scholarly journals Localization of acid phosphatase activity in the apoplast of root nodules of pea (Pisum sativum)

2011 ◽  
Vol 75 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Marzena Sujkowska ◽  
Wojciech Borucki ◽  
Władysław Golinowski
Keyword(s):  
Enzyme Activity ◽  
Acid Phosphatase ◽  
Pisum Sativum ◽  
Root Nodule ◽  
Root Nodules ◽  
Outer Part ◽  
Inorganic Phosphorus ◽  
Infection Thread ◽  
Symbiotic Bacteria ◽  
Infection Threads

Changes in the activity of acid phosphatase (AcPase) in the apoplast of pea root nodule were investigated. The activity was determined using lead and cerium methods. The results indicated a following sequence of AcPase activity appearance during the development of the infection thread: 1) low AcPase activity appears in the outer part of cells of symbiotic bacteria; 2) bacteria show increased AcPase activity, and the enzyme activity appears in the thread walls; 3) activity exhibits also matrix of the infection thread; 4) bacteria just before their release from the infection threads show high AcPase activity; 5) AcPase activity ceases after bacteria transformation into bacteroids. The increase in bacterial AcPase activity may reflect a higher demand for inorganic phosphorus necessary for propagation of the bacteria within the infection threads and/or involved in bacteria release from the infection threads.

scholarly journals Alfalfa Root Nodule Invasion Efficiency Is Dependent on Sinorhizobium melilotiPolysaccharides

2000 ◽  
Vol 182 (15) ◽  
pp. 4310-4318 ◽  
Author(s):  
Brett J. Pellock ◽  
Hai-Ping Cheng ◽  
Graham C. Walker
Keyword(s):  
Molecular Weight ◽  
Sinorhizobium Meliloti ◽  
Root Nodule ◽  
Fluorescent Protein ◽  
Infection Thread ◽  
Low Molecular Weight ◽  
Infection Threads ◽  
Green Fluorescent ◽  
K Antigen ◽  
Alfalfa Root

ABSTRACT The soil bacterium Sinorhizobium meliloti is capable of entering into a nitrogen-fixing symbiosis with Medicago sativa (alfalfa). Particular low-molecular-weight forms of certain polysaccharides produced by S. meliloti are crucial for establishing this symbiosis. Alfalfa nodule invasion by S. meliloti can be mediated by any one of three symbiotically important polysaccharides: succinoglycan, EPS II, or K antigen (also referred to as KPS). Using green fluorescent protein-labeled S. meliloti cells, we have shown that there are significant differences in the details and efficiencies of nodule invasion mediated by these polysaccharides. Succinoglycan is highly efficient in mediating both infection thread initiation and extension. However, EPS II is significantly less efficient than succinoglycan at mediating both invasion steps, and K antigen is significantly less efficient than succinoglycan at mediating infection thread extension. In the case of EPS II-mediated symbioses, the reduction in invasion efficiency results in stunted host plant growth relative to plants inoculated with succinoglycan or K-antigen-producing strains. Additionally, EPS II- and K-antigen-mediated infection threads are 8 to 10 times more likely to have aberrant morphologies than those mediated by succinoglycan. These data have important implications for understanding how S. meliloti polysaccharides are functioning in the plant-bacterium interaction, and models are discussed.

scholarly journals The Noncanonical Heat Shock Protein PvNod22 Is Essential for Infection Thread Progression During Rhizobial Endosymbiosis in Common Bean

2019 ◽  
Vol 32 (8) ◽  
pp. 939-948
Author(s):  
Jonathan Rodríguez-López ◽  
Alejandrina Hernández López ◽  
Georgina Estrada-Navarrete ◽  
Federico Sánchez ◽  
Claudia Díaz-Camino
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Common Bean ◽  
Root Nodule ◽  
Plant Immunity ◽  
Small Heat Shock Protein ◽  
Infection Thread ◽  
Nodule Development ◽  
Virus Induced Gene Silencing ◽  
Infection Threads

