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1.
Methods Mol Biol ; 2224: 47-60, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33606205

RESUMO

Like bacterial and cytoplasmic ribosomes, mitoribosomes are large ribonucleoprotein complexes with molecular weights in the range of several million Daltons. Traditionally, studying the assembly of such high molecular weight complexes is done using ultracentrifugation through linear density gradients, which remains the method of choice due to its versatility and superior resolving power in the high molecular weight range. Here, we present a protocol for the analysis of mitoribosomal assembly in heart mitochondrial extracts using linear density sucrose gradients that we have previously employed to characterize the essential role of different mitochondrial proteins in mitoribosomal biogenesis. This protocol details in a stepwise manner a typical mitoribosomal assembly analysis starting with isolation of mitochondria, preparation and ultracentrifugation of the gradients, fractionation and ending with SDS-PAGE, and immunoblotting of the gradient fractions. Even though we provide an example with heart mitochondria, this protocol can be directly applied to virtually all mouse tissues, as well as cultured cells, with little to no modifications.


Assuntos
Ribossomos Mitocondriais/fisiologia , Animais , Coração/fisiologia , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Mitocôndrias/fisiologia , Proteínas Mitocondriais/metabolismo , Ribossomos Mitocondriais/metabolismo , Biogênese de Organelas , Sacarose/metabolismo , Ultracentrifugação/métodos
2.
Carbohydr Polym ; 255: 117384, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33436213

RESUMO

Prebiotics are known for their ability to modulate the composition of the human microbiome and mediate health-promoting benefits. Endo-levanases, which hydrolyze levan into short-chain FOS, could be used for the production of levan-based prebiotics. The novel endo-levanase (LevB2286) from Azotobacter chroococcum DSM 2286, combines an exceptionally high specific activity with advantageous hydrolytic properties. Starting from levan isolated from Timothy grass, LevB2286 produced FOS ranging from DP 2 - 8. In contrast to endo-levanases described in the literature, LevB2286 formed minor amounts of fructose and levanbiose, even with greatly extended incubation. The combined activity of LevB2286 and the levansucrase LevS1417 from Gluconobacter japonicus LMG 1417 led to a one-step synthesis of levan-type FOS from sucrose. 387.4 ± 17.3 g L-1 FOS were produced within 48 h by the production strategy based on crude cell extract of recombinant Escherichia coli expressing levS1417 and levB2286 simultaneously.


Assuntos
Azotobacter/enzimologia , Proteínas de Bactérias/metabolismo , Gluconobacter/enzimologia , Glicosídeo Hidrolases/metabolismo , Hexosiltransferases/metabolismo , Oligossacarídeos/biossíntese , Prebióticos/análise , Azotobacter/genética , Proteínas de Bactérias/genética , Dissacarídeos/química , Dissacarídeos/metabolismo , Escherichia coli/enzimologia , Escherichia coli/genética , Frutanos/química , Frutanos/metabolismo , Frutose/química , Frutose/metabolismo , Expressão Gênica , Gluconobacter/genética , Glicosídeo Hidrolases/genética , Hexosiltransferases/genética , Humanos , Hidrólise , Oligossacarídeos/química , Phleum/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sacarose/química , Sacarose/metabolismo
3.
Int J Mol Sci ; 22(2)2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33445606

RESUMO

Increased consumption of high fat/sucrose (HF/S) diets has contributed to rising rates of obesity and its co-morbidities globally, while also negatively impacting male reproductive health. Our objective was to examine whether adding a methyl donor cocktail to paternal HF/S diet (HF/S+M) improves health status in fathers and offspring. From 3-12 weeks of age, male Sprague Dawley rats consumed a HF/S or HF/S+M diet. Offspring were followed until 16 weeks of age. Body composition, metabolic markers, gut microbiota, DNA methyltransferase (DNMT) and microRNA expression were measured in fathers and offspring. Compared to HF/S, paternal HF/S+M diet reduced fat mass in offspring (p < 0.005). HF/S+M fathers consumed 16% fewer kcal/day, which persisted in HF/S+M female offspring and was explained in part by changes in serum glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) levels. Compared to HF/S, HF/S+M fathers had a 33% improvement in days until conception and 300% fewer stillbirths. In fathers, adipose tissue DNMT3a and hepatic miR-34a expression were reduced with HF/S+M. Adult male offspring showed upregulated miR-24, -33, -122a and -143 expression while females exhibited downregulated miR-33 expression. Fathers and offspring presented differences in gut microbial signatures. Supplementing a paternal HF/S diet with methyl-donors improved fertility, physiological outcomes, epigenetic and gut microbial signatures intergenerationally.


