scholarly journals Lotus japonicus symbiosis signaling genes and their role in the establishment of root-associated bacterial and fungal communities

2019 ◽  
Author(s):  
Rafal Zgadzaj ◽  
Thorsten Thiergart ◽  
Zoltán Bozsóki ◽  
Ruben Garrido-Oter ◽  
Simona Radutoiu ◽  
...  
Keyword(s):  
Lotus Japonicus ◽  
Am Fungi ◽  
Internal Transcribed Spacers ◽  
Natural Soil ◽  
Host Genotype ◽  
Symbiotic Relationships ◽  
Community Profiling ◽  
Community Shifts ◽  
Wild Legume

AbstractThe wild legume Lotus japonicus engages in mutualistic symbiotic relationships with arbuscular mycorrhiza (AM) fungi and nitrogen-fixing rhizobia. Using plants grown in natural soil and community profiling of bacterial 16S rRNA genes and fungal internal transcribed spacers (ITS), we examined here the role of the Lotus symbiosis genes RAM1, NFR5, SYMRK, and CCaMK in structuring bacterial and fungal root-associated communities. We found host genotype-dependent community shifts in the root and rhizosphere compartments that were mainly confined to bacteria in nfr5 or fungi in ram1 mutants, whilst symRK and ccamk plants displayed major changes across both microbial kingdoms. We observed in all AM mutant roots an almost complete depletion of a large number of Glomeromycota taxa that was accompanied by a concomitant enrichment of Helotiales and Nectriaceae fungi, suggesting compensatory niche replacement within the fungal community. A subset of Glomeromycota whose colonization is strictly dependent on the common symbiosis pathway was retained in ram1 mutants, indicating that RAM1 is dispensable for intraradical colonization by some Glomeromycoyta fungi. However, intraradical colonization by certain Burkholderiaceae taxa is dependent on AM root infection, thereby revealing a microbial interkingdom interaction. Our findings imply a broad role for Lotus symbiosis genes in structuring the root microbiota.

scholarly journals Influence on Different Types of Mycorrhizal Fungi on Crop Productivity in Ecosystem

2015 ◽  
Vol 38 ◽  
pp. 9-15 ◽  
Author(s):  
K. Ramakrishnan ◽  
G. Bhuvaneswari
Keyword(s):  
Mycorrhizal Fungi ◽  
Current Knowledge ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Heavy Metal Stress ◽  
Crop Productivity ◽  
Symbiotic Relationships ◽  
Potential Benefits ◽  
Mycorrhizal Interactions

Mycorrhizal fungi greatly enhanced the ability of plants to take up phosphorus and other nutrients those are relatively immobile and exist in low concentration in the soil solution. Fungi can be important in the uptake of other nutrients by the host plant. Mycorrhizae establish symbiotic relationships with plants and play an essential role in plant growth, disease protection, and overall soil quality. Of the seven types of mycorrhizae described in current scientific literature (arbuscular, ecto, ectendo, arbutoid, monotropoid, ericoid and orchidaceous mycorrhizae), the arbuscular and ectomycorrhizae are the most abundant and widespread. This chapter presents an overview of current knowledge of mycorrhizal interactions, processes, and potential benefits to society. The molecular basis of nutrient exchange between arbuscular mycorrhizal (AM) fungi and host plants is presented; the role of AM fungi in disease protection, alleviation of heavy metal stress and increasing grain production. Most land plants form associations with mycorrhizal fungi. Mycorrhizas are mutualistic associations between fungi and plant roots. They are described as symbiotic because the fungus receives photo synthetically derived carbon compounds and the plant has increased access to mineral nutrients and sometimes water.

scholarly journals GmVTL1 is an iron transporter on the symbiosome membrane of soybean with an important role in nitrogen fixation

2020 ◽  
Author(s):  
Ella M. Brear ◽  
Frank Bedon ◽  
Aleksandr Gavrin ◽  
Igor S. Kryvoruchko ◽  
Ivone Torres-Jerez ◽  
...  
Keyword(s):  
Lotus Japonicus ◽  
List Type ◽  
Symbiotic Relationships ◽  
Iron Transporter ◽  
Symbiosome Membrane ◽  
Transporter Family ◽  
Root Transformation ◽  
Carbon Substrates ◽  
Infected Cells

