The fine structure of conidial development in the genus Torula. III. T. graminis Desm.

1976 ◽  
Vol 22 (6) ◽  
pp. 858-866 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Conidiogenous Cell ◽  
Conidial Development ◽  
Hyaline Zone

Torula graminis produced blastoconidia in acropetalous chains after the evagination of a characteristic conidiogenous cell. Conidia consisted of up to 15 cells and their cell wall was differentiated into an outer melanized zone and an inner hyaline zone. A consistent cytoplasmic feature of conidial cells was the presence of dictyosomal-like membranous stacks often closely associated with the nucleus. Vesicles that developed from the dictyosomal-like cisternae were probably involved in conidial wall synthesis.

The fine structure of conidiogenesis in Alysidium resinae (=Torula ramosa)

1977 ◽  
Vol 55 (6) ◽  
pp. 676-684 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Conidiogenous Cell ◽  
Mechanical Rupture

Conidia of Alysidium resinae (Fr.) M. B. Ellis (=Torula ramosa Peck) arise enteroblastically from polyblastic, ampulliform conidiogenous cells after mechanical rupture of the conidiogenous cell wall and are produced in either branched or unbranched acropetalous chains, successively younger conidia being produced enteroblastically from the immediately older conidia. There is no indication that conidial evagination occurs via enzymatically produced channels in the parent wall, protrusion being exclusively mechanical. Attention is drawn to the controversy surrounding the enteroblastic tretic mode of conidiogenesis.

The fine structure of conidial development in the genus Torula. I. T. herbarum (Pers.) Link ex S. F. Gray and T. herbarum f. quaternella Sacc.

1975 ◽  
Vol 21 (11) ◽  
pp. 1661-1675 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Walls ◽  
Conidiogenous Cell ◽  
Outer Electron ◽  
Transmission Electron ◽  
Conidial Development ◽  
Dense Zone ◽  
Hyaline Zone ◽  
Lateral Walls

Conidiogenesis in Torula herbarum and T. herbarum f. quaternella was observed by scanning and transmission electron microscopy. Conidia of the former were shown to be made up of three equally sized cells capped by a distinctive, and easily recognizable, conidiogenous cell. Conidiogenous cells also arose terminally on erect hyphae and on prostrate hyphae. The single-layered conidial cell walls were differentiated into an inner hyaline zone and an outer electron-dense zone formed by the deposition of melanin. Conidiogenous cells lacked melanin at the apex and, before conidiation, the lateral walls were strengthened by a further deposition of melanin. The apex bulged outwards and was modified into a new multicelled conidium bearing another apical conidiogenous cell. Continued development of new conidia resulted in an acropetal chain which became disarticulated after cytolysis within the conidiogenous cell. The relative distinctions between holoblastic and enteroblastic development are discussed and it is concluded that the conidia should be referred to as blastoconidia.

The fine structure of conidial development in the genus Torula. II. T. caligans (Batista and Upadhyay) M. B. Ellis and T. terrestris Misra

1975 ◽  
Vol 21 (12) ◽  
pp. 1921-1929 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Conidiogenous Cell ◽  
The Other ◽  
Conidial Development ◽  
Lowermost Part ◽  
Systematic Relationships ◽  
Lateral Walls ◽  
Scanning Electron

Conidia of Torula caligans (Batista & Upadhyay) M. B. Ellis comb. nov. and T. terrestris Misra were examined by transmission- and scanning-electron microscopy. Torula caligans produced four-celled conidia in which the central cells were distinctly larger than the basal and apical cells. Conidia of T. terrestris were 4- to 7-celled long and ellipsoidal in shape. Conidiogenous cells in both species developed melanin only within the lowermost part of the lateral walls while the other cells of the conidium were uniformly melanized around the circumference of the cell; melanin in these cells being deposited within, at least, half the width of the cell wall. In both species new conidia arose from evagination of the hyaline apex of the conidiogenous cell and are therefore blastoconidia. The systematic relationships between T. caligans and T. terrestris and other species of the genus Torula are discussed.

