deleterious effects on plants of biotic and abiotic environmental stresses. It can also relieve heavy metal (HM) toxicity, although its alleviating mechanism remains unknown. In this study, we compared HM-stressed (Cu, Hg, Cd and Pb, 100 µM each) wheat seedlings without NAC treatment and in combination with NAC (1 mM). In comparison to HMs alone, NAC treatment in combination with HMs (Cu, Cd, Hg and Pb, respectively) stimulated root growth (1.1-, 1.5-, 10.5- and 1.9-fold), and significantly increased fresh (1.3-, 1.5-, 4.3- and 1.4-fold) and dry (1.2-, 1.5-, 2.5- and 1.2-fold) mass. Combination treatment also led to significant reductions in HM concentrations (1.3-, 1.4-, 4- and 1.1-fold, respectively). GSH (1.1 - 1.8-fold), TBARS (1.4 - 2.7-fold) and H2O2 (1.6 - 1.8-fold) contents in treatment with HMs alone were significantly mitigated by the NAC combination. Some of the antioxidant enzyme activities increased or reduced by some HM treatments alone were stimulated by a combination of NAC with HMs, or remained unchanged or changed only insignificantly, supported by the phenolic pool of the plant. Ferulic, p-comaric and syringic acids were the major phenolic acids (PAs) in the roots in free, ester, glycoside and ester-bound forms, and their concentrations were increased by HM treatments alone, in comparison to the control seedlings, while PAs concentrations were relatively reduced by NAC in combination with HMs. These results indicate that NAC can alleviate HM toxicity and improve the growth of HM-stressed wheat seedlings by coordinated induction of the phenolic pool and the antioxidant defence system.


Assuntos
Acetilcisteína/farmacologia , Antioxidantes/farmacologia , Metais Pesados/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poluentes do Solo/toxicidade , Triticum/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Hidroxibenzoatos/metabolismo , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/crescimento & desenvolvimento , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Triticum/enzimologia , Triticum/crescimento & desenvolvimento
5.
Gene ; 710: 210-217, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31176733

RESUMO

Low temperature is a key stress factor for the growth and development of wheat (Triticum aestivum L.), and glycometabolism plays an important role in plant cold tolerance. Our previous study identified trehalose 6-phosphate synthase 11 gene (TaTPS11), which had a significantly different expression pattern between a high freezing-tolerant wheat cultivar and a low freezing-tolerant wheat cultivar. In this study, TaTPS11 was isolated from a winter-hardy wheat cultivar (D1) and overexpressed in Arabidopsis thaliana to study its effect on cold tolerance in plants. Transgenic plants expressing TaTPS11 had lower sucrose content, higher starch content, and higher activity of key enzyme (sucrose phosphate synthase, sucrose synthase, and invertase) involved in sucrose metabolism. In addition, the expression level of sucrose non-fermenting 1-related kinase 1 (SnRK1), which catalyzes the sucrose in plants, increased in the TaTPS11-overexpressed plants. These results indicated that heterologous expression of TaTPS11 influenced carbohydrate metabolism in Arabidopsis plants. The resultant plants had a significantly higher survival rate after -5 °C treatment for 2 h and exhibited enhanced cold tolerance without unfavorable phenotypes compared to wild-type. Our findings indicated that manipulation of TaTPS11 improved cold tolerance in plants and TaTPS11 had potential values in wheat cold-tolerance breeding.


Assuntos
Arabidopsis/genética , Resposta ao Choque Frio , Monoéster Fosfórico Hidrolases/genética , Triticum/enzimologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Metabolismo dos Carboidratos , Regulação da Expressão Gênica de Plantas , Monoéster Fosfórico Hidrolases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Proteínas Serina-Treonina Quinases/genética , Reação em Cadeia da Polimerase em Tempo Real , Sacarose/metabolismo , Triticum/genética
6.
Int J Mol Sci ; 20(9)2019 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-31035313

