scholarly journals Molecular Analyses of the Distribution and Function of Diazotrophic Rhizobia and Methanotrophs in the Tissues and Rhizosphere of Non-Leguminous Plants

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 408 ◽  
Author(s):  
Yoneyama ◽  
Terakado-Tonooka ◽  
Bao ◽  
Minamisawa
Keyword(s):  
N2 Fixation ◽  
Active Nitrogen ◽  
Leguminous Plants ◽  
Molecular Analyses ◽  
Nitrogen Fixers ◽  
Research Perspectives ◽  
Enzymatic Reduction ◽  
And Function ◽  
Biological Nitrogen ◽  
Bradyrhizobium Spp

Biological nitrogen fixation (BNF) by plants and its bacterial associations represent an important natural system for capturing atmospheric dinitrogen (N2) and processing it into a reactive form of nitrogen through enzymatic reduction. The study of BNF in non-leguminous plants has been difficult compared to nodule-localized BNF in leguminous plants because of the diverse sites of N2 fixation in non-leguminous plants. Identification of the involved N2-fixing bacteria has also been difficult because the major nitrogen fixers were often lost during isolation attempts. The past 20 years of molecular analyses has led to the identification of N2 fixation sites and active nitrogen fixers in tissues and the rhizosphere of non-leguminous plants. Here, we examined BNF hotspots in six reported non-leguminous plants. Novel rhizobia and methanotrophs were found to be abundantly present in the free-living state at sites where carbon and energy sources were predominantly available. In the carbon-rich apoplasts of plant tissues, rhizobia such as Bradyrhizobium spp. microaerobically fix N2. In paddy rice fields, methane molecules generated under anoxia are oxidized by xylem aerenchyma-transported oxygen with the simultaneous fixation of N2 by methane-oxidizing methanotrophs. We discuss the effective functions of the rhizobia and methanotrophs in non-legumes for the acquisition of fixed nitrogen in addition to research perspectives.

RADIOACTIVE NITROGEN IN THE STUDY OF N2 FIXATION BY NON-LEGUMINOUS PLANTS

Science ◽  
1940 ◽  
Vol 91 (2372) ◽  
pp. 578-579 ◽  
Author(s):  
S. RUBEN ◽  
W. Z. HASSID ◽  
M. D. KAMEN
Keyword(s):  
N2 Fixation ◽  
Leguminous Plants

scholarly journals Acacia longifolia: A Host of Many Guests Even after Fire

Diversity ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 250
Author(s):  
Joana Guedes de Jesus ◽  
Rogério Tenreiro ◽  
Cristina Máguas ◽  
Helena Trindade
Keyword(s):  
Bacterial Communities ◽  
Plant Nitrogen ◽  
Partial Sequencing ◽  
Molecular Approaches ◽  
Nitrogen Fixers ◽  
Isotopic Analyses ◽  
Legume Symbiosis ◽  
Acacia Longifolia ◽  
One Year ◽  
Bradyrhizobium Spp

Acacia longifolia is a worldwide invader that cause damage in ecosystems, expanding largely after wildfires, which promote germination of a massive seed bank. As a legume, symbiosis is determinant for adaptation. Our study aims to isolate a wider consortium of bacteria harboured in nodules, including both nitrogen and non-nitrogen fixers. Furthermore, we aim to evaluate the effects of fire in nodulation and bacterial diversity on young acacias growing in unburnt and burnt zones, one year after the fire. For this, we used molecular approaches, M13 fingerprinting and 16S rRNA partial sequencing, to identify species/genera involved and δ15N isotopic composition in leaves and plant nodules. Nitrogen isotopic analyses in leaves suggest that in unburnt zones, nitrogen fixation contributes more to plant nitrogen content. Overall, A. longifolia seems to be promiscuous and despite Bradyrhizobium spp. dominance, Paraburkholderia spp. followed by Pseudomonas spp. was also found. Several species not previously reported as nitrogen-fixers were identified, proposing other functions besides ammonia acquisition. Our study shows that bacterial communities are different in nodules after fire. Fire seems to potentiate nodulation and drives symbiosis towards nitrogen-fixers. Taken together, a multifunctional community inside nodules is pointed out which potentiate A. longifolia invasiveness and adaptation.

