Search results for "Medicago"
showing 10 items of 107 documents
Interaction between Medicago truncatula and Pseudomonas fluorescens: evaluation of costs and benefits across an elevated atmospheric CO2.
2012
10 pages; International audience; Soil microorganisms play a key role in both plants nutrition and health. Their relation with plant varies from mutualism to parasitism, according to the balance of costs and benefits for the two partners of the interaction. These interactions involved the liberation of plant organic compounds via rhizodeposition. Modification of atmospheric CO2 concentration may affect rhizodeposition and as a consequence trophic interactions that bind plants and microorganisms. Positive effect of elevated CO2 on plants are rather well known but consequences for micoorganisms and their interactions with plants are still poorly understood. A gnotobiotic system has been devel…
Fluorescent pseudomonads harboring type III secretion genes are enriched in the mycorrhizosphere of Medicago truncatula
2011
Type III secretion systems (T3SSs) of Gram-negative bacteria mediate direct interactions with eukaryotic cells. Pseudomonas spp. harboring T3SS genes (T3SS+) were previously shown to be more abundant in the rhizosphere than in bulk soil. To discriminate the contribution of roots and associated arbuscular mycorrhizal fungi (AMF) on the enrichment of T3SS+ fluorescent pseudomonads in the rhizosphere of Medicago truncatula, their frequency was assessed among pseudomonads isolated from mycorrhizal and nonmycorrhizal roots and from bulk soil. T3SS genes were identified by PCR targeting a conserved hrcRST DNA fragment. Polymorphism of hrcRST in T3SS+ isolates was assessed by PCR-restriction fragm…
Digestion of bamboo compared to grass and lucerne in a small hindgut fermenting herbivore, the guinea pig (Cavia porcellus)
2022
Bamboo is an enigmatic forage, representing a niche food for pandas and bamboo lemurs. Bamboo might not represent a suitable forage for herbivores relying on fermentative digestion, potentially due to its low fermentability. To test this hypothesis, guinea pigs (n = 36) were used as model species and fed ad libitum with one of three forages (bamboo, lucerne, or timothy grass) in a fresh or dried state, with six individuals per group, for 3 weeks. The nutrient composition and in vitro fermentation profile of bamboo displayed low fermentation potential, i.e. high lignin and silica levels together with a gas production (Hohenheim gas test) at 12 h of only 36% of that of lucerne and grass. Alth…
Microdiversity of Burkholderiales associated with mycorrhizal and nonmycorrhizal roots of Medicago truncatula
2008
The genetic diversity of bacterial communities associated with mycorrhizal and nonmycorrhizal roots of Medicago truncatula was characterized by two approaches. Firstly, phylogenetic analysis was performed on 164 partial 16S rRNA gene-intergenic spacer (IGS) sequences from operational taxonomic units previously shown to be preferentially associated with mycorrhizal roots. These sequences were distributed into three branches corresponding to Comamonadaceae, Oxalobacteraceae and Rubrivivax subgroups. Most sequences were obtained from mycorrhizal roots, indicating the preferential association of the corresponding families with mycorrhizal roots. A second phylogenetic analysis was performed on t…
TheMedicago truncatulahypermycorrhizal B9 mutant displays an altered response to phosphate and is more susceptible toAphanomyces euteiches
2014
Inorganic phosphate (Pi) plays a key role in the development of arbuscular mycorrhizal (AM) symbiosis, which is favoured when Pi is limiting in the environment. We have characterized the Medicago truncatula hypermycorrhizal B9 mutant for its response to limiting (P/10) and replete (P2) Pi. On P2, mycorrhization was significantly higher in B9 plants than in wild-type (WT). The B9 mutant displayed hallmarks of Pi-limited plants, including higher levels of anthocyanins and lower concentrations of Pi in shoots than WT plants. Transcriptome analyses of roots of WT and B9 plants cultivated on P2 or on P/10 confirmed the Pi-limited profile of the mutant on P2 and highlighted its altered response t…
Effets de la nutrition et du génotype de la plante sur la résistance de Medicago truncatula à Aphanomyces euteiches
2016
SPEIPMUBAGROSUPINRA; Dans la nature, les plantes ont la capacité de mettre en oeuvre des réponses immunitaires pour faire face aux microorganismes pathogènes. Cependant, ces réponses de défense sont coûteuses en énergie et conduisent la plante à détourner une partie de ces ressources destinées à d’autres traits de vie comme la croissance. Ce compromis défense/croissance est largement conditionné par la disponibilité extérieure en nutriments. Afin de mieux décrire et comprendre les liens entre la nutrition et la défense, nous avons analysé l’impact de la nutrition azotée et l’effet de la variabilité génétique végétale sur la capacité de la légumineuse Medicago truncatula à résister à un agen…
Effects of plant nutrition and genotype on Medicago truncatula defense responses against Aphanomyces euteiches
2014
SPEIPM; International audience
Productivity and canopy modification of Medicago arborea as affected by defoliation management and genotype in a Mediterranean environment
2004
Medicago arborea is one of the most potentially valuable fodder shrubs in a Mediterranean environment because of its high preference by small ruminants and its nutritive value. Edible biomass production is affected by agronomic and environmental factors. A study, carried out in an inland area of Sicily in the growing seasons of 1994/95, 1995/96 and 1996/97, evaluated the forage production and canopy modification in a M. arborea plantation after (i) commencing defoliation 1 or 2 years after transplanting and (ii) defoliating only in autumn (A), only in early summer (S) or in both seasons (A and S). Six clones derived from five different Mediterranean populations were used. Plant age at the f…
Identification of bacterial groups preferentially associated with mycorrhizal roots of Medicago truncatula
2007
ABSTRACT The genetic structures of bacterial communities associated with Medicago truncatula Gaertn. cv. Jemalong line J5 (Myc + Nod + ) and its symbiosis-defective mutants TRV48 (Myc + Nod − ) and TRV25 (Myc − Nod − ) were compared. Plants were cultivated in a fertile soil (Châteaurenard, France) and in soil from the Mediterranean basin showing a low fertility (Mas d'Imbert, France). Plant growth, root architecture, and the efficiency of root symbiosis of the three plant genotypes were characterized in the two soils. Structures of the bacterial communities were assessed by automated-ribosomal intergenic spacer analysis (A-RISA) fingerprinting from DNA extracted from the rhizosphere soil an…
Polish Yellow Sweet Clover (Melilotus officinalis L.) Honey, Chromatographic Fingerprints, and Chemical Markers
2017
A case study of Polish Melilotus officinalis honey was presented for the first time. Gas chromatography–mass spectrometry (GC-MS) (after steam distillation, Soxhlet extraction, ultrasonic solvent extraction, and solid phase extraction (SPE)) and targeted high performance liquid chromatography with a photodiode array detector (HPLC-PAD) were applied to determine the characteristic components of honey. While ubiquitous in most honeys, carbohydrates, terpene derivatives, and phenylacetic acid dominated in the Soxhlet extracts (25.54%) and in the application of SPE (13.04%). In addition, lumichrome (1.85%) was found, and may be considered as a marker of this honey. Due to the presence of these …