The potential relationship of stilbene (resveratrol) synthesis to anthocyanin content in grape berry skins

The relationship between the production of resveratrol, a phytoalexin related to grape disease resistance, and the anthocyanin content of grape berries in diverse Vitis species has been investigated. Previous studies have reported that the phytoalexin production potential of grapes suddenly declines at veraison. The results obtained here from assaying resveratrol and anthocyanins from grape berries in different developmental stages suggest that chalcone synthase (EC 2.3.1.74), the key enzyme involved in anthocyanin biosynthesis, may compete with stilbene (resveratrol) synthase (EC 2.3.1.-), such that the decrease of the ability of grapes to synthesize resveratrol in response to UV-irradiation observed after the onset of fruit ripening may be a consequence of the concomitant rise of anthocyanin accumulation in fruits

On the importance of 3D stress state in 2D earthquake rupture simulations with off-fault deformation

During the last decades, many numerical models have been developed to investigate the conditions for seismic and aseismic slip. Those models explore the behavior of frictional faults, embedded in either elastic or inelastic mediums, and submitted to a far field loading (seismic cycle models), or initial stresses (single dynamic rupture models). Those initial conditions impact both on-fault and off-fault dynamics. Because of the sparsity of direct measurements of fault stresses, modelers have to make assumptions about these initial conditions. To this day, Anderson's theory is the only framework that can be used to link fault generation and reactivation to the three-dimensional stress field. In this work we look at the role of the three dimensional stress field in modelling a 2D strike-slip fault under plane-strain conditions. We show that setting up the incorrect initial stress field, based on Anderson's theory, can lead to underestimation of the damage zone width by up to a factor of six, for the studied cases. Moreover, because of the interactions between fault slip and off-fault deformation, initial stress field influences the rupture propagation. Our study emphasizes the need to set up the correct initial 3D stress field, even in 2D numerical simulations

Endogenous polyamine concentrations in juvenile, adult and micropropagated grapevine (Vitis vinifera L. cv. Pinot noir)

Research Not

Metabolic Engineering of Yeast and Plants for the Production of the Biologically Active Hydroxystilbene, Resveratrol

Resveratrol, a stilbenic compound deriving from the phenyalanine/polymalonate route, being stilbene synthase the last and key enzyme of this pathway, recently has become the focus of a number of studies in medicine and plant physiology. Increased demand for this molecule for nutraceutical, cosmetic and possibly pharmaceutic uses, makes its production a necessity. In this context, the use of biotechnology through recombinant microorganisms and plants is particularly promising. Interesting results can indeed arise from the potential of genetically modified microorganisms as an alternative mechanism for producing resveratrol. Strategies used to tailoring yeast as they do not possess the genes that encode for the resveratrol pathway, will be described. On the other hand, most interest has centered in recent years, on STS gene transfer experiments from various origins to the genome of numerous plants. This work also presents a comprehensive review on plant molecular engineering with the STS gene, resulting in disease resistance against microorganisms and the enhancement of the antioxidant activities of several fruits in transgenic lines

Resveratrol content of two Californian table grape cultivars

Research Note

Radioprotection opérationnelle pour la réalisation des scintigraphies myocardiques aux Hôpitaux Universitaires de Genève: travail de Bachelor

Les maladies cardiovasculaires représentent aujourd'hui la première cause de décès dans les pays développés dont la Suisse. Ces maladies sont caractérisées par une atteinte du cœur ainsi que des vaisseaux de l'organisme et plus particulièrement des artères coronaires qui nourrissent le muscle cardiaque, le myocarde. Ce sont principalement des maladies qui évoluent dans le temps, leurs fréquences augmentent avec certains facteurs de risques comme l'âge, le mode de vie telle que la sédentarité, le tabac, l'alcool, le diabète, l'obésité, l'hypertension ou encore le taux de cholestérol. D'autres facteurs peuvent impliquer cette maladie comme les antécédents familiaux ou le sexe. La maladie coronarienne est l'une des maladies cardio-vasculaires les plus fréquentes. Elle correspond à un rétrécissement ou une obstruction des artères coronaires, telles que des parties du cœur ne reçoivent plus ou pas assez de sang. Ceci peut entraîner l'angine de poitrine, un infarctus du myocarde, ou encore un arrêt cardio-circulatoire. En suisse, le risque d'en être atteint est de 23% chez les hommes et de 18% chez les femmes. Elle représente donc un défi et un enjeu majeur de santé publique. Diverses techniques d'imageries peuvent être réalisées afin de diagnostiquer la maladie, définir son extension, faire un choix de traitement et réaliser un suivi des patients. La scintigraphie du myocarde est l'un des principaux examens réalisés dans le cadre du diagnostic de l'infarctus. Cette technique d'imagerie médicale de médecine nucléaire consiste à utiliser un produit radioactif afin d'évaluer le fonctionnement du myocarde. L'utilisation de la radioactivité implique un principe de radioprotection pour les patients, le personnel soignant mais aussi de l'environnement de soin, c'est à dire la zone de réalisation de l'examen et plus précisément, le service de cardiologie des HUG dans le cadre de notre étude. Il devient alors primordial de réaliser des contrôles, des mesures ainsi qu'une interprétation pointilleuse des résultats obtenus

Large-scale proteomic analysis of the grapevine leaf apoplastic fluid reveals mainly stress-related proteins and cell wall modifying enzymes

BACKGROUND: The extracellular space or apoplast forms a path through the whole plant and acts as an interface with the environment. The apoplast is composed of plant cell wall and space within which apoplastic fluid provides a means of delivering molecules and facilitates intercellular communications. However, the apoplastic fluid extraction from in planta systems remains challenging and this is particularly true for grapevine (Vitis vinifera L.), a worldwide-cultivated fruit plant. Large-scale proteomic analysis reveals the protein content of the grapevine leaf apoplastic fluid and the free interactive proteome map considerably facilitates the study of the grapevine proteome. RESULTS: To obtain a snapshot of the grapevine apoplastic fluid proteome, a vacuum-infiltration-centrifugation method was optimized to collect the apoplastic fluid from non-challenged grapevine leaves. Soluble apoplastic protein patterns were then compared to whole leaf soluble protein profiles by 2D-PAGE analyses. Subsequent MALDI-TOF/TOF mass spectrometry of tryptically digested protein spots was used to identify proteins. This large-scale proteomic analysis established a well-defined proteomic map of whole leaf and leaf apoplastic soluble proteins, with 223 and 177 analyzed spots, respectively. All data arising from proteomic, MS and MS/MS analyses were deposited in the public database world-2DPAGE. Prediction tools revealed a high proportion of (i) classical secreted proteins but also of non-classical secreted proteins namely Leaderless Secreted Proteins (LSPs) in the apoplastic protein content and (ii) proteins potentially involved in stress reactions and/or in cell wall metabolism. CONCLUSIONS: This approach provides free online interactive reference maps annotating a large number of soluble proteins of the whole leaf and the apoplastic fluid of grapevine leaf. To our knowledge, this is the first detailed proteome study of grapevine apoplastic fluid providing a comprehensive overview of the most abundant proteins present in the apoplast of grapevine leaf that could be further characterized in order to elucidate their physiological function

Evaluation of Hungarian Wines for Resveratrol by Overpressured Layer Chromatography

A method, including solid phase extraction sample preparation, overpressured layer chromatographic separation and subsequent densitometric evaluation, was developed for measurement of total resveratrol (cis- and trans-isomers) content of wine. The amount of resveratrol was determined in wine samples from different winemaking regions of Hungary. The total resveratrol was high in Hungarian red wines (3.6–11 mg/L), and much lower in white ones (0.04–1.5 mg/L)

Use of grapevine cell cultures for the production of phytostilbenes of cosmetic interest

AbstractPlant cell cultures constitute pesticide-free sources for obtaining plant secondary metabolites or plant extracts. Additionally, they do not contain any fungal contaminants, mycotoxins or heavy metals providing to the consumer potential health benefits and justifying the development of this technology at an industrial scale. Significant production levels of these secondary metabolites can be obtained through the use of elicitors, which activate plant defense mechanisms. Resveratrol, a well-known grapevine polyphenolic compound which possesses potent antioxidant and antiaging activities as well as a protective action on skin, is a good example of such plant secondary metabolites. Resveratrol and its oligomeric derivatives are used by several companies of cosmetic products but their extraction from vine stems and similar vegetal sources remains difficult. Therefore grapevine cell suspensions could represent interesting systems for the large-scale bioproduction of those compounds. Here we present an update of the methods used for the production of phytostilbenes by using grapevine cell cultures and the results obtained

Quantifying sediment mass redistribution from joint time-lapse gravimetry and photogrammetry surveys

The accurate quantification of sediment mass redistribution is central to the study of surface processes, yet it remains a challenging task. Here we test a new combination of terrestrial gravity and drone photogrammetry methods to quantify sediment mass redistribution over a 1 km2 area. Gravity and photogrammetry are complementary methods. Indeed, gravity changes are sensitive to mass changes and to their location. Thus, by using photogrammetry data to constrain this location, the sediment mass can be properly estimated from the gravity data. We carried out three joint gravimetry–photogrammetry surveys, once a year in 2015, 2016 and 2017, over a 1 km^2 area in southern Taiwan, featuring both a wide meander of the Laonong River and a slow landslide. We first removed the gravity changes from non-sediment effects, such as tides, groundwater, surface displacements and air pressure variations. Then, we inverted the density of the sediment with an attempt to distinguish the density of the landslide from the density of the river sediments. We eventually estimate an average loss of 3.7 \ub1 0.4  7 10^9 kg of sediment from 2015 to 2017 mostly due to the slow landslide. Although the gravity devices used in this study are expensive and need week-long surveys, new instrumentation currently being developed will enable dense and continuous measurements at lower cost, making the method that has been developed and tested in this study well-suited for the estimation of erosion, sediment transfer and deposition in landscapes