SEM Studies on Vessels in Ferns. 8. Platyzoma

1999 ◽  
Vol 47 (2) ◽  
pp. 277 ◽  
Author(s):  
Sherwin Carlquist ◽  
Edward L. Schneider ◽  
Kevin F. Kenneally
Keyword(s):  
Water Availability ◽  
Secondary Wall ◽  
Selective Advantage ◽  
Wall Material ◽  
Perforation Plate ◽  
Potential Value ◽  
Wide Range ◽  
Vessel Elements ◽  
Perforation Plates ◽  
Scanning Electron

Using scanning electron microscopy (SEM), vessels are demonstrated for roots and rhizomes of Platyzoma microphyllum R.Br. Because vessels are not in simple linear series, but have tips in contact with tips of other vessels, vessel elements may have several end walls, and each of these can bear a perforation plate. Vessels in roots are narrow, but have wide perforations. In rhizomes, perforation plates have a wide range of morphology. The most notable of these involves displacement and, frequently, fusion of adjacent bars of secondary wall material, so that large perforations tend to alternate with narrow perforations or with two or three fused bars. Porose pit membranes are present in narrower perforations. The presence of wide perforations achieved by means of bar displacement characterises not merely Platyzoma, but other ferns as well: Microgramma and Phlebodium. These three genera of ferns experience marked fluctuation in water availability, so that not only are vessels of potential value for rapid conduction during brief periods of water availability, but the presence of perforation plates conducive to such rapid conduction is of theoretical selective advantage as well. Stelar fibres that bear crystals on external surfaces of walls are reported for roots of Platyzoma. Such fibres have not been reported hitherto for ferns.

Perforation Plate Strucrure in Comptonia Peregrina (Myricaceae)

IAWA Journal ◽  
1984 ◽  
Vol 5 (3) ◽  
pp. 217-223 ◽  
Author(s):  
A. F. Muhammad
Keyword(s):  
Secondary Wall ◽  
Structural Variation ◽  
Secondary Xylem ◽  
Wall Material ◽  
Perforation Plate ◽  
Plate Structure ◽  
Developmental Factors ◽  
Sequential Development ◽  
Vessel Elements ◽  
Perforation Plates

The sequential development of vessel elements in the primary and secondary xylem of Comptonia peregrina (L.) Coult. was studied. Scalariform, transitional, simple and scalaroid perforation plates were common in this species. The structural variation of these plates was interpreted on the basis of some developmental factors such as: I) width of the ceJl face and the distance between helical gyres; 2) type and distribution of secondary wall material in the form of strand, sheet or both; 3) localised and differential deposition of wall material and bar breakdown. These factors may work alone or in combination to determine the perforation plate structure.

Perforation Plate Development in Knightia excelsa R. Br. : A Scanning Electron Microscope Study

1972 ◽  
Vol 20 (1) ◽  
pp. 79 ◽  
Author(s):  
BA Meylan ◽  
BG Butterfield
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Microscope Study ◽  
Secondary Wall ◽  
Electron Microscope Study ◽  
Middle Lamella ◽  
Scanning Electron Microscope Study ◽  
Perforation Plate ◽  
Perforation Plates ◽  
Scanning Electron

The development of perforation plates in the vessels of Knightia excelsa R. Br. is described. The primary walls and middle lamella in the region of the perforation remain intact late in the differentiation of the adjoining vessel members. Only after the secondary wall has been laid down, forming prominent borders over this perforation partition, does the latter show any sign of degeneration. The breakdown process involves a change in the nature of the partition, which becomes granular in appearance. Small holes then develop in it before its final disappearance.

Scalariform Perforation Plate Development in Laurelia novae-zelandiae A. Cunn. : A Scanning Electron Microscope Study

1972 ◽  
Vol 20 (3) ◽  
pp. 253 ◽  
Author(s):  
BG Butterfield ◽  
BA Meylan
Keyword(s):  
Electron Microscope ◽  
Secondary Wall ◽  
Electron Microscope Study ◽  
Middle Lamella ◽  
Scanning Electron Micrographs ◽  
Scanning Electron Microscope Study ◽  
Perforation Plate ◽  
Enzymatic Action ◽  
Perforation Plates ◽  
Scanning Electron

The development of the scalariform perforation plates in Laurelia novae- zelandiae A. Cunn. is described and illustrated with scanning electron micrographs. The primary walls and middle lamella in the areas to be perforated remain intact late in the differentiation of .the adjoining vessel members. After the secondary wall has beenlaid down on other areas of the vessel member walls, the perforation partitions are broken down by an enzymatic action on the surface of the partitions. This process leaves a network of fibrils which later disappear, possibly by the action of the transpiration stream.

