Search results for "RARA"

DRADEM campaign - 2016 July - Scientific report

2016

The DRADEM campaign was performed from July 9th to 21th 2016 on board the Pourquoi Pas?, in the Exclusive Economic Zones of Suriname and French Guyana. This campaign belongs to a program dedicated to geological investigations of the Demerara plateau, following the GUYAPLAC (2003) and IGUANES (2013) campaigns, and before the MARGATS campaign (2016). The aims of the DRADEM campaign were to map the continental slope of the transform margin north of the Demerara plateau, and to dredge the rocks outcropping in the slope.We completed the bathymetric mapping of the continental slope, including part of the edged of the Demerara plateau. These new bathymetric data confirm the segmentation of the tra…

Campagne DRADEM – Juillet 2016 - Rapport scientifique

2016

La campagne DRADEM s’est déroulée du 9 au 21 Juillet 2016 à bord du Pourquoi Pas ?, dans les zones économique exclusives du Suriname et de la Guyane. Cette campagne s’inscrit dans un programme d’étude géologique du plateau de Demerara, dans la suite des campagnes GUYAPLAC (2003), IGUANES (2013), et avant MARGATS (2016). Les objectifs de la campagne DRADEM étaient de cartographier la pente continentale de la marge transformante bordant au Nord le Plateau de Demerara, et d’échantillonner par dragage les roches qui y affleurent.La bathymétrie de la totalité de la pente continentale et une partie de la bordure du plateau ont été cartographiées, confirmant la segmentation de cette m…

Characterization of Pea (Pisum Sativum L.) genes implicated in arbuscular mycorrhiza formation and function

2010

The arbuscular mycorrhizal (AM) association results from a successful interaction between the genomes of the two symbiotic partners. In this context, the aim of my research was to better characterize the role of the late stage symbiosis-related pea genes PsSym36, PsSym33 and PsSym40 in the functional AM (i) by investigating the effect of mutations in the three genes on fungal and plant gene responses and (ii) by creating conditions for the localization of two of the genes, PsSym36 and PsSym40, on the pea genetic map for future map-based cloning. The expression of a subset of ten fungal and eight plant genes,previously reported to be activated during mycorrhiza development, was compared in G…

Effect of cadmium on growth, isoflavonoid and protein accumulation patterns in mycorrhizal roots of Medicago truncatula

2007

International audience; Ecosystems are submitted to various abiotic stresses, among which heavy metals represent major industrial pollutants. Cadmium (Cd), that has damaging effects on plant metabolism, occurs in agricultural environments through industrial pollution and human activities, including phosphate fertiliser and sewage sludge applications. Metal availability to plants can be modulated by soil microorganisms, including arbuscular mycorrhizal (AM) fungi. In the present work, Cd effects on the model legume Medicago truncatula inoculated or not with the AM fungus Glomus intraradices have been studied at 3 levels: (1) plant biomass production together with green part chlorophyll quant…

Effect of the pea (Pisum sativum L.) gene PsSym36 on Glomus intraradices gene expression

2007

International audience; The Pisum sativum L. mutant RisNod24 (Pssym36) is defective for arbuscular mycorrhiza formation in late stages of AM. Recent studies identified some plant genes up- and down- regulated at stage of arbuscular development using pea mutant RisNod24, but nothing is still known about fungal gene inactivation. To investigate effect of PsSym36 pea gene on fungal gene expression, Glomus intraradices genes which have been previously identified as markers of successful symbiosis development (Seddas et al., unpublished results) were chosen. List of AM genes used in this study: signalling, transcription, protein turn-over (RHO/GDP dissociation inhibitor, Peptidylprolyl isomerase…

Arbuscular mycorhizal proteomes: what news at the nearby and distant horizon?

2007

International audience; Proteomics has soon emerged as a powerful tool to point out protein modifications in roots interacting with arbuscular mycorrhiza (AM) fungi. Depending on the developmental mycorrhizal stage and on the available amount of mycorrhizal material, untargeted and/or sub-cellular proteomic approaches were applied to reveal and identify proteins whose accumulation was modified during the AM colonisation of Medicago truncatula roots. For the early stage of symbiosis, the protein patterns obtained from noninoculated roots and roots synchronized for appressorium formation in wild-type (Jemalong J5), penetration-defective (TRV25, dmi3) and autoregulation-defective (TR122, sunn)…

Genes encoding transcription factors in Glomus intraradices and their expression at the appressoria stage of arbuscular mycorrhiza interactions

2007

International audience; Molecular pathways governing the life cycle of arbuscular mycorrhizal (AM) fungi and their symbiotic interactions with root tissues are not yet fully understood. Most studies fo fungal responses to host plants have targeted developmental stages before root contact (germinating spores), or after root colonization (intraradical mycelium). We are focusing on the early cell events of appressoria contact with the root surface which are essential to the successful outcome of the AM symbiosis. Recent monitoring of Glomus intraradices gene expression at this stage has revealed differential fungal responses to roots of host and non-host (Myc- mutants) M. truncatula (Seddas et…

Tracing of the inoculated arbuscular mycorrhizal fungal strain Glomus intraradices BEG140 in a field experiment over 3 years

2010

Is this fungus everywhere? Elucidating the genetic structure of populations of the arbuscular mycorrhizal fungus Glomus intraradices

2010

Arbuscular mycorrhizal fungi (Glomeromycota) are ubiquitous mutualistic associates of plants. Only relatively recently it has become possible to study the population biology of some species of these fungi. The model organism Glomus intraradices has been found across an extremely wide range of habitats and succession stages on different continents using molecular identification approaches. We used regions of the mitochondrially-encoded rDNA as novel molecular markers to resolve the intraspecies structure of G. intraradices and found a high diversity of mitochondrial haplotypes among isolates from all over the world. These markers for the first time also offer to genotype G. intraradices dire…

Mitochondrial genotyping of isolates of the arbuscular mycorrhizal fungus "Glomus intraradices" from the isolate collection of the International Bank…

2011

International audience; The culture collection of the International Bank of Glomeromycota (BEG) provides an important service to scientific community and industry by acting as a repository for well-defined AMF isolates which are made available to the public. The most widely-used species has been referred to as "Glomus intraradices", and was recently renamed Rhizophagus irregularis. This species has emerged as a model organism for experimental research and is the subject of the first AMF genome to be sequenced. The only genetic marker that can currently be used to distinguish strains of R. irregularis in field settings is the mitochondrial large subunit (mtLSU). In addition, genetically dist…