scholarly journals Root nodule structure in Chamaecytisus podolicus

2017 ◽  
Vol 70 (2) ◽  
Author(s):  
Monika Skawińska ◽  
Barbara Łotocka ◽  
Tomasz Ruszkowski ◽  
Piotr Banaszczak ◽  
Ewa Znojek
Keyword(s):  
Root Nodule ◽  
Root Nodules ◽  
Structural Features ◽  
Meristematic Cells ◽  
Indeterminate Nodules ◽  
Infection Threads ◽  
Root Nodule Structure ◽  
Infected Cells ◽  
First Time ◽  
Sister Cells

By means of microscopic analyses, it was shown that root nodules formed by <em>Chamaecytisus podolicus</em> exhibited all structural features typical for indeterminate nodules of temperate genistean shrubs: (<em><strong>i</strong></em>) apical nodule meristem composed of infected and non-infected domains, (<em><strong>ii</strong></em>) parenchymatous bacteroid-containing tissue with infected cells only resulting from mitotic activity of infected meristematic cells, (<em><strong>iii</strong></em>) absence of infection threads, and (<em><strong>iv</strong></em>) convoluted bacteroids singly enclosed in a symbiosome membrane. For the first time, it was shown that the nodule meristem is organized into longitudinal files of sister cells.

Organization of microtubules in developing pea root nodule cells

2001 ◽  
Vol 79 (7) ◽  
pp. 777-786
Author(s):  
A L Davidson ◽  
W Newcomb
Keyword(s):  
Rhizobium Leguminosarum ◽  
Root Nodule ◽  
Root Nodules ◽  
Cell Cortex ◽  
Cortical Microtubules ◽  
Microtubule Organization ◽  
Pea Root ◽  
Fluorescence And Electron Microscopy ◽  
Infected Cells ◽  
Cytoplasmic Microtubules

Pisum sativum L. (pea) root nodule cells undergo many cellular changes in response to infection by Rhizobium leguminosarum bv. viciae. These include cell growth, organelle reorganization, and changes relating to the increase in the number of bacteria within the cell. The objective of this study was to characterize microtubule organization during nodule cell development. The organization of microtubules was examined in developing pea root nodules using fluorescence and electron microscopy techniques. Immunolabelling of microtubules in meristematic cells showed diffuse fluorescence in the cell cortex and adjacent to the nuclear envelope. Recently infected cells contained randomly oriented cortical microtubules and cytoplasmic microtubules that were fragmented with diffuse fluorescence. Infected cells contained an extensive network of long, randomly arranged cortical microtubules with some parallel bundles. Cytoplasmic microtubules in single optical sections of infected cells appeared as short undulating filaments; however, overlapping images from a Z-series of an infected cell showed that the microtubules are long and wavy, and generally radiate inward from the cell cortex.Key words: nodule, microtubules, Rhizobium, pea, symbiosis.

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.

Formation and structure of root nodules induced on Macroptilium atropurpureum inoculated with various species of Rhizobium

1991 ◽  
Vol 69 (7) ◽  
pp. 1520-1532 ◽  
Author(s):  
Michael J. Trinick ◽  
Celia Miller ◽  
Paul A. Hadobas
Keyword(s):  
Rhizobium Leguminosarum ◽  
Rhizobium Meliloti ◽  
Root Nodules ◽  
Matrix Material ◽  
Immunogold Labelling ◽  
Infection Threads ◽  
Glass Tubes ◽  
Infected Cells ◽  
Macroptilium Atropurpureum ◽  
Nodule Tissue

Fifteen strains of Rhizobium leguminosarum biovar trifolii formed ineffective nodules and (or) nodule-like structures (rhizobia were re-isolated from both structures) on Macroptilium atropurpureum grown in enclosed glass tubes. Bacteria were observed among the parenchyma cells surrounding the nodule-like structures. One variant of R. leguminosarum biovar trifolii (NGR66/ST) isolated from M. atropurpureum formed nodules on this host that exhibited abnormal intercellular and intracellular infection. The bacteria (NGR66/ST) were contained within threadlike structures, surrounded by matrix material. The identities of the Rhizobium strains were confirmed serologically after reisolation and in sections of nodule tissue using immunogold labelling. Rhizobium leguminosarum biovar phaseoli strain NGR76 isolated from Phaseolus vulgaris formed nodules on M. atropurpureum resembling those formed by effective Bradyrhizobium strains. The association was partially effective in nitrogen fixation, and this was reflected in the nodule structure. The percentage of cells infected was lower than that in fully effective nodules. There was a high frequency of infected cells showing degeneration; these were located throughout the nodule tissue and were often adjacent to healthy infected cells. The rhizobia appeared to infect new nodule cells via infection threads, which were abundant both intercellularly and intracellularly in young, mature, and degenerating host nodule cells. Strains of R. leguminosarum biovar viceae and Rhizobium meliloti were unable to induce nodule-like structures on M. atropurpureum. Key words: Macroptilium, Bradyrhizobium, Rhizobium, microscopy, nodule, structure.