Assuntos
Biomarcadores/metabolismo , Epigênese Genética/genética , Microbioma Gastrointestinal/genética , Sacarose/metabolismo , Animais , Composição Corporal/genética , Dieta Hiperlipídica , Suplementos Nutricionais , Pai , Feminino , Fertilidade/genética , Peptídeo 1 Semelhante ao Glucagon/genética , Masculino , MicroRNAs/genética , Obesidade/genética , Peptídeo YY/genética , Gravidez , Efeitos Tardios da Exposição Pré-Natal/genética , Ratos , Ratos Sprague-Dawley
4.
Life Sci ; 267: 118944, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33359749

RESUMO

AIMS: Liver cirrhosis is the main chronic liver disease and is considered a catabolic disease. Cirrhotic patients have a low energy intake and high energy expenditure at rest, leading to metabolic disorders. Malnutrition is associated with complications of cirrhosis and has been shown that a nutritional intervention with increase of energy intake improves the survival of cirrhotic patients. Therefore, our aim was to evaluate the effect of a high sucrose diet in the liver of animals with cirrhosis induced by thioacetamide and investigate the mechanism involved. MAIN METHODS: Male Wistar rats were divided into three groups: Control; Thioacetamide; and Thioacetamide + high sucrose diet. The thioacetamide was administrated (100 mg kg-1) intraperitoneally and the sucrose was offered in drinking water (300 g L-1). KEY FINDINGS: The administration of thioacetamide was associated with fibrosis and inflammatory infiltrate in the liver and increased levels of transaminases enzymes. The high sucrose diet promoted a reduction of theses parameters in cirrhotic rats. The malnutrition observed in cirrhotic rats was attenuated by the high sucrose diet shown by the improvements in weight loss, subcutaneous fat, and caloric intake. The high sucrose diet also attenuated the oxidative stress present in the liver of animals with thioacetamide-induced cirrhosis. SIGNIFICANCE: The high sucrose diet had anti-inflammatory and anti-oxidant effects in the liver of animals with thioacetamide-induced cirrhosis. In addition, the high sucrose diet also improved malnutrition and catabolism present in cirrhosis. Thus, a high sucrose diet may be a therapeutic option for cirrhotic patients in a catabolic state.


Assuntos
Sacarose na Dieta/farmacologia , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/metabolismo , Animais , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Dieta , Sacarose na Dieta/metabolismo , Inflamação , Fígado/metabolismo , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Sacarose/metabolismo , Sacarose/farmacologia , Tioacetamida/efeitos adversos , Tioacetamida/farmacologia
5.
Food Chem ; 339: 127883, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32889132

RESUMO

Selenium is an essential trace element that improves fruit quality and nutritional value. However, the effect of sodium selenite on apple quality and its relative sucrose metabolism activity remains unclear. In this study, we investigated the roles of selenite spraying, in improving Fuji apple quality and sucrose metabolism-related enzyme activity. Results showed that foliar spraying of sodium selenite significantly (P < 0.05) increased apple fruit yield and internal quality, but no significant effects on external quality. The apple yield, vitamin C content, sugar-acid ratio and total soluble sugar increased 4.4% to 11.7%, 4.68% to 20.86%, 3.07% to 31.57%, and 4.53% to 18.89%, respectively. Se content is 9.5-fold compared to the control. Significant correlations were observed between neutral invertase, sucrose synthase activity and sucrose phosphate synthase enzymes, and sucrose phosphate synthase enzyme was most crucial. Spraying sodium selenite of 100-150 mg/L could be appropriate for improving Fuji apple yield and quality.


Assuntos
Malus/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Selenito de Sódio/farmacologia , Sacarose/metabolismo , Ácido Ascórbico/metabolismo , Qualidade dos Alimentos , Frutas/efeitos dos fármacos , Frutas/enzimologia , Frutas/metabolismo , Glucosiltransferases/metabolismo , Malus/enzimologia , Malus/metabolismo , beta-Frutofuranosidase/metabolismo
6.
Nefrología (Madrid) ; 40(6): 640-646, nov.-dic. 2020. tab, graf
Artigo em Inglês | IBECS | ID: ibc-197200

RESUMO

INTRODUCTION: The lack of adherence to phosphate -binders (PB) is the most important factor in not achieving the objectives of serum phosphorus (sP). Studies in the real-world population are needed to understand the influence of PBs on adherence and how to modify it. METHODS: Prospective study conducted during 3 months in usual clinical practice. Out of 105 hemodialysis patients, 57 were switched to SFOH and 48 maintained their baseline treatment (control group). sP levels and the percentage of patients with sP levels < 5mg/dl were compared. Adherence before and after introduction of SFOH, number of pills of PB, preferences in the administration mode and side effects were analyzed. RESULTS: The percentage of patients with controlled sP (< 5 mg/dl) increased significantly in the SFOH users' group (62.1-92.9%, p < 0.001), but not in the control group (83-83.3%, p = NS). The average of daily tablets decreased significantly in the SFOH group (7.2-2.3 comp, p < 0.001), but not in the control group (5.6-5.6, p = NS) and 100% of the patients used only one PB in SFOH group. The use of SFOH increased the adherence according to the SMAQ questionnaire (57.8-84.3%; OR 13.1, p < 0.001). The possibility to choose the preferred mode of administration (split-swallowing 89% compared to chewing 11%), improved the acceptance (44.7-78%). 14% of the patients experienced side effects and in 5.2% SFOH was discontinued for this reason. CONCLUSIONS: SFOH controlled serum sP in 93% of patients, 100% in monotherapy, and with fewer tablets. The exploration and adaptation of preferences in the mode of administration influenced the acceptance of the drug by the patient and, probably, the future adherence


INTRODUCCIÓN: La falta de adherencia a los captores del fósforo es el factor más importante para no lograr los objetivos del fósforo sérico (Ps). Se necesitan estudios en la población del mundo real para comprender la influencia de los CP sobre la adherencia y como modificarla. OBJETIVOS: Evaluar la eficacia y la adherencia de un nuevo CP, oxihidróxido sucroférrico (OHSF) en pacientes en hemodiálisis y la influencia de un cambio en el modo de administración del fármaco sobre la aceptación del mismo. MÉTODOS: Estudio prospectivo realizado durante 3 meses en práctica clínica habitual. De 105 pacientes de hemodiálisis, 57 pacientes con P mal controlado (p < 5 mg/dl) fueron cambiados a OHSF y 48 mantuvieron su tratamiento inicial (grupo control). Se compararon los niveles de Ps y el porcentaje de pacientes con niveles de Ps < 5 mg/dl. Se analizó la adherencia antes y después de la introducción de OHSF, el número de comprimidos de captores del P, los efectos secundarios y el grado de aceptación del fármaco tras ofrecer varias alternativas en el modo de administración. RESULTADOS: El porcentaje de pacientes con P controlado (< 5 mg/dl) aumentó significativamente a los 3 meses de seguimiento en el grupo de pacientes con OHSF (62,1 al 92,9%; p < 0,001), pero no en el grupo de control (83 al 83,3%; p = NS). El promedio de comprimidos diarios disminuyó significativamente en el grupo OHSF (7,2 a 2,3 comprimidos; p < 0,001), pero no en el grupo control (5,6 a 5,6; p = NS) y todos los pacientes en tratamiento con OHSF se controlaron con monoterapia. El uso de OHSF aumentó la adherencia según el cuestionario SMAQ (57,8 al 84,3%; OR: 13,1; p < 0,001). La posibilidad de elegir el modo de administración preferido (cortar-tragar 89% en comparación con masticar 11%) mejoró la aceptación (44,7 al 78%) de los pacientes. El 14% de los pacientes experimentaron efectos secundarios y en 5,2% se suspendió el OHSF por esta razón. CONCLUSIONES: OHSF controló el P sérico en el 93% de los pacientes, siendo la totalidad de ellos en monoterapia, y con menor número de comprimidos a corto plazo. La exploración y adaptación de las preferencias en el modo de administración influyó en la aceptación del fármaco por parte del paciente y, probablemente en la adherencia futura


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Diálise Renal/métodos , Fósforo/sangue , Compostos Férricos/metabolismo , Sacarose/metabolismo , Combinação de Medicamentos , Estudos Prospectivos , Inquéritos e Questionários , Resultado do Tratamento , Cooperação e Adesão ao Tratamento , Análise de Variância , Reprodutibilidade dos Testes
7.
PLoS One ; 15(12): e0244198, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33373388

RESUMO

High temperatures induce early bolting in lettuce (Lactuca sativa L.), which decreases both quality and production. However, knowledge of the molecular mechanism underlying high temperature promotes premature bolting is lacking. In this study, we compared lettuce during the bolting period induced by high temperatures (33/25 °C, day/night) to which raised under controlled temperatures (20/13 °C, day/night) using iTRAQ-based phosphoproteomic analysis. A total of 3,814 phosphorylation sites located on 1,766 phosphopeptides from 987 phosphoproteins were identified after high-temperature treatment,among which 217 phosphoproteins significantly changed their expression abundance (116 upregulated and 101 downregulated). Most phosphoproteins for which the abundance was altered were associated with the metabolic process, with the main molecular functions were catalytic activity and transporter activity. Regarding the functional pathway, starch and sucrose metabolism was the mainly enriched signaling pathways. Hence, high temperature influenced phosphoprotein activity, especially that associated with starch and sucrose metabolism. We suspected that the lettuce shorten its growth cycle and reduce vegetative growth owing to changes in the contents of starch and soluble sugar after high temperature stress, which then led to early bolting/flowering. These findings improve our understanding of the regulatory molecular mechanisms involved in lettuce bolting.


Assuntos
Resposta ao Choque Térmico , Alface/metabolismo , Fosfoproteínas/metabolismo , Proteoma/metabolismo , Amido/metabolismo , Sacarose/metabolismo , Alface/crescimento & desenvolvimento , Fosfoproteínas/genética , Proteoma/genética
8.
Int J Food Microbiol ; 335: 108903, 2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33065381

RESUMO

Societal demand for plant-based foods is increasing. In this context, soya products fermented using lactic acid bacteria (LAB) are appealing because of their potential health and nutritional benefits. The thermophilic LAB Streptococcus thermophilus is an essential starter species in the dairy industry. However, while its physiology is well characterized, little is known about its general metabolic activity or its techno-functional properties when it is grown in soya milk. In this study, S. thermophilus LMD-9 growth, sugar production, and lactic acid production in soya milk versus cow's milk were measured. Additionally, the main metabolic pathways used by the bacterium when growing in soya milk were characterized using a proteomic approach. Streptococcus thermophilus LMD-9 growth decreased soya milk pH, from 7.5 to 4.9, in 5 h. During fermentation, acidification thus occurred in tandem with lactate production and increasing population size (final population: 1.0 × 109 CFU/ml). As growth proceeded, sucrose was consumed, and fructose was produced. The proteomic analysis (LC-MS/MS) of the strain's cytosolic and cell envelope-associated proteins revealed that proteins related to amino acid transport and nitrogen metabolism were the most common among the 328 proteins identified (63/328 = 19.2% of total proteins). The cell-wall protease PrtS was present, and an LMD-9 deletion mutant was constructed by interrupting the prtS gene (STER_RS04165 locus). Acidification levels, growth levels, and final population size were lower in the soya milk cultures when the ΔprtS strain versus the wild-type (wt) strain was used. The SDS-PAGE profile of the soluble proteins in the supernatant indicated that soya milk proteins were less hydrolyzed by the ΔprtS strain than by the wt strain. It was discovered that S. thermophilus can grow in soya milk by consuming sucrose, can hydrolyze soya proteins, and can produce acidification levels comparable to those in cow's milk. This study comprehensively examined the proteomics of S. thermophilus grown in soya milk and demonstrated that the cell-wall protease PrtS is involved in the LAB's growth in soya milk and in the proteolysis of soya proteins, which are two novel findings. These results clarify how S. thermophilus adapts to soya milk and can help inform efforts to develop new fermented plant-based foods with better-characterized biochemical and microbiological traits.


Assuntos
Proteínas de Bactérias/metabolismo , Serina Endopeptidases/metabolismo , Leite de Soja/metabolismo , Streptococcus thermophilus/crescimento & desenvolvimento , Streptococcus thermophilus/metabolismo , Animais , Fermentação , Ácido Láctico/análise , Ácido Láctico/metabolismo , Redes e Vias Metabólicas , Leite/química , Leite/metabolismo , Leite/microbiologia , Proteínas do Leite/metabolismo , Nitrogênio/metabolismo , Proteômica , Leite de Soja/química , Proteínas de Soja/metabolismo , Streptococcus thermophilus/enzimologia , Sacarose/metabolismo , Açúcares/análise , Açúcares/metabolismo
9.
Proc Natl Acad Sci U S A ; 117(38): 23970-23981, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32883877

RESUMO

Fruit set is the process whereby ovaries develop into fruits after pollination and fertilization. The process is induced by the phytohormone gibberellin (GA) in tomatoes, as determined by the constitutive GA response mutant procera However, the role of GA on the metabolic behavior in fruit-setting ovaries remains largely unknown. This study explored the biochemical mechanisms of fruit set using a network analysis of integrated transcriptome, proteome, metabolome, and enzyme activity data. Our results revealed that fruit set involves the activation of central carbon metabolism, with increased hexoses, hexose phosphates, and downstream metabolites, including intermediates and derivatives of glycolysis, the tricarboxylic acid cycle, and associated organic and amino acids. The network analysis also identified the transcriptional hub gene SlHB15A, that coordinated metabolic activation. Furthermore, a kinetic model of sucrose metabolism predicted that the sucrose cycle had high activity levels in unpollinated ovaries, whereas it was shut down when sugars rapidly accumulated in vacuoles in fruit-setting ovaries, in a time-dependent manner via tonoplastic sugar carriers. Moreover, fruit set at least partly required the activity of fructokinase, which may pull fructose out of the vacuole, and this could feed the downstream pathways. Collectively, our results indicate that GA cascades enhance sink capacities, by up-regulating central metabolic enzyme capacities at both transcriptional and posttranscriptional levels. This leads to increased sucrose uptake and carbon fluxes for the production of the constituents of biomass and energy that are essential for rapid ovary growth during the initiation of fruit set.


Assuntos
Frutas , Giberelinas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Carbono/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Lycopersicon esculentum/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Redes e Vias Metabólicas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Sacarose/metabolismo , Transcriptoma/genética
10.
PLoS One ; 15(8): e0226235, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797046