SummaryLegumes establish symbiotic relationships with soil bacteria (rhizobia), housed in nodules on plant roots. The plant supplies carbon substrates and other nutrients to the bacteria in exchange for fixed nitrogen. The exchange occurs across a plant-derived symbiosome membrane (SM), which encloses rhizobia to form a symbiosome. Iron supplied by the plant is crucial for the rhizobial enzyme nitrogenase that catalyses N2 fixation, but the SM iron transporter has not been identified.We use complementation of yeast and plant mutants, real-time PCR, hairy root transformation, microscopy and proteomics to demonstrate the role of soybean GmVTL1 and 2.Both are members of the vacuolar iron transporter family and homologous to Lotus japonicus SEN1 (LjSEN1), previously shown to be essential for N2 fixation. GmVTL1 expression is enhanced in nodule infected cells and both proteins are localised to the SM.GmVTL1 and 2 transport iron in yeast and GmVTL1 restores N2 fixation when expressed in the Ljsen1 mutant.Three GmVTL1 amino acid substitutions that reduce iron transport in yeast also block N2 fixation in Ljsen1 plants.We conclude GmVTL1 is responsible for transport of iron across the SM to bacteroids and plays a crucial role in the N2-fixing symbiosis.

scholarly journals Root nodule symbiosis in Lotus japonicus drives the establishment of distinctive rhizosphere, root, and nodule bacterial communities

2016 ◽  
Vol 113 (49) ◽  
pp. E7996-E8005 ◽  
Author(s):  
Rafal Zgadzaj ◽  
Ruben Garrido-Oter ◽  
Dorthe Bodker Jensen ◽  
Anna Koprivova ◽  
Paul Schulze-Lefert ◽  
...  
Keyword(s):  
Community Structure ◽  
Plant Growth ◽  
Root Nodule ◽  
Lotus Japonicus ◽  
Direct Consequence ◽  
Rrna Gene ◽  
Nitrogen Fixing ◽  
Model Legume ◽  
Symbiotic Relationships

Lotus japonicus has been used for decades as a model legume to study the establishment of binary symbiotic relationships with nitrogen-fixing rhizobia that trigger root nodule organogenesis for bacterial accommodation. Using community profiling of 16S rRNA gene amplicons, we reveal that in Lotus, distinctive nodule- and root-inhabiting communities are established by parallel, rather than consecutive, selection of bacteria from the rhizosphere and root compartments. Comparative analyses of wild-type (WT) and symbiotic mutants in Nod factor receptor5 (nfr5), Nodule inception (nin) and Lotus histidine kinase1 (lhk1) genes identified a previously unsuspected role of the nodulation pathway in the establishment of different bacterial assemblages in the root and rhizosphere. We found that the loss of nitrogen-fixing symbiosis dramatically alters community structure in the latter two compartments, affecting at least 14 bacterial orders. The differential plant growth phenotypes seen between WT and the symbiotic mutants in nonsupplemented soil were retained under nitrogen-supplemented conditions that blocked the formation of functional nodules in WT, whereas the symbiosis-impaired mutants maintain an altered community structure in the nitrogen-supplemented soil. This finding provides strong evidence that the root-associated community shift in the symbiotic mutants is a direct consequence of the disabled symbiosis pathway rather than an indirect effect resulting from abolished symbiotic nitrogen fixation. Our findings imply a role of the legume host in selecting a broad taxonomic range of root-associated bacteria that, in addition to rhizobia, likely contribute to plant growth and ecological performance.