RESUMO

Seed storage proteins must be hydrolyzed by proteases to deliver the amino acids essential for embryo growth and development. Several groups of proteases involved in this process have been identified in both the monocot and the dicot species. This review focuses on the implication of proteases during germination in two cereal species, barley and wheat, where proteolytic control during the germination process has considerable economic importance. Formerly, the participation of proteases during grain germination was inferred from reports of proteolytic activities, the expression of individual genes, or the presence of individual proteins and showed a prominent role for papain-like and legumain-like cysteine proteases and for serine carboxypeptidases. Nowadays, the development of new technologies and the release of the genomic sequences of wheat and barley have permitted the application of genome-scale approaches, such as those used in functional genomics and proteomics. Using these approaches, the repertoire of proteases known to be involved in germination has increased and includes members of distinct protease families. The development of novel techniques based on shotgun proteomics, activity-based protein profiling, and comparative and structural genomics will help to achieve a general view of the proteolytic process during germination.


Assuntos
Germinação/fisiologia , Hordeum/enzimologia , Hordeum/fisiologia , Peptídeo Hidrolases/metabolismo , Proteínas de Plantas/metabolismo , Triticum/enzimologia , Triticum/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Germinação/genética , Peptídeo Hidrolases/genética , Proteínas de Plantas/genética
7.
Nat Plants ; 5(5): 480-485, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30988404

RESUMO

Developing herbicide-tolerant varieties by genome editing holds great promise for addressing the worsening weed problems in wheat cultivation1. Here, we generated transgene-free wheat germplasms harbouring herbicide tolerance mutations that confer tolerance to sulfonylurea-, imidazolinone- and aryloxyphenoxy propionate-type herbicides by base editing the acetolactate synthase (ALS) and acetyl-coenzyme A carboxylase genes. These stackable herbicide tolerance traits provide a potentially powerful tool for weed management. In addition, we found that base editing at the wheat ALS Pro-174 codon (TaALS-P174) endowed wheat with sufficient resistance to nicosulfuron herbicide in MS growth medium to allow selection. When the TaALS-P174 editor was coupled with editors for other targets of interest, co-editing occurred in the nicosulfuron-resistant plants, and selection for resistance in growth medium enriched the frequency of coupled targets by several-fold. This selectable co-editing system has the potential to greatly bolster adoption of base editing for crop improvement applications.


Assuntos
Edição de Genes/métodos , Resistência a Herbicidas/genética , Triticum/genética , Acetolactato Sintase/genética , Acetolactato Sintase/metabolismo , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Alelos , Códon/genética , Marcadores Genéticos/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Característica Quantitativa Herdável , Alinhamento de Sequência , Triticum/efeitos dos fármacos , Triticum/enzimologia , Controle de Plantas Daninhas/métodos
8.
Plant Physiol Biochem ; 139: 342-349, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30952086

RESUMO

Melatonin (MEL) has been widely reported to be beneficial to plant growth and development, but few studies have combined investigations of the performance and function of MEL with detailed physiologically based analyses of nitrogen (N) uptake and metabolism in staple crops. In this study, the effect of MEL application on winter wheat seedling growth and grain yield were investigated in hydroponic and pot experiments at different N levels. The result showed that application of 1 µM MEL in hydroponic solution significantly improved the wheat seedling growth under both N sufficient and deficient conditions, but the effect of MEL on promoting seedling growth was prominent under N deficient condition. Meanwhile, MEL-treated plants maintained higher N contents and nitrate nitrogen levels in shoot under N deficient condition, and also maintained higher nitrate nitrogen levels in root. Further investigation showed that nitrate reductase (NR) and glutamine synthetase (GS) activities were higher in MEL-treated plants than that of MEL-untreated plants under N deficiency. The N absorption calculated based on N contents and biomass showed that MEL could promote the N absorption under N deficient condition. In pot experiment, pre-soaking of seeds with 100 µM MEL enhanced per-plant yield by 16% under N sufficient condition and 23% under N deficient condition. Taken together, the results of this study indicate that MEL is involved in promoting N uptake and assimilation through up-regulating the activities of N uptake and metabolism related enzymes and, ultimately, promotes the plant growth and yield, especially under N deficient condition.


