Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 116
Filtrar
1.
Cell Mol Biol (Noisy-le-grand) ; 69(4): 16-23, 2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-37329553

RESUMO

Today, using elastography and ultrasound images is the best method for diagnosing breast cancer for dense tissues, especially for women under 30 years old, which is used to detect the exact border of masses. Besides, using quantitative microscopic criteria that are less tasteful seems to be useful in predicting the behavior of the tumor and its prognosis. Ki-67 is an antigen corresponding to a nuclear non-histone protein produced by cells in proliferative phases. In this article, ultrasound and elastography images of patients were collected, and breast masses were identified. The proposed algorithm includes pre-processing, feature extraction, and classification. To remove the speckle noise, two pre-processing steps are used, and after segmenting each data with its appropriate color channel, statistical features and features based on the morphology of suspicious areas are extracted. Also, sections of paraffin blocks of samples fixed in formalin were prepared and stained by immunohistochemical staining with Ki-67 monoclonal antibody, and the cell proliferation index was determined in the prepared slides. The relationship between Ki-67 positivity and microscopic grade was studied. The feature extraction results show that elastography is chosen as a more appropriate method than ultrasound due to the separation in terms of color channels. The most appropriate proposed combined methods, namely RBF-Kmeans, MLP-SCG, and RBF-SOM, have been used to classify features. The combined MLP-SCG classifier with an average accuracy of 96% and an average of 98% has improved significantly compared to other methods.


Assuntos
Neoplasias da Mama , Técnicas de Imagem por Elasticidade , Humanos , Feminino , Adulto , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/metabolismo , Antígeno Ki-67/metabolismo , Proliferação de Células , Algoritmos
2.
Compr Rev Food Sci Food Saf ; 22(3): 1794-1816, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36856534

RESUMO

Heavy metals are of particular concern in grape and wine processing, especially copper. The sources of copper are diverse, including vineyard soil, copper-containing pesticides on the fruit surface, copper wine-making equipment, and exogenous addition in winemaking. Copper has potential risks to human nerves, metabolism, and others. It can inhibit yeast growth, delay fermentation, and also mediate oxidation reactions, which has a huge impact on the nutritional quality and sensory quality of fresh wine and aged wine. It is therefore crucial to detect, quantify, and remove copper from grapes and wine. However, the copper situations in the wine industries of various countries are complicated and diverse, and the existing forms of copper are quite different, which makes the research challenging. This review summarizes and analyzes the existence and influence of copper in the wine industry by analyzing the sources of, the current situation regarding, and the detection and removal methods for copper in wine. With the study, a better understanding of copper's impact on wine production will be gained, facilitating further control of copper in wine and helping the wine industry grow.


Assuntos
Vitis , Vinho , Humanos , Vinho/análise , Cobre/metabolismo , Solo , Leveduras
3.
Crit Rev Food Sci Nutr ; 62(24): 6783-6808, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33825545

RESUMO

Wine is a high-value alcoholic beverage welcomed by consumers because of its flavor and nutritional value. The key information on wine bottle label is the basis of consumers' choice, which also becomes a target for manufacturers to adulterate, including geographical origin, grape variety and vintage. With the improvement of wine adulteration technology, modern technological means are needed to solve the above mentioned problems. The chemical basis of wine determines the type of technique used. Detection technology can be subdivided into four groups: mass spectrometry techniques, spectroscopic techniques, chromatography techniques, and other techniques. Multivariate statistical analysis of the data was performed by means of chemometrics methods. This paper outlines a series of procedures for wine classification and identification, and classified the analytical techniques and data processing methods used in recent years with listing their principles, advantages and disadvantages to help wine researchers choose appropriate methods to meet the challenge and ensure wine traceability and authenticity.