Microbial processes in the rhizosphere soil of a heavy metals-contaminated Mediterranean salt marsh: A facilitating role of AM fungi

Chemosphere ◽  
2006 ◽  
Vol 64 (1) ◽  
pp. 104-111 ◽  
Author(s):  
L. Carrasco ◽  
F. Caravaca ◽  
J. Álvarez-Rogel ◽  
A. Roldán
Keyword(s):  
Heavy Metals ◽  
Salt Marsh ◽  
Rhizosphere Soil ◽  
Am Fungi ◽  
Microbial Processes

scholarly journals RED KING CRAB IN THE COASTAL BARENTS SEA: A REVIEW OF MMBI STUDIES

2020 ◽  
Vol 11 (4) ◽  
pp. 134-150
Author(s):  
A.G. Dvoretsky ◽  
Keyword(s):  
Barents Sea ◽  
Benthic Communities ◽  
Red King Crab ◽  
Indigenous Status ◽  
King Crab ◽  
Symbiotic Relationships ◽  
The Barents Sea ◽  
Fishery Science

In 1960th, red king crab was intentionally introduced into the Barents Sea. This species has formed a new self-sustaining population. In Russian waters, the commercial fishery of red king crab was started in 2004. Non-indigenous status and high commercial value of the crab have led to growing interest in the study of its biology and ecology. Red king crab has been intensively studied by specialists of Murmansk Marine Biological Institute to evaluate the role of this crab in local benthic communities and provide a theoretic basis and important applications for fishery science. New data on the population dynamics, symbiotic relationships, feeding and reproduction of red king crab have been obtained from long-term studies in coastal waters of the Barents Sea. Significant results of these studies are presented in this review.

scholarly journals Comparison of nodule endophyte composition, diversity, and gene content between Medicago truncatula genotypes

2021 ◽  
Author(s):  
Mannix Burns ◽  
Brendan Epstein ◽  
Liana Burghardt
Keyword(s):  
Functional Groups ◽  
Medicago Truncatula ◽  
Root Nodules ◽  
Bacterial Endophytes ◽  
Host Genotype ◽  
Model Legume ◽  
Symbiotic Relationships ◽  
Functional Assays ◽  
Altered Gene ◽  
Significant Direct Effect

Leguminous plants form symbiotic relationships with rhizobia. These nitrogen-fixing bacteria live in specialized root organs called nodules. While rhizobia form the most notable host relationship within root nodules, other bacterial endophytes also inhabit these root nodules and can influence host-rhizobia interactions as well as exert effects of their own, whether beneficial or detrimental. In this study, we investigate differences in nodule communities between genotypes (A17 and R108) of a single plant species, the model legume Medicago truncatula. While diversity of endophytes in nodules was similar across hosts, both nodule endophyte composition and gene functional groups differed. In contrast to the significant direct effect of host genotype, neither the presence nor identity of a host in the previous generation (either A17 or R108) had a significant effect on the nodule endophyte diversity or composition. However, whether or not a host was present altered gene functional groups. We conclude that genetic variation within a legume host species can play an important role in the establishment of nodule microbiomes. Further studies, including GWAS and functional assays, can open the door for engineering and optimizing nodule endophyte communities that promote growth or have other beneficial qualities.

Role of AM Fungi and PGPR in Alleviating Stress Responses and Inducing Defense Mechanism

2021 ◽  
pp. 355-371
Author(s):  
Zeenat Mushtaq ◽  
Shahla Faizan ◽  
Basit Gulzar ◽  
Humira Mushtaq
Keyword(s):  
Stress Responses ◽  
Defense Mechanism ◽  
Am Fungi

scholarly journals Heritability jointly explained by host genotype and microbiome: will improve traits prediction?

2020 ◽  
Author(s):  
Denis Awany ◽  
Emile R Chimusa
Keyword(s):  
Genetic Variants ◽  
Association Studies ◽  
Heritability Estimate ◽  
Substantial Part ◽  
Phenotypic Variance ◽  
Genome Wide Association Studies ◽  
Host Genotype ◽  
Genome Wide ◽  
Heritability Estimation