Assuntos
Melatonina/metabolismo , Nitrogênio/metabolismo , Triticum/metabolismo , Glutamato-Amônia Ligase/metabolismo , Nitrato Redutase/metabolismo , Triticum/enzimologia
9.
Plant Physiol Biochem ; 139: 366-378, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30954019

RESUMO

Catalase proteins play a crucial role in detoxifying hydrogen peroxide, generated during plant growth, and in response to various environmental stresses. Despite their importance, little is known about their localization and expression in wheat. In this study, we identified and characterized a novel peroxisomal catalase gene from Triticum monococcum, designated as TmCAT1. Phylogenetic analysis revealed that TmCAT1 shared high identity with TdCAT1 and other plant catalases belonging to subfamily 1. We predicted the 3D structure model and the oligomerization arrangement of TmCAT1. Besides, we displayed an arrangement in asymmetric unit, which involved interactions including, mainly, residues from N-terminal domain. Interestingly, sequence analysis indicated that TmCAT1, like TdCAT1, had the peroxisomal targeting signal (PTS1) around its C-terminus. Transient expression of TmCAT1-GFP and TdCAT1-GFP in tobacco leaves revealed that the two fused proteins are targeted into peroxisomes. However, the truncated forms lacking the tripeptide QKL remained in the cytosol. Concerning the expression profile analysis, TmCAT1 is expressed especially in leaves in normal condition. On the other hand, it is up-regulated by different stress incorporating salt, osmotic, oxidative, heavy metal and hormones stresses. Functional analysis by heterologous expression in yeast cells showed that TmCAT1 improved tolerance to multiple abiotic stresses. The presence of important cis-regulatory elements in the promoter region of TmCAT1 strongly reinforces the interest of this gene in plant adaptation to various stresses.


Assuntos
Catalase/metabolismo , Peroxissomos/metabolismo , Triticum/enzimologia , Triticum/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Filogenia , Proteínas de Plantas/metabolismo , Estresse Fisiológico/fisiologia
10.
Int J Mol Sci ; 20(8)2019 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-31003470

RESUMO

The 12-oxo-phytodienoic acid reductases (OPRs), which belong to the old yellow enzyme (OYE) family, are flavin mononucleotide (FMN)-dependent oxidoreductases with critical functions in plants. Despite the clear characteristics of growth and development, as well as the defense responses in Arabidopsis, tomato, rice, and maize, the potential roles of OPRs in wheat are not fully understood. Here, forty-eight putative OPR genes were found and classified into five subfamilies, with 6 in sub. I, 4 in sub. II, 33 in sub. III, 3 in sub. IV, and 2 in sub. V. Similar gene structures and conserved protein motifs of TaOPRs in wheat were identified in the same subfamilies. An analysis of cis-acting elements in promoters revealed that the functions of OPRs in wheat were mostly related to growth, development, hormones, biotic, and abiotic stresses. A total of 14 wheat OPR genes were identified as tandem duplicated genes, while 37 OPR genes were segmentally duplicated genes. The expression patterns of TaOPRs were tissue- and stress-specific, and the expression of TaOPRs could be regulated or induced by phytohormones and various stresses. Therefore, there were multiple wheat OPR genes, classified into five subfamilies, with functional diversification and specific expression patterns, and to our knowledge, this was the first study to systematically investigate the wheat OPR gene family. The findings not only provide a scientific foundation for the comprehensive understanding of the wheat OPR gene family, but could also be helpful for screening more candidate genes and breeding new varieties of wheat, with a high yield and stress resistance.


Assuntos
Genoma de Planta/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Estresse Fisiológico/genética , Triticum/genética , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Família Multigênica/genética , Oryza/genética , Filogenia , Reguladores de Crescimento de Planta/genética , Regiões Promotoras Genéticas/genética , Triticum/enzimologia , Zea mays/metabolismo
11.
J Food Sci ; 84(5): 946-953, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30947368

