FINE STRUCTURE OF WHEAT STEM RUST UREDOSPORES

1964 ◽  
Vol 42 (11) ◽  
pp. 1503-1508 ◽  
Author(s):  
P. G. Williams ◽  
G. A. Ledingham
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Higher Plants ◽  
Puccinia Graminis ◽  
Resting Cells ◽  
Oil Bodies ◽  
Wheat Stem Rust ◽  
Cytoplasmic Structures ◽  
Vacuolar Membranes ◽  
Germ Tubes

The fine structure of uredospores and germ tubes of Puccinia graminis f. sp. trilici is described from electron micrographs of cells fixed in KMnO4. In terms of their principal cytoplasmic structures (nuclei, mitochondria, endoplasmic reticulum, and protoplasmic and vacuolar membranes) these cells bear a general resemblance to other fungi and higher plants but differences between resting cells and germ tubes were noted in the size of oil bodies and the structure and extent of the endoplasmic reticulum.

Electron microscopy of susceptible and resistant near-isogenic (sr6/Sr6) lines of wheat infected by Puccinia graminis tritici. I. The host–pathogen interface in the compatible (sr6/P6) interaction

1978 ◽  
Vol 56 (23) ◽  
pp. 2955-2966 ◽  
Author(s):  
D. E. Harder ◽  
R. Rohringer ◽  
D. J. Samborski ◽  
W. K. Kim ◽  
J. Chong
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Growth Stages ◽  
Puccinia Graminis ◽  
Interfacial Zone ◽  
Wheat Stem Rust ◽  
Host Cytoplasm ◽  
Lattice Arrangement ◽  
Rough Er ◽  
Formed Part

Membrane associations in the interfacial zone between host cytoplasm and haustoria of wheat stem rust are reported. The invaginated host plasmalemma (IPL) adhered tightly to the haustorial neck wall above an indistinct zone at the base of the neck. There was extensive proliferation of host endoplasmic reticulum (ER) near haustoria during the formative growth stages of the haustoria. Most of the proliferation occurred along the neck from the neck ring region to the area at the base of the haustorial body where the extrahaustorial sheath became evident. Closely spaced arrays of ER occurred along the neck and radiated into the host cytoplasm. The ER was closely associated with the IPL in the vicinity of the neck wall, and at points of contact or near contact, the ER was ribosome free and stained more densely. There was luminal continuity between ER cisternae and the extrahaustorial sheath matrix. In the host cytoplasm adjacent to haustoria, ER-derived membranous complexes were found. These complexes consisted of a lattice arrangement of large tubules and small tubules, the latter containing a thread of denser staining material at their centers. The large tubules were bounded by lightly stained membranes, whereas the membranes of the small tubules stained more densely. These complexes were interconnected by rough ER to form networks in host cytoplasm. The complexes formed part of the interface between host and pathogen through connections with the invaginated host plasmalemma.

Nucleoli in differentiated germ tubes of wheat rust uredospores

1970 ◽  
Vol 48 (9) ◽  
pp. 1693-1695 ◽  
Author(s):  
Larry D. Dunkle ◽  
William P. Wergin ◽  
Paul J. Allen
Keyword(s):  
Electron Microscopy ◽  
Heat Shock ◽  
Nuclear Envelope ◽  
Outer Membrane ◽  
Ribosomal Rna ◽  
Stem Rust ◽  
Wheat Stem Rust ◽  
Cytoplasmic Structures ◽  
Germ Tubes ◽  
Wheat Rust

Nucleoli observed by electron microscopy are illustrated in germ tubes of wheat stem rust uredospores which have been induced by heat shock to differentiate infection structures. The presence of nucleoli in these structures suggests that this obligate parasite may possess the capacity of synthesizing ribosomal RNA independently of its host. In addition to nucleoli, heterochromatin is characteristically observed appressed to the inner membrane of the nuclear envelope. This material is associated with distinct cytoplasmic structures which are appressed to the outer membrane of the nuclear envelope and resemble developing centrioles in other fungi.

scholarly journals CHROMATOPHORE DEVELOPMENT, PITS, AND OTHER FINE STRUCTURE IN THE RED ALGA, LOMENTARIA BAILEYANA (HARV.) FARLOW

1962 ◽  
Vol 12 (3) ◽  
pp. 553-569 ◽  
Author(s):  
G. Benjamin Bouck
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Higher Plants ◽  
Red Alga ◽  
Cellular Structures ◽  
Secretory Function ◽  
Thin Sections ◽  
Floridean Starch ◽  
Oriented Parallel

Thin sections of the red alga, Lomentaria baileyana, a tubular member of the Rhodymeniales, were examined after permanganate fixation and Araldite embedding. Many of the cellular structures in Lomentaria were found to be similar to analogous structures in animals and higher plants. However, in the walls between cells are modified areas generally known as pits which are unique to the higher orders of red algae (Florideae). In this study the pits were found to consist of a plug-like structure surrounded by an uninterrupted membrane apparently continuous with the plasma membrane. Examination of the chromatophore revealed a characteristic limiting membrane, a relatively sparse distribution of plates, no grana, and a single disc apparently oriented parallel to the limiting membrane. In addition to their origin from non-lamellate proplastids, chromatophores were found capable of division by simple constriction. Floridean starch grains were observed outside the chromatophore and the possibility of an association of the first formed grains with portions of the endoplasmic reticulum is considered. Gland cells seem to have a high proportion of Golgi components (dictyosomes), and are believed to have some kind of secretory function. Many of the Golgi vesicles seem to open on the wall and presumably discharge their contents.

Uredospore development in Puccinia graminis

1969 ◽  
Vol 47 (12) ◽  
pp. 2061-2064 ◽  
Author(s):  
M. A. Ehrlich ◽  
H. G. Ehrlich
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Electron Microscope ◽  
Wall Layer ◽  
Tangential Section ◽  
Puccinia Graminis ◽  
Lipid Bodies ◽  
External Wall ◽  
Additional Information ◽  
Spine Development

The present paper reports a number of electron microscope observations on the protoplasm and walls of developing spores which provide additional information on uredospore wall and spine development and on the fine structure of organelles, particularly of mitochondria and endoplasmic reticulum and of lipid bodies in developing spores. Micrographs of partially extracted uredospore walls and of chromium-shadowed extracted sections demonstrate the architecture of the wall as seen in cross and tangential section. Three distinct wall zones are clearly visible with the external wall layer forming the boundary of the germinal pore.

FINE STRUCTURE OF PLASMODIOPHORA BRASSICAE IN SPOROGENESIS

1967 ◽  
Vol 45 (9) ◽  
pp. 1665-1669 ◽  
Author(s):  
P. H. Williams ◽  
Sharon S. McNabola
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Host Cell ◽  
Outer Membrane ◽  
Lipid Droplets ◽  
Plasmodiophora Brassicae ◽  
Cell Cytoplasm ◽  
Host Cell Cytoplasm ◽  
Vacuolar Membranes ◽  
Sporangial Wall

The vegetative Plasmodium of Plasmodiophora brassicae is contained within host cell cytoplasm. The multinucleate Plasmodium contains numerous large lipid droplets and is replete with mitochondria, dictyosomes, endoplasmic reticulum, and ribosomes. A 250 Å thick osmiophilic plasmodial envelope is characteristic of the vegetative Plasmodium. This envelope is composed of two closely appressed membranes each consisting of a pair of electron-dense layers. As sporogenesis is initiated, the outer membrane of the plasmodial envelope disintegrates, leaving the Plasmodium surrounded by the plasmodial membrane. Nucleoli disappear and numerous vacuoles and vesicles appear in the cytoplasm of the parasite. Vacuoles appear to be formed from invaginations of the plasmodial membrane. These vacuoles become aligned in planes of cleavage around each nucleus, forming the boundaries of each future sporangium. As these vacuoles coalesce, the nucleus of each young resting sporangium becomes surrounded with cytoplasm and is enveloped by the vacuolar membranes. Spines form on the sporangial membrane as aggregates of residual vacuolar material. The sporangial wall is then deposited between the sporangial membrane and the spines. Intact host nuclei, mitochondria, and plastids can be found dispersed among the mature resting sporangia. The host plasmalemma is the only membrane surrounding the mass of resting sporangia. The uninucleate resting sporangium is rich in lipid and contains those organelles found in the vegetative Plasmodium.

scholarly journals Fine structure of lipotubuloids (elaioplasts) in Ornithogalum umbellatum L. I.