scholarly journals Glycyrrhiza uralensis Nodules: Histological and Ultrastructural Organization and Tubulin Cytoskeleton Dynamics

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2508
Author(s):  
Anna V. Tsyganova ◽  
Anna B. Kitaeva ◽  
Artemii P. Gorshkov ◽  
Pyotr G. Kusakin ◽  
Alexandra R. Sadovskaya ◽  
...  
Keyword(s):  
Food Industry ◽  
Structural Organization ◽  
Glycyrrhiza Uralensis ◽  
Ultrastructural Organization ◽  
Indeterminate Nodules ◽  
Infection Threads ◽  
Infected Cells ◽  
Cytoskeletal Elements ◽  
Cytoskeleton Dynamics ◽  
Intermediate Pattern

Chinese liquorice (Glycyrrhiza uralensis Fisch. ex DC.) is widely used in the food industry and as a medicine. Like other legumes, G. uralensis forms symbiotic nodules. However, the structural organization of G. uralensis nodules is poorly understood. In this study, we analyzed the histological and ultrastructural organization and dynamics of the tubulin cytoskeleton in various cells from different histological zones of indeterminate nodules formed by two strains of Mesorhizobium sp. The unusual walls of infection threads and formation of multiple symbiosomes with several swollen bacteroids were observed. A large amount of poly-β-hydroxybutyrate accumulated in the bacteroids, while the vacuoles of meristematic and uninfected cells contained drop-shaped osmiophilic inclusions. Immunolocalization of the tubulin cytoskeleton and quantitative analysis of cytoskeletal elements revealed patterns of cortical microtubules in meristematic, infected and uninfected cells, and of endoplasmic microtubules associated with infection structures, typical of indeterminate nodules. The intermediate pattern of endoplasmic microtubules in infected cells was correlated with disordered arrangement of symbiosomes. Thus, analysis of the structural organization of G. uralensis nodules revealed some ancestral features more characteristic of determinate nodules, demonstrating the evolutionary closeness of G. uralensis nodulation to more ancient members of the legume family.

scholarly journals Morphology of root nodules and nodule-like structures formed by Rhizobium and Agrobacterium strains containing a Rhizobium meliloti megaplasmid.

1983 ◽  
Vol 97 (3) ◽  
pp. 787-794 ◽  
Author(s):  
C H Wong ◽  
C E Pankhurst ◽  
A Kondorosi ◽  
W J Broughton
Keyword(s):  
Normal Development ◽  
Rhizobium Meliloti ◽  
Root Nodules ◽  
Root Hairs ◽  
Host Cells ◽  
Donor Strain ◽  
Intercellular Spaces ◽  
Infection Threads ◽  
Infected Cells ◽  
Rhizobium Sp

We examined expression of the megaplasmid pRme41b of Rhizobium meliloti in two different Rhizobium sp. Strains and in Agrobacterium tumefaciens. Transfer of pRme41b into these bacteria was facilitated by insertion of a recombinant plasmid coding for mobilization functions of RP4 into the nif region (Kondorosi, A., E. Kondorosi, C.E. Pankhurst, W. J. Broughton, and Z. Banfalvi, 1982, Mol. Gen. Genet., 188:433-439). In all cases, transconjugants formed nodule-like structures on the roots of Medicago sativa. These structures were largely composed of meristematic cells but they were not invaded by bacteria. Bacteria were found only within infection threads in root hairs, and within intercellular spaces of the outermost cells of the structures. The donor strain of R. meliloti containing pAK11 or pAK12 in pRme41b initially produced nodules on M. sativa that did not fix nitrogen (Fix-). In these nodules, bacteria were released from infection threads into the host cells but they did not multiply appreciably. Any bacteroids formed degenerated prematurely. In some cases, however, reversion to a Fix+ phenotype occurred after 4 to 6 wk. Bacteria released into newly infected cells in these nodules showed normal development into bacteriods.