RESUMO

Germination of wheat maximizes phytochemical content and antioxidant activity while altering chemical composition, gluten content, and pasting properties. This study investigated the effect of short-term imbibition on gene expression profiles and the physical and functional characteristics of wheat. Changes in gene expression profiles of wheat during short-term imbibition (0, 16, and 24 hr) were evaluated by DNA microarray analysis. Gene Ontology (GO) analysis was carried out to categorize the function of genes with altered expression. Genes related to cellulose and cell wall synthesis were upregulated by imbibition for 16 hr, whereas those associated with polysaccharide catabolism and nucleosome assembly were upregulated in the subsequent 8 hr. The genes related to proteases and gluten were expressed in dry seeds but disappeared after 16 hr of imbibition. Genes encoding α-amylase were not expressed in dry seeds whereas those encoding ß-amylase were expressed in dry seeds and downregulated by imbibition. According to quantitative real-time PCR and enzymatic activity assay, α-Amylase expression increased by imbibition and reached a maximum 24 hr after imbibition, with a corresponding increase in enzymatic activity. Pasting properties of flour made from wheat seeds imbibed for different times were decreased when seeds were imbibed for over 16 hr, by examination with Rapid Visco Analyzer. Gluten content did not significantly change until 24-hr imbibition, although expression of genes encoding gliadin and glutenin disappeared by 16-hr imbibition. The data indicated that it was possible to use 16-hr imbibed wheat, with up to the 50% w/w replacement of nonimbibed wheat.


Assuntos
Farinha/análise , Regulação da Expressão Gênica de Plantas , Germinação/genética , Sementes , Triticum/genética , Água , alfa-Amilases/metabolismo , Antioxidantes , Grão Comestível , Qualidade dos Alimentos , Perfilação da Expressão Gênica , Genes de Plantas , Gliadina/metabolismo , Glutens/análise , Glutens/metabolismo , Humanos , Análise em Microsséries , Plântula/metabolismo , Sementes/enzimologia , Triticum/enzimologia , Triticum/metabolismo
12.
Ecotoxicol Environ Saf ; 172: 380-387, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30731269

RESUMO

The different wheat varieties have different tolerance to cadmium stress, while the mechanisms underlying the Cd tolerance are still poorly understood. A pot experiment was conducted to study the changes of antioxidant enzyme activities and endogenous hormones in wheat (Triticum aestivum) genotypes differing in cadmium (Cd) accumulation (low = Pingan 8 and high = Bainong 160) in different growth stages under Cd stress. The Cd treatment (3 mg/kg) increased the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and concentrations of malondialdehyde (MDA) and abscisic acid (ABA); in contrast, it reduced the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), intercellular carbon dioxide concentration (Ci) and the concentrations of gibberellin (GA3), auxin (IAA) and zeatin nucleoside (ZR) in wheat leaves compared to the CK (without Cd). The antioxidant enzyme activities were higher in Bainong 160 than Pingan 8 under Cd stress. In addition, the changes in endogenous hormone concentration were smaller in Bainong 160 than Pingan 8 leaves. The correlation coefficients of Bainong 160 and Pingan 8 were 0.87 and 0.66, respectively. Our results suggest that high Cd accumulation (greater Cd tolerance) in Bainong 160 is associated with higher photosynthetic parameters, higher activities of antioxidant enzyme and higher concentration of hormones than Pingan 8.


Assuntos
Cádmio/toxicidade , Estresse Fisiológico , Triticum/efeitos dos fármacos , Ácido Abscísico/análise , Catalase/metabolismo , Giberelinas/análise , Ácidos Indolacéticos/análise , Malondialdeído/metabolismo , Peroxidases/metabolismo , Fotossíntese/efeitos dos fármacos , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Superóxido Dismutase/metabolismo , Triticum/enzimologia , Zeatina/análise
13.
J Agric Food Chem ; 67(9): 2660-2669, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30739449

RESUMO

The wheat catalase gene ( wcat1) was cloned and overexpressed in Pichia pastoris. The purified wCat1 exhibits its highest activity at pH 7.5 and 35 °C with Km and Vmax of 22.95 mM and 0.24 µmol/min, respectively. wCat1 could markedly improve the farinographic properties of dough, with the stability time increasing and degree of softening decreasing, and enhance the rheological properties of dough. wCat1 could also elevate bread-making quality, with increased specific volume of the bread and decreased hardness, gumminess, and chewiness, which are attributable to increased amounts of SDS-insoluble protein in dough, resulting in extended glutenin networks and thus larger pores in the fermented dough and bread crumb. The decrease of hydrogen peroxide and increase of free thiol groups in wCat1-treated dough suggest that the decomposition of hydrogen peroxide by wCat1 likely promotes disulfide-bond formation and thus the cross-linking of dough proteins.