Scanning electron microscopy of Fusarium oxysporum f.sp. lycopersici in xylem vessels of wilt-resistant and susceptible tomato plants

1980 ◽  
Vol 58 (22) ◽  
pp. 2360-2366 ◽  
Author(s):  
Erik L. Stromberg ◽  
Malcolm E. Corden
Keyword(s):  
Electron Microscopy ◽  
Hyphal Growth ◽  
Susceptible Host ◽  
Vessel Elements ◽  
Host Pathogen ◽  
Race 1 ◽  
Perforation Plates ◽  
Susceptible Tomato ◽  
Scanning Electron ◽  
Pathogen Combinations

Vessels in stems of 'Jefferson' (race 1 resistant and race 2 susceptible) and 'Bonny Best' (race 1 and 2 susceptible) tomato cultivars inoculated with Fusarium oxysporum f.sp. lycopersici race 1 or 2 were examined by scanning electron microscopy. Four days after inoculation of Jefferson with conidia of race 1, the inoculum conidia and resultant hyphae generally were collapsed, whereas in the susceptible host–pathogen combinations the inoculum conidia and hyphae appeared normal. Neither the plants of the resistant nor the susceptible host-pathogen combinations had perforation plates or tyloses within vessel elements capable of trapping conidia or effectively blocking hyphal growth. The perforation plates of all vessel elements are reduced to slightly lipped rims and thus provide unrestricted apertures for hyphal growth and conidial movement in the transpiration stream. In the susceptible host–pathogen combinations, mycelial growth often filled the vessels, but no sporulation was noted. Frequent lateral spread of the pathogen occurred between adjacent vessels through the bordered pit-pairs. Infrequent occurrence of tyloses and a lack of occlusions by tyloses in the resistant host–pathogen combination suggest that vascular wilt resistance within the stem is not due primarily to physical containment of the pathogen in the vessels. Collapsed conidia and hyphae in the resistant host–pathogen combination suggests that fungitoxic materials in the vessels suppress the pathogen and contribute to resistance.

Vestured Scalariform Perforation Plate Openings in Neomyrtus pedunculata

1974 ◽  
Vol 22 (2) ◽  
pp. 425 ◽  
Author(s):  
BG Butterfield ◽  
BA Meylan
Keyword(s):  
Electron Micrograph ◽  
Scanning Electron Micrograph ◽  
Perforation Plate ◽  
Perforation Plates ◽  
Scanning Electron

The occurrence of vestures in the corners of the last few openings at each end of the scalariform perforation plates in Neomyrtus pedunculata is recorded and illustrated with a scanning electron micrograph.

ANALYSIS OF CAMBIUM AND DIFFERENTIATING VESSEL ELEMENTS IN KALOPANAX PICTUS USING RESIN CAST REPLICAS

IAWA Journal ◽  
2001 ◽  
Vol 22 (1) ◽  
pp. 15-28 ◽  
Author(s):  
Peter Kitin ◽  
Yuzou Sano ◽  
Ryo Funada
Keyword(s):  
Organic Material ◽  
Cell Walls ◽  
Three Dimensional ◽  
Wall Material ◽  
Acidic Solutions ◽  
Kalopanax Pictus ◽  
Bordered Pits ◽  
Vessel Elements ◽  
Cambial Cells ◽  
Perforation Plates

A resin-casting method with subsequent scanning electron microscopy (SEM) was used to examine the three-dimensional (3-D) shapes of cells and the cell walls of cambium and differentiating xylem. Glutaraldehyde- fixed and dehydrated specimens were embedded in polystyrene and then organic material was removed by digestion with acidic solutions or enzymes. The acidic solutions used for treatment were sulphuric acid and a mixture of acetic acid and hydrogen peroxide and the enzymes used for treatment were pectinase and cellulase, with a final treatment with sodium hypochlorite. Both methods could be used for studies of the differentiation of cambial cells; however, digestion with enzymes allowed better preservation of the 3-D organisation of the tissue. Negative replicas of inner surfaces of cell walls of differentiating vessel elements revealed the sequential stages of the development of bordered pits and perforation plates. Future bordered pits at the early stages of the differentiation of cell walls were demarcated by the accumulation of organic material between adjacent pit membranes. Subsequent deposition of cell wall material resulted in formation of pit cavities and the rims of perforation plates.

Perforation Plates in Vessels of Citharexylum Myrianthum Cham. (Verbenaceae)

IAWA Journal ◽  
1989 ◽  
Vol 10 (1) ◽  
pp. 27-34 ◽  
Author(s):  
A. Vidal Gomes ◽  
L. Lopes Teixeira ◽  
E. Gomes Schaitza ◽  
R. M. Hofmeister
Keyword(s):  
Central Portion ◽  
Wall Material ◽  
Perforation Plate ◽  
Perforation Plates ◽  
Unusual Type

An unusual type of perforation plate is reported for Citharexylum myrianthum (Verbenaceae). It is a multiple perforation variant with a radiating pattern of wall material from a thickened central portion. In C. myrianthum it occurs together with simple and foraminatereticulate perforatio n plates; four types of combination perforation plates are also reported.

Three-Dimensional Imaging and Analysis of Differentiating Secondary Xylem by Confocal Microscopy

IAWA Journal ◽  
2003 ◽  
Vol 24 (3) ◽  
pp. 211-222 ◽  
Author(s):  
Peter Kitin ◽  
Yuzou Sano ◽  
Ryo Funada
Keyword(s):  
Secondary Wall ◽  
Three Dimensional ◽  
Wall Formation ◽  
Kalopanax Pictus ◽  
Bordered Pits ◽  
Vessel Elements ◽  
Ray Cells ◽  
Secondary Wall Formation ◽  
Ray Parenchyma Cells ◽  
Perforation Plates

We examined the three-dimensional (3-D) structure of differentiating xylem in a hardwood tree, Kalopanax pictus, by confocallaser scanning microscopy (CLSM) using relatively thick, hand-cut histological sections. 3-D studies of plant tissues by mechanical serial sectioning with a microtome are very time-con suming. By contrast, the preparation of samples for CLSM is easier and the 3-D structure of intact tissue is preserved during optical sectioning. We obtained extended-focus images of the surface of specimens and these images resembled the stereographic images obtained by scanning electron microscopy. In addition , we observed radial files of cambial derivative cells at various stages of differenti ation and the internal structure along the 'z' axis of specimens on serial optical sections. We analysed the developmental changes in the morphology of cambial derivat ive cells, for example, the 3-D shape and arrangement of cells, the readjustment of the position of cells, and the development of secondary walls, pits and perforation plates. Our results showed that the arrangement of the differentiating xylem cells mirror s that of the cambial cell s. Deviations from the longitudinal orientation of vessel elements were specified by similar patterns of orientation of fusiform and ray cambial cells. The development of vessel elements progressed more rapidly than that of other xylem elements. When secondary walls with bordered pits and perforation plates with membranes were present in vessel elements and their expansion ceased, no secondary wall formation was detected in adjacent ray cells. The delay in secondary wall formation by the ray parenchyma cells, as compared to that by vessel elements, might facilitate the readju stment of the position of cells in the developing xylem tissue that is a consequence of the considerable expan sion of the vessel elements.

VESSEL MEMBERS IN THE STEM OF DIOSCOREA ALATA L.

1967 ◽  
Vol 45 (2) ◽  
pp. 155-167 ◽  
Author(s):  
J. J. Shah ◽  
K. Unnikrishnan ◽  
K. V. Poulose
Keyword(s):  
Vessel Element ◽  
Dioscorea Alata ◽  
Gujarat State ◽  
Perforation Plate ◽  
Vessel Elements ◽  
Ontogenetic Study ◽  
Final Length ◽  
The Common ◽  
Perforation Plates ◽  
Mother Nucleus

The internodal and nodal vessel elements and certain aspects of their ontogeny in the stem of Dioscorea alata L., the common cultivated yam of Gujarat State, India, are described. The internodal vessel elements are unusually long with foraminate, scalariform, reticulate, or rarely simple perforation plates. The nodal vessel elements are comparatively short with two to five perforation plates. They generally differ from internodal vessel elements in characters such as (i) size and shape and (ii) nature, number, inclination, and distribution of perforation plates. The ontogenetic study of the vessel element revealed that the coenocytic condition is a result of frequent mitotic divisions of the mother nucleus. The formation of the perforation plate occurs after the vessel element has reached final length. The protoplast persists after the formation of the perforation plate. In D. alata the cell wall in the region of the perforation shows primordial pits.

A comparative cytological analysis of fungal endophytes in the sporophyte rhizomes and vascularized gametophytes of Tmesipteris and Psilotum

2005 ◽  
Vol 83 (11) ◽  
pp. 1443-1456 ◽  
Author(s):  
Jeffrey G. Duckett ◽  
Roberto Ligrone
Keyword(s):  
Fungal Endophytes ◽  
Vascular Anatomy ◽  
Arbuscular Mycorrhizas ◽  
Wall Material ◽  
Electron Microscopic ◽  
Cortical Cells ◽  
Vascular Elements ◽  
Vessel Elements ◽  
Perforation Plates ◽  
Hyphal Coils

This article describes the results of a light and electron microscopic study of the fungal endophytes and vascular anatomy in the rhizomes and gametophytes of Tmesipteris and Psilotum. The parenchymatous cortical cells of the rhizomes and subterranean gametophytes of Tmesipteris and Psilotum contain intracellular aseptate glomeromycotean fungi resembling the “Paris-type” of arbuscular mycorrhizas found in seed plants. The fungi differentiate into multinucleate vesicles and hyphal coils, both containing bacteria-like structures and accumulating lipid masses and crystals as they age. After several cycles of infection in the same cell, degenerate hyphae form amorphous masses encased by host wall material. Nearly identical host–fungus cytology between the autotrophic sporophytes and the heterotrophic gametophytes suggests that these psilophyte associations are exploitative of the fungus in both generations. Following the description of tracheids nearly 60 years ago in the gametophytes of Psilotum, vascular elements are described for the first time in the haploid generation of Tmesipteris. Close similarities between the water- and food-conducting elements in both generations, viz. vessel elements with scalariform perforation plates and sieve cells with refractive spherules and lacking callose at all stages in their develoment, add support to the homologous theory of the alternations of generations. Mitochondrial aggregations, cross-linked by small electron-opaque rods, are common in the stelar cells of both generations and appear to be a unique feature of the psilophyte clade.

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