In the establishment of plant-rhizobial symbiosis, the plant hosts express nodulin proteins during root nodule organogenesis. A limited number of nodulins have been characterized, and these perform essential functions in root nodule development and metabolism. Most nodulins are expressed in the nodule and at lower levels in other plant tissues. Previously, we isolated Nodulin 22 (PvNod22) from a common bean (Phaseolus vulgaris L.) cDNA library derived from Rhizobium-infected roots. PvNod22 is a noncanonical, endoplasmic reticulum (ER)-localized, small heat shock protein that confers protection against oxidative stress when overexpressed in Escherichia coli. Virus-induced gene silencing of PvNod22 resulted in necrotic lesions in the aerial organs of P. vulgaris plants cultivated under optimal conditions, activation of the ER-unfolded protein response (UPR), and, finally, plant death. Here, we examined the expression of PvNod22 in common bean plants during the establishment of rhizobial endosymbiosis and its relationship with two cellular processes associated with plant immunity, the UPR and autophagy. In the RNA interference lines, numerous infection threads stopped their progression before reaching the cortex cell layer of the root, and nodules contained fewer nitrogen-fixing bacteroids. Collectively, our results suggest that PvNod22 has a nonredundant function during legume-rhizobia symbiosis associated with infection thread elongation, likely by sustaining protein homeostasis in the ER.

A correlated light and electron microscopic study of symbiotic growth and differentiation in Pisum sativum root nodules

1976 ◽  
Vol 54 (18) ◽  
pp. 2163-2186 ◽  
Author(s):  
William Newcomb
Keyword(s):  
Electron Microscopy ◽  
Pisum Sativum ◽  
Rhizobium Leguminosarum ◽  
Root Nodules ◽  
Light And Electron Microscopy ◽  
Infection Thread ◽  
Electron Microscopic ◽  
Cortical Cells ◽  
Garden Pea ◽  
Host Cytoplasm

Plants of the garden pea Pisum sativum cv. Little Marvel were grown in aeroponic culture to facilitate observations and microscopy and were inoculated with Rhizobium leguminosarum, and nodules were sampled at five weekly intervals for light and electron microscopy. The invasion of the cortical cells by the infection thread, the structure of the infection thread, and the release of bacteria from it into the host cytoplasm and the subsequent symbiotic growth and differentiation of the two organisms are described in detail. The fine structure of the nodule is correlated with light microscopic observations and morphogenesis. A restriction in the use of the term 'vesicle' is proposed because of the current multiple and confusing usage of the term. The loss of the nodule meristem and its morphogenetic significance are discussed.

scholarly journals Transcriptomic analysis with the progress of symbiosis in ‘crack-entry’ legume Arachis hypogaea highlights its contrast with ‘infection thread’ adapted legumes

2018 ◽  
Author(s):  
Kanchan Karmakar ◽  
Anindya Kundu ◽  
Ahsan Z Rizvi ◽  
Emeric Dubois ◽  
Dany Severac ◽  
...  
Keyword(s):  
Arachis Hypogaea ◽  
Root Nodule ◽  
Infection Thread ◽  
Symbiotic Genes ◽  
Cortical Cells ◽  
Transcriptional Dynamics ◽  
Infection Threads ◽  
Spread Of Infection ◽  
Molecular Framework ◽  
Nodule Symbiosis

ABSTRACTIn root-nodule symbiosis, rhizobial invasion and nodule organogenesis is host controlled. In most legumes, rhizobia enter through infection-threads and nodule primordium in the cortex is induced from a distance. But in dalbergoid legumes like Arachis hypogaea, rhizobia directly invade cortical cells through epidermal cracks to generate the primordia. Herein we report the transcriptional dynamics with the progress of symbiosis in A. hypogaea at 1dpi: invasion; 4dpi: nodule primordia; 8dpi: spread of infection in nodule-like structure; 12dpi: immature nodules containing rod-shaped rhizobia; and 21dpi: mature nodules with spherical symbiosomes. Expression of putative orthologue of symbiotic genes in ‘crack-entry’ legume A. hypogaea was compared with infection thread adapted model legumes. The contrasting features were (i) higher expression of receptors like LYR3, EPR3 as compared to canonical NFRs (ii) late induction of transcription factors like NIN, NSP2 and constitutive high expression of ERF1, EIN2, bHLH476 and (iii) induction of divergent pathogenesis responsive PR-1 genes. Additionally, symbiotic orthologues of SymCRK, FLOT4, ROP6, RR9, NOOT and SEN1 were not detectable and microsynteny analysis indicated the absence of RPG and DNF2 homologues in diploid parental genomes of A. hypogaea. The implications are discussed and a molecular framework that guide ‘crack-entry’ symbiosis in A. hypogaea is proposed.