Assuntos
Catalase/genética , Catalase/metabolismo , Farinha , Manipulação de Alimentos/métodos , Proteínas Recombinantes/metabolismo , Triticum/enzimologia , Clonagem Molecular , Fermentação , Qualidade dos Alimentos , Expressão Gênica , Glutens/análise , Pichia/enzimologia , Pichia/genética , Reologia
14.
Carbohydr Polym ; 208: 285-293, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30658802

RESUMO

Levans and inulins are fructans with mainly ß-(2→6) and ß-(2→1) linkages, respectively. Levans are produced by many lactic acid bacteria, e.g. during sourdough fermentation. Levans have shown prebiotic properties and may also function as in situ-produced hydrocolloids. So far, levan contents have been measured by acid hydrolysis, which cannot distinguish levans from e.g. inulins. In order to develop a specific analysis for levan in food matrices, a Paenibacillus amylolyticus endolevanase was combined with exoinulinase for levan hydrolysis. A separate endoinulinase treatment was used to detect the possible presence of inulin. Interfering sugars were removed by a pre-wash with aqueous ethanol. Levan content was estimated from fructose and glucose released in the hydrolysis, with a correction made for the residual fructose and glucose-containing sugars. The method was validated using wheat model doughs spiked with commercial Erwinia levan, and tested by analyzing levan content in Leuconostoc mesenteroides DSM 20343-fermented fava bean doughs.


Assuntos
Frutanos/metabolismo , Lactobacillales/enzimologia , Lactobacillales/metabolismo , Fermentação/fisiologia , Glicosídeo Hidrolases/metabolismo , Inulina/metabolismo , Polissacarídeos/metabolismo , Triticum/enzimologia , Triticum/metabolismo , Vicia faba/enzimologia , Vicia faba/metabolismo
15.
Artigo em Inglês | MEDLINE | ID: mdl-30596331

RESUMO

The roles of enzymatic reactions and redox reactions caused by reactive oxygen species (ROS) in formaldehyde metabolism in tomatoes and wheat seedlings and the changes in peroxidase (POD) and catalase (CAT) activities in plants were investigated. Differences in the breakdown of added formaldehyde between fresh and boiled plant extracts were determined to calculate the contributions of different removal mechanisms. Two plant seedlings efficiently removed formaldehyde from air when its level varied from 0.65 to 1.91 mg m-3; meanwhile, the maximum rate at which tomato seedlings transported formaldehyde from air to the rhizosphere solution reached 182.26 µg h-1 kg-1 FW (fresh weight). Metabolism in plants was mainly responsible for the formaldehyde dissipation. The enzymatic contribution to formaldehyde dissipation decreased with increasing shoot exposure time or air formaldehyde level, while the redox contribution increased in importance because of an increasing level of ROS. The different enzymatic antioxidant activities of plants resulted in different levels of ROS and hence different tolerance and removal efficiencies toward formaldehyde. The self-enhancing ability of plants to remove formaldehyde via redox reactions suggested that the formaldehyde removal efficiency could be enhanced by plant adaptation to environmental stress.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/prevenção & controle , Antioxidantes/metabolismo , Formaldeído/análise , Espécies Reativas de Oxigênio/metabolismo , Plântula/enzimologia , Catalase/metabolismo , Lycopersicon esculentum/enzimologia , Lycopersicon esculentum/crescimento & desenvolvimento , Oxirredução , Peroxidases/metabolismo , Plântula/crescimento & desenvolvimento , Estresse Fisiológico , Triticum/enzimologia , Triticum/crescimento & desenvolvimento
16.
Appl Biochem Biotechnol ; 188(3): 569-584, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30552625

RESUMO

Citrate synthase (CS) and NADP-dependent isocitrate dehydrogenase (NADP-ICDH) have been considered as candidate enzymes to provide carbon skeletons for nitrogen assimilation, i.e., production of 2-oxoglutarate required by the glutamine synthetase/glutamate synthase cycle. The CS and NADP-ICDH cDNAs were encoded for polypeptides of 402 and 480 amino acids with an estimated molecular weight of 53.01 and 45 kDa and an isoelectric point of 9.08 and 5.98, respectively. Phylogenetic analysis of these proteins in wheat across kingdoms confirmed the close relationship with Aegilops tauschii and Hordeum vulgare. Further, their amino acid sequences were demonstrated to have some conserved motifs such as Mg2+ or Mn2 binding site, catalytic sites, NADP binding sites, and active sites. In-silico-identified genomic sequences for the three homeologues A, B, and Dof CS and NADP-ICDH were found to be located on long arm of chromosomes 5 and 3, and sequence analysis also revealed that the three homeologues consisted of 13 and 15 exons, respectively. The total expression analysis indicated that both genes are ubiquitously expressed in shoot and root tissues under chronic as well as transient nitrogen stress. However, they are differentially and contrastingly expressed but almost in a coordinated manner in both the tissues. Under chronic as well as transient stress, both the genes in shoot tissue showed downregulation, lowest at 6 h of transient stress. However, in the root tissue, trend was found opposite except with exceptions. Moreover, all the three homeologues of both the genes were transcribed differentially, and the ratio of the individual homeologues transcripts to total homeologues transcripts also varied with the tissue, i.e., shoots or roots, as well as with nitrogen stress treatments. Thus, cDNA as well as genomic sequence information, apparent expression at different time point of nitrogen stress, and coordination between these enzymes would be ultimately linked to nitrate assimilation and nitrogen use efficiency in wheat.


Assuntos
Citrato (si)-Sintase/genética , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Isocitrato Desidrogenase/genética , Nitrogênio/metabolismo , Estresse Fisiológico , Triticum/enzimologia , Triticum/genética , Sequência de Aminoácidos , Sítios de Ligação , Mapeamento Cromossômico , Cromossomos de Plantas , Citrato (si)-Sintase/química , Citrato (si)-Sintase/metabolismo , DNA Complementar/genética , Genes de Plantas , Isocitrato Desidrogenase/química , Isocitrato Desidrogenase/metabolismo , Magnésio/metabolismo , Manganês/metabolismo , Peso Molecular , Filogenia
17.
Plant Physiol Biochem ; 135: 242-252, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30584966

RESUMO

MAPK phosphatases (MKPs) are relevant negative regulators of MAPKs in eukaryotes as they mediate the feedback control of MAPK cascades in multiple cellular processes. Despite their relevance, our knowledge on the role of cereal MKPs in stress tolerance is scarce and TMKP1 remains today the only studied MKP in wheat. TMKP1 was previously reported to be involved in plant salt stress tolerance. Moreover, TMKP1 was shown to interact with calmodulin (CaM), 14-3-3 and TMPK3/TMPK6 proteins, which regulate its catalytic activity. To further understand the functional properties of TMKP1, we investigate here the contribution of its phosphorylation status, and of TMPK3 together with CaM and bivalent cations on the catalytic activity. In-gel kinase assays revealed that TMKP1 can be phosphorylated by similar wheat and Arabidopsis MAPKs, including most likely MPK3 and MPK6. In addition, we provide evidence for the capacity of wheat TMPK3 to bind to TMKP1 via a conserved Kinase Interacting Domain (KID) located on its C-terminal part. This interaction leads to a stimulation of TMKP1 activity in the presence of Mn2+ or Mg2+ ions, but to its inhibition in the presence of Ca2+ ions. However, the phosphorylation status of TMKP1 seems to be dispensable for TMKP1 activation by TMPK3. Remarkably, in assays combining TMPK3 with CaM/Ca2+ complex, we registered rather an inhibition of TMKP1 activity which however can be suppressed by Mn2+ cations. Our data are in favor of complex differential regulation of TMKP1 by its MPK substrates, metallic cations that might help in fine-tuning the plant cellular responses to various stresses.