Assuntos
Vitis , Vinho , Bebidas Alcoólicas/análise , Espectrometria de Massas/métodos , Análise Multivariada , Vitis/química , Vinho/análise
4.
J Sci Food Agric ; 102(1): 383-395, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34143902

RESUMO

BACKGROUND: The influence of foliar nitrogen fertilizer during veraison (FNFV) on anthocyanin accumulation and chromatic characteristics of 'Cabernet Sauvignon' grapes over two seasons was investigated. RESULTS: Urea and phenylalanine fertilizers (TU and TP, respectively) and a control were sprayed three times at veraison. In 2018, TU displayed a significant enhancement in total individual anthocyanin content and a* and Cab * profiles. In 2019, FNAV significantly improved the content of total non-acylated, acylated anthocyanin and total individual anthocyanin, and the profiles of L*, a* and Cab *, except a* in TU. The whole process from phenylalanine variation to anthocyanin accumulation in grape skins was analyzed. On the whole, after the first FNFV to harvest, the increase in phenylalanine metabolism, abscisic acid content, effects of PAL (Phenylalanine ammonia lyase), UFGT (UDP glucose-flavonoid 3-O-glucosyltransferase) and transcript concentrations of VvPAL and VvUFGT involved in anthocyanin biosynthesis were also strong evidence explaining the increased anthocyanin and chromatic profiles in 2019. CONCLUSION: Overall, FNFV for nitrogen-deficient grapevines could significantly improve grape color, especially in the 2019 veraison with a proper climate. © 2021 Society of Chemical Industry.


Assuntos
Antocianinas/análise , Fertilizantes/análise , Frutas/crescimento & desenvolvimento , Nitrogênio/metabolismo , Vitis/metabolismo , Antocianinas/metabolismo , Frutas/química , Frutas/metabolismo , Nitrogênio/análise , Fenilalanina Amônia-Liase/metabolismo , Proteínas de Plantas/metabolismo , Vitis/química , Vitis/crescimento & desenvolvimento
5.
Crit Rev Food Sci Nutr ; 61(14): 2372-2398, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32551848

RESUMO

Proanthocyanidins (PAs) are important secondary metabolites crucial for the quality of grape berry and wine. Despite important advances in our understanding of the structural and regulatory genes involved in the PAs biosynthesis pathway, our knowledge about the details of biosynthetic and regulatory networks, especially the mechanism of polymerization and transportation remains limited. We provided an overview of the latest discoveries related to the mechanisms of grape PAs structure, astringency properties, detection methods, biosynthesis and transportation. We also summarized the environmental influencing factors of PAs synthesis in grape. Future trends were discussed.


Assuntos
Proantocianidinas , Vitis , Vinho , Adstringentes , Percepção , Proantocianidinas/análise , Vinho/análise
6.
J Sci Food Agric ; 101(11): 4435-4443, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-33611788

RESUMO

Crop thinning is a common practice performed in the vineyard consisting of whole clusters or individual fruits being removed after flowering is attained. Current studies have reported that unripe grape products as verjuice and sour grape sauce contain high content of bioactive compounds such as polyphenols, sugars, organic acids, nitrogenous compounds and sterols. This mini-review overviewed the bioactive components obtained from thinned unripe grapes such as phenolic compounds, sugars, organic acids, minerals, nitrogen compounds and sterols, and their use as antibrowning and whitening agents, natural catalysts, food preservative and food additive. In addition, their beneficial effects for human health also were reviewed, as well as the practices to maximize the extraction of antioxidant compounds. Therefore, revalorizing the waste from this management practice in viticulture can increase the vineyard sustainability and farmers' economic profits. © 2021 Society of Chemical Industry.


Assuntos
Produção Agrícola/métodos , Vitis/crescimento & desenvolvimento , Antioxidantes/análise , Frutas/química , Frutas/crescimento & desenvolvimento , Polifenóis/análise , Vitis/química
7.
J Sci Food Agric ; 101(8): 3214-3224, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33211320

RESUMO

BACKGROUND: Anthocyanins, a major flavonoid class, determine the color and quality of wine. Recent research revealed that basal leaf removal can increase the content of these compounds. This study determined the effects of basal leaf removal on the anthocyanin profiles of Cabernet Sauvignon grapes. RESULTS: The effects of basal leaf removal on anthocyanin composition in Cabernet Sauvignon grapes were investigated over two growing seasons. Leaf removal at 5% veraison (VB6) and at 100% veraison (VC6) was compared with a control. Reducing sugar and total anthocyanin contents in the leaf removal group were significantly higher than in the control group at harvest for both vintages. Leaf removal increased the content of individual anthocyanins and significantly improved the malvidin-3-O-glucoside (Mv-3-glc), peonidin-3-O-glucoside (Pn-3-glc), and malvidin-3-O-(6-acetyl)-glucoside (Mv-3-acglc) content of the VB6 group. At harvest, VB6 treatment increased the transcript abundance of structural and regulator genes in the anthocyanin pathway, especially VvF3'5'H, VvLDOX, and VvDFR. CONCLUSIONS: Our results suggest that leaf removal at 5% veraison may be useful for improving the anthocyanin content in grapes. © 2020 Society of Chemical Industry.


Assuntos
Antocianinas/biossíntese , Produção Agrícola/métodos , Frutas/química , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Vitis/crescimento & desenvolvimento , Antocianinas/análise , Cromatografia Líquida de Alta Pressão , Frutas/genética , Frutas/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Vitis/química , Vitis/genética , Vitis/metabolismo
8.
J Sci Food Agric ; 101(4): 1288-1300, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32869302

RESUMO

Nitrogen is involved in the winemaking process from grapevine growth to wine fermentation, and its precise utilization in vineyards can regulate grape and wine quality. Foliar nitrogen application during veraison (FNAV) could prevent nitrogen deficiency in grape and must in nitrogen-deficient vineyards. Moreover, FNAV also could improve certain flavor components of grape and wine, but little attention has been paid to FNAV. Therefore, this paper mainly reviews the difficulties encountered in current applications of nitrogen in vineyards and wineries, and the advantages of FNAV over the addition of nitrogen in soil and wineries. And it discusses that FNAV can increase yeast-assimilable nitrogen and phenolics, and scarcely affect volatile components of grape (must and wine), and points out the existing problems including the core issue and then puts forward future research directions. This information may indicate future directions for research, and provide a reference for viticulturists and winemakers on the precise application of nitrogen on grapevine and must to further improve grape and wine quality in nitrogen-deficient vineyards. © 2020 Society of Chemical Industry.


Assuntos
Aromatizantes/química , Nitrogênio/metabolismo , Vitis/química , Vinho/análise , Fazendas , Aromatizantes/metabolismo , Frutas/química , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Frutas/microbiologia , Humanos , Saccharomyces cerevisiae/metabolismo , Vitis/crescimento & desenvolvimento , Vitis/metabolismo , Vitis/microbiologia
9.
Mol Plant Microbe Interact ; 32(5): 622-634, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30489195

RESUMO

Verticillium dahliae is a soilborne fungus and the primary causal agent of vascular wilt diseases worldwide. The fungus produces melanized microsclerotia that are crucially important for the survival and spread of V. dahliae. There are no fungicides available that are both effective and environmentally friendly to suppress the fungus. Previously, Bacillus subtilis C232 was isolated from soil and was demonstrated to suppress microsclerotia formation in V. dahliae. In this study, liquid chromatography coupled with mass spectrometry revealed that the antifungal substance is actually a mixture of lipopeptides. Exposure of V. dahliae to these lipopeptides resulted in hyphal swelling, cell lysis, and downregulation of melanin-related genes. RNA sequencing analyses of the lipopeptide-suppressed transcriptome during microsclerotial development revealed that 5,974 genes (2,131 upregulated and 3,843 downregulated) were differentially expressed versus nonsuppressive conditions. Furthermore, gene ontology enrichment analyses revealed that genes involved in response to stress, cellular metabolic processes, and translation were significantly enriched. Additionally, the lipopeptides inhibited expression of genes associated with secondary metabolism, protein catabolism, and the high-osmolarity glycerol response signaling pathway. Together, these findings provide evidence for the mechanism by which B. subtilis lipopeptides suppress microsclerotia formation. The transcriptomic insight garnered here may facilitate the development of biological agents to combat Verticillium wilt.


Assuntos
Genoma Fúngico , Lipopeptídeos , Interações Microbianas , Transcriptoma , Verticillium , Bacillus subtilis/fisiologia , Hifas/metabolismo , Lipopeptídeos/metabolismo
10.
Environ Microbiol ; 21(8): 2977-2996, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31136051

RESUMO

The fungus Verticillium dahliae causes vascular wilt disease on more than 200 plant species worldwide. This fungus can survive for years in soil as melanized microsclerotia. We found that VdCmr1, a transcription factor, is required for the melanin production and increased survival following UV irradiation in V. dahliae but not for microsclerotia production or virulence. Here, we provided evidence how VdCmr1 protects against high temperature (HT) and UV irradiation in V. dahliae. The results indicate that VdCmr1 mediates entry to the diapause period in V. dahliae in response to HT and contributes to the expression of proteins to minimize protein misfolding and denaturation. VdCmr1 deletion results in the misregulation of DNA repair machinery, suggestive of reduced DNA repair capacity following UV irradiation and in correlation with the low survival rate of UV-treated VdCmr1 mutants. We discovered a putative VdCmr1-dependent gene cluster associated with secondary metabolism and stress responses. We also functionally characterized two VdCmr1-responsive genes participating in HT and UV response. These results shed further light on the roles of VdCmr1 in protection from HT or UV irradiation, and the additional insights into the mechanisms of this protection may be useful to exploit for more effective disease control.


Assuntos
Proteínas Fúngicas/metabolismo , Temperatura Alta , Raios Ultravioleta , Verticillium/efeitos da radiação , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica/efeitos da radiação , Doenças das Plantas/microbiologia , Deleção de Sequência , Fatores de Transcrição/genética , Verticillium/genética , Virulência/genética
11.
Molecules ; 24(24)2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31888183

RESUMO

3-Alkyl-2-methoxypyrazines (MPs) contribute to the herbaceous flavor characteristics of wine and are generally considered associated with poor-quality wine. To control the MPs in grapes and wine, an accurate understanding of MP metabolism is needed. This review covers factors affecting people in the perception of MPs. Also, the history of O-methyltransferases is revisited, and the present review discusses the MP biosynthesis, degradation, and biochemical regulation. We propose the existence of a cycle between MPs and 3-alkyl-2-hydropyrazines (HPs), which proceeds via O-(de)methylation steps. This cycle governs the MP contents of wines, which make the cycle the key participant in MP regulation by genes, environmental stimuli, and microbes. In conclusion, a comprehensive metabolic pathway on which the HP-MP cycle is centered is proposed after gaining insight into their metabolism and regulation. Some directions for future studies on MPs are also proposed in this paper.


Assuntos
Pirazinas/química , Pirazinas/metabolismo , Vitis/química , Vitis/metabolismo , Vinho/análise , Catálise , Fermentação , Regulação da Expressão Gênica , Redes e Vias Metabólicas , Metilação , Estrutura Molecular , Odorantes , Percepção Olfatória , Pirazinas/análise , Olfato , Vitis/genética
12.
Molecules ; 24(15)2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31366183

RESUMO

The aim of this paper was to investigate how maturity affects the aroma characteristics of Cabernet Sauvignon wine. A series of four Vitis vinifera cv. Cabernet Sauvignon wines were produced from grapes of different harvest dates. The berries of sequential harvest treatments showed an increase in total soluble solids and anthocyanin and a decrease in titratable acidity. Berry shriveling was observed as berry weight decreased. In the wines, anthocyanin, dry extract, alcoholic strength, and pH were enhanced with the sequential harvest, whereas polyphenol and tannin were decreased. The concentrations of volatile compounds in sequential harvests were found to be at higher levels. Isopentanol, phenylethyl alcohol, ethyl acetate, ethyl lactate, benzaldehyde, citronellol, and linalool significantly increased when harvest was delayed by one or two weeks. Through a principal component analysis, the volatile compounds and phenols characterizing each harvest date were clearly differentiated. These results suggest that sequential harvest may be an optional strategy for winemakers to produce high-quality wine.


Assuntos
Frutas/química , Odorantes/análise , Vitis/química , Compostos Orgânicos Voláteis/isolamento & purificação , Vinho/análise , Antocianinas/biossíntese , Antocianinas/isolamento & purificação , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Polifenóis/biossíntese , Polifenóis/classificação , Polifenóis/isolamento & purificação , Análise de Componente Principal , Taninos/biossíntese , Taninos/classificação , Taninos/isolamento & purificação , Fatores de Tempo , Vitis/crescimento & desenvolvimento , Vitis/metabolismo , Compostos Orgânicos Voláteis/classificação , Compostos Orgânicos Voláteis/metabolismo
13.
Molecules ; 24(2)2019 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-30641873

RESUMO

The concentrations of trace elements in wines and health risk assessment via wine consumption were investigated in 315 wines. Samples were collected from eight major wine-producing regions in China. The concentrations of twelve trace elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) and Duncan's multiple range test was applied to analyze significant variations (p < 0.05) of trace elements in different regions. Based on a 60 kg adult drinker consuming 200 mL of wine per day, the estimated daily intake (EDI) of each element from wines was far below the provisional tolerable daily intake (PTDI). Health risk assessment indicated the ingestion influence of individual elements and combined elements through this Chinese wine daily intake did not constitute a health hazard to people. However, Cr and Mn were the potential contaminants of higher health risk in Chinese wines. The cumulative impact of wine consumption on trace elements intake in the daily diet of drinkers should not be ignored due to the presence of other intake pathways.


Assuntos
Medição de Risco , Análise Espectral , Oligoelementos/análise , Vinho/análise , China , Humanos , Espectrometria de Massas , Controle de Qualidade
14.
Microbiology (Reading) ; 164(4): 685-696, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29485393

RESUMO

Verticillium dahliae is a soilborne fungus that causes vascular wilt diseases on numerous plant species worldwide. The production of darkly melanized microsclerotia is crucial in the disease cycle of V. dahliae, as these structures allow for long-term survival in soil. Previously, transcriptomic and genomic analysis identified a cluster of genes in V. dahliae that encodes some dihydroxynaphthalene (DHN) melanin biosynthetic pathway homologues found in related fungi. In this study, we explored the roles of cluster-specific transcription factor VdCmr1, as well as two other genes within the cluster encoding a polyketide synthase (VdPKS1) and a laccase (VdLac1), enzymes at initial and endpoint steps in DHN melanin production. The results revealed that VdCmr1 and VdPKS1 are required for melanin production, but neither is required for microsclerotia production. None of the three genes were required for pathogenesis on tobacco and lettuce. Exposure of ΔVdCmr1 and wild-type strains to UV irradiation, or to high temperature (40 °C), revealed an approx. 50 % reduction of survival in the ΔVdCmr1 strain, relative to the wild-type strain, in response to either condition. Expression profiles revealed that expression of some melanin biosynthetic genes are in part dependent on VdCmr1. Combined data indicate VdCmr1 is a key regulator of melanin biosynthesis, and that via regulation of melanogenesis, VdCmr1 affects survival of V. dahliae in response to abiotic threats. We conclude with a model showing regulation of VdCmr1 by a high osmolarity glycerol response (Hog)-type MAP kinase pathway.


Assuntos
Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Melaninas/biossíntese , Fatores de Transcrição/metabolismo , Verticillium/genética , Proteínas Fúngicas/genética , Deleção de Genes , Lacase/genética , Modelos Biológicos , Naftóis , Doenças das Plantas/microbiologia , Policetídeo Sintases/genética , Temperatura , Fatores de Transcrição/genética , Raios Ultravioleta , Verticillium/metabolismo , Verticillium/efeitos da radiação
15.
Molecules ; 23(8)2018 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-30096898

RESUMO

Amino acid contents and their derived volatile compositions in Cabernet Sauvignon grapes and wines after regulated deficit irrigation (RDI) were investigated during the 2015 and 2016 growing seasons in Yinchuan (NingXia, China). High-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) were used for amino acid and volatile compound analyses. Three RDI strategies were tested: 60% (RDI-1), 70% (RDI-2), and 80% (RDI-3) of grapevine estimated evapotranspiration (ETc), and 100% ETc was used as the control group (CK). RDI-treated vines had lower yields and berry weights with higher total soluble solids than the control treatment. RDI-1 increased proline levels in berries and wines. RDI-2 enhanced tyrosine and asparagine levels in wines. RDI-3 enhanced arginine, alanine, valine, leucine, and isoleucine levels in berries and wines. RDI-2 and RDI-3 increased the concentrations of 2-methyl-1-butyl acetate, benzaldehyde, 3-methyl-1-pentanol, and 3-methyl-1-butanol in wines. The accumulation of volatile compounds was closely related to the amino acid concentrations-especially isoleucine, valine, and leucine-in grapes. Our results showed that RDI treatments altered amino acid concentrations and their derived volatile compositions in wines.


Assuntos
Irrigação Agrícola , Aminoácidos/análise , Frutas/química , Vitis/química , Compostos Orgânicos Voláteis/análise , Vinho/análise , Análise por Conglomerados , Tempo (Meteorologia)
16.
Fungal Genet Biol ; 108: 26-35, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28917999

RESUMO

The fungus Verticillium dahliae causes vascular wilt disease on various plant species resulting in devastating yield losses worldwide. The capacity of V. dahliae to colonize in host plant xylem and disseminate by microsclerotia has led to studies to evaluate genes associated with pathogenesis and microsclerotia formation. Here, we identified and characterized a V. dahliae homolog to Skn7, a two-component stress response regulator of Saccharomyces cerevisiae. Results showed that melanized microsclerotia formation and conidiation were significantly inhibited in the VdSkn7 deletion mutants. VdSkn7-deficient mutants displayed severe growth defect under heat shock, cell wall perturbing agents and H2O2, and were significantly less virulent but were not sensitive to osmotic stresses compared to the wild-type strain. Finally, we demonstrated that VdSkn7 is required for the plant penetration. Taken together, our study thus provides new evidence on the functional conservation and divergence of Skn7 orthologs among fungal organisms and indicates that VdSkn7 contributes to microsclerotial development, virulence and stress response of V. dahliae.


Assuntos
Genes Fúngicos , Verticillium/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/fisiologia , Deleção de Genes , Resposta ao Choque Térmico , Peróxido de Hidrogênio/farmacologia , Mutagênese , Doenças das Plantas/microbiologia , Transdução de Sinais , Esporos Fúngicos , Nicotiana/microbiologia , Verticillium/efeitos dos fármacos , Verticillium/patogenicidade , Verticillium/fisiologia , Virulência
17.
Sensors (Basel) ; 16(9)2016 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-27618059

RESUMO

The study proposes a small U-shaped bending-induced interference optical fiber sensor; this novel sensor is a probe-type sensor manufactured using a mechanical device, a heat source, optical fiber and a packaging module. This probe-type sensor overcomes the shortcomings of conventional optical fibers, including being difficult to repair and a tendency to be influenced by external forces. We manufactured three types of sensors with different curvature radiuses. Specifically, sensors with three radiuses (1.5 mm, 2.0 mm, and 3.0 mm) were used to measure common water and glucose solutions with concentrations of between 6% and 30% (the interval between concentrations was 4%). The results show that the maximal sensitivity was 0.85 dB/% and that the linearly-dependent coefficient was 0.925. The results further show that not only can the small U-shaped bending-induced interference optical fiber sensor achieve high sensitivity in the measurement of glucose solutions, but that it can also achieve great stability and repeatability.

18.
Molecules ; 21(10)2016 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-27754331

RESUMO

The anthocyanin composition, fatty acids, and volatile aromas are important for Cabernet Sauvignon grape quality. This study evaluated the effect of exogenous abscisic acid (ABA) and methyl jasmonate (MeJA) on the anthocyanin composition, fatty acids, lipoxygenase activity, and the volatile compounds of Cabernet Sauvignon grape berries. Exogenous ABA and MeJA improved the content of total anthocyanins (TAC) and individual anthocyanins. Lipoxygenase (LOX) activity also increased after treatment. Furthermore, 16 fatty acids were detected. The linoleic acid concentration gradually increased with ABA concentration. The fatty acid content decreased with increasing MeJA concentration and then increased again, with the exception of linoleic acid. After exogenous ABA and MeJA treatment, the C6 aroma content increased significantly. Interestingly, the exogenous ABA and MeJA treatments improved mainly the content of 1-hexanol, hexanal, and 2-heptanol. These results provide insight into the effect of plant hormones on wine grapes, which is useful for grape quality improvement.