scholarly journals The Ethylene Responsive Factor Required for Nodulation 1 (ERN1) Transcription Factor Is Required for Infection-Thread Formation in Lotus japonicus

2017 ◽  
Vol 30 (3) ◽  
pp. 194-204 ◽  
Author(s):  
Yasuyuki Kawaharada ◽  
Euan K. James ◽  
Simon Kelly ◽  
Niels Sandal ◽  
Jens Stougaard
Keyword(s):  
Transcription Factor ◽  
Root Nodule ◽  
Lotus Japonicus ◽  
Epidermal Cells ◽  
Infection Thread ◽  
Nod Factor ◽  
Infection Threads ◽  
Thread Formation ◽  
Ethylene Responsive Factor ◽  
Infection Thread Formation

Several hundred genes are transcriptionally regulated during infection-thread formation and development of nitrogen-fixing root nodules. We have characterized a set of Lotus japonicus mutants impaired in root-nodule formation and found that the causative gene, Ern1, encodes a protein with a characteristic APETALA2/Ethylene Responsive Factor (AP2/ERF) transcription-factor domain. Phenotypic characterization of four ern1 alleles shows that infection pockets are formed but root-hair infection threads are absent. Formation of root-nodule primordia is delayed and no normal transcellular infection threads are found in the infected nodules. Corroborating the role of ERN1 (ERF Required for Nodulation1) in nodule organogenesis, spontaneous nodulation induced by an autoactive CCaMK and cytokinin–induced nodule primordia were not observed in ern1 mutants. Expression of Ern1 is induced in the susceptible zone by Nod factor treatment or rhizobial inoculation. At the cellular level, the pErn1:GUS reporter is highly expressed in root epidermal cells of the susceptible zone and in the cortical cells that form nodule primordia. The genetic regulation of this cellular expression pattern was further investigated in symbiotic mutants. Nod factor induction of Ern1 in epidermal cells was found to depend on Nfr1, Cyclops, and Nsp2 but was independent of Nin and Nf-ya1. These results suggest that ERN1 functions as a transcriptional regulator involved in the formation of infection threads and development of nodule primordia and may coordinate these two processes.

Localization of acid phosphatase activity in the apoplast of pea (Pisum sativum L.) root nodules grown under phosphorus deficiency

2006 ◽  
Vol 28 (3) ◽  
pp. 263-271 ◽  
Author(s):  
Marzena Sujkowska ◽  
Wojciech Borucki ◽  
Władysław Golinowski
Keyword(s):  
Acid Phosphatase ◽  
Pisum Sativum ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Root Nodules ◽  
Phosphorus Deficiency ◽  
Pisum Sativum L

scholarly journals Morphogenesis of root nodules in white clover. III. The effect of mutation in nod IJ genes of the microsymbiont upon the DNA level in the host tissue

2014 ◽  
Vol 67 (1) ◽  
pp. 23-29
Author(s):  
Barbara Łotocka ◽  
Władysław Golinowski
Keyword(s):  
White Clover ◽  
Rhizobium Leguminosarum ◽  
Root Nodule ◽  
Nuclear Dna ◽  
Root Nodules ◽  
Root Hairs ◽  
Infection Threads ◽  
Dna Contents ◽  
Mutant Strains ◽  
Nuclear Dna Contents

On the basis of cytophotometric measurements a slightly increased DNA level in the nuclei of curled root hairs containing infection threads was observed in white clover inoculated with wild and mutant strains of <em>Rhizobium leguminosarum</em> biovar. <em>trifolii</em>, as compared to normal root hairs of te same plants. Cells of the root nodule primordia in 72 h after the inoculation, as compared to the root primary cortex, demonstrated an increased level of the nuclear DNA. No differences were observed in the nuclear DNA contents in individual layers of the cortex of the 28 day-old nodules. Generally it was low, varying from 2c to 4c. The meristematic and bacteroidal tissues in the effective nodules were characterized by a higher DNA level, as compared to the respective zones in ineffective nodules induced with the strains ANU261 (<em>nod I<sup>*</sup></em>) and ANU262 (<em>nod J<sup>*</sup></em>). The DNA level in the effective bacteroidal tissue varied from 4c to 32c, while in the tissue containing the strain ANU26l only the 2c-8c nuclei could be found and in the tissue with the strain ANU262 - the 4c-16c nuclei.

Cytoplasmic bridge formation in the nodule apex of actinorhizal root nodules

1999 ◽  
Vol 77 (9) ◽  
pp. 1351-1357 ◽  
Author(s):  
R Howard Berg
Keyword(s):  
Structural Changes ◽  
Root Nodules ◽  
Parenchyma Cell ◽  
Infection Process ◽  
Infection Thread ◽  
Cytoplasmic Bridge ◽  
Cortical Cells ◽  
Infection Threads ◽  
Related Plant ◽  
Cytoplasmic Bridges

High-pressure frozen - freeze-substituted actinorhizal root nodules of several distantly related plant genera were used to document the sequence of structural changes in cortical cells of the nodule apex that happened prior to their infection. The sequence of mobilization of the plant cell cytoplasm requisite to infection by Frankia was (i) penetration of the parenchyma cell vacuole by cytoplasmic strands, which contained microtubules; (ii) movement of the nucleus and other organelles (Golgi stacks, endoplasmic reticulum, mitochondria), involved later in growth of the infection thread, to the cell center on these strands; (iii) thickening of some of these strands generally located at midpoints of the wall, forming cytoplasmic bridges (preinfection threads); and (iv) infection of the cell by initiation of infection threads (containing Frankia) within the cytoplasmic bridges. The infection thread was caged in microtubules that were oriented along its axis, suggesting the cytoskeleton had a major role in the infection process, perhaps guiding the growth of the infection thread across the cell. The coalignment of cytoplasmic bridges, along several cells, towards the advancing microsymbiont suggested Frankia secretes a diffusible signal eliciting this host response.Key words: actinorhiza, cryofixation, development, infection, microtubules, symbiosis.

scholarly journals Isolation and characterization of the membrane envelope enclosing the bacteroids in soybean root nodules.

1978 ◽  
Vol 78 (3) ◽  
pp. 919-936 ◽  
Author(s):  
D P Verma ◽  
V Kazazian ◽  
V Zogbi ◽  
A K Bal
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Host Cell ◽  
Root Nodules ◽  
Infection Thread ◽  
Hypodermic Needle ◽  
Soybean Root ◽  
Isolation And Characterization ◽  
Infection Threads ◽  
Membrane Envelope

The membrane envelope enclosing the bacteroids in soybean root nodules is shown by ultrastructural and biochemical studies to be derived from, and to retain the characteristics of, the host cell plasma membrane. During the early stages of the infection process, which occurs through an invagination, Rhizobium becomes surrounded by the host cell wall and plasma membrane, forming the infection thread. The cell wall of the infection thread is degraded by cellulolytic enzyme(s), leaving behind the enclosed plasma membrane, the membrane envelope. Cellulase activity in young nodules increases two- to threefold as compared to uninfected roots, and this activity is localized in the cell wall matrix of the infection threads. Membrane envelopes were isolated by first preparing bacteroids enclosed in the envelopes on a discontinuous sucrose gradient followed by passage through a hypodermic needle, which released the bacteroids from the membranes. This membrane then sedimented at the interface of 34--45% sucrose (mean density of 1.14 g/cm3). Membranes were characterized by phosphotungstic acid (PTA)-chromic acid staining. ATPase activity, and localization, sensitivity to nonionic detergent Nonidet P-40 (NP-40) and sodium dodecyl sulfate (SDS) gel electrophoresis. These analyses revealed a close similarity between plasma membrane and the membrane envelope. Incorporation of radioactive amino acids into the membrane envelope proteins was sensitive to cycloheximide, suggesting that the biosynthesis of these proteins is primarily under host-cell control. No immunoreactive material to leghemoglobin antibodies was found inside or associated with the isolated bacteroids enclosed in the membrane envelope, and its location is confined to the host cell cytoplasmic matrix.

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