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1.
Front Plant Sci ; 13: 757852, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35845638

RESUMO

Terrestrial orchids can form tubers, organs modified to store energy reserves. Tubers are an attractive source of nutrients, and salep, a flour made from dried orchid tubers, is the source of traditional beverages. Tubers also contain valuable secondary metabolites and are used in traditional medicine. The extensive harvest of wild orchids is endangering their populations in nature; however, orchids can be cultivated and tubers mass-produced. This work illustrates the importance of plant-fungus interaction in shaping the content of orchid tubers in vitro. Orchid plants of Dactylorhiza sp. grown in asymbiotic culture were inoculated with a fungal isolate from Tulasnella calospora group and, after 3 months of co-cultivation, tubers were analyzed. The fungus adopted the saprotrophic mode of life, but no visible differences in the morphology and biomass of the tubers were detected compared to the mock-treated plants. To elucidate the mechanisms protecting the tubers against fungal infestation, proteome, metabolome, and lipidome of tubers were analyzed. In total, 1,526, 174, and 108 proteins, metabolites, and lipids were quantified, respectively, providing a detailed snapshot of the molecular process underlying plant-microbe interaction. The observed changes at the molecular level showed that the tubers of inoculated plants accumulated significantly higher amounts of antifungal compounds, including phenolics, alkaloid Calystegine B2, and dihydrophenanthrenes. The promoted antimicrobial effects were validated by observing transient inhibition of Phytophthora cactorum growth. The integration of omics data highlighted the promotion of flavonoid biosynthesis, the increase in the formation of lipid droplets and associated production of oxylipins, and the accumulation of auxin in response to T. calospora. Taken together, these results provide the first insights into the molecular mechanisms of defense priming in orchid tubers and highlight the possible use of fungal interactors in biotechnology for the production of orchid secondary metabolites.

2.
Int J Mol Sci ; 21(24)2020 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-33322721

RESUMO

Phytophthora is arguably one of the most damaging genera of plant pathogens. This pathogen is well suited to transmission via the international plant trade, and globalization has been promoting its spread since the 19th century. Early detection is essential for reducing its economic and ecological impact. Here, a shotgun proteomics approach was utilized for Phytophthora analysis. The collection of 37 Phytophthora isolates representing 12 different species was screened for species-specific peptide patterns. Next, Phytophthora proteins were detected in planta, employing model plants Solanum tuberosum and Hordeum vulgare. Although the evolutionarily conserved sequences represented more than 10% of the host proteome and limited the pathogen detection, the comparison between qPCR and protein data highlighted more than 300 protein markers, which correlated positively with the amount of P. infestans DNA. Finally, the analysis of P. palmivora response in barley revealed significant alterations in plant metabolism. These changes included enzymes of cell wall metabolism, ROS production, and proteins involved in trafficking. The observed root-specific attenuation in stress-response mechanisms, including the biosynthesis of jasmonates, ethylene and polyamines, and an accumulation of serotonin, provided the first insight into molecular mechanisms behind this particular biotic interaction.


Assuntos
Hordeum/microbiologia , Peptídeos/metabolismo , Phytophthora infestans/isolamento & purificação , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Solanum tuberosum/microbiologia , Cromatografia Líquida , Hordeum/enzimologia , Hordeum/metabolismo , Espectrometria de Massas , Redes e Vias Metabólicas , Phytophthora infestans/genética , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Reação em Cadeia da Polimerase , Proteômica , Espécies Reativas de Oxigênio/metabolismo , Solanum tuberosum/metabolismo , Estresse Fisiológico
3.
Opt Lett ; 42(18): 3566-3569, 2017 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-28914903

RESUMO

A silicon nitride waveguide is a promising platform for integrated photonics, particularly due to its low propagation loss compared to other complementary metal-oxide-semiconductor compatible waveguides, including silicon-on-insulator. Input/output coupling in such thin optical waveguides is a key issue for practical implementations. Fiber-to-chip grating couplers in silicon nitride usually exhibit low coupling efficiency because the moderate index contrast leads to weak radiation strengths and poor directionality. Here, we present the first, to the best of our knowledge, experimental demonstration of a recently proposed apodized-imaging fiber-to-chip grating coupler in silicon nitride that images an in-plane waveguide mode to an optical fiber placed at a specific distance above the chip. By employing amplitude and phase apodization, the diffracted optical field of the grating is matched to the fiber mode. High grating directionality is achieved by using staircase grating teeth, which produce a blazing effect. Experimental results demonstrate an apodized-imaging grating coupler with a record coupling efficiency of -1.5 dB and a 3 dB bandwidth of 60 nm in the C-band.

