Publications by authors named "Jansa J"

Article Synopsis
  • Biocrusts are crucial for primary production and nutrient cycling in drylands, yet their role in transferring biologically fixed carbon (C) and nitrogen (N) to mineral soil is not well understood.
  • Experimental studies showed that while biocrusts can modulate CO fluxes, drought severely limits their ability to uptake carbon, leading to a decline in net carbon gain.
  • Climate change, particularly warming, disrupts the beneficial effects of biocrusts on mineral soil composition and diminishes biological nitrogen fixation, threatening overall soil health and ecosystem functions.
View Article and Find Full Text PDF

Background And Aims: Clonal growth is widespread among herbaceous plants, and helps them to cope with environmental heterogeneity through resource integration via connecting clonal organs. Such integration is considered to balance heterogeneity by translocation of resources from rich to poor patches. However, such an 'equalization' strategy is only one of several possible strategies.

View Article and Find Full Text PDF

Objective: To evaluate the epidemiological evolution and economic impact of COVID-19 pandemic in the European Union (EU) and worldwide, and the effects of control strategies on them.

Material And Methods: We collected incidence, mortality, and gross domestic product (GDP) data between the first quarter of 2020 and of 2023. Then, we reviewed the effectiveness of the mitigation and zero-COVID control strategies.

View Article and Find Full Text PDF

Differences in functioning among various genotypes of arbuscular mycorrhizal (AM) fungi can determine their fitness under specific environmental conditions, although knowledge of the underlying mechanisms still is very fragmented. Here we compared seven homokaryotic isolates (genotypes) of Rhizophagus irregularis, aiming to characterize the range of intraspecific variability with respect to hyphal exploration of organic nitrogen (N) resources, and N supply to plants. To this end we established two experiments (one in vitro and one in open pots) and used N-chitin as the isotopically labeled organic N source.

View Article and Find Full Text PDF

Fungi are among the few organisms on the planet that can metabolize recalcitrant carbon (C) but are also known to access recently produced plant photosynthate. Therefore, improved quantification of growth and substrate utilization by different fungal ecotypes will help to define the rates and controls of fungal production, the cycling of soil organic matter, and thus the C storage and CO buffering capacity in soil ecosystems. This pure-culture study of fungal isolates combined a dual stable isotope probing (SIP) approach, together with rapid analysis by tandem pyrolysis-gas chromatography-isotope ratio mass spectrometry to determine the patterns of water-derived hydrogen (H) and inorganic C assimilated into lipid biomarkers of heterotrophic fungi as a function of C substrate.

View Article and Find Full Text PDF

Arbuscular mycorrhizal (AM) fungi are supposedly competing with ammonia-oxidizing microorganisms (AO) for soil nitrogen in form of ammonium. Despite a few studies directly addressing AM fungal and AO interactions, mostly in artificial cultivation substrates, it is not yet clear whether AM fungi can effectively suppress AO in field soils containing complex indigenous microbiomes. To fill this knowledge gap, we conducted compartmentalized pot experiments using four pairs of cropland and grassland soils with varying physicochemical properties.

View Article and Find Full Text PDF

Introduction: The hyphosphere of arbuscular mycorrhizal (AM) fungi is teeming with microbial life. Yet, the influence of nutrient availability or nutrient forms on the hyphosphere microbiomes is still poorly understood.

Methods: Here, we examined how the microbial community (prokaryotic, fungal, protistan) was affected by the presence of the AM fungus in the rhizosphere and the root-free zone, and how different nitrogen (N) and phosphorus (P) supplements into the root-free compartment influenced the communities.

View Article and Find Full Text PDF

Phosphorus (P) for carbon (C) exchange is the pivotal function of arbuscular mycorrhiza (AM), but how this exchange varies with soil P availability and among co-occurring plants in complex communities is still largely unknown. We collected intact plant communities in two regions differing c. 10-fold in labile inorganic P.

View Article and Find Full Text PDF

It is well understood that agricultural management influences arbuscular mycorrhizal (AM) fungi, but there is controversy about whether farmers should manage for AM symbiosis. We assessed AM fungal communities colonizing wheat roots for three consecutive years in a long-term (> 14 yr) tillage and fertilization experiment. Relationships among mycorrhizas, crop performance, and soil ecosystem functions were quantified.

View Article and Find Full Text PDF

Specific biomarker molecules are increasingly being used for detection and quantification in plant and soil samples of arbuscular mycorrhizal (AM) fungi, an important and widespread microbial guild heavily implicated in transfers of nutrients and carbon between plants and soils and in the maintenance of soil physico-chemical properties. Yet, concerns have previously been raised as to the validity of a range of previously used approaches (e.g.

View Article and Find Full Text PDF

Soil microbial necromass is an important contributor to soil organic matter (>50%) and it is largely composed of microbial residues. In soils, fragmented cell wall residues are mostly found in their polysaccharide forms of fungal chitin and bacterial peptidoglycan. Microbial necromass biomarkers, particularly amino sugars (AS) such as glucosamine (GlcN) and muramic acid (MurA) have been used to trace fungal and bacterial residues in soils, and to distinguish carbon (C) found in microbial residues from non-microbial organic C.

View Article and Find Full Text PDF
Article Synopsis
  • Arbuscular mycorrhizal fungi (AMF) enhance crop tolerance to drought by improving water transport in soils and extending root lengths, which helps plants access water during dry spells.
  • The study uses a soil-plant hydraulic model to show how AMF can delay the onset of stress related to drought, as they improve the balance between water loss through transpiration and the water available to the plant.
  • The authors emphasize the need for further research to understand the complex interactions between soil, roots, and AMF, particularly in the context of climate change and water availability.
View Article and Find Full Text PDF

Plants impact the development of their rhizosphere microbial communities. It is yet unclear to what extent the root cap and specific root zones contribute to microbial community assembly. To test the roles of root caps and root hairs in the establishment of microbiomes along maize roots (Zea mays), we compared the composition of prokaryote (archaea and bacteria) and protist (Cercozoa and Endomyxa) microbiomes of intact or decapped primary roots of maize inbred line B73 with its isogenic root hairless (rth3) mutant.

View Article and Find Full Text PDF

Plant-plant interactions and coexistence can be directly mediated by symbiotic arbuscular mycorrhizal (AM) fungi through asymmetric resource exchange between the plant and fungal partners. However, little is known about the effects of AM fungal presence on resource allocation in mixed plant stands. Here, we examined how phosphorus (P), nitrogen (N) and carbon (C) resources were distributed between coexisting con- and heterospecific plant individuals in the presence or absence of AM fungus, using radio- and stable isotopes.

View Article and Find Full Text PDF

Polychlorinated biphenyl (PCB)-contaminated soils represent a major treat for ecosystems health. Plant biostimulation of autochthonous microbial PCB degraders is a way to restore polluted sites where traditional remediation techniques are not sustainable, though its success requires the understanding of site-specific plant-microbe interactions. In an historical PCB contaminated soil, we applied DNA stable isotope probing (SIP) using C-labeled 4-chlorobiphenyl (4-CB) and 16S rRNA MiSeq amplicon sequencing to determine how the structure of total and PCB-degrading bacterial populations were affected by different treatments: biostimulation with Phalaris arundinacea subjected (PhalRed) or not (Phal) to a redox cycle and the non-planted controls (Bulk and BulkRed).

View Article and Find Full Text PDF

In response to the COVID-19 pandemic, the European Union/European Economic Area (EU/EEA) countries implemented a wide set of non-pharmaceutical interventions (NPIs), sometimes with limited knowledge on their effect and impact on population. The European Centre for Disease Prevention and Control (ECDC) and the European Commission's Joint Research Centre (JRC) developed a Response Measures Database (ECDC-JRC RMD) to archive NPIs in 30 EU/EEA countries from 1 January 2020 to 30 September 2022. We aimed to introduce a tool for the wider scientific community to assess COVID-19 NPIs effect and impact in the EU/EEA.

View Article and Find Full Text PDF

Both plants and their associated arbuscular mycorrhizal (AM) fungi require nitrogen (N) for their metabolism and growth. This can result in both positive and negative effects of AM symbiosis on plant N nutrition. Either way, the demand for and efficiency of uptake of mineral N from the soil by mycorrhizal plants are often higher than those of nonmycorrhizal plants.

View Article and Find Full Text PDF
Article Synopsis
  • A study analyzed triacylglycerols (TAGs) with positional isomers of specific fatty acids from three microorganisms: brewer's yeast, green alga, and a mycorrhizal fungus.
  • Various regioisomers and enantiomers of TAGs were identified using reversed phase chromatography/mass spectrometry, highlighting distinct separation abilities based on the arrangement of fatty acids.
  • Notably, the study found that TAGs in the mycorrhizal fungus predominantly showed unique structures with palmitvaccenic acid, suggesting a similar biosynthetic process across these microorganisms.
View Article and Find Full Text PDF

Phosphorus (P) acquisition is key for plant growth. Arbuscular mycorrhizal fungi (AMF) help plants acquire P from soil. Understanding which factors drive AMF-supported nutrient uptake is essential to develop more sustainable agroecosystems.

View Article and Find Full Text PDF

Objective: Multiple sclerosis (MS) may result in activity and participation limitations, including the performance of activities of daily living (ADL). This study aims at systematically investigate ADL performance by using Assessment of Motor and Process Skills (AMPS) in people with MS (PwMS) of all disease types and within the Kurtzke Expanded Disability Status Scale (EDSS) range from 1.0 - 8.

View Article and Find Full Text PDF

Arbuscular mycorrhizal (AM) fungi lack efficient exoenzymes to access organic nutrients directly. Nevertheless, the fungi often obtain and further channel to their host plants a significant share of nitrogen (N) and/or phosphorus from such resources, presumably via cooperation with other soil microorganisms. Because it is challenging to disentangle individual microbial players and processes in complex soil, we took a synthetic approach here to study N-labelled chitin (an organic N source) recycling via microbial loop in AM fungal hyphosphere.

View Article and Find Full Text PDF

Climate extremes pose enormous threats to natural ecosystems. Arbuscular mycorrhizal (AM) fungi are key plant symbionts that can affect plant community dynamics and ecosystem stability. However, knowledge about how AM fungal communities respond to climate extremes in natural ecosystems remains elusive.

View Article and Find Full Text PDF