Fine structure of conidiogenesis in the mosquito pathogen Culicinomyces clavosporus (Deuteromycotina)

1983 ◽  
Vol 61 (10) ◽  
pp. 2618-2625 ◽  
Author(s):  
A. O. Inmann III ◽  
C. E. Bland
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Classification Scheme ◽  
Conidiogenous Cell ◽  
Dense Core ◽  
Dense Core Vesicles ◽  
Conidiogenous Locus ◽  
Mode Of Development ◽  
Mosquito Pathogen ◽  
Primary Conidium

Conidiogenesis in Culicinomyces clavosporus Couch, Romney, and Rao (Deuteromycotina) is initiated with the growth of conidiogenous cells from vegetative hyphae. Formation of the primary conidium itself begins with a conidial initial which grows through the bilaminar wall at the tip of the conidiogenous cell, wall remnants of the conidiogenous cell often collapsing to form a collarette at the base of conidia. This factor, in addition to the fixed conidiogenous locus, shows that the conidiogenous cell is a phialide. As the conidial initial enlarges, a bilaminar well is synthesized around the cell, and cytoplasmic organelles migrate through the neck of the phialide into the initial. Once the conidium is mature, a septum is formed across the open neck of the phialide and two organelles (dense-core vesicles and autophagosomes), unique to conidia, become evident. The mode of development is enteroblastic–phialidic; Culicinomyces clavosporus is placed therefore in section IVB of the Hughes–Tubaki–Barron classification scheme described by B. Kendrick for the Deuteromycotina.

Fine structure of conidiogenesis in the holoblastic, sympodial Tritirachium roseum

1973 ◽  
Vol 51 (11) ◽  
pp. 2033-2036 ◽  
Author(s):  
Terrence M. Hammill
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Fine Structure ◽  
Conidiogenous Cell ◽  
Full Size ◽  
Distal Half ◽  
Electron Transmission ◽  
Proximal Half ◽  
Conidiogenous Locus ◽  
Fertile Region

Electron microscopy of conidiogenesis in Tritirachium roseum was done on material fixed in glutaraldehyde followed by OsO4. The walls of conidiogenous cells, though pigmented, lacked well-defined differential electron-transmission layers. Conidial initials developed without the appearance of a rupture in the conidiogenous cell wall, i.e., development was holoblastic. Each successively produced conidiogenous locus developed below and to one side of the previously formed conidium, and the fertile region of the conidiogenous cell elongated in a geniculate pattern. After each conidial initial reached full size, it was delimited by a centripetally developing septum, which increased in thickness, became double, and split during conidial secession. The distal half of a split septum formed the conidial base; the proximal half remained as part of the conidiogenous cell wall. Upon conidial secession, basal frills on conidia, and secession scars on conidiogenous cells were especially conspicuous.

Fine Structure of Swarmers of Cladophora and Chaetomorpha

1971 ◽  
Vol 9 (3) ◽  
pp. 581-601
Author(s):  
D. G. ROBINSON ◽  
R. D. PRESTON
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Spatial Arrangement ◽  
Cell Wall Synthesis ◽  
Fibrous Layer ◽  
Etching Technique ◽  
Freeze Etching

Naked swarmers of both Cladophora rupestris and Chaetomorpha melagonium have been examined by the freeze-etching technique. The swarmers of Cladophora, collected just after settling, reveal several layers of granules external to the plasmalemma and internal to the so-called ‘fibrous-layer’. Chaetomorpha swarmers collected just before settling show extrusion of vesicles through the plasmalemma. The structures associated with the membranes are discussed in relation to known features of these swarmers already observed by sectioning. The role of granules in the synthesis of cell wall microfibrils is strengthened though the spatial arrangement of the granules seen in this investigation does not completely fulfil the ‘ordered granule’ hypothesis. Description of, and comments on, features related to cell wall synthesis, particularly the Golgi and vacuolar systems, are given.

CELL WALL CHEMISTRY AND FINE STRUCTURE IN LEPTOIDS OF DENDROLIGOTRICHUM (BRYOPHYTA): THE END WALL

1978 ◽  
Vol 65 (9) ◽  
pp. 1027-1031 ◽  
Author(s):  
Daniel C. Scheirer
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Cell Wall Chemistry ◽  
End Wall

World-Wide Research, Fine Structure of Cytoplasm in Relation to Plant Cell Wall

1965 ◽  
Vol 13 (5) ◽  
pp. 405-407 ◽  
Author(s):  
M. C. Ledbetter
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Plant Cell ◽  
World Wide ◽  
Plant Cell Wall

scholarly journals The Cell Wall Structure of Xylem Parenchyma

1952 ◽  
Vol 5 (2) ◽  
pp. 223 ◽  
Author(s):  
AB Wardrop ◽  
HE Dadswell
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Secondary Cell Wall ◽  
Primary Cell Wall ◽  
Wall Structure ◽  
Xylem Parenchyma ◽  
Cell Axis ◽  
X Ray ◽  
Ray Methods ◽  
Longitudinal Cell

The fine structure of the cell wall of both ray and vertical parenchyma has been investigated. In all species examined secondary thickening had occurred. In the primary cell wall the micellar orientation was approximately trans"erse to the longitudiJ)aI cell axis. Using optical and X-ray methods the secondary cell wall was shown to possess a helical micellar organization, the micelles being inclined between 30� and 60� to the longitudinal cell axis.

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