Taxonomic, phylogenetic and functional diversity of root-associated fungi in bromeliads: effects of host identity, life forms and nutritional modes.

Bromeliads represent a major component of neotropical forests and encompass a considerable diversity of life forms and nutritional modes. Bromeliads explore highly stressful habitats and root-associated fungi may play a crucial role in this, but the driving factors and variations in root-associated fungi remain largely unknown. We explored root-associated fungal communities in 17 bromeliad species and their variations linked to host identity, life forms and nutritional modes by using ITS1 gene-based high-throughput sequencing and by characterizing fungal functional guilds.

Opportunities and risks of biofertilization for leek production in urban areas: Influence on both fungal diversity and human bioaccessibility of inorganic pollutants.

The influence of biofertilization with arbuscular mycorrhizal fungi (AMF) on trace metal and metalloids (TM) - Pb, Cd and Sb - uptake by leek (Allium porrum L.) grown in contaminated soils was investigated. The effect of biofertilization on human bioaccessibility of the TM in the plants was also examined.

Influence of arbuscular mycorrhizal fungi on antimony phyto-uptake and compartmentation in vegetables cultivated in urban gardens.

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Context: Urban areas are often contaminated with various forms of persistent metal (loid) and emerging contaminants such as antimony (Sb). Thus, in the context of urban agriculture where sustainable practices such as biofertilizers application (arbuscular mycorrhizal fungi, AMF) could improve nutrient transfer from the soil to the vegetables, the effect of AMF on metal (loid) mobility and human bioaccessibility is still poorly known.

Exploring fungus-plant N transfer in a tripartite ant-plant-fungus mutualism.

Background And Aims: The plant Hirtella physophora, the ant Allomerus decemarticulatus and a fungus, Trimmatostroma sp., form a tripartite association. The ants manipulate both the plant trichomes and the fungus to build galleries under the stems of their host plant used to capture prey.

Assessment of Ustilago maydis as a fungal model for root infection studies.

Ustilago maydis is a fungus infecting aerial parts of maize to form smutted galls. Due to its interest as a genetic tool in plant pathology, we evaluated its ability to penetrate into plant roots. The fungus can penetrate between epidermic root cells, forming inter and intracellular pseudohyphae.

Antimony bioavailability: knowledge and research perspectives for sustainable agricultures.

The increasing interest in urban agriculture highlights the crucial question of crop quality. The main objectives for environmental sustainability are a decrease in chemical inputs, a reduction in the level of pollutants, and an improvement in the soil's biological activity. Among inorganic pollutants emitted by vehicle traffic and some industrial processes in urban areas, antimony (Sb) is observed on a global scale.

Evolution of the plant-microbe symbiotic 'toolkit'.

Beneficial associations between plants and arbuscular mycorrhizal fungi play a major role in terrestrial environments and in the sustainability of agroecosystems. Proteins, microRNAs, and small molecules have been identified in model angiosperms as required for the establishment of arbuscular mycorrhizal associations and define a symbiotic 'toolkit' used for other interactions such as the rhizobia-legume symbiosis. Based on recent studies, we propose an evolutionary framework for this toolkit.

Origin of strigolactones in the green lineage.

The aims of this study were to investigate the appearance of strigolactones in the green lineage and to determine the primitive function of these molecules. We measured the strigolactone content of several isolated liverworts, mosses, charophyte and chlorophyte green algae using a sensitive biological assay and LC-MS/MS analyses. In parallel, sequence comparison of strigolactone-related genes and phylogenetic analyses were performed using available genomic data and newly sequenced expressed sequence tags.

Strigolactones affect lateral root formation and root-hair elongation in Arabidopsis.

Strigolactones (SLs) have been proposed as a new group of plant hormones, inhibiting shoot branching, and as signaling molecules for plant interactions. Here, we present evidence for effects of SLs on root development. The analysis of mutants flawed in SLs synthesis or signaling suggested that the absence of SLs enhances lateral root formation.

Role of mitochondria in the response of arbuscular mycorrhizal fungi to strigolactones.

The plant signals strigolactones activate seed germination of the parasitic weeds (Striga and Orobanche), growth of arbuscular mycorrhizal (AM) fungi and have recently been described as a new class of plant hormones that inhibit shoot branching. In AM fungi, the synthetic strigolactone analogue GR24 rapidly stimulates mitochondrial metabolism (within minutes) and biogenesis (within one hour). New gene expression, more active nuclear division and cell proliferation occur later (within days).

GR24, a synthetic analog of strigolactones, stimulates the mitosis and growth of the arbuscular mycorrhizal fungus Gigaspora rosea by boosting its energy metabolism.

Arbuscular mycorrhizal (AM) fungi are obligate biotrophs that participate in a highly beneficial root symbiosis with 80% of land plants. Strigolactones are trace molecules in plant root exudates that are perceived by AM fungi at subnanomolar concentrations. Within just a few hours, they were shown to stimulate fungal mitochondria, spore germination, and branching of germinating hyphae.

Arbuscular mycorrhizal fungi reveal distinct patterns of anastomosis formation and hyphal healing mechanisms between different phylogenic groups.

The significance of anastomosis formation and the hyphal healing mechanism (HHM) for functionality and integrity of the arbuscular mycorrhizal (AM) fungal mycelial network remains poorly documented. Four Glomeraceae and three Gigasporaceae were cultured monoxenically. Anastomosis formation was assessed using the grid line method, while HHM was time-lapse monitored.

Root factors induce mitochondrial-related gene expression and fungal respiration during the developmental switch from asymbiosis to presymbiosis in the arbuscular mycorrhizal fungus Gigaspora rosea.

During spore germination, arbuscular mycorrhizal (AM) fungi show limited hyphal development in the absence of a host plant (asymbiotic). In the presence of root exudates, they switch to a new developmental stage (presymbiotic) characterized by extensive hyphal branching. Presymbiotic branching of the AM fungus Gigaspora rosea was induced in liquid medium by a semipurified exudate fraction from carrot (Daucus carota) root organ cultures.