Assuntos
Calmodulina/metabolismo , Fosfatase 1 de Especificidade Dupla/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas de Plantas/metabolismo , Triticum/metabolismo , Cálcio/metabolismo , Magnésio/metabolismo , Manganês/metabolismo , Fosforilação , Triticum/enzimologia
18.
Acta Biol Hung ; 69(4): 449-463, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30587016

RESUMO

The major aim of the present study was to investigate the influence of juglone (JU; 5-hydroxy-1,4-naphthoquinone) treatments on the expression level of Cat1, Cat2 and Cat3 genes, encoding the respective catalase isozymes in maize (Zea mays L.) and wheat (Triticum aestivum L.) seeds. In parallel, germination efficiency, catalase (CAT) activity and hydrogen peroxide (H2O2) content in juglone-exposed cereal seeds were assessed. Juglone applications significantly stimulated abundance of three target catalase transcripts as well as induced CAT activity and generation of H2O2 in both maize and wheat kernels. Furthermore, germination process of juglone-affected maize seeds was more severe suppressed than in case of wheat kernels. The role of juglone in triggering the oxidative stress as well as antioxidative responses in seeds of the studied model cereal species are discussed.


Assuntos
Catalase/genética , Perfilação da Expressão Gênica/métodos , Naftoquinonas/farmacologia , Proteínas de Plantas/genética , Sementes/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Triticum/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Catalase/biossíntese , Indução Enzimática/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Isoenzimas , Proteínas de Plantas/biossíntese , Sementes/enzimologia , Sementes/genética , Triticum/enzimologia , Triticum/genética , Zea mays/enzimologia , Zea mays/genética
19.
J Agric Food Chem ; 66(45): 12034-12041, 2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30375224

RESUMO

Distribution of phytic acid and phytase activity in pea seeds was analyzed and compared with those in wheat grains under identical assay conditions (55 °C, pH 5.5). Most total phytic acid content and phytase activity were found in pea cotyledons. In wheat grains, debranning resulted in a 70% reduction in phytic acid content, whereas more than 40% of the total phytase activity remained. The possibility to hydrolyze phytic acid by use of ground debranned wheat as a source of phytase in blends with pea cotyledon flour was investigated. The Michaelis-Menten parameters for each endogenous enzyme were identified and used to predict the rate of phytic acid hydrolysis. Results demonstrate a synergistic effect between the two phytase activities, enabling a 70-95% reduction of phytic acid depending on pea/wheat flour ratios in a relatively short time (4 h). This reduction appears to be able to increase zinc bioavailability but remains insufficient for iron.


Assuntos
6-Fitase/química , Ervilhas/enzimologia , Proteínas de Plantas/química , Triticum/enzimologia , Concentração de Íons de Hidrogênio , Ferro/química , Cinética , Ervilhas/química , Ácido Fítico/química , Sementes/química , Sementes/enzimologia , Temperatura Ambiente , Triticum/química , Zinco/química
20.
Plant Physiol Biochem ; 132: 222-228, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30218894

RESUMO

Waterlogging is one of the most common abiotic stress types in wheat production in many rainy areas of the world. Two locally widely grown winter wheat (Triticum aestivum L. cv Yumai 34 and Yangmai 9) were subjected to post-anthesis waterlogging in a pot experiment to investigate the impacts of waterlogging on the starch synthesis and the physiochemical properties. Post-anthesis waterlogging significantly decreased grain weight and affected the content of starch components. Waterlogging down-regulated the activity and expression of genes encoding soluble starch synthase [SSS (EC 2.4.1.21)], while up-regulated those of the granule bound starch synthase I [GBSSI (EC:2.4.1.242)]. This further resulted in decreased amylopectin content and increased amylose content. Waterlogging also caused a reduction in the number of starch granules, while increased the mean diameter of starch granules in mature grains, which was mainly due to an increase in the volume frequency percent of the A-type starch granules. Waterlogging also lowered the peak viscosity and trough viscosity of starch, but did not affect the breakdown viscosity and peak time. We concluded that the modified expressions of the starch synthase encoding genes were responsible for the changed size distribution of starch granules, which finally affected the starch pasting properties of wheat growing under post-anthesis waterlogging conditions.


Assuntos
Sementes/metabolismo , Amido/biossíntese , Amido/química , Triticum/metabolismo , Água , Farinha , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Sintase do Amido/genética , Sintase do Amido/metabolismo , Triticum/enzimologia , Triticum/genética , Viscosidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA