62 research outputs found
High-throughput gene-expression quantification of grapevine defense responses in the field using microfluidic dynamic arrays
Background The fight against grapevine diseases due to biotrophic pathogens usually requires the massive use of chemical fungicides with harmful environmental effects. An alternative strategy could be the use of compounds able to stimulate plant immune responses which significantly limit the development of pathogens in laboratory conditions. However, the efficiency of this strategy in natura is still insufficient to be included in pest management programs. To understand and to improve the mode of action of plant defense stimulators in the field, it is essential to develop reliable tools that describe the resistance status of the plant upon treatment.[br/][br/]
Results We have developed a pioneering tool (âNeoViGen96â chip) based on a microfluidic dynamic array platform allowing the expression profiling of 85 defense-related grapevine genes in 90 cDNA preparations in a 4 h single run. Two defense inducers, benzothiadiazole (BTH) and fosetyl-aluminum (FOS), have been tested in natura using the âNeoViGen96â chip as well as their efficacy against downy mildew.[br/]
BTH-induced grapevine resistance is accompanied by the induction of PR protein genes (PR1, PR2 and PR3), genes coding key enzymes in the phenylpropanoid pathway (PAL and STS), a GST gene coding an enzyme involved in the redox status and an ACC gene involved in the ethylene pathway.[br/]
FOS, a phosphonate known to possess a toxic activity against pathogens and an inducing effect on defense genes provided a better grapevine protection than BTH. Its mode of action was probably strictly due to its fungicide effect at high concentrations because treatment did not induce significant change in the expression level of selected defense-related genes.[br/]
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Conclusions The NeoViGen96â chip assesses the effectiveness of plant defense inducers on grapevine in vineyard with an excellent reproducibility. A single run with this system (4 h and 1,500 âŹ), corresponds to 180 qPCR plates with conventional Q-PCR assays (Stragene system, 270 h and 9,000 âŹ) thus a throughput 60â70 times higher and 6 times cheaper. Grapevine responses after BTH elicitation in the vineyard were similar to those obtained in laboratory conditions, whereas our results suggest that the protective effect of FOS against downy mildew in the vineyard was only due to its fungicide activity since no activity on plant defense genes was observed. This tool provides better understanding of how the grapevine replies to elicitation in its natural environment and how the elicitor potential can be used to reduce chemical fungicide inputs
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Glucose inhibits cardiac muscle maturation through nucleotide biosynthesis.
The heart switches its energy substrate from glucose to fatty acids at birth, and maternal hyperglycemia is associated with congenital heart disease. However, little is known about how blood glucose impacts heart formation. Using a chemically defined human pluripotent stem-cell-derived cardiomyocyte differentiation system, we found that high glucose inhibits the maturation of cardiomyocytes at genetic, structural, metabolic, electrophysiological, and biomechanical levels by promoting nucleotide biosynthesis through the pentose phosphate pathway. Blood glucose level in embryos is stable in utero during normal pregnancy, but glucose uptake by fetal cardiac tissue is drastically reduced in late gestational stages. In a murine model of diabetic pregnancy, fetal hearts showed cardiomyopathy with increased mitotic activity and decreased maturity. These data suggest that high glucose suppresses cardiac maturation, providing a possible mechanistic basis for congenital heart disease in diabetic pregnancy
Conceiving of addicted pleasures: A âmodernâ paradox
Drawing on research with people who inject drugs in London, UK, this article will explore how participants conceived of pleasure, and try to understand some of the tensions that ensued. There is a strong sense in participantsâ accounts that drug use is at points pleasurable but it should not, or rather, could not be conceived of in this way. As such, the article will reflect on several situations in which pleasure came up during fieldwork but was quickly redirected towards addiction using terms such as âdenialâ. Trying to make sense of this seemingly paradoxical dynamic, in which pleasure can be addictive, but addiction cannot be pleasurable, I turn to some of the practices that actively keep pleasure and addiction apart, indeed, in some areas of the addiction sciences, antithetical. That is, a singular account of pleasure is produced as freely chosen (of the âfreeâ subject) in opposition to the determined nature of addiction (of the automated brain or object). These realities materialise in participantsâ accounts, but due to their constructed nature they also collapse and multiply. This âhybridisationâ is what Bruno Latour refers to as the paradox of the Moderns. Considering pleasure, however, as both natural and cultural, it is better conceived of as always in tension, expressed by participants as âmixed feelingsâ, âlove/hateâ, âsweet and sourâ, âgood things and bad thingsâ. Against a backdrop of neglect, especially within the context of injecting drug use, such conceptualisation can help acknowledge pleasure where it is least conceivable and yet perhaps has the most to offer
Expression quantitative de l'évolution du nombre de boutons floraux et de baies du débourrement à la vendange chez deux cultivars de <em>Vitis vinifera</em> L., le Grenache et le Carignan
Les chutes de boutons floraux, nulles jusqu'Ă la floraison, sont beaucoup plus importantes chez le Grenache (76 pour cent), cultivar reconnu sensible Ă la coulure et dont les grappes portent un plus grand nombre de fleurs, que chez le Carignan (56 pour cent). Les pertes se situent essentiellement entre le 5e et le 10e jours aprĂšs l'anthĂšse chez le Grenache, le 5e et le 15e jours chez le Carignan.
