Search results for "Tabac"
showing 10 items of 131 documents
Orobanche rameuse du tabac (Phelipanche ramosa L.) : Identifier de nouvelles solutions conventionnelles et de biocontrôle
2019
The branching broomrape, Phelipanche ramosa L. is an obligate parasitic plant, which in a few years became a major agronomic problem for tobacco crops in France. Two approaches, aiming at controlling broomrape were tested within the framework of the ELIOT project grouping Arvalis, the CT2F cooperative and the INRA center of Dijon. The first relates to sulfonylurea herbicides, including rimsulfuron and sulfosulfuron and a systemic herbicide of the cyclohexanediones family, clethodim. The results, although instructive, do not reflect an effective control of broomrape. The second approach deals with the search for soil-borne fungi that are pathogenic to broomrape. A large number of fungal stra…
Rôle de la Dynamique Membranaire dans la Mise en Place des Mécanismes de Défense chez le Tabac
2011
Cryptogein, a protein secreted by the oomycete Phytophthora cryptogea, induces defense mechanisms in tobacco. Several proteins involved in the associated signaling pathway were identified and localized on the plasma membrane (PM). A fraction resistant to solubilization by detergent named DIMs for Detergent Insoluble Membranes, enriched in sterols an sphigolipids had been isolated from tobacco PM. It was proved to contain proteins previously identified as actors of the signaling cascade triggered by cryptogein. In animal cells, the dynamic association of proteins to sterol and sphingolipid rich microdomains under the influence of a biological stimulus plays an essential role in the regulatio…
Rôle de la dynamique de la membrane plasmique dans la mise en place des réactions de défense chez le tabac
2007
National audience; Lors des interactions entre les plantes et les microorganismes, des molécules spécifiques élicitent les réponses de défense des cellules végétales. La cryptogéine, une élicitine produite par l’oomycète Phytophtora cryptogea, induit une réponse hypersensible (HR) et une résistance non systémique chez le tabac (1). Aussi bien sur plante entière que sur suspension cellulaire, la reconnaissance au niveau de la membrane plasmique et la fixation de cet éliciteur par un récepteur non identifié déclenche une cascade d’événements au niveau de la membrane plasmique comme un influx rapide de calcium, des efflux d’ions, une alcalinisation extracellulaire. De plus, une NADPH oxydase, …
Membrane dynamics of sugar transports in tobacco-microbe interactions
2017
SPEINRAUBIPM DOCT; Plants can influence microorganism population through exudation of sugars notably as carbon source. Indeed, the type of plant-microorganism interaction (PMI) is linked to the trophic exchanges between plant and microorganism. Microorganisms are thus able to “manipulate” the host to modify sugar fluxes. In mycorrhizal symbiosis, the plant has a supply of nutrients by the fungal partner, which in return receives sugars. In pathogenic relationship, the microorganism will divert sugars provided by the plant without compensation. Despite identification of sugar transporters at biotrophic interfaces, molecular and cellular mechanisms by which microorganisms operate the distribu…
Calcium signaling in plant defense: involvement of subcellular compartments and glutamate receptorsCalcium signaling in plant defense: involvement of…
2012
Réponses des cellules de Nicotiana tabacum à des molécules microbiennes : évènements de signalisation précoce, influence de la dynamique membranaire …
2018
Responses of Nicotiana tabacum cells to microbial molecule treatments: early signaling events,influence of membrane dynamics, and sugar fluxesIn their natural environment plants are in close interaction with beneficial, neutral, or pathogenicmicrobes, which are highly dependent on carbon resources exuded by plant roots. Sugar transport, which isa key process of plant physiology, is essential to support the fate of plant-microbe interactions. Duringevolution, plants have acquired the ability to perceive microbial molecules, initiating specific signaltransduction cascades and leading to adapted response for microbe lifestyles (avirulent, virulent, or benefic).Plant survival will depend on the…
External and internal elimination of supernumerary larvae in the whitefly parasitoid Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae)
2008
Abstract The solitary parasitoid Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) is one of the key biological control agents of the whitefly Bemisia argentifolii Bellows & Perring, also known as B. tabaci (Gennadius) B-biotype (Homoptera: Aleyrodidae). We present new information on its biology, and particularly about larval elimination during the first instar in cases of superparasitism. For the first time, physical elimination of supernumerary larvae was observed, both outside and inside the host. These findings are documented with confocal microscopy images and video recordings. We observed more than 350 B. argentifolii nymphs, parasitized with one, two or more than two larvae. Physi…
Globularia nudicaulis, a new host of Cucumber mosaic virus
2006
) is a perennial, foundnaturally on European mountains at altitudes between 900 and 2000 m.In June 2004, G. nudicaulis plants, with a yellow mosaic and/or variega-tion on malformed leaves, were noted among plant species cultivated in theBotanical Garden at Bologna University, Italy. No elongated virus-likeparticles were observed in affected-leaf extracts by transmission electronmicroscopy using a leaf dip method. By applying a protein A sandwichenzyme-linked immunosorbent assay (PAS-ELISA) technique ( Edwards Csystemic symptoms were observed in Nicotiana tabacum , N. benthamiana ,N. glutinosa, N. clevelandii and Capsicum annuum, and Cucumis sativusand C. melo. Reverse transcription-polymera…
Changes in the density of microtubular networks in mesophyll cells and mesophyll derived protoplasts of Nicotiana and Triticum during leaf development
1993
Changes in the density of microtubular mesh-works were analysed in mesophyll cells and mesophyll derived protoplasts of Nicotiana tabacum L. and Triticum aestivum L. during leaf development. The main purpose of this study was to test whether the low density, if not lack, of microtubular networks recently described in protoplasts that had been isolated from fully differentiated mesophyll cells happened during protoplast isolation or whether the loss of microtubules actually occurred during differentiation of the leaf tissue. Immunofluorescence microscopy showed that the density of the microtubular cytoskeleton in the leaf tissue decreased steadily after cessation of cell growth in both speci…
Desarrollo de métodos analíticos para evaluar la efectividad de cosméticos antipolución
2021
La contaminación ambiental es un problema tanto local como global de gran importancia en la actualidad. En concreto, la contaminación urbana es uno de los principales peligros para la salud humana, y en especial para la salud de la piel, lo que ha provocado un incremento de la concienciación y la preocupación con respecto a los niveles de contaminación en aire. La aparición de cosméticos antipolución, destinados a combatir estos efectos negativos sobre la salud humana, es el resultado de dicha preocupación. Sin embargo, el desarrollo de metodologías analíticas adecuadas para la evaluación de su efectividad es un gran desafío. Por ello, la presente Tesis se centra en el desarrollo de métodos…