Mucin gene structure and expression: protection vs. adhesion

1995 ◽  
Vol 269 (5) ◽  
pp. G613-G627 ◽  
Author(s):  
B. J. Van Klinken ◽  
J. Dekker ◽  
H. A. Buller ◽  
A. W. Einerhand
Keyword(s):  
Molecular Biology ◽  
Gene Structure ◽  
Lymphocyte Activation ◽  
Structure And Function ◽  
Lymphocyte Homing ◽  
Major Step ◽  
Molecular Analyses ◽  
Specific Receptors ◽  
Gene Structure And Expression ◽  
And Function

The cloning of mucin cDNAs brought about by the application of molecular biology and molecular analyses constitutes a major step in understanding mucin structure and function. Here two classes of mucins are described: epithelium-associated and endothelium/leukocyte-associated mucins, which have thus far been described separately in the literature. The epithelial mucins are generally believed to play a role in cytoprotection. The endothelial and leukocyte class of mucins are adhesion molecules involved in lymphocyte homing and lymphocyte activation or are part of the adhesion cascade that plays a role in the initiation of inflammation. Mucins in general contain many threonine and serine residues, which are extensively O-glycosylated. Due to this profound glycosylation, mucins have a filamentous conformation. By virtue of their extended filamentous, and often negatively charged, structure, mucins can act as a barrier protecting the cell. However, when an opposing cell has specific receptors for mucins, adhesion can override the barrier function. Therefore, mucins may be powerful two-edged swords: they are both protective and adhesive.

scholarly journals Übersetzungen in Enzyklopädien

2021 ◽  
pp. 185-202
Author(s):  
Hans-Jürgen Lüsebrink
Keyword(s):  
Second Line ◽  
Research Perspectives ◽  
Intercultural Adaptation ◽  
Fundamental Research ◽  
Age Of Enlightenment ◽  
And Function

ZusammenfassungThis paper addresses the questions posed in the SPP project “Translational Dimensions of French Encyclopaedism in the Age of Enlightenment, 1680–1800” (directors: Susanne Greilich/Regensburg, Hans-Jürgen Lüsebrink/Saarbrücken). The paper distinguishes two fundamental research perspectives in the analysis of encyclopaedic works in a translation context: first, the translation of encyclopaedic works into other languages, which often involved intercultural adaptation; and second, the use and function of translations, together with reflections on and criticism thereof, in encyclopaedic works. This second line of investigation will be pursued with reference to the articles on “Translation” in the Encyclopédie (1751–1772) and its Supplement (1777–1778) by Diderot and D'Alembert and the Encyclopédie Méthodique (1782–1832) as well as to the volumes of the Encyclopédie Méthodique on Philosophie moderne, edited and partly written by J.-A. Naigeon, especially the article on Hume.

scholarly journals EFFECT OF PHOSPHATE ON NODULE PRIMORDIA OF SOYBEAN (Glycine max Merrill) IN ACID SOILS IN RHIZOTRON EXPERIMENTS

2016 ◽  
Vol 5 (2) ◽  
pp. 37 ◽  
Author(s):  
Setiyo Hadi Waluyo ◽  
Tek An Lie ◽  
Leendert ’t Mannetje
Keyword(s):  
Nitrogen Fixation ◽  
Root Growth ◽  
Acid Soils ◽  
Nodule Formation ◽  
Soybean Plant ◽  
Limiting Nutrients ◽  
West Sumatra ◽  
And Function ◽  
Biological Nitrogen ◽  
Positive Effect

To clarify whether P had a direct or indirect effect on the nodulation  process of soybean grown in acid soils from Sitiung, West Sumatra, Indonesia, a series of rhizotron experiments, with special attention given to formation of nodule primordia, was conducted at Laboratory of  Microbiology, Wageningen University in 1998-2000. It was shown that Ca and P were essential nutrients for root growth, nodule formation, and growth of soybean in the acid soils (Oxisols). Ca increased root growth, number of nodule primordia, nodules, and growth of the soybean plant. This positive effect of Ca was increased considerably by the application of P. Ca and P have a synergistic effect on biological nitrogen fixation (BNF) of soybean in acid soils. Ca is important for the establishment of nodules, whilst P is essential for the development and function of the formed nodules. P increased number of nodule primordia, thus it also has an important role in the initiation of nodule formation. From this study, it can be concluded that Ca and P are the most limiting nutrients for BNF of soybean in the acid soils of Sitiung, West Sumatra, Indonesia.

scholarly journals Determination of N2 and N2O Fixation Rates in Leguminous Plants and Three Different Soil Types by Labeling Experiments with Stable Nitrogen Isotopes

2018 ◽  
Author(s):  
Martin Nowak ◽  
Felix Koegler
Keyword(s):  
N2 Fixation ◽  
Root Nodules ◽  
Microbial Transformation ◽  
Terrestrial Ecosystems ◽  
Soil Types ◽  
Wetland Soils ◽  
N2o Emissions ◽  
Fixation Rate ◽  
Leguminous Plants ◽  
Uptake Rates

Nitrogen (N) is an essential nutrient and plays an important role in plant growth and physiology. In addition, N is also the limiting nutrient in most terrestrial ecosystems. The increasing use of N fertilizers increases agricultural production, but also has negative impacts on biodiversity, water quality and increases emissions of greenhouse gases such as nitrogen oxides (NOx) and nitrous oxide (N2O) into the atmosphere. N2O is a strong greenhouse gas and the product of microbial transformation processes of N introduced into soil and groundwater (nitrification and denitrification). The production of N2O in soils is highly dependent on oxygen and water content, soil temperature and texture and the available amount of reactive nitrogen (NO3- or NH4+). In agricultural soils, N2O emissions are also influenced by the type of fertilizer used, crops grown, soil pH and NO3- concentration. Refined forms of land management, such as the cultivation of legumes, can reduce the use of fertilizers and thus also the emission of N2O. Legumes can use symbiotic nodule bacteria (rhizobia) to bind atmospheric N2 and make it available to the plant. Non-symbiotic soil microorganisms such as cyanobacteria or other heterotrophic and autotrophic prokaryotes are also able to fix N2. Furthermore, the N2-fixing enzyme nitrogenase, which is specific for most organisms, is not specific for other N2 compounds, especially N2O. To study the N2 and N2O fixation potential of soils and legumes, experiments with isotope-enriched N-gases (100 mol% 15N2 and 15N2O) were performed. Three different soil types (forest, meadow and wetland) as well as legume plants inoculated with rhizobia bacteria (Rhizobium leucaneae) (Leucaena leucocephala) were incubated in microcosms with different mixing ratios of N2 and N2O over a period of one week. The measured 15N enrichment was then used to determine the biological uptake rates. Both in plants and in soils admixtures of up to 40% N2O had no influence on the N2 fixation rate. N2 uptake rates were 1.2 ± 0.4 ug N gdw-1 d- 1in forest and grassland soils and 3.9 ± 1.2 ug N gdw-1 d- 1 in wetland soils. In contrast, the N2 fixation rates of leguminous plants were significantly higher (130 ± 40 ug N gdw-1 d- 1), with the highest accumulation not in root nodules but in the roots. In both plants and soil, the N2O fixation of 0.2 ± 0.1 ug N gdw-1 d- 1 could only be measured from a concentration of 4 vol%. The results indicate that both soils and legumes have a high potential to bind atmospheric nitrogen in the form of both N2 but not N2O. The fate of nitrogen in soil needs to be further investigated. N2 fixation seems to play an important role in wetland soils. Legumes in particular have the potential for NH4+ input and N2O reduction, as most of the solid nitrogen has been transferred to the roots, which can contribute significantly to soil nutrient input.

scholarly journals Effect of bio-fertilizers on foliage and floral traits of chrysanthemum cv Little Pink

2021 ◽  
Vol 17 (2) ◽  
pp. 162-166
Author(s):  
Shashank Dixit ◽  
A.K. Panday ◽  
Anurag Bajpay
Keyword(s):  
Growth Habit ◽  
Floral Traits ◽  
Live Cells ◽  
Dendranthema Grandiflora ◽  
Nitrogen Fixers ◽  
Phosphate Solubilizing ◽  
Biological Nitrogen ◽  
Asteraceae Family ◽  
Vast Range ◽  
Pot Plant

Chrysanthemum (Dendranthema grandiflora) is a leading commercial flower crop from asteraceae family grown for cut and loose flowers and also as a pot plant. It is preferred practically due to vast range of shapes and size of flowers, brilliance of colour tones, long lasting floret life, diversity of height and growth habit of the plant, especially hardy nature, relative ease to grow all the year round and versatility of use. Biofertilizers are the multiplied live cells of beneficial strains of micro-organism, are used as biological nitrogen fixers, Phosphate solubilizing, and also used for mineralization of nitrogen and transformation of several elements like sulphur and iron etc. into available forms. The present investigation was conducted at the Horticulture experimental field of Janta College, Bakewar in Complete Randomize Design with 4 treatments and 4 replications. Observations were recorded for vegetative and floral traits upon various biofertilizers treatments viz., T1: Control, T2: (FYM 50% + Soil 50% + 2gm PSB @Per pot), T3 : (FYM 50% + Soil 50% + 2gm Azotobacter @Per pot) and T4: (FYM 50% + Soil 50% + 1gm PSB + 1g Azotobacter@Per pot).

scholarly journals Heterotrophic bacterial diazotrophs are more abundant than their cyanobacterial counterparts in metagenomes covering most of the sunlit ocean

2021 ◽  
Author(s):  
Tom O. Delmont ◽  
Juan Jose Pierella Karlusich ◽  
Iva Veseli ◽  
Jessika Fuessel ◽  
A. Murat Eren ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogen Balance ◽  
Large Scale ◽  
Current View ◽  
Low Oxygen ◽  
Nitrogen Fixers ◽  
Large Size ◽  
Genomic Characterization ◽  
Biological Nitrogen ◽  
Nifh Genes

Biological nitrogen fixation is a major factor contributing to microbial primary productivity in the open ocean. The current view depicts a few cyanobacterial diazotrophs as the most relevant marine nitrogen fixers, whereas heterotrophic diazotrophs are more diverse and considered to have lower impacts on the nitrogen balance. Here, we used 891 Tara Oceans metagenomes to create a manually curated, non-redundant genomic database corresponding to free-living, as well as filamentous, colony-forming, particle-attached and symbiotic bacterial and archaeal populations occurring in the surface of five oceans and two seas. Notably, the database provided the genomic content of eight cyanobacterial diazotrophs including Trichodesmium populations and a newly discovered population similar to Richelia, as well as 40 heterotrophic bacterial diazotrophs organized into three main functional groups that considerably expand the known diversity of abundant marine nitrogen fixers compared to previous genomic surveys. Critically, these 48 populations may account for more than 90% of cells containing known nifH genes and occurring in the sunlit ocean, suggesting that the genomic characterization of the most abundant marine diazotrophs may be nearing completion. The newly identified heterotrophic bacterial diazotrophs are widespread, express their nifH genes in situ, and co-occur under nitrate-depleted conditions in large size fractions where they might form aggregates providing the low-oxygen microenvironments required for nitrogen fixation. Most significantly, we found heterotrophic bacterial diazotrophs to be more abundant than cyanobacterial diazotrophs in most metagenomes from the open oceans and seas. This large-scale environmental genomic survey emphasizes the considerable potential of heterotrophs in the marine nitrogen balance.

Endothelial and Cardiac Dysfunction in Inflammatory Bowel Diseases: Does Treatment Modify the Inflammatory Load on Arterial and Cardiac Structure and Function?

2019 ◽  
Vol 18 (1) ◽  
pp. 27-37
Author(s):  
Charilaos Triantafyllou ◽  
Maria Nikolaou ◽  
Ignatios Ikonomidis ◽  
Giorgos Bamias ◽  
Ioannis Papaconstantinou
Keyword(s):  
Inflammatory Bowel Diseases ◽  
Structure And Function ◽  
Cardiac Structure ◽  
Gastrointestinal Physiology ◽  
Research Perspectives ◽  
Increased Risk ◽  
Bowel Diseases ◽  
Inflammatory Bowel ◽  
Cardiac Structure And Function ◽  
And Function

Inflammatory bowel diseases (IBD), largely represented by Crohn’s disease (CD) and ulcerative colitis (UC), alter gastrointestinal physiology and mucosal immunity through a complex inflammatory process. These diseases can lead to significant arterial endothelial dysfunction. There is also evidence linking IBD with a modification of cardiac structure and function. A growing body of research has associated IBD with an acceleration of arterial stiffness and atherosclerosis and an increased risk of cardiovascular (CV) morbidity and mortality. The focus of this review is two-fold. Firstly, the literature on IBD in relation to CV dysfunction was evaluated (mainly based on 25 relevant surveys carried out between 2005 and 2018). The vast majority of these studies support a significant association of IBD with a deterioration in CV function. Secondly, the literature available regarding the effect of IBD treatment on CV dysfunction was considered based on studies published between 2007 and 2018. This literature search suggests that IBD treatment may have the potential to ameliorate CV dysfunction resulting in CV benefits. This review will analyse the literature as well as consider emerging research perspectives regarding how IBD treatment could improve CV dysfunction.

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