RESUMO

Plant-derived fuels and chemicals from renewable biomass have significant potential to replace reliance on petroleum and improve global carbon balance. However, plant biomass contains significant fractions of oligosaccharides that are not usable natively by many industrial microorganisms, including Escherichia coli, Saccharomyces cerevisiae, and Zymomonas mobilis. Even after chemical or enzymatic hydrolysis, some carbohydrate remains as non-metabolizable oligosaccharides (e.g., cellobiose or longer cellulose-derived oligomers), thus reducing the efficiency of conversion to useful products. To begin to address this problem for Z. mobilis, we engineered a strain (Z. mobilis GH3) that expresses a glycosyl hydrolase (GH) with ß-glucosidase activity from a related α-proteobacterial species, Caulobacter crescentus, and subjected it to an adaptation in cellobiose medium. Growth on cellobiose was achieved after a prolonged lag phase in cellobiose medium that induced changes in gene expression and cell composition, including increased expression and extracellular release of GH. These changes were reversible upon growth in glucose-containing medium, meaning they did not result from genetic mutation but could be retained upon transfer of cells to fresh cellobiose medium. After adaptation to cellobiose, our GH-expressing strain was able to convert about 50% of cellobiose to glucose within 24 h and use it for growth and ethanol production. Alternatively, pre-growth of Z. mobilis GH3 in sucrose medium enabled immediate growth on cellobiose. Proteomic analysis of cellobiose- and sucrose-adapted strains revealed upregulation of secretion-, transport-, and outer membrane-related proteins, which may aid release or surface display of GHs, entry of cellobiose into the periplasm, or both. Our two key findings are that Z. mobilis can be reprogrammed to grow on cellobiose as a sole carbon source and that this reprogramming is related to a natural response of Z. mobilis to sucrose that promotes sucrase production.


Assuntos
Celobiose/metabolismo , Zymomonas/crescimento & desenvolvimento , Zymomonas/metabolismo , Adaptação Fisiológica/fisiologia , Biomassa , Reprogramação Celular/genética , Reprogramação Celular/fisiologia , Celulose/metabolismo , Expressão Gênica/genética , Glucose/metabolismo , Hidrolases/metabolismo , Proteômica , Sacarase/metabolismo , Sacarose/metabolismo , Zymomonas/genética , beta-Glucosidase/metabolismo
11.
Plant Mol Biol ; 104(4-5): 359-378, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32754876

RESUMO

KEY MESSAGE: An integrative comparative transcriptomic approach on six sugar beet varieties showing different amount of sucrose loss during storage revealed genotype-specific main driver genes and pathways characterizing storability. Sugar beet is next to sugar cane one of the most important sugar crops accounting for about 15% of the sucrose produced worldwide. Since its processing is increasingly centralized, storage of beet roots over an extended time has become necessary. Sucrose loss during storage is a major concern for the sugar industry because the accumulation of invert sugar and byproducts severely affect sucrose manufacturing. This loss is mainly due to ongoing respiration, but changes in cell wall composition and pathogen infestation also contribute. While some varieties can cope better during storage, the underlying molecular mechanisms are currently undiscovered. We applied integrative transcriptomics on six varieties exhibiting different levels of sucrose loss during storage. Already prior to storage, well storable varieties were characterized by a higher number of parenchyma cells, a smaller cell area, and a thinner periderm. Supporting these findings, transcriptomics identified changes in genes involved in cell wall modifications. After 13 weeks of storage, over 900 differentially expressed genes were detected between well and badly storable varieties, mainly in the category of defense response but also in carbohydrate metabolism and the phenylpropanoid pathway. These findings were confirmed by gene co-expression network analysis where hub genes were identified as main drivers of invert sugar accumulation and sucrose loss. Our data provide insight into transcriptional changes in sugar beet roots during storage resulting in the characterization of key pathways and hub genes that might be further used as markers to improve pathogen resistance and storage properties.


Assuntos
Beta vulgaris/genética , Beta vulgaris/metabolismo , Armazenamento de Alimentos , Proteínas de Plantas/genética , Beta vulgaris/anatomia & histologia , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Lignina/metabolismo , Raízes de Plantas/anatomia & histologia , Sacarose/análise , Sacarose/metabolismo , Açúcares/análise , Açúcares/metabolismo
12.
PLoS One ; 15(8): e0236129, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760076

RESUMO

Salix matsudana, a member of Salicaceae, is an important ornamental tree in China. Because of its capability to tolerate high salt conditions, S. matsudana also plays an important ecological role when grown along Chinese coastal beaches, where the salinity content is high. Here, we aimed to elucidate the mechanism of higher salt tolerance in S. matsudana variety '9901' by identifying the associated genes through RNA sequencing and comparing differential gene expression between the S. matsudana salt-tolerant and salt-sensitive samples treated with 150 mM NaCl. Transcriptomic comparison of the roots of the two samples revealed 2174 and 3159 genes responsive to salt stress in salt-sensitive and salt-tolerant sample, respectively. Real-time polymerase chain reaction analysis of 9 of the responsive genes revealed a strong, positive correlation with RNA sequencing data. The genes were enriched in several pathways, including carbon metabolism pathway, plant-pathogen interaction pathway, and plant hormone signal transduction pathway. Differentially expressed genes (DEGs) encoding transcription factors associated with abiotic stress responses and salt stress response network were identified; their expression levels differed between the two samples in response to salt stress. Hub genes were also revealed by weighted gene co-expression network (WGCNA) analysis. For functional analysis of the DEG encoding sedoheptulose-1,7-bisphosphatase (SBPase), the gene was overexpressed in transgenic Arabidopsis, resulting in increased photosynthetic rates, sucrose and starch accumulation, and enhanced salt tolerance. Further functional characterization of other hub DEGs will reveal the molecular mechanism of salt tolerance in S. matsudana and allow the application of S. matsudana in coastal afforestation.


Assuntos
Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes/fisiologia , Salix/fisiologia , Tolerância ao Sal/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Fotossíntese/genética , Raízes de Plantas , Plantas Geneticamente Modificadas , RNA-Seq , Salinidade , Amido/metabolismo , Sacarose/metabolismo
13.
Food Chem ; 332: 127437, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32645670

RESUMO

In 'Crimson Seedless' grapes, the appearance of senescence caused by abnormal dark red color, the loss of crisp taste caused by the decrease in firmness, and the fading of sweetness caused by the decrease in total soluble sugar (TSS) are the main problems affecting its edible qualities after storage. In the mesocarp, burdock fructooligosaccharide (BFO) restricted sucrose export; therefore, more carbohydrates were retained directly leading to higher TSS and sweetness, and cell osmotic pressure and firmness were retained indirectly. In the exocarp, BFO restricted sucrose import; therefore, the signal molecule sucrose was reduced and the senescence-related processes were inhibited. The downregulation of SUC12 and SUC27 by BFO may play an important role in restricting sucrose transportation. The opposing effects exhibited by exogenous sucrose treatments compared to those of BFO further verified these mechanisms. Based on the above mechanisms, sucrose transportation mediates the fresh-keeping effects of BFO in 'Crimson Seedless' grapes.


Assuntos
Oligossacarídeos/metabolismo , Sacarose/metabolismo , Vitis/metabolismo , Transporte Biológico , Frutas/química , Frutas/metabolismo , Oligossacarídeos/análise , Sacarose/análise , Vitis/química
14.
Chemosphere ; 256: 127156, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32559889

RESUMO

Plant growth-promoting bacteria (PGPB) can promote root uptake and shoot accumulation of cadmium (Cd) in hyperaccumulator plants, but the mechanisms by which PGPB accelerate root-to-shoot transport of Cd is still unknown. A better understanding of these mechanisms is necessary to develop the strategies that can promote the practical phytoextraction of Cd-polluted soils. In this study, we found that Pseudomonas fluorescens accelerates a reversed and a long-distance transport of Cd and sucrose in Sedum alfredii, by examining the xylem and phloem sap and by quantifying the concentrations of Cd and sucrose in shoot and root. The transcriptome sequencing has revealed the up-regulated expressions of starch metabolism and sucrose biosynthesis related genes in the shoots of Cd hyperaccumulator plant S. alfredii that was inoculated with PGPB P. fluorescens. In addition, the genes of sugar, cation and anion transporters were also up-regulated by bacterial treatment, showing a complicated co-expression network with sucrose biosynthesis related genes. The expression levels of Cd transporter genes, such as ZIP1, ZIP2, HMA2, HMA3 and CAX2, were elevated after PGPB inoculation. As a result, the PGPB successfully colonized the root, and promoted the sucrose shoot-to-root transport and Cd root-to-shoot transport in S. alfredii. Since non-photosynthetic root-associated bacteria usually obtain sugars from photosynthetic plants, our results highlight the importance of PGPB-induced changes in hyperaccumlator plants for both the host and the PGPB.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Pseudomonas fluorescens/fisiologia , Sedum/metabolismo , Fotossíntese , Desenvolvimento Vegetal , Raízes de Plantas/metabolismo , Pseudomonas fluorescens/metabolismo , Poluentes do Solo/metabolismo , Sacarose/metabolismo
15.
Appl Environ Microbiol ; 86(16)2020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-32561577

RESUMO

This study compares the metabolic properties of kojibiose, trehalose, sucrose, and xylitol upon incubation with representative oral bacteria as monocultures or synthetic communities or with human salivary bacteria in a defined medium. Compared to sucrose and trehalose, kojibiose resisted metabolism during a 48-h incubation with monocultures, except for Actinomyces viscosus Incubations with Lactobacillus-based communities, as well as salivary bacteria, displayed kojibiose metabolism, yet to a lesser extent than sucrose and trehalose. Concurring with our in vitro findings, screening for carbohydrate-active enzymes revealed that only Lactobacillus spp. and A. viscosus possess enzymes from glycohydrolase (GH) families GH65 and GH15, respectively, which are associated with kojibiose metabolism. Donor-dependent differences in salivary microbiome composition were noted, and differences in pH drop during incubation indicated different rates of sugar metabolism. However, functional analysis indicated that lactate, acetate, and formate evenly dominated the metabolic profile for all sugars except for xylitol. 16S rRNA gene sequencing analysis and α-diversity markers revealed that a significant shift of the microbiome community by sugars was more pronounced in sucrose and trehalose than in kojibiose and xylitol. In Streptococcus spp., a taxon linked to cariogenesis dominated in sucrose (mean ± standard deviation, 91.8 ± 6.4%) and trehalose (55.9 ± 38.6%), representing a high diversity loss. In contrast, Streptococcus (5.1 ± 3.7%) was less abundant in kojibiose, which instead was dominated by Veillonella (26.8 ± 19.6%), while for xylitol, Neisseria (29.4 ± 19.1%) was most abundant. Overall, kojibiose and xylitol incubations stimulated cariogenic species less yet closely maintained an abundance of key phyla and genera of the salivary microbiome, suggesting that kojibiose has low cariogenic properties.IMPORTANCE This study provides a detailed scientific insight on the metabolism of a rare disaccharide, kojibiose, whose mass production has recently been made possible. While the resistance of kojibiose was established with monocultures, delayed utilization of kojibiose was observed with communities containing lactobacilli and A. viscosus as well as with complex communities of bacteria from human saliva. Kojibiose is, therefore, less metabolizable than sucrose and trehalose. Moreover, although conventional sugars cause distinct shifts in salivary microbial communities, our study has revealed that kojibiose is able to closely maintain the salivary microbiome composition, suggesting its low cariogenic properties. This study furthermore underscores the importance and relevance of microbial culture and ex vivo mixed cultures to study cariogenicity and substrate utilization; this is in sharp contrast with tests that solely rely on monocultures such as Streptococcus mutans, which clearly fail to capture complex interactions between oral microbiota.


Assuntos
Bactérias/metabolismo , Microbiota , Boca/microbiologia , Açúcares/metabolismo , Xilitol/metabolismo , Dissacarídeos/metabolismo , Humanos , Cinética , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Sacarose/metabolismo , Trealose/metabolismo
16.
PLoS One ; 15(6): e0235415, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32598354

RESUMO

To better understand the mechanism of inherent salt resistance in Jerusalem artichoke (Helianthus tuberosus L.), physiological and metabolic responses of tubers at the initiation stage of sprouting under different salt stress levels were evaluated in the present study. As a result, 28 metabolites were identified using proton nuclear magnetic resonance (1H-NMR) spectroscopy. Jerusalem artichoke tubers showed minor changes in metabolic response under moderate salt stress when they had not yet sprouted, where metabolism was downregulated at the start of sprouting and then upregulated significantly after plants became autotrophic. However, mild and severe salt stress levels caused different metabolic response patterns. In addition, the accumulation of fructose and sucrose was enhanced by moderate salt stress, while glucose was highly consumed. Aspartate and asparagine showed accelerated accumulation in sprouting Jerusalem artichoke tubers that became autotrophic, suggesting the enhancement of photosynthesis by moderate salt stress.


Assuntos
Frutose/metabolismo , Glucose/metabolismo , Helianthus/metabolismo , Tubérculos/metabolismo , Estresse Salino , Sacarose/metabolismo , Helianthus/crescimento & desenvolvimento , Fotossíntese , Tubérculos/crescimento & desenvolvimento
17.
Microb Cell Fact ; 19(1): 101, 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398084

RESUMO

BACKGROUND: Poly-γ-glutamic acid (γ-PGA) is a promising biopolymer and has been applied in many fields. Bacillus siamensis SB1001 was a newly isolated poly-γ-glutamic acid producer with sucrose as its optimal carbon source. To improve the utilization of carbon source, and then molasses can be effectively used for γ-PGA production, 60cobalt gamma rays was used to mutate the genes of B. siamensis SB1001. RESULTS: Bacillus siamensis IR10 was screened for the production of γ-PGA from untreated molasses. In batch fermentation, 17.86 ± 0.97 g/L γ-PGA was obtained after 15 h, which is 52.51% higher than that of its parent strain. Fed-batch fermentation was performed to further improve the yield of γ-PGA with untreated molasses, yielding 41.40 ± 2.01 g/L of γ-PGA with a productivity of 1.73 ± 0.08 g/L/h. An average γ-PGA productivity of 1.85 g/L/h was achieved in the repeated fed-batch fermentation. This is the first report of such a high γ-PGA productivity. The analysis of the enzyme activities showed that they were affected by the carbon sources, enhanced ICDH and GDH, and decreased ODHC, which are important for γ-PGA production. CONCLUSION: These results suggest that untreated molasses can be used for economical and industrial-scale production of γ-PGA by B. siamensis IR10.


Assuntos
Bacillus/metabolismo , Melaço , Ácido Poliglutâmico/análogos & derivados , Bacillus/genética , Carbono/metabolismo , Fermentação , Microbiologia Industrial , Ácido Poliglutâmico/biossíntese , Sacarose/metabolismo
18.
PLoS One ; 15(5): e0232694, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32375166

RESUMO

Malus halliana is an iron (Fe)-efficient apple rootstock growing in calcareous soil that shows obvious 'greenness' traits during Fe deficiency. Recent studies have shown that exogenous sugars can be involved in abiotic stress. To identify the key regulatory steps of chlorophyll (Chl) biosynthesis in M. halliana under Fe deficiency and to verify whether exogenous sucrose (Suc) is involved in Fe deficiency stress, we determined the contents of the Chl precursor and the expression of several Chl biosynthetic genes in M. halliana. The results showed that Fe deficiency caused a significant increase in the contents of protoporphyrin IX (Proto IX), Mg-protoporphyrin IX (Mg-Proto IX) and protochlorophyllide (Pchlide) in M. halliana compared to the Fe-sensitive rootstock Malus hupehensis. Quantitative real-time PCR (RT-qPCR) also showed that the expression of protoporphyrinogen oxidase (PPOX), which synthesizes Proto IX, was upregulated in M. halliana and downregulated in M. hupehensis under Fe deficiency. Exogenous Suc application prominently enhanced the contents of porphobilinogen (PBG) and the subsequent precursor, whereas it decreased the level of δ-aminolaevulinic acid (ALA), suggesting that the transformation from ALA to PBG was catalyzed in M. halliana. Additionally, the transcript level of δ-aminolevulinate acid dehydratase (ALAD) was noticeably upregulated after exogenous Suc treatment. This result, combined with the precursor contents, indicated that Suc accelerated the steps of Chl biosynthesis by modulating the ALAD gene. Therefore, we conclude that PPOX is the key regulatory gene of M. halliana in response to Fe deficiency. Exogenous Suc enhances M. halliana tolerance to Fe deficiency stress by regulating Chl biosynthesis.


Assuntos
Clorofila/metabolismo , Ferro/metabolismo , Malus/metabolismo , Sacarose/metabolismo , Protoclorifilida/metabolismo , Protoporfirinas/metabolismo
19.
Int J Food Microbiol ; 326: 108648, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32387971

RESUMO

Consumption of fructan-containing cereal products is considered beneficial for most people, but not for those suffering from irritable bowel syndrome (IBS), as they should avoid the consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (acronym: FODMAP). Controlling fructan levels in cereal products is not trivial. However, controlling yeast invertase-mediated hydrolysis of fructan during dough fermentation might offer a handle to modulate fructan concentrations. In this work, the variability in invertase activity and substrate specificity in an extensive set of industrial Saccharomyces cerevisiae strains is investigated. Analysis showed a high variability in the capacity of these strains to hydrolyse sucrose and fructo-oligosaccharides. Industrial yeast strains with a high activity towards fructo-oligosaccharides efficiently reduced wheat grain fructans during dough fermentation to a final fructan level of 0.3% dm, whereas strains with a low invertase activity yielded fructan levels around 0.6% dm. The non-bakery strains produced lower levels of CO2 in fermenting dough resulting in lower loaf volumes. However, CO2 production and loaf volume could be increased by the addition of 3% glucose. In conclusion, this study shows that variation in yeast invertase activity and specificity can be used to modulate the fructan content in bread, allowing the production of low FODMAP breads, or alternatively, breads with a higher soluble dietary fibre content.


Assuntos
Dissacarídeos/análise , Monossacarídeos/análise , Oligossacarídeos/análise , Saccharomyces cerevisiae/enzimologia , Triticum/química , beta-Frutofuranosidase/metabolismo , Pão/análise , Fermentação , Frutanos/análise , Frutanos/metabolismo , Hidrólise , Síndrome do Intestino Irritável/patologia , Sacarose/metabolismo , Fermento Seco
20.
Plant Physiol Biochem ; 151: 743-750, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32361224

RESUMO

Split application could improve nitrogen (N) uptake and increase sweetpotato yields under reduced N supply; however, little is known about how it affects the process of starch production in storage roots. An experiment was conducted to determine the effects of three N management strategies [conventional basal N management; 80% of the conventional N rate applied as a basal fertilizer; 80% of the conventional N rate equally split at transplanting and 35 days after transplanting] on starch accumulation, enzyme activity and genes expression in the conversion of sucrose to starch and the relationships among them. The results showed that, compared with conventional basal N management, split application decreased sucrose accumulation by 11.78%, but increased starch accumulation by 11.12% through improving the starch accumulation rate under reduced N supply. The ratio of sucrose synthetase to sucrose phosphate synthase, the enzymatic activity of ADP-glucose pyrophosphorylase (AGPP), starch synthase, and the expression of their corresponding genes were promoted by split application under reduced N supply and were positively correlated with starch accumulation rate. AGPP is the rate-limiting enzyme in starch synthesis in storage roots under different N management strategies. These results indicate that starch accumulation was enhanced by split application through regulating the activity and gene expression of key enzymes involved in the conversion of sucrose to starch under reduced N supply.


Assuntos
Ipomoea batatas , Nitrogênio , Amido , Sacarose , Ativação Enzimática/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glucose-1-Fosfato Adenililtransferase/genética , Glucose-1-Fosfato Adenililtransferase/metabolismo , Ipomoea batatas/efeitos dos fármacos , Ipomoea batatas/enzimologia , Ipomoea batatas/genética , Ipomoea batatas/metabolismo , Nitrogênio/farmacologia , Amido/biossíntese , Sacarose/metabolismo
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