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1.
J Agric Food Chem ; 67(37): 10423-10431, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31487168

RESUMO

Plants often produce antifungal peptides and proteins in response to infection. Also wheat, which is the main ingredient of bread dough, contains such components. Here, we show that while some industrial strains of the baker's yeast Saccharomyces cerevisiae can efficiently ferment dough, some other strains show much lower fermentation capacities because they are sensitive to a specific wheat protein. We purified and identified what turned out to be a thaumatin-like protein through a combination of activity-guided fractionation, cation exchange chromatography, reversed-phase HPLC, and LC-MS/MS. Recombinant expression of the corresponding gene and testing the activity confirmed the inhibitory activity of the protein.


Assuntos
Proteínas de Plantas/química , Proteínas de Plantas/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Triticum/química , Cromatografia Líquida , Fermentação , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Saccharomyces cerevisiae/metabolismo , Espectrometria de Massas em Tandem , Triticum/genética , Triticum/metabolismo , Triticum/microbiologia
2.
BMC Plant Biol ; 19(1): 348, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31399046

RESUMO

BACKGROUND: Resistance to pre-harvest sprouting (PHS) is one of the major objectives in wheat breeding programs. However, the complex quantitative nature of this trait presents challenges when breeding for PHS resistance. Characterization of PHS using near-isogenic lines (NILs) targeting major quantitative trait locus/loci (QTL/QTLs) can be an effective strategy for the identification of responsible genes and underlying mechanisms. RESULTS: In this study, multiple pairs of NILs were developed and confirmed for a major QTL located on the 4BL chromosome arm that contributes to PHS resistance in wheat, using a combined heterogeneous inbred family method and a fast generation cycling system. Phenotypic characterization of these confirmed NILs revealed significant differences in PHS resistance between the isolines, where the presence of the resistant allele increased the resistance to sprouting on spikes by 54.0-81.9% (average 70.8%) and reduced seed germination by 59.4-70.5% (average 66.2%). The 90 K SNP genotyping assay on the confirmed NIL pairs identified eight SNPs on 4BL, associated with five candidate genes; two of the candidate genes were related to seed dormancy. Agronomic traits in the NIL pairs were investigated; both plant height and grain number per spike were positively correlated with PHS susceptibility. CONCLUSIONS: This study confirmed multiple pairs of NILs and identified SNPs between PHS isolines, which are valuable resources for further fine-mapping of this locus to clone the major genes for PHS resistance and investigate the possible functional regulation of these genes on important agronomic traits, such as plant height and grain number per spike.


Assuntos
Triticum/genética , Cromossomos de Plantas , Genótipo , Fenótipo , Melhoramento Vegetal , Desenvolvimento Vegetal/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
3.
J Agric Food Chem ; 67(35): 9877-9884, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31398030

RESUMO

Heavy metal contaminants and nutrient deficiencies in soil negatively affect crop growth and human health. The plant cadmium resistance (PCR) protein transports heavy metals. The abundance of PCR is correlated with that of cell number regulator (CNR) protein, and the two proteins have similar conserved domains. Hence, CNR might also participate in heavy metal transport. We isolated and analyzed TaCNR5 from wheat (Triticum aestivum). The expression level of TaCNR5 in the shoots of wheat increased under cadmium (Cd), zinc (Zn), or manganese (Mn) treatments. Transgenic plants expressing TaCNR5 showed enhanced tolerance to Zn and Mn. Overexpression of TaCNR5 in Arabidopsis increased Cd, Zn, and Mn translocation from roots to shoots. The concentrations of Zn and Mn in rice grains were increased in transgenic plants expressing TaCNR5. These roles of TaCNR5 in the translocation and distribution of heavy metals mean that it has potential as a genetic biofortification tool to fortify cereal grains with micronutrients.


Assuntos
Manganês/metabolismo , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Triticum/genética , Zinco/metabolismo , Arabidopsis/química , Arabidopsis/genética , Arabidopsis/metabolismo , Biofortificação , Transporte Biológico , Cádmio/análise , Cádmio/metabolismo , Manganês/análise , Oryza/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Triticum/química , Triticum/metabolismo , Zinco/análise
4.
BMC Plant Biol ; 19(1): 296, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286893

RESUMO

BACKGROUND: Premature senescence of flag leaf severely affects wheat yield and quality. Chlorophyll (Chl) degradation is the most obvious symptom during leaf senescence and catalyzed by a series of enzymes. Pheophytin pheophorbide hydrolase (Pheophytinase, PPH) gene encodes a Chl degradation hydrolase. RESULTS: In this study, the coding, genomic and promoter sequences of wheat TaPPH-A gene were cloned. The corresponding lengths were 1467 bp, 4479 bp and 3666 bp, respectively. Sequence structure analysis showed that TaPPH-A contained five exons and four introns. After the multiple sequences alignment of TaPPH-A genome from 36 accessions in a wheat diversity panel, four SNPs and one 2-bp InDel were observed, which formed two haplotypes, TaPPH-7A-1 and TaPPH-7A-2. Based on the SNP at 1299 bp (A/G), a molecular marker TaPPH-7A-dCAPS was developed to distinguish allelic variation (A/G). Using the molecular markers, 13 SSR, and 116 SNP markers, a linkage map of chromosome 7A were integrated. TaPPH-A was mapped on the chromosome region flanked by Xwmc9 (0.94 cM) and AX-95634545 (1.04 cM) on 7A in a DH population. Association analysis between TaPPH-7A allelic variation and agronomic traits found that TaPPH-7A was associated with TGW in 11 of 12 environments and Chl content at grain-filling stage under drought stress using Population 1 consisted of 323 accessions. The accessions possessed TaPPH-7A-1 (A) had higher TGW and Chl content than those possessed TaPPH-7A-2 (G), thus TaPPH-7A-1 (A) was a favorable allelic variation. By analyzing the frequency of favorable allelic variation TaPPH-7A-1 (A) in Population 2 with 157 landraces and Population 3 with 348 modern cultivars, we found it increased from pre-1950 (0) to 1960s (54.5%), then maintained a relatively stable level about 56% from 1960s to 1990s. CONCLUSION: These results suggested the favorable allelic variation TaPPH-7A-1 (A) should be valuable in enhancing grain yield by improving the source (chlorophyll content) and sink (the developing grain) simultaneously. Furthermore, the newly developed molecular marker TaPPH-7A-dCAPS could be integrated into a breeding kit of screening high TGW wheat for marker-assisted selection.


Assuntos
Haplótipos/genética , Proteínas de Plantas/genética , Triticum/genética , Marcadores Genéticos/genética , Melhoramento Vegetal , Proteínas de Plantas/metabolismo , Triticum/metabolismo
5.
J Agric Food Chem ; 67(31): 8559-8572, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31298518

RESUMO

Avenin-like b protein is rich in cysteine residues, providing the possibility to form intermolecular disulfide bonds and then participate in glutenin polymerization. Site-directed mutagenesis was adopted to produce mutant avenin-like b gene encoding mutant avenin-like b protein, in which one tyrosine codon at the C-terminal is substituted by a cysteine codon. Compared with the control lines, both transgenic lines with wild-type and mutant avenin-like b genes demonstrated superior dough properties. While compared within the transgenic lines, the mutant lines showed relative weaker dough strength and decreased sodium-dodecyl-sulfate sedimentation volumes (from 69.7 mL in line WT alb-1 to 41.0 mL in line Mut alb-4). These inferior dough properties were accompanied by the lower contents of large-sized glutenin polymers, the decreased particle diameters of glutenin macropolymer (GMP), due to the lower content of intermolecular ß-sheets (from 39.48% for line WT alb-2 to 30.21% for line Mut alb-3) and the varied contents of disulfide bonds (from 137.37 µmol/g for line WT alb-1 to 105.49 µmol/g for line Mut alb-4) in wheat dough. The extra cysteine might alter the original disulfide bond structure, allowing cysteine residue usually involved in an intermolecular disulfide bond to become available for an intrachain disulfide bond. Avenin-like b proteins were detected in glutenin macropolymers, providing further evidence for this protein to participate in the polymerization of glutenin. This is the first time to investigate the effect of a specific cysteine residue in the avenin-like b protein on flour quality.