4.
Psiquiatr. biol. (Internet) ; 23(2): 60-66, mayo-ago. 2016. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-153657

RESUMO

En general, los diferentes tratados de farmacología se organizan en torno a una clasificación anatómica-terapéutica-química. Los tratados de «química farmacéutica» suelen organizarse, además, poniendo énfasis en la naturaleza química de los fármacos, así como en los procesos bioquímicos involucrados en su acción. En otras ocasiones, cuando se contempla la fitoterapia desde un punto de vista botánico, como hace la «botánica medicinal», la exposición se realiza mediante un viaje a través de los diferentes taxones que contienen especies con relevancia terapéutica. En cambio, en este artículo de revisión se va a hablar de un grupo de fármacos que, desde los enfoques expositivos anteriores, no tienen mucho que ver pero que, sin embargo, poseen mecanismos farmacodinámicos muy similares, a pesar de que actúen sobre diferentes receptores. Se trata de los agonistas (y antagonistas) parciales. Lógicamente no se revisarán todos en este artículo, sino aquellos que al autor le han parecido más curiosos e interesantes para ilustrar su relación mutua en cuanto al funcionamiento farmacodinámico: vareniclina, buprenorfina, diazepinonas, aripiprazol, memantina. Este es el objetivo de este artículo: la revisión de un grupo de fármacos desde un punto de vista novedoso, como es su mecanismo de acción farmacodinámico común. Entre las conclusiones, está la indicación de este tipo de fármacos cuando se va a intervenir en sistemas bioquímicos y fisiológicos tan complicados que las funciones a tratar no deben ni inhibirse ni potenciarse desmedidamente, sino simplemente modularse. Este es el caso de muchas dolencias que afectan al sistema nervioso (AU)


In general the different treatises of pharmacology are organised around an anatomical-therapeutic-chemical classification. Treatises about «medicinal chemistry» are organised, not only around this, but also emphasise the chemical nature of the drugs, as well as the biochemical processes involved in their action. Furthermore, when herbal medicine is contemplated from a botanical point of view, as does the «medical botany», exposure is performed by a journey through the different taxa containing species with therapeutic relevance. Nevertheless, in this review article a group of drugs is discussed that, from the previous points of view, do not have anything to do with each other. However, they have very similar pharmacodynamic mechanisms, despite acting on different receptors. These are partial agonists (and antagonists). Obviously not all of these will be reviewed in this article, but those more interesting to illustrate their relationship in terms of pharmacodynamic performance: varenicline, buprenorphine, diazepinones, aripiprazole, memantine. This is the purpose of this article: A review of a group of drugs from a novel point of view, such as their common pharmacodynamic mechanism of action. Among the conclusions, is the indication of these drugs to intervene in such complicated biochemical and physiological systems that functions to be treated should neither be inhibited nor enhanced, but simply modulated. This is the case of many diseases that affect the nervous system (AU)


Assuntos
Humanos , Masculino , Feminino , Tratamento Farmacológico/tendências , Buprenorfina/farmacologia , Buprenorfina/uso terapêutico , Vareniclina/farmacologia , Vareniclina/farmacocinética , Vareniclina/uso terapêutico , Aripiprazol/uso terapêutico , Memantina/uso terapêutico , Farmacologia/métodos , Memantina/química , Preparações Farmacêuticas/metabolismo , Analgésicos Opioides/farmacologia , Antagonistas de Entorpecentes/farmacologia , Vômito/tratamento farmacológico
5.
Anal Bioanal Chem ; 408(26): 7321-7, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27236313

RESUMO

A novel label-free electrochemical strategy for nucleic acid detection was developed by using gold electrodes coated with mesoporous silica thin films as sensing interface. The biosensing approach relies on the covalent attachment of a capture DNA probe on the surface of the silica nanopores and further hybridization with its complementary target oligonucleotide sequence, causing a diffusion hindering of an Fe(CN)6 (3-/4-) electrochemical probe through the nanochannels of the mesoporous film. This DNA-mesoporous silica thin film-modified electrodes allowed sensitive (91.7 A/M) and rapid (45 min) detection of low nanomolar levels of synthetic target DNA (25 fmol) and were successfully employed to quantify the endogenous content of Escherichia coli 16S ribosomal RNA (rRNA) directly in raw bacterial lysate samples without isolation or purification steps. Moreover, the 1-month stability demonstrated by these biosensing devices enables their advanced preparation and storage, as desired for practical real-life applications. Graphical abstract Mesoporous silica thin films as scaffolds for the development of novel label-free electrochemical genosensors to perform selective, sensitive and rapid detection of target oligonucleotide sequences. Application towards E. coli determination.


Assuntos
Técnicas Eletroquímicas/métodos , Escherichia coli/genética , Ácidos Nucleicos Imobilizados/química , Hibridização de Ácido Nucleico/métodos , RNA Bacteriano/análise , RNA Ribossômico/análise , Dióxido de Silício/química , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , DNA/análise , DNA/genética , Técnicas Eletroquímicas/instrumentação , Eletrodos , Desenho de Equipamento , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Humanos , Ácidos Nucleicos Imobilizados/genética , Porosidade , RNA Bacteriano/genética , RNA Ribossômico/genética
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