Assuntos
Frutas/química , Extratos Vegetais/análise , Reguladores de Crescimento de Plantas/farmacologia , Vitis/química , Ácido Abscísico/farmacologia , Acetatos/farmacologia , Antocianinas/análise , Ciclopentanos/farmacologia , Ácidos Graxos/análise , Frutas/efeitos dos fármacos , Oxilipinas/farmacologia , Vitis/efeitos dos fármacos , Compostos Orgânicos Voláteis/análise
19.
Fungal Genet Biol ; 82: 201-12, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26235044

RESUMO

Calcium signaling plays crucial roles in ion stress tolerance, sporulation and pathogenicity in fungi. Although the signaling pathway mediated by calcineurin and the calcineurin-responsive zinc finger transcription factor Crz1 is well characterized in other fungi, this pathway is not well characterized in the phytopathogenic fungus, Verticillium dahliae. To better understand the role of this calcineurin-dependent transcription factor in V. dahliae, an ortholog of CRZ1, VdCrz1, was identified and characterized functionally. Transcriptional analysis of VdCrz1 and GFP expression driven by the VdCrz1 promoter indicated that VdCrz1 was involved in microsclerotia development. After targeted deletion of VdCrz1, microsclerotia formation and melanin accumulation were impaired. Furthermore, the ΔVdCrz1 mutants were hypersensitive to high concentrations of Ca(2+) and cell wall-perturbing agents, such as sodium dodecyl sulfate. The addition of Mg(2+) to the medium restores the microsclerotia formation in ΔVdCrz1 mutants. The ΔVdCrz1 mutants exhibited delayed Verticillium wilt symptoms on smoke tree. These results suggest that VdCrz1 plays important roles in Ca(2+) signaling, cell wall integrity, microsclerotia development and full virulence in V. dahliae.


Assuntos
Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Verticillium/genética , Verticillium/metabolismo , Sequência de Aminoácidos , Canais de Cálcio Tipo P/genética , Canais de Cálcio Tipo P/metabolismo , Núcleo Celular/metabolismo , Proteínas Fúngicas/química , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Dados de Sequência Molecular , Mutação , Fenótipo , Filogenia , Doenças das Plantas/microbiologia , Transporte Proteico , Tolerância ao Sal/genética , Alinhamento de Sequência , Fatores de Transcrição/genética , Verticillium/patogenicidade , Virulência/genética , Dedos de Zinco/genética
20.
J Pineal Res ; 57(2): 200-12, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25039750

RESUMO

Grapes are an important economic crop and are widely cultivated around the world. Most grapes are grown in arid or semi-arid regions, and droughts take a heavy toll in grape and wine production areas. Developing effective drought-resistant cultivation measures is a priority for viticulture. Melatonin, an indoleamine, mediates many physiological processes in plants. Herein, we examined whether exogenously applied melatonin could improve the resistance of wine grape seedlings grown from cuttings to polyethylene glycol-induced water-deficient stress. The application of 10% polyethylene glycol (PEG) markedly inhibited the growth of cuttings, caused oxidative stress and damage from H2 O2 and O2∙-, and reduced the potential efficiency of Photosystem II and the amount of chlorophyll. Application of melatonin partially alleviated the oxidative injury to cuttings, slowed the decline in the potential efficiency of Photosystem II, and limited the effects on leaf thickness, spongy tissue, and stoma size after application of PEG. Melatonin treatment also helped preserve the internal lamellar system of chloroplasts and alleviated the ultrastructural damage induced by drought stress. This ameliorating effect may be ascribed to the enhanced activity of antioxidant enzymes, increased levels of nonenzymatic antioxidants, and increased amount of osmoprotectants (free proline). We conclude that the application of melatonin to wine grapes is effective in reducing drought stress.


Assuntos
Antioxidantes/metabolismo , Cloroplastos/efeitos dos fármacos , Melatonina/farmacologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Vitis/efeitos dos fármacos , Vitis/metabolismo , Cloroplastos/ultraestrutura , Microscopia Eletrônica de Transmissão , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/ultraestrutura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA