Preferential nitrogen and carbon exchange dynamics in Mucoromycotina "fine root endophyte"-plant symbiosis.

Mucoromycotina "fine root endophyte" (MFRE) fungi are an understudied group of plant symbionts that regularly co-occur with arbuscular mycorrhizal fungi. The functional significance of MFRE in plant nutrition remains underexplored, particularly their role in plant nitrogen (N) assimilation from the variety of sources typically found in soils. Using four N-labeled N sources to track N transfer between MFRE and Plantago lanceolata, applied singly and in tandem, we investigated N source discrimination, preference, and transfer to host plants by MFRE.

Mobility and growth in confined spaces are important mechanisms for the establishment of in the rhizosphere.

The rhizosphere hosts complex and abundant microbiomes whose structure and composition are now well described by metagenomic studies. However, the dynamic mechanisms that enable micro-organisms to establish along a growing plant root are poorly characterized. Here, we studied how a motile bacterium utilizes the microhabitats created by soil pore space to establish in the proximity of plant roots.

Organic fertilization reduces nitrous oxide emission by altering nitrogen cycling microbial guilds favouring complete denitrification at soil aggregate scale.

Agricultural management practices can induce changes in soil aggregation structure that alter the microbial nitrous oxide (NO) production and reduction processes occurring at the microscale, leading to large-scale consequences for NO emissions. However, the mechanistic understanding of how organic fertilization affects these context-dependent small-scale NO emissions and associated key nitrogen (N) cycling microbial communities is lacking. Here, denitrification gas (NO, N) and potential denitrification capacity NO/(NO + N) were assessed by automated gas chromatography in different soil aggregates (>2 mm, 2-0.

Mitigating Contaminant-Driven Risks for the Safe Expansion of the Agricultural-Sanitation Circular Economy in an Urbanizing World.

The widespread adoption of an agricultural circular economy requires the recovery of resources such as water, organic matter, and nutrients from livestock manure and sanitation. While this approach offers many benefits, we argue this is not without potential risks to human and environmental health that largely stem from the presence of contaminants in the recycled resources (e.g.

Space controlled environment agriculture offers pathways to improve the sustainability of controlled environmental agriculture on Earth.

Terrestrial controlled environment agriculture (CEA) will have an increasingly important role in food production. However, present CEA systems are energy- and resource-hungry and rarely profitable, requiring a step change in design and optimization. Here we argue that the unique nature of space controlled environment agriculture (SpaCEA), which needs to be both highly resource efficient and circular in design, presents an opportunity to develop intrinsically circular CEA systems.

Phyllosphere antibiotic resistome in a natural primary vegetation across a successional sequence after glacier retreat.

The spread of antibiotic-resistance genes (ARGs) has posed a significant threat to human health over the past decades. Despite the fact that the phyllosphere represents a crucial pool of microorganisms, little is known about the profile and drivers of ARGs in less human interference natural habitats. In order to minimize the influence of environmental factors, here we collected leaf samples from the early-, middle- and late-successional stages across a primary vegetation successional sequence within 2 km, to investigate how the phyllosphere ARGs develop in natural habitats.

The potential role of Mucoromycotina 'fine root endophytes' in plant nitrogen nutrition.

Mycorrhizal associations between fungi and plant roots have globally significant impacts on nutrient cycling. Mucoromycotina 'fine root endophytes' (MFRE) are a distinct and recently characterised group of mycorrhiza-forming fungi that associate with the roots of a range of host plant species. Given their previous misidentification and assignment as arbuscular mycorrhizal fungi (AMF) of the Glomeromycotina, it is now important to untangle the specific form and function of MFRE symbioses.

A commercial arbuscular mycorrhizal inoculum increases root colonization across wheat cultivars but does not increase assimilation of mycorrhiza-acquired nutrients.

Production and heavy application of chemical-based fertilizers to maintain crop yields is unsustainable due to pollution from run-off, high CO emissions, and diminishing yield returns. Access to fertilizers will be limited in the future due to rising energy costs and dwindling rock phosphate resources. A growing number of companies produce and sell arbuscular mycorrhizal fungal (AMF) inoculants, intended to help reduce fertilizer usage by facilitating crop nutrient uptake through arbuscular mycorrhizas.

Plant-environment microscopy tracks interactions of with plant roots across the entire rhizosphere.

Our understanding of plant-microbe interactions in soil is limited by the difficulty of observing processes at the microscopic scale throughout plants' large volume of influence. Here, we present the development of three-dimensional live microscopy for resolving plant-microbe interactions across the environment of an entire seedling growing in a transparent soil in tailor-made mesocosms, maintaining physical conditions for the culture of both plants and microorganisms. A tailor-made, dual-illumination light sheet system acquired photons scattered from the plant while fluorescence emissions were simultaneously captured from transparent soil particles and labeled microorganisms, allowing the generation of quantitative data on samples ∼3,600 mm in size, with as good as 5 µm resolution at a rate of up to one scan every 30 min.

Insights into the mechanism of the interference of sulfadiazine on soil microbial community and function.

The accumulation of sulfonamides in the soil environment possessed the potential to change soil microbial community and function. Metabolomics is capable of providing insights into the carbon metabolic pool and molecular mechanisms associated with external stressors. Here we evaluated alternations in soil bacterial community and soil metabolites profiles under sulfadiazine (SDZ) exposure and proposed a potential mechanism that SDZ accumulation in soil affected soil organic matter (SOM) cycling.

Genotypic variation in maize (Zea mays) influences rates of soil organic matter mineralization and gross nitrification.

Agricultural management practices that increase soil organic matter (SOM), such as no-tillage (NT) with crop residue retention, together with crop varieties best able to source nutrients from SOM, may help reverse soil degradation and improve soil nutrient supply and uptake by plants in low-input environments of tropical and subtropical areas. Here, we screened germplasm representing genetic diversity within tropical maize breeding programmes in relation to shaping SOM mineralization. Then we assessed effects of contrasting genotypes on nitrification rates, and genotype-by-management history interactions on these rates.

Impact of land use and management practices on soil nematode communities of Machair, a low-input calcareous ecosystem of conservation importance.

Machair is a vulnerable low-lying coastal ecosystem with internationally recognised conservation importance. It is characterised by wind-blown calcareous shell-sand soils that support a patchwork of low-input land-use types including species rich grasslands and small-scale arable production. In contrast to numerous above-ground studies, few below-ground studies have been made on the Machair.

The Effects of Arbuscular Mycorrhizal Fungal Colonisation on Nutrient Status, Growth, Productivity, and Canker Resistance of Apple ().

We assess whether arbuscular mycorrhizal fungi (AMF) improve growth, nutritional status, phenology, flower and fruit production, and disease resistance in woody perennial crops using apple ( as a study system. In a fully factorial experiment, young trees were grown for 3 years with or without AMF ( and ), and with industrial standard fertiliser applications or restricted fertiliser (10% of standard). We use two commercial scions (Dabinett and Michelin) and rootstocks (MM111 and MM106).

Variable response of nirK and nirS containing denitrifier communities to long-term pH manipulation and cultivation.

Denitrification is a key process responsible for the majority of soil nitrous oxide (N2O) emissions but the influences of pH and cultivation on the soil denitrifier community remain poorly understood. We hypothesised that the abundance and community structure of the total bacterial community and bacterial denitrifiers would be pH sensitive and that nirK and nirS containing denitrifiers would differ in their responses to change in pH and cultivation. We investigated the effect of long-term pH-adjusted soils (ranging from pH 4.

Alternate thermoregulation and functional binding of Escherichia coli type 1 fimbriae in environmental and animal isolates.

Type 1 fimbriae (T1F) are well characterised cell surface organelles expressed by Escherichia coli and required for adherence to mannosylated host tissue. They satisfy molecular Koch's postulates as a virulence determinant and a host-adapted role has been reinforced by reports that T1F expression is repressed at submammalian temperatures. Analysis of a group of 136 environmental and animal E.

Improving intercropping: a synthesis of research in agronomy, plant physiology and ecology.

Intercropping is a farming practice involving two or more crop species, or genotypes, growing together and coexisting for a time. On the fringes of modern intensive agriculture, intercropping is important in many subsistence or low-input/resource-limited agricultural systems. By allowing genuine yield gains without increased inputs, or greater stability of yield with decreased inputs, intercropping could be one route to delivering ‘sustainable intensification’.

Genotypic variation in the ability of landraces and commercial cereal varieties to avoid manganese deficiency in soils with limited manganese availability: is there a role for root-exuded phytases?

The marginal agricultural-systems of the Machair in the Western Isles of Scotland often have limited micronutrient availability because of alkaline soils. Traditional landraces of oats, barley and rye are thought to be better adapted to cope with the limited manganese (Mn) availability of these soils. When commercial cultivars are grown on the Machair, limited Mn-availability reduces crop yield and quality.

Arbuscular mycorrhizal fungal networks vary throughout the growing season and between successional stages.

To date, few analyses of mutualistic networks have investigated successional or seasonal dynamics. Combining interaction data from multiple time points likely creates an inaccurate picture of the structure of networks (because these networks are aggregated across time), which may negatively influence their application in ecosystem assessments and conservation. Using a replicated bipartite mutualistic network of arbuscular mycorrhizal (AM) fungal-plant associations, detected using large sample numbers of plants and AM fungi identified through molecular techniques, we test whether the properties of the network are temporally dynamic either between different successional stages or within the growing season.

Symbiotic relationships between soil fungi and plants reduce N2O emissions from soil.

N2O is a potent greenhouse gas involved in the destruction of the protective ozone layer in the stratosphere and contributing to global warming. The ecological processes regulating its emissions from soil are still poorly understood. Here, we show that the presence of arbuscular mycorrhizal fungi (AMF), a dominant group of soil fungi, which form symbiotic associations with the majority of land plants and which influence a range of important ecosystem functions, can induce a reduction in N2O emissions from soil.

Soil nitrate reducing processes - drivers, mechanisms for spatial variation, and significance for nitrous oxide production.

The microbial processes of denitrification and dissimilatory nitrate reduction to ammonium (DNRA) are two important nitrate reducing mechanisms in soil, which are responsible for the loss of nitrate ([Formula: see text]) and production of the potent greenhouse gas, nitrous oxide (N(2)O). A number of factors are known to control these processes, including O(2) concentrations and moisture content, N, C, pH, and the size and community structure of nitrate reducing organisms responsible for the processes. There is an increasing understanding associated with many of these controls on flux through the nitrogen cycle in soil systems.

Arbuscular mycorrhizal fungal communities in plant roots are not random assemblages.

We investigated whether arbuscular mycorrhizal fungal (AMF) communities in plant roots are random subsets of the local taxon pool or whether they reflect the action of certain community assembly rules. We studied AMF small subunit rRNA gene sequence groups in the roots of plant individuals belonging to 11 temperate forest understorey species. Empirical data were compared with null models assuming random association.

Plant influence on nitrification.

Modern agriculture has promoted the development of high-nitrification systems that are susceptible to major losses of nitrogen through leaching of nitrate and gaseous emissions of nitrogen oxide (NO and N2O), contributing to global warming and depletion of the ozone layer. Leakage of nitrogen from agricultural systems forces increased use of nitrogen fertilizers and causes water pollution and elevated costs of food production. Possible strategies for prevention of these processes involve various agricultural management approaches and use of synthetic inhibitors.

Pathogenesis, parasitism and mutualism in the trophic space of microbe-plant interactions.

Microbe-host interactions can be categorised as pathogenic, parasitic or mutualistic, but in practice few examples exactly fit these descriptions. New molecular methods are providing insights into the dynamics of microbe-host interactions, with most microbes changing their relationship with their host at different life-cycle stages or in response to changing environmental conditions. Microbes can transition between the trophic states of pathogenesis and symbiosis and/or between mutualism and parasitism.

Plant treatment, pollutant load, and soil type effects in rhizosphere ecology of trace element polluted soils.

Re-vegetation of trace element contaminated soils can alter the pH and chelating capacity in the rhizosphere, increasing the mobility of pollutants, which, in turn, may impact on rhizosphere ecology. In this study a short-term pot experiment was carried out in order to investigate the multi-factorial effects of: buffering capacity (sandy-loam and loam soils); pollutant load (0%, 1.3%, and 4% of pyrite sludge), and the presence/absence of plant (Lolium perenne L.