Increased Carbon Partitioning to Secondary Metabolites Under Phosphorus Deficiency in Fisch. Is Modulated by Plant Growth Stage and Arbuscular Mycorrhizal Symbiosis.

Phosphorus (P) is one of the macronutrients limiting plant growth. Plants regulate carbon (C) allocation and partitioning to cope with P deficiency, while such strategy could potentially be influenced by plant growth stage and arbuscular mycorrhizal (AM) symbiosis. In a greenhouse pot experiment using licorice () as the host plant, we investigated C allocation belowground and partitioning in roots of P-limited plants in comparison with P-sufficient plants under different mycorrhization status in two plant growth stages.

Contrasting Nitrogen Fertilisation Rates Alter Mycorrhizal Contribution to Barley Nutrition in a Field Trial.

Controlled environment studies show that arbuscular mycorrhizal fungi (AMF) may contribute to plant nitrogen (N) uptake, but the role of these near-ubiquitous symbionts in crop plant N nutrition under natural field conditions remains largely unknown. In a field trial, we tested the effects of N fertilisation and barley ( L.) cultivar identity on the contribution of AMF to barley N uptake using N tracers added to rhizosphere soil compartments.

Aphids Influence Soil Fungal Communities in Conventional Agricultural Systems.

Arbuscular mycorrhizal fungi (AMF) form symbioses with the roots of most plant species, including cereals. AMF can increase the uptake of nutrients including nitrogen (N) and phosphorus (P), and of silicon (Si) as well as increase host resistance to various stresses. Plants can simultaneously interact with above-ground insect herbivores such as aphids, which can alter the proportion of plant roots colonized by AMF.

Arbuscular Mycorrhizal Fungi and Plant Chemical Defence: Effects of Colonisation on Aboveground and Belowground Metabolomes.

Arbuscular mycorrhizal fungal (AMF) colonisation of plant roots is one of the most ancient and widespread interactions in ecology, yet the systemic consequences for plant secondary chemistry remain unclear. We performed the first metabolomic investigation into the impact of AMF colonisation by Rhizophagus irregularis on the chemical defences, spanning above- and below-ground tissues, in its host-plant ragwort (Senecio jacobaea). We used a non-targeted metabolomics approach to profile, and where possible identify, compounds induced by AMF colonisation in both roots and shoots.

Arbuscular mycorrhizal fungi reduce nitrous oxide emissions from N O hotspots.

Nitrous oxide (N O) is a potent, globally important, greenhouse gas, predominantly released from agricultural soils during nitrogen (N) cycling. Arbuscular mycorrhizal fungi (AMF) form a mutualistic symbiosis with two-thirds of land plants, providing phosphorus and/or N in exchange for carbon. As AMF acquire N, it was hypothesized that AMF hyphae may reduce N O production.

Using the Evidence-Based Practice Service Nursing Bundle to Increase Patient Satisfaction.

Abstractintroduction: Patient satisfaction and patient experience goals are often linked to financial consequences. Although the link does exist, the bottom line is not only about money; it's about providing a quality experience for ED patients and creating an environment that engages staff. Evidence-based practice (EBP) strategies that have positive impact on patient perceptions of their ED care and increased satisfaction ratings include AIDET, Hourly Rounding, and Bedside Shift Report, which incorporate updates of test results and explanations of events occurring during a patient's visit.

Carbon and phosphorus exchange may enable cooperation between an arbuscular mycorrhizal fungus and a phosphate-solubilizing bacterium.

Arbuscular mycorrhizal fungi (AMF) transfer plant photosynthate underground which can stimulate soil microbial growth. In this study, we examined whether there was a potential link between carbon (C) release from an AMF and phosphorus (P) availability via a phosphate-solubilizing bacterium (PSB). We investigated the outcome of the interaction between the AMF and the PSB by conducting a microcosm and two Petri plate experiments.

Resolving the 'nitrogen paradox' of arbuscular mycorrhizas: fertilization with organic matter brings considerable benefits for plant nutrition and growth.

Arbuscular mycorrhizal fungi (AMF) can transfer nitrogen (N) to host plants, but the ecological relevance is debated, as total plant N and biomass do not generally increase. The extent to which the symbiosis is mutually beneficial is thought to rely on the stoichiometry of N, phosphorus (P) and carbon (C) availability. While inorganic N fertilization has been shown to elicit strong mutualism, characterized by improved plant and fungal growth and mineral nutrition, similar responses following organic N addition are lacking.

Fishing for nutrients in heterogeneous landscapes: modelling plant growth trade-offs in monocultures and mixed communities.

The problem of how best to find and exploit essential resources, the quality and locations of which are unknown, is common throughout biology. For plants, the need to grow an efficient root system so as to acquire patchily distributed soil nutrients is typically complicated by competition between plants, and by the costs of maintaining the root system. Simple mechanistic models for root growth can help elucidate these complications, and here we argue that these models can be usefully informed by models initially developed for foraging fish larvae.

Phosphate concentration and arbuscular mycorrhizal colonisation influence the growth, yield and expression of twelve PHT1 family phosphate transporters in foxtail millet (Setaria italica).

Phosphorus (P) is an essential element which plays several key roles in all living organisms. Setaria italica (foxtail millet) is a model species for panacoid grasses including several millet species widely grown in arid regions of Asia and Africa, and for the bioenergy crop switchgrass. The growth responses of S.

Interactions between arbuscular mycorrhizal fungi and organic material substrates.

Arbuscular mycorrhizal (AM) associations are widespread and form between ca. two-thirds of all land plants and fungi in the phylum Glomeromycota. The association is a mutualistic symbiosis with the fungi enhancing nutrient capture for the plant while obtaining carbon in return.

An arbuscular mycorrhizal fungus significantly modifies the soil bacterial community and nitrogen cycling during litter decomposition.

Arbuscular mycorrhizal fungi (AMF) perform an important ecosystem service by improving plant nutrient capture from soil, yet little is known about how AMF influence soil microbial communities during nutrient uptake. We tested whether an AMF modifies the soil microbial community and nitrogen cycling during litter decomposition. A two-chamber microcosm system was employed to create a root-free soil environment to control AMF access to (13) C- and (15) N-labelled root litter.

Interactions between an arbuscular mycorrhizal fungus and a soil microbial community mediating litter decomposition.

We investigated arbuscular mycorrhizal fungi (AMF) alteration of microbial mediation of litter decomposition. AMF (Glomus hoi) were either allowed access to or excluded from Plantago lanceolata L. root litter embedded in soil; litter was labeled with either (13) C only or (13) C and (15) N.

Growth and symbiotic effectiveness of an arbuscular mycorrhizal fungus in organic matter in competition with soil bacteria.

Arbuscular mycorrhizal (AM) fungi can enhance the rate of decomposition of organic material, and can acquire nitrogen (N) from organic sources, although they are not saprotrophs. These fungi may instead indirectly influence decomposition through interactions with other soil microorganisms. We investigated the impact of both AM hyphae and a bacterial filtrate on N capture by a host plant from sterilized organic material (Lolium perenne shoots dual labelled with (15) N and (13) C), using compartmented microcosms.

Substantial nitrogen acquisition by arbuscular mycorrhizal fungi from organic material has implications for N cycling.

Arbuscular mycorrhizal (AM) fungi are obligate biotrophs that acquire carbon (C) solely from host plants. AM fungi can proliferate hyphae in, and acquire nitrogen (N) from, organic matter. Although they can transfer some of that N to plants, we tested the hypothesis that organic matter is an important N source for the AM fungi themselves.

Mycorrhizas and biomass crops: opportunities for future sustainable development.

Central to soil health and plant productivity in natural ecosystems are in situ soil microbial communities, of which mycorrhizal fungi are an integral component, regulating nutrient transfer between plants and the surrounding soil via extensive mycelial networks. Such networks are supported by plant-derived carbon and are likely to be enhanced under coppiced biomass plantations, a forestry practice that has been highlighted recently as a viable means of providing an alternative source of energy to fossil fuels, with potentially favourable consequences for carbon mitigation. Here, we explore ways in which biomass forestry, in conjunction with mycorrhizal fungi, can offer a more holistic approach to addressing several topical environmental issues, including 'carbon-neutral' energy, ecologically sustainable land management and CO(2) sequestration.

Temperature dependence of respiration in roots colonized by arbuscular mycorrhizal fungi.

* The arbuscular mycorrhizal (AM) symbiosis is ubiquitous, and the fungus represents a major pathway for carbon movement in the soil-plant system. Here, we investigated the impacts of AM colonization of Plantago lanceolata and temperature on the regulation of root respiration (R). * Warm-grown AM plants exhibited higher rates of R than did nonAM plants, irrespective of root mass.

Mycorrhizal respiration: implications for global scaling relationships.

Most plant species form mycorrhizas, yet these are neglected by plant physiologists. One consequence of this neglect is reduced ability to predict plant respiration, because respiration rate (R) in mycorrhizal roots might be higher than in non-mycorrhizal roots owing to increased substrate availability associated with enhanced nutrient uptake, coupled with increased respiratory product demand. Other predictions include that mycorrhizal colonization will affect scaling of R with tissue nitrogen concentrations; that mycorrhizal and non-mycorrhizal root R differ in their response to nutrient supply; and that the impact of colonization on R is related to fungal biomass.

Root decisions.

Root systems have recognizable developmental plans when grown in solution or agar; however, these plans often must be modified to cope with the prevailing conditions in the soil environment such as the avoidance of obstacles and the exploitation of nutrient-rich patches or water zones. The modular structure of roots enables them to respond to their environment, and roots are very adaptive at modifying growth throughout the root system to concentrate their efforts in the areas that are the most profitable. Roots also form associations with microorganisms as a strategy to enhance resource capture.

Arbuscular mycorrhizal fungi can transfer substantial amounts of nitrogen to their host plant from organic material.

Nitrogen (N) capture by arbuscular mycorrhizal (AM) fungi from organic material is a recently discovered phenomenon. This study investigated the ability of two Glomus species to transfer N from organic material to host plants and examined whether the ability to capture N is related to fungal hyphal growth. Experimental microcosms had two compartments; these contained either a single plant of Plantago lanceolata inoculated with Glomus hoi or Glomus intraradices, or a patch of dried shoot material labelled with (15)N and (13)carbon (C).

Real-time PCR and microscopy: are the two methods measuring the same unit of arbuscular mycorrhizal fungal abundance?

To enable quantification of mycelial abundance in mixed-species environments, eight new TaqMan((R)) real-time PCR assays were developed for five arbuscular mycorrhizal fungal (AMF, Glomeromycota) taxa. The assays targeted genes encoding 18S rRNA or actin, and were tested on DNA from cloned gene fragments, from spores, mycelia, and from root-free soil, and on reverse-transcribed rRNA templates from entire mycelia and from colonized roots. The assays showed high specificity, sensitivity, and reproducibility, enabling reliable quantitation over broad ranges of template molecules.

Plant and mycorrhizal regulation of rhizodeposition.

The loss of carbon from roots (rhizodeposition) and the consequent proliferation of microorganisms in the surrounding soil, coupled with the physical presence of a root and processes associated with nutrient uptake, gives rise to a unique zone of soil called the rhizosphere. In this review, we bring together evidence to show that roots can directly regulate most aspects of rhizosphere C flow either by regulating the exudation process itself or by directly regulating the recapture of exudates from soil. Root exudates have been hypothesized to be involved in the enhanced mobilization and acquisition of many nutrients from soil or the external detoxification of metals.