Search results for "Mycorrhiza"
showing 10 items of 284 documents
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…
Isolation and characterization of N transporters putatively involved in the Hebeloma cylindrosporum-Pinus pinaster ectomycorrhizal association
2007
International audience; Studies of nitrogen metabolism in ectomycorrhizas have demonstrated that the fungal symbiont plays a fully integrated role in plant root metabolism and participates actively in the assimilation and transfer of newly absorbed nitrogen compounds by transferring amino acids. In symbiotic associations, such as mycorrhizas, location of the symbiosis ensures that mycelial growth of the fungus into soil provides access to nutrients in the soil solution. Changes in the distribution and activity of membrane-bound transport proteins in response to symbiotic interactions need to be investigated. In recent years several genes from H. cylindrosporum and P. pinaster, putatively in…
Arbuscular mycorrhiza (AM): the first glomeromycotan sugar transporter is characterized by using the unique geosiphon symbiosis with cyanobacteria to…
2007
International audience; In the arbuscular mycorrhizas (AM), the symbiotic interface is the site of nutrient exchange where the mycobiont receives up to 20% of the photosynthates of the photobiont as carbohydrates. We have, for the first time, functionally characterised a monosaccharide transporter type, represented by GpMST1, putatively playing a role in this process (Schüßler, A., Martin, H., Cohen, D., Fitz, M., and Wipf, D. 2006. Characterization of a carbohydrate transporter from symbiotic glomeromycotan fungi. Nature 444:933-936.). Together with the arbuscular mycorrhizal (AM) fungi, forming endomycorrhiza with the majority of land plants, Geosiphon pyriformis belongs to the Glomeromyc…
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)…
Changes in polypeptide profiles of two pea genotypes inoculated with the arbuscular mycorrhizal fungus Glomus mosseae
1994
The symbiotic interaction between pea roots ('Pisum sativum' L.) and the endomycorrhizal fungus 'Glomus mosseae' should lead to specific gene expression of both symbionts. In order to detect symbiosis-related proteins (endomycorrhizins), we used two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) after phenolic extraction of total soluble proteins. Furthermore, to better characterize the molecular changes after fungal infection, two pea genotypes available in our laboratory were used: cv. Frisson (myc⁺) and an isogenic mycorrhiza-resistant mutant (myc⁻). The latter prevents intraradical fungal development. Several differences were observed in polypeptide patterns of silver-stained …
Mycorrhizal inocula: innovations or more rational use?
2007
International audience; At present, commercial arbuscular mycorrhizal (AM) inocula are produced in nursery plots, containers with different substrates and plants, aeroponic systems or, more recently, in vitro (1). Different formulated products are available on the market, which creates the need for the establishment of standards for widely accepted quality control. In particular, inoculum formulation should be optimised for maximum symbiosis efficiency together with the absence of pathogens. In some methods of inoculum production the presence of other soil microbes cannot be avoided. In these cases technological innovations are requested for monitoring microbial populations for an optimal m…
The arbuscular mycorrhizal symbiosis a modulator of cadmium stress
2008
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, such as 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 quantif…
Could subcellular proteomics of root plastids teach us more about mycorrhizal symbiosis?
2007
International audience; The arbuscular mycorrhizal (AM) symbiosis is a mutualistic association between soil-borne fungi and the roots of most plant species. Involving the bilateral exchange of nutrients, the symbiosis is connected to drastic changes in plant cell organelle morphology and physiology. Root plastids, in particular, are forming extensive, network-like structures covering the main symbiotic interface, i.e., intracellular, highly branched haustorium-like fungal structures called arbuscules. These plastid networks are highly dynamic and are formed and degraded concomitantly with the formation and degradation of arbuscules. By producing basic metabolic building blocks like fatty ac…
Host preference in dark septate root endophytes of prairie grasses
2007
International audience; Microbiological examination of prairie grass roots usually reveals the presence of diverse mycorrhizal and dark septate endophytic (DSE) fungi. Some of these fungi can enhance plant resistance to abiotic stress in extreme environments. The host specificity of two DSE fungi isolated from pure stands of crested wheatgrass and Russian wildrye in southwest Saskatchewan was assessed in microcosms. Pure cultures of endophytic fungal isolates were obtained after plating surface sterile root pieces on Potato dextrose agar. Plugs containing these fungi were used to individually inoculate germinated surface sterile seeds of crested wheatgrass and Russian wildrye, and control p…
Bacillus consortium positively impacts arbuscular mycorrhizal fungi community, plant phosphate nutrition and potato yield in Solanum tuberosum cv. Ja…
2022
Many agricultural soils are naturally poor in plant available phosphorus (P), although total P stocks can exceed plant requirements by more than 100-fold. The reason for such apparent contradiction is that P is complexed under organic and inorganic forms, but only free inorganic orthophosphate (Pi) ions are available to plants and soil organisms. The high immobility of Pi in soil, the low soil solution circulation associated with a rapid root absorption lead to the development of a depletion zone around the roots. As a consequence, P is frequently a limiting factor for plant growth and development.Arbuscular mycorrhizal (AM) fungi are estimated to colonize the vast majority of crop plants a…