2015 ◽  
Vol 40 (3) ◽  
pp. 451-465 ◽  
Author(s):  
M. Kwiatkowska
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Rotary Motion ◽  
Osmiophilic Granules

The bodies occurring in the ovary epidermis cells of <i>Ornithogalum umbellatum</i>, rich in lipids have been earlier described as elaioplasts. They consist of agglomerations of osmiophilic granules within the cytoplasm, caught in a network of, and interconnected by, a system of interesecting microtubules. These structures have been named lipotubuloids. They translocate in the cell by way of a progressive-rotary motion. Endoplasmic reticulum membranes, ribosomes and very scarse mitochondria and Golgi structures occur within the lipotubuloids.

The fine structure of reproducing Toxoplasma gondii

Parasitology ◽  
1963 ◽  
Vol 53 (3-4) ◽  
pp. 643-649 ◽  
Author(s):  
Emeka G. Olisa
Keyword(s):  
Endoplasmic Reticulum ◽  
United Kingdom ◽  
Fine Structure ◽  
Toxoplasma Gondii ◽  
Binary Fission ◽  
The United Kingdom ◽  
Research Scholarship ◽  
Fixation Techniques ◽  
Different Shapes ◽  
Nigerian Government

1. Different shapes and forms found in Toxoplasma gondii are associated with reproduction and growth. The functions of the toxoneme and the conoid are discussed.2. A new structure, ‘lamella spiralis', is described in relation to the nucleus and the endoplasmic reticulum.3. T. gondii reproduces either by dividing into two (binary fission) or by multiple division (schizogony), and by a type of endogenous budding. In the latter case small portions pinched off from the nucleus are rounded up to form several small organisms named ‘morulae'.The author gratefully acknowledges the interest and valuable suggestions of Dr G. A. Gresham, M.D., who supervised this work; Dr J. M. Davis and Mr F. Allen, who were kind enough to read the manuscript critically, and Mr W. A. Mowlam for his technical help and advice on fixation techniques.This work was carried out during the tenure of a research scholarship awarded by the United Kingdom Department of Technical Co-operation and the Eastern Nigerian Government.

scholarly journals Prevalence and Distribution of Common Barberry, the Alternate Host of Puccinia graminis, in Minnesota

Plant Disease ◽  
2005 ◽  
Vol 89 (2) ◽  
pp. 159-163 ◽  
Author(s):  
P. D. Peterson ◽  
K. J. Leonard ◽  
J. D. Miller ◽  
R. J. Laudon ◽  
T. B. Sutton
Keyword(s):  
United States ◽  
Stem Rust ◽  
Active Sites ◽  
The United States ◽  
Puccinia Graminis ◽  
Alternate Host ◽  
Wheat Stem Rust ◽  
State Program ◽  
Cereal Production ◽  
Active Class

A federal and state program operated from 1918 until the 1980s to eradicate common barberry (Berberis vulgaris), the alternate host of Puccinia graminis, from the major areas of cereal production in the United States. Over 500 million bushes were destroyed nationally during the program, approximately 1 million in Minnesota. Some sites in Minnesota where barberry bushes were destroyed remained in the “active” class when eradication was phased out in the 1980s. Active sites were defined as those on which there was still a possibility of emergence of barberry seedlings or sprouts arising from the parent bush. In the present study, from 1998 to 2002, 72 of the approximately 1,200 active sites in Minnesota were surveyed. Areas within 90 m of mapped locations of previously destroyed bushes were searched carefully at each site. Reemerged barberry plants were found on 32 sites. The reproductive status and GPS coordinates were recorded for each reemerged bush. More than 90% of the barberry bushes were found in counties with less than 400 ha of wheat per county, mostly in southeastern Minnesota, but one bush was found in a major wheat-producing county in northwestern Minnesota. Reemergence of barberry may serve as a source of new wheat stem rust races in future epidemics.

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