Search results for "CORR"
showing 10 items of 6535 documents
Combined phosphate and nitrogen limitation generates a nutrient stress transcriptome favorable for arbuscular mycorrhizal symbiosis in M edicago trun…
2013
International audience; Arbuscular mycorrhizal (AM) symbiosis is stimulated by phosphorus (P) limitation and contributes to P and nitrogen (N) acquisition. However, the effects of combined P and N limitation on AM formation are largely unknown. Medicago truncatula plants were cultivated in the presence or absence of Rhizophagus irregularis (formerly Glomus intraradices) in P-limited (LP), N-limited (LN) or combined P- and N-limited (LPN) conditions, and compared with plants grown in sufficient P and N. The highest AM formation was observed in LPN, linked to systemic signaling by the plant nutrient status. Plant free phosphate concentrations were higher in LPN than in LP, as a result of cros…
Transcriptional responses of Medicago truncatula upon sulfur deficiency stress and arbuscular mycorrhizal symbiosis
2014
International audience; Sulfur plays an essential role in plants' growth and development and in their response to various abiotic and biotic stresses despite its leachability and its very low abundance in the only form that plant roots can uptake (sulfate). It is part of amino acids, glutathione (GSH), thiols of proteins and peptides, membrane sulfolipids, cell walls and secondary products, so reduced availability can drastically alter plant growth and development. The nutritional benefits of symbiotic interactions can help the plant in case of S deficiency. In particular the arbuscular mycorrhizal (AM) interaction improves N, P and S plant nutrition, but the mechanisms behind these exchang…
Organelle protein changes in arbuscular mycorrhizal Medicago truncatula roots as deciphered by subcellular proteomics
2019
Prod 2020-8c SPE IPM INRA UB CNRS; The roots of most land plants can enter a symbiotic relationship with arbuscular mycorrhizal (AM) soil‐borne fungi belonging to the phylum Glomeromycota, which improves the mineral nutrition of the host plant. The fungus enters the root through the epidermis and grows into the cortex where it differentiates into a highly branched hyphal structure called the arbuscule. The role of the plant membrane system as the agent for cellular morphogenesis and signal/nutrient exchanges is especially accentuated during AM endosymbiosis. Notably, fungal hyphae are always surrounded by the host membrane, which is referred to as the perifungal membrane around intracellula…
Genome of an arbuscular mycorrhizal fungus provides insight into the oldest plant symbiosis
2013
International audience; The mutualistic symbiosis involving Glomeromycota, a distinctive phylum of early diverging Fungi, is widely hypothesized to have promoted the evolution of land plants during the middle Paleozoic. These arbuscular mycorrhizal fungi (AMF) perform vital functions in the phosphorus cycle that are fundamental to sustainable crop plant productivity. The unusual biological features of AMF have long fascinated evolutionary biologists. The coenocytic hyphae host a community of hundreds of nuclei and reproduce clonally through large multinucleated spores. It has been suggested that the AMF maintain a stable assemblage of several different genomes during the life cycle, but thi…
Construction and validation of cDNA-based Mt6k-RIT macro- and microarrays to explore root endosymbioses in the model legume Medicago truncatula
2004
To construct macro- and microarray tools suitable for expression profiling in root endosymbioses of the model legume Medicago truncatula, we PCR-amplified a total of 6048 cDNA probes representing genes expressed in uninfected roots, mycorrhizal roots and young root nodules [Nucleic Acids Res. 30 (2002) 5579]. Including additional probes for either tissue-specific or constitutively expressed control genes, 5651 successfully amplified gene-specific probes were used to grid macro- and to spot microarrays designated Mt6k-RIT (M. truncatula 6k root interaction transcriptome). Subsequent to a technical validation of microarray printing, we performed two pilot expression profiling experiments usin…
Effects of Arbuscular Mycorrhizal Fungi on the Vegetative Vigor of Ailanthus altissima (Mill.) Swingle Seedlings under Sustained Pot Limitation
2018
In order to invade new ecosystems, invasive alien plants need to cope with different microbial communities. Whilst the ability to avoid antagonists is well recognized, the opportunity to establish mutualistic associations is less known, even in widespread invasive species such as Ailanthus altissima (Mill.) Swingle. We sought to evaluate whether the beneficial effects of arbuscular mycorrhizal fungi (AMF) on Ailanthus seedlings are maintained over time, under prolonged pot limitation. We compared three-month-, three-year- and four-year-old mycorrhizal seedlings grown in natural forest soil (NT) with seedlings grown in sterilized (ST) and non-mycorrhizal (NM) soils, in pots of 3.4 L (22 &tim…
25S rDNA-based molecular monitoring of glomalean fungi in sewage sludge-treated field plots
2001
Recycling of sewage wastes in agriculture is likely to affect the biological activity of soils through contamination of ecosystems by pathogens and metallic or organic micropollutants. The impact of sewage sludge spreading under field conditions on arbuscular mycorrhiza (AM) formation by a community of glomalean fungi was evaluated using a nested polymerase chain reaction (PCR) and discriminating primers based on 25S rDNA polymorphisms to detect different fungal species within root systems. Medicago truncatula was grown in soil of field plots amended or not with a composted sewage sludge, spiked or not with organic or metallic micropollutants. Overall AM development in roots decreased with …
A Network Model for the Correlation between Epistasis and Genomic Complexity
2008
The study of genetic interactions (epistasis) is central to the understanding of genome organization and evolution. A general correlation between epistasis and genomic complexity has been recently shown, such that in simpler genomes epistasis is antagonistic on average (mutational effects tend to cancel each other out), whereas a transition towards synergistic epistasis occurs in more complex genomes (mutational effects strengthen each other). Here, we use a simple network model to identify basic features explaining this correlation. We show that, in small networks with multifunctional nodes, lack of redundancy, and absence of alternative pathways, epistasis is antagonistic on average. In c…
Sugar transporters in plants and in their interactions with fungi.
2012
International audience; Sucrose and monosaccharide transporters mediate long distance transport of sugar from source to sink organs and constitute key components for carbon partitioning at the whole plant level and in interactions with fungi. Even if numerous families of plant sugar transporters are defined; efflux capacities, subcellular localization and association to membrane rafts have only been recently reported. On the fungal side, the investigation of sugar transport mechanisms in mutualistic and pathogenic interactions is now emerging. Here, we review the essential role of sugar transporters for distribution of carbohydrates inside plant cells, as well as for plant fungal interactio…
The Medicago truncatula sucrose transporter family: characterization and implication of key members in carbon partitioning towards arbuscular mycorrh…
2012
We identified de novo sucrose transporter (SUT) genes involved in long-distance transport of sucrose from photosynthetic source leaves towards sink organs in the model leguminous species Medicago truncatula. The iden- tification and functional analysis of sugar transporters provide key information on mechanisms that underlie carbon partitioning in plant-microorganism interactions. In that way, full-length sequences of the M. truncatula SUT (MtSUT) family were retrieved and biochemical characterization of MtSUT members was performed by heterologous expression in yeast. The MtSUT family now comprises six genes which distribute among Dicotyledonous clades. MtSUT1-1 and MtSUT4-1 are key members…