Nodule Formation and Function

2001 ◽  
pp. 101-146 ◽  
Author(s):  
Anthony J. Gordon ◽  
Peter J. Lea ◽  
Charles Rosenberg ◽  
Jean-Charles Trinchant
Keyword(s):  
Nodule Formation ◽  
And Function

scholarly journals Differential Effects of Combined N Sources on Early Steps of the Nod Factor–Dependent Transduction Pathway in Lotus japonicus

2007 ◽  
Vol 20 (8) ◽  
pp. 994-1003 ◽  
Author(s):  
Ani Barbulova ◽  
Alessandra Rogato ◽  
Enrica D'Apuzzo ◽  
Selim Omrane ◽  
Maurizio Chiurazzi
Keyword(s):  
Root Nodules ◽  
Lotus Japonicus ◽  
Small Scale ◽  
Nodule Formation ◽  
Inhibitory Effects ◽  
Nod Factor ◽  
Mesorhizobium Loti ◽  
N Sources ◽  
N Starvation ◽  
And Function

The development of nitrogen-fixing nodules in legumes is induced by perception of lipochitin-oligosaccharide signals secreted by a bacterial symbiont. Nitrogen (N) starvation is a prerequisite for the formation, development, and function of root nodules, and high levels of combined N in the form of nitrate or ammonium can completely abolish nodule formation. We distinguished between nitrate and ammonium inhibitory effects by identifying when and where these combined N sources interfere with the Nod-factor-induced pathway. Furthermore, we present a small-scale analysis of the expression profile, under different N conditions, of recently identified genes involved in the Nod-factor-induced pathway. In the presence of high levels of nitrate or ammonium, the NIN gene fails to be induced 24 h after the addition of Nod factor compared with plants grown under N-free conditions. This induction is restored in the hypernodulating nitrate-tolerant har1-3 mutant only in the presence of 10 and 20 mM KNO3. These results were confirmed in Lotus plants inoculated with Mesorhizobium loti. NIN plays a key role in the nodule organogenesis program and its downregulation may represent a crucial event in the nitrate-dependent pathway leading to the inhibition of nodule organogenesis.

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 Porphyromonas gingivalis Lipids Inhibit Osteoblastic Differentiation and Function

2010 ◽  
Vol 78 (9) ◽  
pp. 3726-3735 ◽  
Author(s):  
Yu-Hsiung Wang ◽  
Jin Jiang ◽  
Qiang Zhu ◽  
Amer Z. AlAnezi ◽  
Robert B. Clark ◽  
...  
Keyword(s):  
Gene Expression ◽  
Porphyromonas Gingivalis ◽  
Osteoblast Differentiation ◽  
Marker Genes ◽  
Nodule Formation ◽  
Dependent Manner ◽  
Bone Homeostasis ◽  
Total Lipids ◽  
And Function ◽  
Calvarial Osteoblast

ABSTRACT Porphyromonas gingivalis produces unusual sphingolipids that are known to promote inflammatory reactions in gingival fibroblasts and Toll-like receptor 2 (TLR2)-dependent secretion of interleukin-6 from dendritic cells. The aim of the present study was to examine whether P. gingivalis lipids inhibit osteoblastic function. Total lipids from P. gingivalis and two fractions, phosphoglycerol dihydroceramides and phosphoethanolamine dihydroceramides, were prepared free of lipid A. Primary calvarial osteoblast cultures derived from 5- to 7-day-old CD-1 mice were used to examine the effects of P. gingivalis lipids on mineralized nodule formation, cell viability, apoptosis, cell proliferation, and gene expression. P. gingivalis lipids inhibited osteoblast differentiation and fluorescence expression of pOBCol2.3GFP in a concentration-dependent manner. However, P. gingivalis lipids did not significantly alter osteoblast proliferation, viability, or apoptosis. When administered during specific intervals of osteoblast growth, P. gingivalis total lipids demonstrated inhibitory effects on osteoblast differentiation only after the proliferation stage of culture. Reverse transcription-PCR confirmed the downregulation of osteoblast marker genes, including Runx2, ALP, OC, BSP, OPG, and DMP-1, with concurrent upregulation of RANKL, tumor necrosis factor alpha, and MMP-3 genes. P. gingivalis total lipids and lipid fractions inhibited calvarial osteoblast gene expression and function in vivo, as determined by the loss of expression of another osteoblast differentiation reporter, pOBCol3.6GFPcyan, and reduced uptake of Alizarin complexone stain. Finally, lipid inhibition of mineral nodule formation in vitro was dependent on TLR2 expression. Our results indicate that inhibition of osteoblast function and gene expression by P. gingivalis lipids represents a novel mechanism for altering alveolar bone homeostasis at periodontal disease sites.

scholarly journals Transcription of ENOD8 in Medicago truncatula Nodules Directs ENOD8 Esterase to Developing and Mature Symbiosomes

2008 ◽  
Vol 21 (4) ◽  
pp. 404-410 ◽  
Author(s):  
Laurent Coque ◽  
Purnima Neogi ◽  
Catalina Pislariu ◽  
Kimberly A. Wilson ◽  
Christina Catalano ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Immunoblot Analysis ◽  
Nodule Formation ◽  
Nitrogenous Compounds ◽  
Symbiosome Membrane ◽  
The Matrix ◽  
And Function ◽  
Infected Nodule

In Medicago truncatula nodules, the soil bacterium Sinorhizobium meliloti reduces atmospheric dinitrogen into nitrogenous compounds that the legume uses for its own growth. In nitrogen-fixing nodules, each infected cell contains symbiosomes, which include the rhizobial cell, the symbiosome membrane surrounding it, and the matrix between the bacterium and the symbiosome membrane, termed the symbiosome space. Here, we describe the localization of ENOD8, a nodule-specific esterase. The onset of ENOD8 expression occurs at 4 to 5 days postinoculation, before the genes that support the nitrogen fixation capabilities of the nodule. Expression of an ENOD8 promoter–gusA fusion in nodulated hairy roots of composite transformed M. truncatula plants indicated that ENOD8 is expressed from the proximal end of interzone II to III to the proximal end of the nodules. Confocal immunomicroscopy using an ENOD8-specific antibody showed that the ENOD8 protein was detected in the same zones. ENOD8 protein was localized in the symbiosome membrane or symbiosome space around the bacteroids in the infected nodule cells. Immunoblot analysis of fractionated symbiosomes strongly suggested that ENOD8 protein was found in the symbiosome membrane and symbiosome space, but not in the bacteroid. Determining the localization of ENOD8 protein in the symbiosome is a first step in understanding its role in symbiosome membrane and space during nodule formation and function.

scholarly journals The role of microRNAs in the legume–Rhizobium nitrogen-fixing symbiosis

2020 ◽  
Vol 71 (5) ◽  
pp. 1668-1680 ◽  
Author(s):  
Nhung T Hoang ◽  
Katalin Tóth ◽  
Gary Stacey
Keyword(s):  
Vascular System ◽  
Regulation Of Gene Expression ◽  
Lotus Japonicus ◽  
Nodule Formation ◽  
Nitrogen Fixing ◽  
Rna Molecules ◽  
Physiological Processes ◽  
Leaf Tissues ◽  
And Function

Abstract Under nitrogen starvation, most legume plants form a nitrogen-fixing symbiosis with Rhizobium bacteria. The bacteria induce the formation of a novel organ called the nodule in which rhizobia reside as intracellular symbionts and convert atmospheric nitrogen into ammonia. During this symbiosis, miRNAs are essential for coordinating the various plant processes required for nodule formation and function. miRNAs are non-coding, endogenous RNA molecules, typically 20–24 nucleotides long, that negatively regulate the expression of their target mRNAs. Some miRNAs can move systemically within plant tissues through the vascular system, which mediates, for example, communication between the stem/leaf tissues and the roots. In this review, we summarize the growing number of miRNAs that function during legume nodulation focusing on two model legumes, Lotus japonicus and Medicago truncatula, and two important legume crops, soybean (Glycine max) and common bean (Phaseolus vulgaris). This regulation impacts a variety of physiological processes including hormone signaling and spatial regulation of gene expression. The role of mobile miRNAs in regulating legume nodule number is also highlighted.

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 Aluminum adjuvants elicit fibrin-dependent extracellular traps in vivo

Blood ◽  
2010 ◽  
Vol 116 (24) ◽  
pp. 5191-5199 ◽  
Author(s):  
Michael W. Munks ◽  
Amy S. McKee ◽  
Megan K. MacLeod ◽  
Roger L. Powell ◽  
Jay L. Degen ◽  
...  
Keyword(s):  
T Cell ◽  
The Body ◽  
Nodule Formation ◽  
Adjuvant Effect ◽  
Adjuvant Activity ◽  
Aluminum Salts ◽  
Extracellular Traps ◽  
Dnase Treatment ◽  
And Function

Abstract It has been recognized for nearly 80 years that insoluble aluminum salts are good immunologic adjuvants and that they form long-lived nodules in vivo. Nodule formation has long been presumed to be central for adjuvant activity by providing an antigen depot, but the composition and function of these nodules is poorly understood. We show here that aluminum salt nodules formed within hours of injection and contained the clotting protein fibrinogen. Fibrinogen was critical for nodule formation and required processing to insoluble fibrin by thrombin. DNase treatment partially disrupted the nodules, and the nodules contained histone H3 and citrullinated H3, features consistent with extracellular traps. Although neutrophils were not essential for nodule formation, CD11b+ cells were implicated. Vaccination of fibrinogen-deficient mice resulted in normal CD4 T-cell and antibody responses and enhanced CD8 T-cell responses, indicating that nodules are not required for aluminum's adjuvant effect. Moreover, the ability of aluminum salts to retain antigen in the body, the well-known depot effect, was unaffected by the absence of nodules. We conclude that aluminum adjuvants form fibrin-dependent nodules in vivo, that these nodules have properties of extracellular traps, and the nodules are not required for aluminum salts to act as adjuvants.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

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