Search results for "biologie du sol"
showing 10 items of 18 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…
Temperature and pH define the realised niche space of arbuscular mycorrhizal fungi
2021
Made available in DSpace on 2021-06-25T11:52:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-04 European Regional Development Fund (Centre of Excellence EcolChange) University of Tartu (Estonian Research Council ) Moscow State University Natural Sciences and Engineering Research Council of Canada Discovery Grant Russian Science Foundation Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Swedish Research Council (Vetenskapsradet) The arbuscular mycorrhizal (AM) fungi are a globally distributed group of soil organisms that play critical roles in ecosystem function. However, the ecological niches of individual AM fungal taxa are poorly understood. We collected > 300 s…
Reciprocal interactions between plants and fluorescent pseudomonads in relation to iron in the rhizosphere
2013
SPE EA Section 15 : Engineering the rhizosphere: The "biased rhizosphere" concept Ouvrage en 2 volumes Résumé du livre : Molecular Microbial Ecology of the Rhizosphere covers current knowledge on the molecular basis of plant-microbe interactions in the rhizosphere. Also included in the book are both reviews and research-based chapters describing experimental materials and methods. Edited by a leader in the field, with contributions from authors around the world, Molecular Microbial Ecology of the Rhizosphere brings together the most up-to-date research in this expanding area, and will be a valuable resource for molecular microbiologists and plant soil scientists, as well as upper level stud…
A Peptidoglycan-Remodeling Enzyme Is Critical for Bacteroid Differentiation in Bradyrhizobium spp. During Legume Symbiosis.
2016
International audience; In response to the presence of compatible rhizobium bacteria, legumes form symbiotic organs called nodules on their roots. These nodules house nitrogen-fixing bacteroids that are a differentiated form of the rhizobium bacteria. In some legumes, the bacteroid differentiation comprises a dramatic cell enlargement, polyploidization, and other morphological changes. Here, we demonstrate that a peptidoglycan-modifying enzyme in Bradyrhizobium strains, a DD-carboxypeptidase that contains a peptidoglycan-binding SPOR domain, is essential for normal bacteroid differentiation in Aeschynomene species. The corresponding mutants formed bacteroids that are malformed and hypertrop…
Peaks of in situ N2O emissions are influenced by N2O producing and reducing microbial communities across arable soils
2018
International audience; Introduction Agriculture is the main source of terrestrial N2O emissions, a potent greenhouse gas and the main cause of ozone depletion ((Hu et al., 2015). The reduction of N2O into N2 by microorganisms carrying the nitrous oxide reductase gene (nosZ) is the only known biological process eliminating this greenhouse gas. Recent studies showed that a previously unknown clade of N2O-reducers (nosZII) was related to the potential capacity of the soil to act as a N2O sink (see Hallin et al., 2017 and references therein). However little is known about how this group responds to different agricultural practices. Here, we investigated how N2O-producers and N2O-reducers were …
Occurrence of CTX-M Producing Escherichia coli in Soils, Cattle, and Farm Environment in France (Burgundy Region).
2012
Article en open access; International audience; CTX-M [a major type of extended-spectrum beta-lactamase (ESBU] producing Escherichia coli are increasingly involved in human infections worldwide. The aim of this study was to investigate potential reservoirs for such strains: soils, cattle, and farm environment. The prevalence of bla(CTX-M) genes was determined directly from soil DNA extracts obtained from 120 sites in Burgundy (France) using real-time PCR. bla(CTX-M) targets were found in 20% of the DNA extracts tested. Samples of cattle feces (n = 271) were collected from 182 farms in Burgundy. Thirteen ESBL-producing isolates were obtained from 12 farms and further characterized for the pr…
Root-induced decomposer growth and plant N uptake are not positively associated among a set of grassland plants
2007
Abstract It is known that plant species can induce development of different soil decomposer communities and that they differ in their influence on organic matter decomposition and N mineralization in soil. However, no study has so far assessed whether these two observations are related to each other. Based on the hypothesis that root-induced growth of soil decomposers leads to accelerated decomposition of SOM and increased plant N availability in soil, we predicted that (1) among a set of grassland plants the abundance of soil decomposers in the plant rhizosphere is positively associated with plant N uptake from soil organic matter. To test this, we established grassland microcosms consisti…
Nodulating symbiotic bacteria and soil quality
2005
Chapitre 9 : Plant microbe interactions and soil quality Partie : 9-2; International audience
Evaluation agroécologique de systèmes de culture en zone tropicale humide : Cas de la mise en valeur agricole d'une savane herbacée acide (Plaine des…
2013
Dans les régions tropicales humides, concilier intensification agricole et protection des ressources naturelles est un défi majeur et difficile à relever. Dans les savanes acides du nord-est laotien, des systèmes de culture de semis direct sur couverture végétale (SCV), basés sur les trois principes du non-labour, d’une couverture permanente du sol, et sur la pratique de rotations culturales diversifiées, sont proposés comme alternative technique à l’intensification agricole conventionnelle basée sur le labour. Si ces systèmes ont connu une diffusion importante et rapide dans les grandes agricultures mécanisées, leur diffusion reste néanmoins à ce jour limitée en contexte de petite agricult…
Isoproturon
2010
Frequent use of phenylurea herbicide isoproturon (IPU) in agricultural fields has resulted not only in the contamination of the natural resources including soil and water but also in the adaptation of the soil microflora to its rapid degradation. However, up to now, the mechanisms underlying this microbial adaptation are not well elucidated. The aim of this study was to explore the processes and factors implicated in IPU degradation from the agricultural field to the genes coding for catabolic genes. The study carried out at the experimental field of Epoisses cropped with a winter wheat / barley / rape seed crop rotation indicated that as a result of its periodically repeated use, the soil …