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.

scholarly journals A comparative cytological and morphometric analysis of vacuolation in central tissue of the effective and ineffective pea (Pisum sativum L.) root nodules

2011 ◽  
Vol 76 (2) ◽  
pp. 109-118 ◽  
Author(s):  
Wojciech Borucki
Keyword(s):  
Root Nodule ◽  
Root Nodules ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Thin Layers ◽  
Central Vacuole ◽  
Dynamic Changes ◽  
Pea Root ◽  
Dimensional Reconstruction ◽  
Infected Cells

Vacuoles play very important physiological roles in plant cells. Pea root nodules, which exhibit distinct zonation (meristematic zone and central tissue zones), may serve as a good experimental model for the investigations of vacuole development and its importance to cell and tissue functioning. Moreover, the nodule central tissue is composed of both infected and uninfected cells which play different physiological roles and differ in the level of vacuolation. Cytological observations revealed that central vacuoles of the infected cells of the effective nodules expand toward cell walls. Thus only thin layers of the cytoplasm separate each central vacuole from plasma membrane and cell wall. This finding is discussed from the viewpoint of improved exchange of solutes and water between the central vacuole and apoplast of the infected cell. Three-dimensional reconstruction of the vacuoles of infected cells within a fragment of effective nodule central tissue, showed their spatial arrangement. Possible advantages coming from the spatial arrangement of vacuoles within the central tissue are discussed. A comparative study of the central tissue (bacteroidal tissue) and meristem vacuolation of the effective and ineffective pea root nodules is also presented. Morphometric measurements revealed that the effective nodule central tissue was more vacuolated than the ineffective one. It was proved that maturation of the infected cells involves dynamic changes in their vacuolation. Having numerous fixing nitrogen bacteroids, the infected cells of effective central tissue were less vacuolated than uninfected cells. On the other hand, both infected and uninfected cells of the effective central tissue showed a much higher level of vacuolation in nitrogen-fixing zone than cells of the same type in ineffective tissue. These results indicate that vacuolation is an important factor in development and functioning of pea root nodule central tissue.

scholarly journals Localization of Superoxide Dismutases and Hydrogen Peroxide in Legume Root Nodules

2004 ◽  
Vol 17 (12) ◽  
pp. 1294-1305 ◽  
Author(s):  
Maria C. Rubio ◽  
Euan K. James ◽  
Maria R. Clemente ◽  
Bruna Bucciarelli ◽  
Maria Fedorova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Enzyme Inhibitors ◽  
Root Nodules ◽  
Strong Support ◽  
Immunogold Electron Microscopy ◽  
Superoxide Dismutases ◽  
Signal Molecule ◽  
Infection Threads ◽  
Infected Cells ◽  
Nodule Tissue

Superoxide dismutases (SODs) catalyze the dismutation of superoxide radicals to O2 and H2O2 and thus represent a primary line of antioxidant defense in all aerobic organisms. H2O2 is a signal molecule involved in the plant's response to pathogen attack and other stress conditions as well as in nodulation. In this work, we have tested the hypothesis that SODs are a source of H2O2 in indeterminate alfalfa (Medicago sativa) and pea (Pisum sativum) nodules. The transcripts and proteins of the major SODs of nodules were localized by in situ RNA hybridization and immunogold electron microscopy, respectively, whereas H2O2 was localized cytochemically by electron microscopy of cerium-perfused nodule tissue. The transcript and protein of cytosolic CuZnSOD are most abundant in the meristem (I) and invasion (II) zones, interzone II-III, and distal part of the N2-fixing zone (III), and those of MnSOD in zone III, especially in the infected cells. At the subcellular level, CuZnSOD was found in the infection threads, cytosol adjacent to cell walls, and apoplast, whereas MnSOD was in the bacteroids, bacteria within infection threads, and mitochondria. The distinct expression pattern of CuZnSOD and MnSOD suggests specific roles of the enzymes in nodules. Large amounts of H2O2 were found at the same three nodule sites as CuZnSOD but not in association with MnSOD. This colocalization led us to postulate that cytosolic CuZnSOD is a source of H2O2 in nodules. Furthermore, the absence or large reduction of H2O2 in nodule tissue preincubated with enzyme inhibitors (cyanide, azide, diphenyleneiodonium, diethyldithiocarbamate) provides strong support to the hypothesis that at least some of the H2O2 originates by the sequential operation of an NADPH oxidase- like enzyme and CuZnSOD. Results also show that there is abundant H2O2 associated with degrading bacteroids in the senescent zone (IV), which reflects the oxidative stress ensued during nodule senescence.

