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1.
Food Chem ; 330: 127318, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32569935

RESUMO

The objective of this study was to determine the biophysical properties of buckwheat (BW) endosperm and their influences on detachment of intact cells, starch gelatinization and digestibility. The intact cells were isolated from BW kernels by dry milling and sieving. The microscopy and texture analysis showed intact endosperm cells could be detached easily due to the fragile structure and low hardness of BW endosperm. More than 70% intact cells were found in commercial light flour. The starch granules entrapped in intact cells exhibited a delay gelatinization and restricted swelling behavior (2-3 â„ƒ higher onset gelatinization temperature than isolated starch). Starch in BW flour had a markedly lower extent of digestion compared to the broken cells and isolated starch. This study provided a new mechanistic understanding of low glycemic index of BW food, and could guide the processing of BW flour to retain slow digestion properties.


Assuntos
Endosperma/citologia , Fagopyrum/citologia , Fagopyrum/metabolismo , Farinha , Amido/farmacocinética , Culinária , Digestão , Endosperma/química , Endosperma/metabolismo , Fagopyrum/química , Farinha/análise , Gelatina , Índice Glicêmico , Tamanho da Partícula , Células Vegetais/química , Células Vegetais/metabolismo , Amido/química , Temperatura
2.
Plant Sci ; 291: 110336, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31928684

RESUMO

Wheat grain nitrogen content displays large variations within different pearling fractions of grains because of radial gradients in the protein content. We identified how spatiotemporal mechanisms regulate this. The protein gradients emerged clearly at 19 days after anthesis, with the highest N content in aleurone and seed coat, followed by outer endosperm, whereas the lowest was in middle and inner endosperm. Laser microdissection, qRT-PCR and LC-MS were used to dissect tissue from aleurone, outer endosperm, middle endosperm, inner endosperm and transfer cells, measure gene expression and levels of free and protein-bound amino acids, respectively. The results showed that different FAA transportation pathways worked in parallel during grain filling stage while the grain protein gradient did not follow spatial expression of storage proteins. Additionally, two nitrogen (N) topdressing timings were conducted, either at the emergence of top third leaf (standard timing) or top first leaf (delayed timing), finding that delayed N topdressing enhanced both amino acids supply and protein synthesis capacity. The results provide insight into protein synthesis and amino acid transport pathways in endosperm and suggest targets for the enhancement of specialty pearled wheat with higher quality.


Assuntos
Aminoácidos/metabolismo , Endosperma/química , Proteínas de Plantas/metabolismo , Sementes/química , Triticum/genética , Endosperma/crescimento & desenvolvimento , Endosperma/metabolismo , Triticum/química , Triticum/metabolismo
3.
Food Chem ; 305: 125436, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514047

RESUMO

The physicochemical properties of wheat bran have an effect on its technofunctional and nutritional profile. The possibility to induce physicochemical modifications in wheat bran using microfluidisation was investigated. An I-optimal experimental design was used to investigate the effect of microfluidisation processing parameters (pressure, number of passes, bran concentration and initial particle size) on important properties of wheat bran (particle size, microstructure, chemical composition, water retention capacity (WRC), extractability, viscosity and sedimentation). With the parameters used in this study, microfluidisation reduced wheat bran median particle size to 14.8 µm and disintegrated starch granules from the attached endosperm. This coincided with an increased extractability of starch and arabinoxylan. While the initial particle size was of minor importance, a higher pressure, larger number of passes and lower bran concentration during microfluidisation resulted in a smaller particle size, higher WRC and extractability, and an increased viscosity and stability in a 2% wheat bran suspension.


Assuntos
Fibras na Dieta/análise , Triticum/química , Endosperma/química , Tamanho da Partícula , Amido , Viscosidade , Água , Xilanos
4.
Food Chem ; 302: 125274, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31404869

RESUMO

Limited hydrolysis of rice endosperm protein isolate was carried out with acid and neutral endoproteases to evaluate the relationship between degree of hydrolysis and techno-functional properties. The highest studied degree of hydrolysis was 5.4% corresponding to 55.2% protein solubility. Solubility increased as a function of degree of hydrolysis with higher efficiency by acid endoprotease. Colloidal stability of the protein suspensions steadily increased with increasing degree of hydrolysis. Higher colloidal stability values were achieved by neutral endoprotease (31-89%) compared to that by acid endoprotease (20-75%). On the other hand, the absolute values of zeta potential and surface hydrophobicity decreased as a function of degree of hydrolysis leading to higher values by neutral endoprotease (-21.4 mV and 21.7 mV) than by acid endoprotease (-813.4 mV and 11.7 mV). Foaming, gel formation and water holding properties improved only until degree of hydrolysis values of 1.5% (neural endoprotease) and 1.9% (acid endoprotease).


Assuntos
Endosperma/química , Oryza/química , Proteínas de Plantas/química , Concentração de Íons de Hidrogênio , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Peptídeo Hidrolases/metabolismo , Proteínas de Plantas/metabolismo , Solubilidade
5.
Carbohydr Polym ; 224: 115063, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472844

RESUMO

In wheat endosperm, mannan, is poorly documented. Nevertheless, this hemicellulosic polysaccharide might have a determinant role in wheat grain development since, in Arabidopsis thaliana, mutants with a reduced amount of mannan show an altered seed development. In order to gain knowledge about mannan in wheat, we have determined its biochemical structure in wheat endosperm where mannose content is about 0.2% (dry weight basis). We developed a method of enzymatic fingerprinting and isolated mannan-enriched fractions to decipher its fine structure. Although it is widely accepted that the class of mannan present in grass cell walls is glucomannan, our data indicate that, in wheat endosperm, this hemicellulose is only represented by short unsubstituted chains of 1,4 linked D-mannose residues and is slightly acetylated. Our study provides information regarding the interactions of mannan with other cell wall components and help to progress towards the understanding of monocot cell wall architecture and the mannan synthesis in wheat endosperm.


Assuntos
Endosperma/química , Mananas/química , Triticum/química , Parede Celular/química , Mananas/metabolismo , beta-Manosidase/metabolismo
6.
Food Funct ; 10(8): 4674-4684, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31292590

RESUMO

Wheat grain roller milling disrupts starch containing endosperm cell walls and extracts white flour. Many wheat based food processes involve simultaneous use of heat and water which then cause starch to gelatinize and enhance its digestibility. In this study, the impact of starch enclosure in intact endosperm cell walls on starch physicochemical properties and digestibility was investigated. Wheat kernels milled into coarse farina (average particle size: 705 µm) contained a substantial portion of intact cells and exhibited 15-30% lower Rapid Visco Analyzer peak viscosity readings than flour and fine farina (average particle size: 85 and 330 µm, respectively) since its higher level of intact cell walls limited the swelling of the enclosed starch. Xylanase use in situ substantially degraded coarse farina cell walls and increased their swelling and viscosifying potential. Following full gelatinization of the different samples, the starch in coarse farina was digested at a 40% lower rate in an in vitro gastrointestinal digestion assay, but still to a similar extent to that in fully gelatinized flour. This indicates that while wheat endosperm cell walls are permeable to pancreatic amylase, they can sufficiently slow down enzyme diffusion. When xylanase treatment was performed after starch gelatinization and pasting, the rates of starch digestion were similar for all samples evidencing that cell walls act as physical barriers to enzyme diffusion and thus retard its digestion. The present findings offer ways to produce wheat-based foods with sustained energy release benefits.


Assuntos
Parede Celular/química , Endosperma/química , Manipulação de Alimentos/métodos , Amido/química , Triticum/química , Biocatálise , Parede Celular/metabolismo , Digestão , Endo-1,4-beta-Xilanases/química , Endosperma/metabolismo , Farinha/análise , Gelatina/química , Gelatina/metabolismo , Humanos , Tamanho da Partícula , Sementes/química , Amido/metabolismo , Triticum/metabolismo , Viscosidade , alfa-Amilases/química
7.
Food Chem ; 289: 299-307, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30955616

RESUMO

Rice is a staple food in many countries around the world and it is a source of not only the nutrients, but also toxic elements. In this study, we evaluated four degrees of polishing and determined the elemental content (P, S, K, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Cd, Hg, Pb) in brown rice, rice bran and the resulting white rice using microwave assisted decomposition followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. Additionally, individual rice grains at every polishing step were analyzed by laser ablation ICP-MS to generate elemental distribution maps. While P, K, Mn and Fe were predominantly located in bran layer, S, Cu, Zn, As, Se, Mo, Cd, and Hg were present in both the bran and endosperm. As the elemental distribution in the grain varies, polishing to produce white rice results in removal of different amounts of nutrient and toxic elements.


Assuntos
Metais Pesados/análise , Nutrientes/análise , Oryza/química , Fibras na Dieta/análise , Endosperma/química , Endosperma/metabolismo , Espectrometria de Massas , Micro-Ondas , Oryza/metabolismo , Oligoelementos/análise
8.
Int J Biol Macromol ; 133: 243-252, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30974141

RESUMO

Bromothymol blue (BTB) was fixed on the cationic cellulose fibers (CCFs) to prepare pH sensitive fibers (pH-SFs). The pH-SFs as intelligent indicator were added into the semen cassiae gum (SCG) as a weakly acidic matrix to prepare a visual-olfactory film. The 13C NMR results show that the CCFs were successfully obtained by introducing hydroxypropyltriethylamine groups which showed strong affinity to BTB molecules. Rheology results demonstrated that all of the film-forming solutions were shear-thinned fluids with non-Newtonian behavior. Scanning electronic microscopy showed that the addition of pH-SFs makes the film surface rougher and rougher. The addition of pH-SFs < 3% improved the tensile strength of the film. The visual-olfactory film was sensitive to ammonia with a highly visible color change from pale yellow to blue-green. The SCG-3SFs film pre-treated in NaOH solution changed from blue to pale yellow while the raw milk was close to spoilage. The light yellow SCG-3SFs film changed to blue-green as the freshwater shrimp changed from fresh to spoilage. The results indicate that the visual-olfactory film can be used for perceiving the freshness of milk and freshwater shrimp.


Assuntos
Cassia/química , Proteínas na Dieta/análise , Qualidade dos Alimentos , Mananas/análise , Paladar , Amônia/química , Animais , Azul de Bromotimol/química , Proteínas na Dieta/química , Endosperma/química , Concentração de Íons de Hidrogênio , Fenômenos Mecânicos , Leite/microbiologia , Reologia , Alimentos Marinhos/microbiologia , Visão Ocular
9.
Planta ; 249(2): 333-350, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30194535

RESUMO

MAIN CONCLUSION: Predominant gene isoforms and expression bias in lipid metabolism pathways are highly conserved between oil-producing Arecaceae crop species coconut and oil palm, but diverge in non-oil-producing species date palm. Coconut (Cocos nucifera), African oil palm (Elaeis guineensis) and date palm (Phoenix dactylifera) are three major crop species in the Arecaceae family for which genome sequences have recently become available. Coconut and African oil palm both store oil in their endosperms, while date palm fruits contain very little oil. We analyzed fatty acid composition in three coconut tissues (leaf, endosperm and embryo) and in two African oil palm tissues (leaf and mesocarp), and identified 806, 840 and 848 lipid-related genes in 22 lipid metabolism pathways from the coconut, African oil palm and date palm genomes, respectively. The majority of lipid-related genes were highly homologous and retained in homologous segments between the three species. Genes involved in the conversion of pyruvate to fatty acid had a five-to-sixfold higher expression in the coconut endosperm and oil palm mesocarp than in the leaf or embryo tissues based on Fragments Per Kilobase of transcript per Million mapped reads values. A close evolutionary relationship between predominant gene isoforms and high conservation of gene expression bias in the lipid and carbohydrate gene metabolism pathways was observed for the two oil-producing species coconut and oil palm, differing from that of date palm, a non-oil-producing species. Our results elucidate the similarities and differences in lipid metabolism between the three major Arecaceae crop species, providing important information for physiology studies as well as breeding for fatty acid composition and oil content in these crops.


Assuntos
Arecaceae/metabolismo , Cocos/metabolismo , Ácidos Graxos/metabolismo , Phoeniceae/metabolismo , Arecaceae/genética , Cocos/genética , Endosperma/química , Ácidos Graxos/análise , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Genoma de Planta/genética , Metabolismo dos Lipídeos/genética , Redes e Vias Metabólicas/genética , Phoeniceae/genética , Filogenia , Folhas de Planta/química , Ácido Pirúvico/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Sementes/química , Homologia de Sequência , Transcriptoma
10.
Food Sci Technol Int ; 25(1): 16-23, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30111176

RESUMO

The aims were (i) to optimize the parboiling/decorticating process by assessing the effects of parboiling soaking temperature (60-80 ℃) and pearling time (4-6 min and 5.5-9.5 min for red and white sorghum) on endosperm yield and ash content, to obtain pregelatinized refined flours from parboiling sorghum (RF-PS) and (ii) to evaluate the final content of selected nutrients in RF-PS obtained in these optimal conditions. Endosperm yield decreased with the increase of pearling time, and a maximum around 70 ℃ soaking temperature was observed. Ash content decreased with increasing soaking temperature and pearling time. The optimal conditions of soaking temperature-pearling time were 73.3 ℃-4.8 min for red sorghum and 67.9 ℃-8.6 min for white sorghum, considering maximum endosperm yield and ash content lower than 0.65 g/100 g. In RF-PS obtained under optimal conditions, protein, lipid, Cu, and free polyphenols were higher in red sorghum than white sorghum (10.16 ± 0.62 vs. 9.42 ± 0.61 g/100 g, 0.89 ± 0.16 vs. 0.62 ± 0.11 g/100 g, 2.08 ± 0.21 vs. 1.88 ± 0.20 mg/kg, 79.51 ± 14.51 vs. 63.82 ± 4.33 mg/100 g). Fe, Zn, Ca, and Na were higher in white sorghum than red sorghum (20.61 ± 2.92 vs. 17.56 ± 0.98 mg/kg, 11.94 ± 0.84 vs. 9.58 ± 1.65 mg/kg, 87.45 ± 12.91 vs. 75.31 ± 12.57 mg/kg, 129.62 ± 9.03 vs. 102.69 ± 28.34 mg/kg). No difference was observed in the contents of ash, Mg, and K. It was possible to improve endosperm yield using a parboiling process prior to decortication. In addition, this process contributes to increase the mineral content in RF-PS.


Assuntos
Endosperma/química , Sorghum/química , Oligoelementos/análise , Grão Comestível/química , Farinha/análise , Manipulação de Alimentos
11.
Arch Oral Biol ; 98: 132-139, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30485826

RESUMO

OBJECTIVE: Food-derived peptides have been reported to exhibit antibacterial activity against periodontal pathogenic bacteria. However, no effect has been shown on inflammation and bone resorption in periodontal pathology. The overall objective of the current study was to investigate how rice peptides influence biological defense mechanisms against periodontitis-induced inflammatory bone loss, and identify their novel functions as a potential anti-inflammatory drug. DESIGN: The expression of inflammatory and osteoclast-related molecules was examined in mouse macrophage-derived RAW 264.7 cell cultures using qPCR. Subsequently, the effect of these peptides on inflammatory bone loss in mouse periodontitis was examined using a mouse model of tooth ligation. Briefly, periodontal bone loss was induced for 7 days in mice by ligating the maxillary second molar and leaving the contralateral tooth un-ligated (baseline control). The mice were microinjected daily with the peptide in the gingiva until the day before euthanization. One week after the ligation, TRAP-positive multinucleated cells (MNCs) were enumerated from five random coronal sections of the ligated sites in each mouse. RESULTS: Rice peptides REP9 and REP11 significantly inhibited transcription activity of inflammatory and osteoclast-related molecules. Local treatment with the rice peptides, in mice subjected to ligature-induced periodontitis, inhibited inflammatory bone loss, explaining the decreased numbers of osteoclasts in bone tissue sections. CONCLUSION: Therefore, these data suggested that the rice peptides possess a protective effect against periodontitis.


Assuntos
Perda do Osso Alveolar/tratamento farmacológico , Antibacterianos/farmacologia , Endosperma/química , Oryza/química , Peptídeos/antagonistas & inibidores , Periodontite/tratamento farmacológico , Extratos Vegetais/farmacologia , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/patologia , Animais , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Reabsorção Óssea/diagnóstico por imagem , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/patologia , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Modelos Animais de Doenças , Gengiva/efeitos dos fármacos , Inflamação , Ligadura , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Dente Molar , Osteoclastos/efeitos dos fármacos , Peptídeos/administração & dosagem , Peptídeos/uso terapêutico , Periodontite/diagnóstico por imagem , Periodontite/patologia , Extratos Vegetais/uso terapêutico , Proteínas de Plantas/administração & dosagem , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/uso terapêutico , Células RAW 264.7 , Microtomografia por Raio-X/métodos
12.
Food Chem ; 276: 129-139, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30409575

RESUMO

This study investigated the structural characteristics of oil bodies from mature coconut (Cocos nucifera L.) fruit. The ultrastructure and the distribution of oil bodies in coconut endosperm were investigated using cryo-scanning electron microscopy. The interfacial characteristics of the oil bodies in suspensions isolated using two different protocols were studied using confocal laser scanning microscopy (CLSM), and the oleosins stabilizing the oil bodies were characterized using sodium dodecyl sulfate polyacrylamide electrophoresis. The oil bodies were found to be preferentially accumulated in endosperm tissues away from the inner endosperm and had a polydisperse size distribution, both intracellularly and in suspensions. The CLSM of oil bodies revealed uniform distribution of proteins and phospholipids at the interface along with glycolipids. Six different proteins were found to be associated with oil bodies some of which were disulfide-linked. This work provides new insights into the structure of coconut oil bodies and mechanisms for their stabilization.


Assuntos
Cocos/ultraestrutura , Endosperma/ultraestrutura , Gotículas Lipídicas/ultraestrutura , Cocos/química , Endosperma/química , Gotículas Lipídicas/química , Microscopia Confocal , Fosfolipídeos/análise , Proteínas de Plantas/análise
13.
Biosci Rep ; 39(1)2019 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-30429235

RESUMO

Complex plant tissues vary in hardness, i.e. some are succulent, while others are complex to break. Besides, plant metabolites, such as polysaccharides, proteins, polyphenols and lipids, can greatly interfere with the RNA extraction. So, in order to obtain a high-quality RNA from the complex tissues (like coconut endosperm, coconut apple and coconut leaf bud) rich in secondary metabolites, a robust method is demanded. Several methods (MRIP, CTAB and TRIZOL) have been used previously for the isolation of quality RNA from the coconut tissues, but without any success. The present study will provide with the details of a new method (Quick and Reliable RNA Extraction Method or QRREM), which have efficiently isolated the intact RNA form the complex tissues of coconut compared with CTAB, Trizol and RNA plant. The method has been validated for the isolation of high-quality intact RNA from the other available plant species (Areca/betel nut, mint and spring onion). The method has various advantages over the other methods in terms of time and cost effectiveness. Furthermore, the resulted RNA from various tissues of coconut performed well in the downstream experiments, i.e. reverse transcription and PCR for the production and amplification of cDNA.


Assuntos
Cocos/química , Endosperma/química , Extração Líquido-Líquido/métodos , RNA de Plantas/isolamento & purificação , Tampões (Química) , Glicerol/química , Fenol/química , Extratos Vegetais/química , Povidona/química , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Solventes/química
14.
BMC Plant Biol ; 18(1): 353, 2018 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-30545290

RESUMO

BACKGROUND: Nitrogen is one basic element of amino acids and grain protein in wheat. In field experiments, wheat plants were subjected to different timing of nitrogen topdressing treatments: at the stages of emergence of the top fifth leaf (TL5), top third leaf (TL3) and top first leaf (TL1) to test the regulatory effects of nitrogen topdressing timing on grain protein quality. The underlying mechanisms were elucidated by clarifying the relationship between proteolysis in vegetative organs and accumulation of amino acids in the endosperm cavity, conversion of amino acids, and storage protein synthesis in endosperm of wheat grain. RESULTS: Delayed nitrogen topdressing up-regulated gene expression related to nitrogen metabolism and protease synthesis in the flag leaf, followed by more free amino acids being transported to both the cavity and the endosperm from 7 days after anthesis (DAA) to 13 DAA in TL1. TL1 enhanced the conversion between free amino acids in endosperm and upregulated the expression of genes encoding high molecular weight (HMW) and low molecular weight (LMW) subunits and protein disulfide isomerases-like (PDIL) proteins, indicating that the synthesis and folding of glutenin were enhanched by delayed nitrogen topdressing. As a consequense, the content of glutenin macropolymers (GMP) and glutenin increased with delaying nitrogen topdressing. CONCLUSIONS: The results highlight the relationship between nitrogen remobilization and final grain protein production and suggest that the nitrogen remobilization processes could be a potential target for improving the quality of wheat grain. Additionally, specific gene expression related to nitrogen topdressing was identified, which conferred more detailed insights into underlying mechanism on the modification protein quality.


Assuntos
Aminoácidos/metabolismo , Grão Comestível/metabolismo , Nitrogênio/metabolismo , Proteínas de Plantas/metabolismo , Triticum/metabolismo , Aminoácidos/análise , Grão Comestível/química , Endosperma/química , Endosperma/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Nitrogênio/administração & dosagem , Folhas de Planta/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
15.
ACS Appl Mater Interfaces ; 10(43): 36664-36674, 2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-30261722

RESUMO

Green electronics on biodegradable substrates from natural sources have gained broad interest because of the advantages of being biodegradable, recyclable, sustainable, and cost-efficient. This study presents a low-cost, yet simple extraction and purification method that explores aqueous extraction and precipitation with ethanol for the synthesis of galactomannan films. In salient contrast to the other materials of natural origin, the process to obtain galactomannan films is energy efficient and environmentally friendly. As an alternative biodegradable material, galactomannan has direct relevance to the recent emerging biodegradable or transient electronics. The galactomannan substrate with temperature sensors and electrodes fabricated from zinc, a biodegradable material noted for its essential biological function, demonstrates a high-precision measurement of temperature and high-fidelity monitoring of electrophysiological signals (electromyogram or electrocardiogram). The resulting disposable sensors disappear without a trace in water and produce environmentally benign end products that could even be used for alkaline soil amendments. The set of materials explored in this study is also stable in organic solutions, enabling solvent-based fabrication that may be combined with recent advances in additive manufacturing techniques for a novel manufacturing method.


Assuntos
Eletrônica , Endosperma/química , Mananas/química , Água/química , Desenho de Equipamento , Fabaceae/química , Galactose/química , Coração/fisiologia , Humanos , Manose/química , Pós , Solubilidade , Temperatura
16.
Proc Natl Acad Sci U S A ; 115(33): E7854-E7862, 2018 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-30061386

RESUMO

The transmission of HIV can be prevented by the application of neutralizing monoclonal antibodies and lectins. Traditional recombinant protein manufacturing platforms lack sufficient capacity and are too expensive for developing countries, which suffer the greatest disease burden. Plants offer an inexpensive and scalable alternative manufacturing platform that can produce multiple components in a single plant, which is important because multiple components are required to avoid the rapid emergence of HIV-1 strains resistant to single microbicides. Furthermore, crude extracts can be used directly for prophylaxis to avoid the massive costs of downstream processing and purification. We investigated whether rice could simultaneously produce three functional HIV-neutralizing proteins (the monoclonal antibody 2G12, and the lectins griffithsin and cyanovirin-N). Preliminary in vitro tests showed that the cocktail of three proteins bound to gp120 and achieved HIV-1 neutralization. Remarkably, when we mixed the components with crude extracts of wild-type rice endosperm, we observed enhanced binding to gp120 in vitro and synergistic neutralization when all three components were present. Extracts of transgenic plants expressing all three proteins also showed enhanced in vitro binding to gp120 and synergistic HIV-1 neutralization. Fractionation of the rice extracts suggested that the enhanced gp120 binding was dependent on rice proteins, primarily the globulin fraction. Therefore, the production of HIV-1 microbicides in rice may not only reduce costs compared to traditional platforms but may also provide functional benefits in terms of microbicidal potency.


Assuntos
Fármacos Anti-HIV , Anticorpos Monoclonais , Endosperma , Anticorpos Anti-HIV , Proteína gp120 do Envelope de HIV/antagonistas & inibidores , HIV-1/química , Oryza , Plantas Geneticamente Modificadas , Fármacos Anti-HIV/química , Fármacos Anti-HIV/metabolismo , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Endosperma/química , Endosperma/genética , Endosperma/metabolismo , Anticorpos Anti-HIV/biossíntese , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/genética , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/metabolismo , Oryza/química , Oryza/genética , Oryza/metabolismo , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo
17.
Plant Physiol Biochem ; 130: 493-500, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30086516

RESUMO

The accumulation and morphology of starch in the pericarp, embryo and endosperm of normal and waxy maize were investigated using whole sections of complete caryopses. Pericarp starch took the form of compound granules, was distributed in the bottom of caryopses, and degraded from the top to the bottom. Embryo starch mostly took the form of simple granules and accumulated in the scutellum beginning approximately 10 DAP. In the endosperm, starch accumulated longitudinally from the top to the bottom and transversely from the centre to the periphery with caryopsis development. The peripheral endosperm cells synthesized starch faster than did the inner ones. Simple and compound starches were both observed, but the compound starch granules were distributed in the central region of the endosperm. At a late stage of development, compound starch was only observed in the bottom central portion of the endosperm. The pericarp starch of normal maize showed higher amylose content than did the embryo and endosperm starch. The waxy maize pericarp and embryo starches had similar amylose contents, but amylose was hardly detected in the endosperm due to the granule-bound starch synthase I gene mutation. The starches from the endosperm, embryo and pericarp of normal and waxy maize all had A-type crystallinity.


Assuntos
Endosperma/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Amido/metabolismo , Zea mays/metabolismo , Amilose/metabolismo , Endosperma/química , Endosperma/metabolismo , Microscopia , Sementes/química , Sementes/metabolismo , Amido/análise , Amido/biossíntese , Difração de Raios X , Zea mays/química , Zea mays/crescimento & desenvolvimento
18.
Plant Sci ; 272: 142-152, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29807585

RESUMO

The improvement of protein quality in maize so far has been based on recessive opaque2 (o2) mutant that along with endosperm-modifiers led to development of quality protein maize (QPM). Recent discovery of nutritional benefits of recessive opaque16 (o16) mutant was of immense significance for further improvement of protein quality. In the present study, o16 was introgressed into o2-based parental inbreds (HKI161, HKI193-1, HKI193-2 and HKI163) of four commercial QPM hybrids (HQPM-1, HQPM-4, HQPM-5 and HQPM-7) released in India, using marker-assisted backcross breeding. Background selection led to high recovery of recurrent parent genome (RPG) to maximum of 95%, and introgressed progenies showed considerable phenotypic resemblance for plant-, ear- and grain- characteristics to their respective recurrent parents. Selection of markers for o2 and o16 led to development of pyramided lines (o2o2/o16o16) that possessed as high as 76% and 91% more lysine and tryptophan over the recurrent parents, respectively. Reconstituted hybrids showed an average enhancement of 49% and 60% in lysine and tryptophan over the original hybrids, with highest enhancement amounting 64% and 86%, respectively. This is first report of enhancement of both lysine and tryptophan by o16 in maize genotypes adaptable to sub-tropics. Moderate variation in lysine and tryptophan was also observed in pyramided lines. Multi-location evaluation of reconstituted hybrids revealed similar grain yield and attributing traits to their original versions. This study signified the role of o16 as supplementary to o2 for nutritional quality enhancement in maize, and improved elite inbreds and hybrids developed here hold great significance in maize biofortification programme.


Assuntos
Biofortificação/métodos , Proteínas de Ligação a DNA/genética , Lisina/metabolismo , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Triptofano/metabolismo , Zea mays/genética , Proteínas de Ligação a DNA/fisiologia , Endosperma/química , Genes de Plantas/genética , Genes de Plantas/fisiologia , Marcadores Genéticos/genética , Hibridização Genética/genética , Lisina/análise , Proteínas de Plantas/fisiologia , Reação em Cadeia da Polimerase , Fatores de Transcrição/fisiologia , Triptofano/análise , Zea mays/metabolismo
19.
Carbohydr Polym ; 195: 1-8, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29804956

RESUMO

Structural, physicochemical characteristics and digestibility of endosperm starches from four mutants (GM01, 03-05) and their parent Guangluai 4 (GLA4) were characterized. GM05 had a little higher apparent amylose content (AAC) and showed little difference in starch and digestion properties from GLA4. However, GM03 and GM04 with increased amount of chalkiness and partial translucent region in the endosperm displayed a distinct starch and digestion properties, which had the RS of 7.9 and 8.4%, respectively. GM03 and GM04 had higher AAC (33-35%), lower degree of crystallinity, lower gelatinization temperature and pasting viscosities, and more amount of B1 (DP 12-24) and B2 (DP 25-36) chains and less amount of B3 chains (DP ≥ 37) in amylopectin. AAC and the amount of B1 chains had positive correlation with RS, but the amount of B3 chains had negative correlation with RS. The results of this study may be applied to design RS by selecting rice germplasm with high AAC and high amount of B1 chains (DP 12-24) of amylopectin.


Assuntos
Amilopectina/química , Amilose/química , Endosperma/química , Mutação , Oryza/química , Hidrólise , Oryza/genética , Viscosidade
20.
PLoS One ; 13(5): e0197126, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29738563

RESUMO

Chromatin immunoprecipitation (ChIP) is usually a reliable technique to find the binding sites of a transcription factor. In the current study, we developed a suitable ChIP method using developing castor bean seeds. A castor bean seed with large and persistent endosperm contains high amounts of storage lipids (ca. 50-60%) and is often considered as a model material to studying seed biology. In oleaginous seeds, due to the rich oils which could seriously affect immunoprecipitation and DNA isolation, it is often difficult to carry out a successful ChIP experiment. Thus, the development of an efficient ChIP method for oleaginous seeds is required. In this study, we modified different steps, including tissue preparation for cross-linking, chromatin washing, sonication and immunoprecipitation of other existing methods. As exemplified by the targeted gene identification of a master regulator WRI1, which regulates fatty acid biosynthesis, we found that the improved ChIP method worked well. We analyzed percentage input and fold changes of the ChIPed DNA. We also made successful ChIP-seq libraries using this method. This method provides a technical support not only for use on castor bean seeds; it might be used equally to analyze protein-DNA interaction in vivo in other oleaginous seeds.


Assuntos
Semente de Rícino/química , Imunoprecipitação da Cromatina/métodos , Óleos Vegetais/química , Sementes/química , Semente de Rícino/genética , Endosperma/química , Endosperma/genética , Ácidos Graxos/biossíntese , Ácidos Graxos/genética , Regulação da Expressão Gênica de Plantas , Lipídeos/química , Lipídeos/genética , Sementes/genética
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