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The falling of flower buds (not until blossoming times) is much more important with the Grenache (16 per cent) cultivar that is recognized more for the grapes carried and the greater number of flowers formed than the Carignan (56 per cent) cultivar. This loss occurs essentially between the fifth and tenth days after the « anthÚse » with the Grenache variety and between the fifth and fifteenth days with the Carignan variety
Study of a Streptomyces sp. derived signals and their plant perception mechanisms
International audienc
Du Terrain pour l'aventure : pratique anti-autoritaire de l'animation des loisirs en milieu urbain
Metabolomics Profile of the Secretome of Space-Flown Oligodendrocytes
Intracranial hypertension (ICP) and visual impairment intracranial pressure (VIIP) are some of the sequels of long-term space missions. Here we sought to determine how space microgravity (”G) impacts the metabolomics profile of oligodendrocyte progenitors (OLPs), the myelin-forming cells in the central nervous system. We report increased glutamate and energy metabolism while the OLPs were in space for 26 days. We also show that after space flight, OLPs (SPC OLPs) display significantly increased mitochondrial respiration and glycolysis. These data are in agreement with our previous work using simulated microgravity. In addition, our global metabolomics approach allowed for the discovery of endogenous metabolites secreted by OLPs while in space that are significantly modulated by microgravity. Our results provide, for the first time, relevant information about the energetic state of OLPs while in space and after space flight. The functional and molecular relevance of these specific pathways are promising targets for therapeutic intervention for humans in long-term space missions to the moon, Mars and beyond
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Metabolomics Profile of the Secretome of Space-Flown Oligodendrocytes.
Intracranial hypertension (ICP) and visual impairment intracranial pressure (VIIP) are some of the sequels of long-term space missions. Here we sought to determine how space microgravity (”G) impacts the metabolomics profile of oligodendrocyte progenitors (OLPs), the myelin-forming cells in the central nervous system. We report increased glutamate and energy metabolism while the OLPs were in space for 26 days. We also show that after space flight, OLPs (SPC OLPs) display significantly increased mitochondrial respiration and glycolysis. These data are in agreement with our previous work using simulated microgravity. In addition, our global metabolomics approach allowed for the discovery of endogenous metabolites secreted by OLPs while in space that are significantly modulated by microgravity. Our results provide, for the first time, relevant information about the energetic state of OLPs while in space and after space flight. The functional and molecular relevance of these specific pathways are promising targets for therapeutic intervention for humans in long-term space missions to the moon, Mars and beyond
Silicon oxide deposition from cold remote plasma on polyethylene powders in fluidized bed
In this work, a fluidized bed has been coupled to a far cold remote nitrogen/oxygen plasma to deposit silicon oxide SiOx from silane SiH4 on the surface of a polyethylene powder. The influence on the characteristics of the silica-like deposit on powders, of several parameters such as the amount of oxygen injected in the plasma, the SiH4 flow rate and the treatment duration, has been studied. First, the particles wettability has been measured by contact angle (Washburn method), knowing that PE is hydrophobic and that silicon oxide would increase its hydrophilicity. The film chemical composition has been analysed by FT-IR spectroscopy. Its organization on the powder surface and its morphology have been studied by FEG SEM. Results indicate that the wettability of powders increases with the whole parameters studied. Deposition seems to occur under the form of nodules; its continuity is not ascertained. This is the reason why the increase of wettability could be due either to a better surface coverage of the deposition or to an increase of its thickness. Additional analyses are in progress to better understand the correlations between the deposition parameters, the plasma features and the deposition characteristics
Nitrogen post-discharge assisted deposition from silane on polymer powders in a fluidized bed
Nowadays, powders represent about 75% of raw materials used in the industry. One of their main characteristics
is their high surface to volume ratio. Therefore, modifying their surface properties is a great scientific and industrial
challenge. In this work, a nitrogen/oxygen post-discharge is used to deposit silicon oxide from silane on polyethylene
powders in a fluidized bed
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