Assuntos
Cisteína/genética , Farinha/análise , Plantas Geneticamente Modificadas/genética , Prolaminas/genética , Triticum/genética , Pão/análise , Cisteína/metabolismo , Dissulfetos/química , Manipulação de Alimentos , Mutagênese Sítio-Dirigida , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/metabolismo , Prolaminas/metabolismo , Triticum/química , Triticum/metabolismo
6.
J Agric Food Chem ; 67(31): 8706-8714, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31310118

RESUMO

Gradients in the contents and compositions of gluten proteins and free amino acids and the expression levels of gluten protein genes in developing wheat caryopses were determined by dividing the caryopsis into three longitudinal sections, namely, proximal (En1), middle (En2), and distal (En3) to embryo. The total gluten protein content was lower in En1 than in En2 and En3, with decreasing proportions of HMW-GS, LMW GS, and α/ß- and γ-gliadins and increasing proportions of ω-gliadins. These differences were associated with the abundances of gluten protein transcripts. Gradients in the proportions of the gluten protein polymers which affect dough processing quality also occurred, but not in total free amino acids. Microscopy showed that the lower gluten protein content in En1 may have resulted, at least in part, from the presence of modified cells in the dorsal part of En1, but the reasons for the differences in composition are not known.


Assuntos
Aminoácidos/química , Glutens/química , Triticum/química , Triticum/embriologia , Farinha/análise , Glutens/genética , Glutens/metabolismo , Triticum/genética , Triticum/metabolismo
7.
J Agric Food Chem ; 67(31): 8441-8451, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31339045

RESUMO

The increase in the atmospheric CO2 concentration is predicted to influence wheat production and grain quality and nutritional properties. In the present study, durum wheat (Triticum durum Desf. cv. Sula) was grown under two different CO2 (400 versus 700 µmol mol-1) concentrations to examine effects on the crop yield and grain quality at different phenological stages (from grain filling to maturity). Exposure to elevated CO2 significantly increased aboveground biomass and grain yield components. Growth at elevated CO2 diminished the elemental N content as well as protein and free amino acids, with a typical decrease in glutamine, which is the most represented amino acid in grain proteins. Such a general decrease in nitrogenous compounds was associated with altered kinetics of protein accumulation, N remobilization, and N partitioning. Our results highlight important modifications of grain metabolism that have implications for its nutritional quality.


Assuntos
Dióxido de Carbono/metabolismo , Sementes/crescimento & desenvolvimento , Triticum/metabolismo , Aminoácidos/química , Aminoácidos/metabolismo , Dióxido de Carbono/análise , Cinética , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Sementes/química , Sementes/metabolismo , Triticum/química , Triticum/crescimento & desenvolvimento
8.
J Agric Food Chem ; 67(30): 8419-8424, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31267740

RESUMO

Increasing the dietary fiber of staple foods such as bread is an attractive way to promote healthy eating in a large part of the population, where dietary fiber consumption is reportedly below the recommended values. However, many consumers prefer white breads, which are typically low in dietary fiber. In this work, white bread was made from two wheat cultivars with differing fiber contents. The resulting breads showed similar quality parameters (volume, specific volume, firmness, inner structure characteristics) with any differences maintained below 7%. Bread digestibility was evaluated using a novel dynamic in vitro digestion model. Reduced digestion rates of 30% were estimated for the high-fiber white bread compared to that in the control. Overall, this work demonstrates the potential to produce healthy, high-fiber white breads that are acceptable to consumers, with a reduced rate of starch digestion, by exploiting a genetic variation in the dietary fiber content of wheat cultivars.


Assuntos
Fibras na Dieta/metabolismo , Triticum/metabolismo , Pão/análise , Fibras na Dieta/análise , Digestão , Farinha/análise , Humanos , Cinética , Amido/química , Amido/metabolismo , Triticum/química
9.
Bioresour Technol ; 289: 121712, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31272803

RESUMO

In this study, effect of hardwood biochar on solid state anaerobic digestion of wheat straw has been investigated. The concentration of biochar was 5, 10, 15, 20, 25 and 30 g/L and added in inoculum along with wheat straw for anaerobic action. Results showed that 10 g/L of hardwood biochar led to 2-fold increment in methane yield (223 L/kg VS) compared to the control (110 L/kg VS). However, increasing the concentration of hardwood biochar did not help in significant increase in methane yield and raised pH and alkalinity up to 8.3 and 24.3 g/L respectively. Principal component analysis showed that methane yield is positively correlated with volatile solid reduction while biochar loading is directly correlated with pH as well as alkalinity and inversely correlated with total volatile fatty acid. This study revealed that biochar may help to maintain syntrophy in the anaerobic reactor and enhance methane yield significantly.


Assuntos
Carvão Vegetal/metabolismo , Metano/biossíntese , Anaerobiose , Ácidos Graxos Voláteis/biossíntese , Triticum/metabolismo
10.
Genome Biol ; 20(1): 139, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307500

RESUMO

BACKGROUND: Bread wheat is an allohexaploid species with a 16-Gb genome that has large intergenic regions, which presents a big challenge for pinpointing regulatory elements and further revealing the transcriptional regulatory mechanisms. Chromatin profiling to characterize the combinatorial patterns of chromatin signatures is a powerful means to detect functional elements and clarify regulatory activities in human studies. RESULTS: In the present study, through comprehensive analyses of the open chromatin, DNA methylome, seven major chromatin marks, and transcriptomic data generated for seedlings of allohexaploid wheat, we detected distinct chromatin architectural features surrounding various functional elements, including genes, promoters, enhancer-like elements, and transposons. Thousands of new genic regions and cis-regulatory elements are identified based on the combinatorial pattern of chromatin features. Roughly 1.5% of the genome encodes a subset of active regulatory elements, including promoters and enhancer-like elements, which are characterized by a high degree of chromatin openness and histone acetylation, an abundance of CpG islands, and low DNA methylation levels. A comparison across sub-genomes reveals that evolutionary selection on gene regulation is targeted at the sequence and chromatin feature levels. The divergent enrichment of cis-elements between enhancer-like sequences and promoters implies these functional elements are targeted by different transcription factors. CONCLUSIONS: We herein present a systematic epigenomic map for the annotation of cis-regulatory elements in the bread wheat genome, which provides new insights into the connections between chromatin modifications and cis-regulatory activities in allohexaploid wheat.


Assuntos
Montagem e Desmontagem da Cromatina , Metilação de DNA , Código das Histonas , Elementos Reguladores de Transcrição , Triticum/genética , Evolução Biológica , Epigenômica , Genoma de Planta , Plântula/metabolismo , Triticum/metabolismo
11.
J Agric Food Chem ; 67(29): 8096-8106, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31260296

RESUMO

Field experiments were conducted on wheat to study the effects of foliar-applied iodine(I) alone, Zn (zinc) alone, and a micronutrient cocktail solution containing I, Zn, Se (selenium), and Fe (iron) on grain yield and grain concentrations of micronutrients. Plants were grown over 2 years in China, India, Mexico, Pakistan, South Africa, and Turkey. Grain-Zn was increased from 28.6 mg kg-1 to 46.0 mg-1 kg with Zn-spray and 47.1 mg-1 kg with micronutrient cocktail spray. Foliar-applied I and micronutrient cocktail increased grain I from 24 µg kg-1 to 361 µg kg-1 and 249 µg kg-1, respectively. Micronutrient cocktail also increased grain-Se from 90 µg kg-1 to 338 µg kg-1 in all countries. Average increase in grain-Fe by micronutrient cocktail solution was about 12%. The results obtained demonstrated that foliar application of a cocktail micronutrient solution represents an effective strategy to biofortify wheat simultaneously with Zn, I, Se and partly with Fe without yield trade-off in wheat.


Assuntos
Biofortificação/métodos , Produção Agrícola/métodos , Iodo/metabolismo , Ferro/metabolismo , Selênio/metabolismo , Triticum/metabolismo , Zinco/metabolismo , China , Fertilizantes/análise , Índia , Iodo/análise , Ferro/análise , México , Micronutrientes/análise , Micronutrientes/metabolismo , Paquistão , Folhas de Planta/química , Folhas de Planta/metabolismo , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Selênio/análise , África do Sul , Triticum/química , Triticum/crescimento & desenvolvimento , Turquia , Zinco/análise
12.
Food Chem ; 298: 125002, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260958

RESUMO

Lipids are only minor wheat flour constituents but play major roles in bread making (BM). Here, the importance of a well-balanced lipid population in BM was studied by applying a lipase from Fusarium oxysporum in the process. Monogalactosyldiacylglycerols and N-acyl phosphatidylethanolamines were the most accessible lipase substrates. Hydrolysis thereof into their corresponding lysolipids was largely if not entirely responsible for loaf volume increases upon lipase application. Degradation of endogenously present lipids and enzymatically released lysolipids caused loaf volume to decrease, confirming that an appropriate balance between different types of lipids is crucial in BM. For optimal dough gas cell stability, the level of lipids promoting lamellar mesophases and, thus, liquid condensed monolayers needs to be maximal while maintaining an appropriate balance between lipids promoting hexagonal I phases, non-polar lipids and lipids promoting hexagonal II or cubic phases.


Assuntos
Pão , Farinha , Lipase/metabolismo , Lipídeos/química , Triticum , Fermentação , Fusarium/enzimologia , Galactolipídeos/química , Galactolipídeos/metabolismo , Hidrólise , Lipase/química , Lisofosfolipídeos/química , Lisofosfolipídeos/metabolismo , Fosfatidiletanolaminas/química , Fosfatidiletanolaminas/metabolismo , Triticum/química , Triticum/metabolismo
13.
Food Chem ; 297: 125000, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253276

RESUMO

Wheat dough has been considered as a complex blend where gluten forms the continuous reticular skeleton and starch granules act as filling particles. The effect of starch on dough behaviors is not clear and the mechanism of starch affecting dough properties needs to be revealed. In this study, the micro-structure and physiochemical properties of starch from six wheat varieties (lines) with different dough properties were investigated, and the rheological properties of wheat dough were determined. Six varieties with significant different starch properties perform various dough behaviors, among which Xinmai 26 with preeminent dough quality has the highest amylose content, B-type starch granule content, short-range ordered degree and starch swelling power but lowest relative crystallinity and gelatinization enthalpy of starch. The findings indicate that starch physicochemical properties also influence the dough behaviors and provide helpful information for demonstrating the effects of starch on dough properties in the protein-starch matrix.


Assuntos
Amido/química , Triticum/metabolismo , Amilose/análise , Farinha/análise , Glutens/química , Reologia , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/ultraestrutura , Temperatura de Transição
14.
Food Chem ; 297: 125008, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253286

RESUMO

The formation of toxic and potentially carcinogenic acrylamide, alongside volatile aroma compounds, was studied after polyphenols ((+)-catechin, quercetin, gallic, ferulic, caffeic acids) were added to model bread. The addition of as little as 0.1% polyphenols to bread significantly reduced acrylamide (16.2-95.2%). In the case of quercetin, a promoting effect was observed (+9.8%) when its concentration increased. Of all the phenolic compounds, regardless of concentration, ferulic acid showed the highest level of acrylamide inhibition. This is probably due to the presence of 4-vinylguaiacol, a degradation derivative with strong antioxidant activity in heterogeneous systems. Although the phenolic compounds mitigate acrylamide, this adversely affected bread volatile profile. At the highest level (2.0%), caffeic acid most significantly suppressed Maillard-type volatiles (75.9%), followed by gallic acid (74.3%), ferulic acid (65.6%), (+)-catechin (62.4%), and quercetin (59.3%). Among polyphenols, ferulic acid decreased yeast fermentation products level the most (33.1%), simultaneously enhancing lipid oxidation product, probably due to inhibition of amylases and yeast activity.


Assuntos
Acrilamida/química , Pão/análise , Polifenóis/química , Triticum/metabolismo , Compostos Orgânicos Voláteis/química , Acrilamida/análise , Antioxidantes/química , Análise por Conglomerados , Ácidos Cumáricos/química , Cromatografia Gasosa-Espectrometria de Massas , Reação de Maillard
15.
Food Chem ; 297: 124938, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253272

RESUMO

There was studied dough made from refined white and brown wheat flours of different granulometry by means of mechanical, thermal analysis and rheological testing. Observed results were confronted with textural properties of breads. Obtained data confirmed that fine refined white flour dough had high ability to elongate and accumulate stress, in contrary, brown fine flour dough exhibited weaker ability to accumulate stress. Observed increase of the complex viscosity associated with the gelatinization was the fastest in coarse dough, where it gained also the highest peak viscosity. The highest water content liberated was found from fine brown flour bread. This triggered lower water availability for hydration of starch granules in the bread during baking process, thus promoting higher moisture loss affecting thus the overall expansion and porosity of the bread matrix. The latter effect was ascribed to the presence of bran particles in brown flour.


Assuntos
Pão/análise , Triticum/metabolismo , Culinária , Farinha/análise , Tamanho da Partícula , Reologia , Temperatura Ambiente , Termogravimetria , Viscosidade
16.
Food Chem ; 297: 124946, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253319

RESUMO

This second paper provides chemical insight of the different phenomena occurring in bread during storage with and without anti-staling enzymes by using near infrared spectroscopy and chemometrics. The target, thus, is three-fold: (1) To monitor the staling process in the top, middle and bottom parts of the white bread loaf by near infrared spectroscopy and to extract chemical information of the different chemical mechanisms occurring in the staling process; (2) to assess the correlation between the near infrared spectroscopy and spatial texture profile analysis in terms of hardness, and (3) to demonstrate the anti-staling effect of the enzymes by showing a collapse of the correlation between near infrared (NIR) spectra and hardness as measured by texture analysis. It is found that NIR spectroscopy in combination with chemometrics (Partial Least Squares Regression) can predict the hardness development of the control bread.


Assuntos
Pão/análise , Manipulação de Alimentos/métodos , Glicosídeo Hidrolases/metabolismo , Espectroscopia de Luz Próxima ao Infravermelho , Triticum/metabolismo , Dureza , Análise dos Mínimos Quadrados , Análise de Componente Principal , Triticum/química
17.
Food Chem ; 295: 110-119, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174739

RESUMO

Amylose (AM) and amylopectin (AP) functionality during bread making was unravelled with a temperature-controlled time domain proton nuclear magnetic resonance (TD 1H NMR) toolbox. Fermented doughs from wheat flour containing starches with atypical AP chain length distribution and/or AM to AP ratio, or supplemented with Bacillus stearothermophilus α-amylase (BStA) were analyzed in situ during baking and cooling. The gelatinization temperature of starch logically depended on AP crystal stability. It was lower when starch contained a higher portion of short AP branches and higher when starch had higher AP content. During cooling, the onset temperature and extent of AM crystallization were positively related to starch AM content. BStA use resulted in slightly weakened starch networks and increased the starch polymers' mobility at the end of baking. That proton distributions evolved in a way corresponding to starch characteristics supports the suggested interpretation of NMR profiles during baking and cooling.


Assuntos
Amilopectina/química , Amilose/química , Farinha/análise , Triticum/metabolismo , Amilases/metabolismo , Pão/análise , Culinária/métodos , Geobacillus stearothermophilus/enzimologia , Espectroscopia de Prótons por Ressonância Magnética , Amido/química , Temperatura Ambiente
18.
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
19.
Food Chem ; 295: 599-606, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174801

RESUMO

The impact of Aqualysin 1 (Aq1), the thermo-active peptidase of Thermus aquaticus, on wheat albumin, globulin, gliadin and glutenin proteins during heat treatment of wheat dough and bread baking was examined. The level of protein extractable in sodium dodecyl sulfate containing medium under non-reducing conditions (SDS-EP-NR) from wheat dough decreases upon heating to a lesser extent when Aq1 is used than in control experiments. The higher SDS-EP-NR level is caused by the release by Aq1 of peptides from the repetitive gluten protein domains during baking. These peptides are also extractable from bread crumb with salt solution. The resultant thermoset gluten network in bread crumb is mainly made up by protein from non-repetitive gluten domains.


Assuntos
Pão/análise , Glutens/química , Peptídeo Hidrolases/metabolismo , Thermus/enzimologia , Triticum/metabolismo , Culinária , Farinha/análise , Glutens/metabolismo , Peso Molecular , Dodecilsulfato de Sódio/química , Temperatura Ambiente
20.
Plant Mol Biol ; 101(1-2): 41-61, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31183604

RESUMO

KEY MESSAGE: Several classes of transcription factors are involved in the activation of defensins. A new type of the transcription factor responsible for the regulation of wheat grain specific defensins was characterised in this work. HD-Zip class IV transcription factors constitute a family of multidomain proteins. A full-length cDNA of HD-Zip IV, designated TaGL7 was isolated from the developing grain of bread wheat, using a specific DNA sequence as bait in the Y1H screen. 3D models of TaGL7 HD complexed with DNA cis-elements rationalised differences that underlined accommodations of binding and non-binding DNA, while the START-like domain model predicted binding of lipidic molecules inside a concave hydrophobic cavity. The 3'-untranslated region of TaGL7 was used as a probe to isolate the genomic clone of TdGL7 from a BAC library prepared from durum wheat. The spatial and temporal activity of the TdGL7 promoter was tested in transgenic wheat, barley and rice. TdGL7 was expressed mostly in ovary at fertilisation and its promoter was active in a liquid endosperm during cellularisation and later in the endosperm transfer cells, aleurone, and starchy endosperm. The pattern of TdGL7 expression resembled that of genes that encode grain-specific lipid transfer proteins, particularly defensins. In addition, GL7 expression was upregulated by mechanical wounding, similarly to defensin genes. Co-bombardment of cultured wheat cells with TdGL7 driven by constitutive promoter and seven grain or root specific defensin promoters fused to GUS gene, revealed activation of four promoters. The data confirmed the previously proposed role of HD-Zip IV transcription factors in the regulation of genes that encode lipid transfer proteins involved in lipid transport and defence. The TdGL7 promoter could be used to engineer cereal grains with enhanced resistance to insects and fungal infections.


Assuntos
Defensinas/genética , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/genética , Triticum/genética , DNA Complementar/genética , Grão Comestível/genética , Grão Comestível/metabolismo , Genes Reporter , Hordeum/genética , Hordeum/metabolismo , Especificidade de Órgãos , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/metabolismo , Triticum/metabolismo , Técnicas do Sistema de Duplo-Híbrido
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