scholarly journals Root Nodule Rhizobia From Undomesticated Shrubs of the Dry Woodlands of Southern Africa Can Nodulate Angolan Teak Pterocarpus angolensis, an Important Source of Timber

2021 ◽  
Vol 12 ◽  
Author(s):  
Wiebke Bünger ◽  
Abhijit Sarkar ◽  
Jann Lasse Grönemeyer ◽  
Janina Zielinski ◽  
Rasmus Revermann ◽  
...  
Keyword(s):  
Southern Africa ◽  
Root Nodule ◽  
Root Nodules ◽  
Plant Growth Promoting Rhizobacteria ◽  
Nitrogen Fixing ◽  
Diverse Range ◽  
Pterocarpus Angolensis ◽  
Plant Growth Promoting ◽  
Additional Reference ◽  
First Time

Pterocarpus angolensis, a leguminous tree native to the dry woodlands of Southern Africa, provides valuable timber, but is threatened by land conversion and overharvesting while showing limited natural regeneration. Nitrogen-fixing root nodule symbionts that could improve establishment of young seedlings have not yet been described. Therefore, we investigated the ability of P. angolensis to form nodules with a diverse range of rhizobia. In drought-prone areas under climate change with higher temperatures, inoculants that are heat-tolerant and adapted to these conditions are likely to be of advantage. Sources of bacterial isolates were roots of P. angolensis from nurseries in the Kavango region, other shrubs from this area growing near Pterocarpus such as Indigofera rautanenii, Desmodium barbatum, Chamaecrista sp., or shrubs from drought-prone areas in Namaqualand (Wiborgia monoptera, Leobordea digitata) or Kalahari (Indigofera alternans). Only slight protrusions were observed on P. angolensis roots, from which a non-nodulating Microbacterium sp. was isolated. Rhizobia that were isolated from nodules of other shrubs were affiliated to Bradyrhizobium ripae WR4T, Bradyrhizobium spp. (WR23/WR74/WR93/WR96), or Ensifer/Mesorhizobium (WR41/WR52). As many plant growth-promoting rhizobacteria (PGPR), nodule isolates produced siderophores and solubilized phosphate. Among them, only the Bradyrhizobium strains nodulated P. angolensis under controlled conditions in the laboratory. Isolates were further characterized by multilocus sequence analysis and were found to be distant from known Bradyrhizobium species. Among additional reference species tested for nodulation on P. angolensis, Bradyrhizobium vignae 7-2T and Bradyrhizobium namibiense 5-10T from the Kavango region of Namibia as well as Bradyrhizobium elkanii LMG6234T and Bradyrhizobium yuanmingense LMG21728T induced nitrogen-fixing nodules, while Bradyrhizobium diazoefficiens USDA110T and Bradyrhizobium tropiciagri SEMIA6148T did not. This suggests a broad microsymbiont range from Bradyrhizobium japonicum and B. elkanii lineages. Phylogenetic analysis of nodC genes indicated that nodulating bradyrhizobia did not belong to a specific symbiovar. Also, for I. rautanenii and Wiborgia, nodule isolates B. ripae WR4T or Mesorhizobium sp. WR52, respectively, were authenticated. Characterization of symbionts inducing effective root nodules in P. angolensis and other shrubs from Subsahara Africa (SSA) give insights in their symbiotic partners for the first time and might help in future to develop bioinoculants for young seedlings in nurseries, and for reforestation efforts in Southern Africa.

The occurrence of infected cells, with persistent infection threads, in legume root nodules

1987 ◽  
Vol 65 (3) ◽  
pp. 553-558 ◽  
Author(s):  
Sergio M. de Faria ◽  
Shona G. McInroy ◽  
Janet I. Sprent
Keyword(s):  
Root Nodules ◽  
Root Hairs ◽  
Infection Process ◽  
Wall Material ◽  
Cell Wall Material ◽  
Legume Trees ◽  
Infection Threads ◽  
Host Cell Wall ◽  
Infected Cells ◽  
Intercellular Spread

A survey of the structure of nodules from primitive legume trees was conducted. All genera examined in the subfamily Caesalpinioideae, some from the Papilionoideae, but none from the Mimosoideae had cells in the central, nitrogen-fixing region in which bacteria were confined by host cell wall material in structures resembling infection threads. However, infection of these cells occurred by intercellular spread of rhizobia rather than by infection threads. It is suggested that infection threads may have evolved in infected cells and later extended to early stages of the infection process including entry into root hairs.

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