Search results for "Maladie"
showing 10 items of 135 documents
The bacterial microbiome of meloidogyne-based disease complex in coffee and tomato
2020
The Meloidogyne-based disease complexes (MDCs) are caused by the interaction of different root-knot nematode species and phytopathogenic fungi. These complexes are devastating several important crops worldwide including tomato and coffee. Despite their relevance, little is known about the role of the bacterial communities in the MDCs. In this study 16s rDNA gene sequencing was used to analyze the bacterial microbiome associated with healthy and infested roots, as well with females and eggs of Meloidogyne enterolobii and M. paranaensis, the causal agents of MDC in tomato and coffee, respectively. Each MDC pathosystems displayed a specific taxonomic diversity and relative abundances constitut…
The rhizosphere of mycorrhizal plants
2002
Providing that appropriate carbon substrates are available, microbial communities are able to develop a range of activities which are crucial in maintaining a biological balance in soil (Bowen and Rovira 1999), a key issue for the sustainability of either natural ecosystems or agroecosystems (Kennedy and Smith 1995). Soil-borne microbes have a particular microhabitat in which to flourish. In particular, they are bound to the surface of soil particles or found in soil aggregates, while others interact specifically with the plant root system (Glick 1995). The root-soil interface is actually a dynamic changing environment, a microcosm where microorganisms, plant roots and soil constituents int…
Use of sewage sludge compost and Trichoderma asperellum isolates to supress Fusarium wilt of tomato
2002
It has been reported that plant growth media amended with composted bark suppress Fusarium wilts whereas media amended with composted municipal sludge aggravate this disease. However, in this study, a compost prepared from vegetable and animal market wastes, sewage sludge and yard wastes showed a high ability to suppress Fusarium wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici race 1. The ability of this compost to suppress Fusarium wilt of tomato was compared with that of a peat mix (peat:vermiculite, 1:1 v/v) and a naturally suppressive soil from Chateaurenard, France. The compost and the soil from Chateaurenard were highly suppressive, whereas the peat mix was highly condu…
Multilocus sequence typing confirms the close genetic inter-relatedness between three distinct flavescence doree phytoplasma strain clusters and grou…
2007
ABSTRACT Vineyards of southern France and northern Italy are affected by the flavescence dorée (FD) phytoplasma, a quarantine pathogen transmitted by the leafhopper of Nearctic origin Scaphoideus titanus . To better trace propagation of FD strains and identify possible passage between the vineyard and wild plant compartments, molecular typing of phytoplasma strains was applied. The sequences of the two genetic loci map and uvrB - degV , along with the sequence of the secY gene, were determined among a collection of FD and FD-related phytoplasmas infecting grapevine, alder, elm, blackberry, and Spanish broom in Europe. Sequence comparisons and phylogenetic analyses consistently indicated the…
Impact of vector dispersal and host-plant fidelity on the dissemination of an emerging plant pathogen
2012
International audience; Dissemination of vector-transmitted pathogens depend on the survival and dispersal of the vector and the vector's ability to transmit the pathogen, while the host range of vector and pathogen determine the breath of transmission possibilities. In this study, we address how the interaction between dispersal and plant fidelities of a pathogen (stolbur phytoplasma tuf-a) and its vector (Hyalesthes obsoletus: Cixiidae) affect the emergence of the pathogen. Using genetic markers, we analysed the geographic origin and range expansion of both organisms in Western Europe and, specifically, whether the pathogen's dissemination in the northern range is caused by resident vecto…
Pseudomonas salomonii sp. nov., pathogenic on garlic, and Pseudomonas palleroniara sp. nov., isolated from rice
2002
International audience; A total of 26 strains, including 15 strains isolated from garlic plants with the typical symptoms of 'Café au lait' disease and 11 strains isolated from diseased or healthy rice seeds and sheaths infested by Pseudomonas fuscovaginae, were compared with 70 type or reference strains of oxidase-positive pathogenic or non-pathogenic fluorescent pseudomonads. The strains were characterized by using a polyphasic taxonomic approach. Numerical taxonomy of phenotypic characteristics showed that the garlic and rice strains were related to each other. However, they clustered into separate phenons, distinct from those of the other strains tested, and were different in several nu…
Le jugement d’oubli dans la maladie d’Alzheimer
2017
International audience; IntroductionAvez-vous déjà eu l’impression d’oublier quelque chose ? Le sentiment d’oubli est très commun dans la vie quotidienne mais a été très peu étudié expérimentalement.ObjectifsL’objectif de cette étude est d’évaluer les jugements d’oubli sur des tâches de mémoire sémantique et épisodique dans le vieillissement normal et dans la maladie d’Alzheimer.Patients et méthodesCinquante jeunes adultes, 35 personnes âgées et 33 patients Alzheimer ont été testés. Les participants effectuaient soit des jugements d’oubli, soit des jugements de rappel sur 2 tâches de mémoire. Pour la tâche de mémoire sémantique, les participants devaient rappeler toutes les régions de Franc…
Low level activity thresholds for changes in NMR biomarkers and genes in high risk subjects for type 2 diabetes
2017
AbstractOur objectives were to determine if there are quantitative associations between amounts and intensities of physical activities (PA) on NMR biomarkers and changes in skeletal muscle gene expressions in subjects with high risk for type 2 diabetes (T2D) performing a 3-month PA intervention. We found that PA was associated with beneficial biomarker changes in a factor containing several VLDL and HDL subclasses and lipids in principal component analysis (P = <0.01). Division of PA into quartiles demonstrated significant changes in NMR biomarkers in the 2nd - 4th quartiles compared to the 1st quartile representing PA of less than 2850 daily steps (P = 0.0036). Mediation analysis of PA-…
Interactions between immune challenges and cancer cells proliferation: timing does matter!
2015
Using first a theoretical framework, we show that repeated short immune challenges could impact the accumulation of cancerous cells through continuous perturbation of immune system efficiency. We discuss for a new indirect role for infectious disease in cancer progression.
Ortervirales: New Virus Order Unifying Five Families of Reverse-Transcribing Viruses
2018
International audience; Reverse-transcribing viruses, which synthesize a copy of genomic DNA from an RNA template, are widespread in animals, plants, algae, and fungi (1, 2). This broad distribution suggests the ancient origin(s) of these viruses, possibly [...]