Abstract As we observe the $70$th anniversary of the publication by Robertson that formalized the notion of ‘heritability’, geneticists remain puzzled by the problem of missing/hidden heritability, where heritability estimates from genome-wide association studies (GWASs) fall short of that from twin-based studies. Many possible explanations have been offered for this discrepancy, including existence of genetic variants poorly captured by existing arrays, dominance, epistasis and unaccounted-for environmental factors; albeit these remain controversial. We believe a substantial part of this problem could be solved or better understood by incorporating the host’s microbiota information in the GWAS model for heritability estimation and may also increase human traits prediction for clinical utility. This is because, despite empirical observations such as (i) the intimate role of the microbiome in many complex human phenotypes, (ii) the overlap between genetic variants associated with both microbiome attributes and complex diseases and (iii) the existence of heritable bacterial taxa, current GWAS models for heritability estimate do not take into account the contributory role of the microbiome. Furthermore, heritability estimate from twin-based studies does not discern microbiome component of the observed total phenotypic variance. Here, we summarize the concept of heritability in GWAS and microbiome-wide association studies, focusing on its estimation, from a statistical genetics perspective. We then discuss a possible statistical method to incorporate the microbiome in the estimation of heritability in host GWAS.

scholarly journals Streamflow recession patterns can help unravel the role of climate and humans in landscape co-evolution

2016 ◽  
Vol 20 (4) ◽  
pp. 1413-1432 ◽  
Author(s):  
Patrick W. Bogaart ◽  
Ype van der Velde ◽  
Steve W. Lyon ◽  
Stefan C. Dekker
Keyword(s):  
Land Cover ◽  
Base Flow ◽  
Natural Soil ◽  
Model Parameters ◽  
Linear Behaviour ◽  
Forested Areas ◽  
Future Landscape ◽  
Do So

Abstract. Traditionally, long-term predictions of river discharges and their extremes include constant relationships between landscape properties and model parameters. However, due to the co-evolution of many landscape properties more sophisticated methods are necessary to quantify future landscape–hydrological model relationships. As a first step towards such an approach we use the Brutsaert and Nieber (1977) analysis method to characterize streamflow recession behaviour of  ≈  200 Swedish catchments within the context of global change and landscape co-evolution. Results suggest that the Brutsaert–Nieber parameters are strongly linked to the climate, soil, land use, and their interdependencies. Many catchments show a trend towards more non-linear behaviour, meaning not only faster initial recession but also slower recession towards base flow. This trend has been found to be independent from climate change. Instead, we suggest that land cover change, both natural (restoration of natural soil profiles in forested areas) and anthropogenic (reforestation and optimized water management), is probably responsible. Both change types are characterised by system adaptation and change, towards more optimal ecohydrological conditions, suggesting landscape co-evolution is at play. Given the observed magnitudes of recession changes during the past 50 years, predictions of future river discharge critically need to include the effects of landscape co-evolution. The interconnections between the controls of land cover and climate on river recession behaviour, as we have quantified in this paper, provide first-order handles to do so.

scholarly journals Mucosal microbial parasites/symbionts in health and disease: an integrative overview

Parasitology ◽  
2019 ◽  
Vol 146 (9) ◽  
pp. 1109-1115 ◽  
Author(s):  
Robert P. Hirt
Keyword(s):  
Host Interactions ◽  
Detection Techniques ◽  
Symbiotic Relationships ◽  
Life Styles ◽  
Mucosal Surfaces ◽  
Microbe Interactions ◽  
Health And Disease ◽  
Host Microbe Interactions ◽  
Species Being

AbstractMicrobial parasites adapted to thrive at mammalian mucosal surfaces have evolved multiple times from phylogenetically distant lineages into various extracellular and intracellular life styles. Their symbiotic relationships can range from commensalism to parasitism and more recently some host–parasites interactions are thought to have evolved into mutualistic associations too. It is increasingly appreciated that this diversity of symbiotic outcomes is the product of a complex network of parasites–microbiota–host interactions. Refinement and broader use of DNA based detection techniques are providing increasing evidence of how common some mucosal microbial parasites are and their host range, with some species being able to swap hosts, including from farm and pet animals to humans. A selection of examples will illustrate the zoonotic potential for a number of microbial parasites and how some species can be either disruptive or beneficial nodes in the complex networks of host–microbe interactions disrupting or maintaining mucosal homoeostasis. It will be argued that mucosal microbial parasitic diversity will represent an important resource to help us dissect through comparative studies the role of host–microbe interactions in both human health and disease.

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