A systematic evaluation of basidiospore symmetry and tegumentation in hypogeous and gasteroid Russulales

1988 ◽  
Vol 66 (12) ◽  
pp. 2561-2573 ◽  
Author(s):  
Steven L. Miller
Keyword(s):  
Light Microscope ◽  
Spore Wall ◽  
Systematic Evaluation ◽  
Spore Morphology ◽  
Spore Surface ◽  
Layer 2 ◽  
Spore Walls ◽  
Poorly Differentiated ◽  
Surface Ornamentation ◽  
Dark Blue

Spore wall architecture and ontogeny of ornamentation in several genera and species of hypogeous and gasteroid Russulales are similar to those described previously for agaricoid Lactarius lignyotellus. Spore walls are composed of four layers, each differing in thickness and electron density. Layer 2 is electron transparent and corresponds to a dark blue, amyloid layer when mounted in Melzer's iodine reagent and viewed with the light microscope. Establishment of spore symmetry may be regulated by the hilar appendix body, which is a poorly differentiated cytoplasmic region in the hilar appendix of asymmetric spores of Macowanites luteolus, Elasmomyces russuloides, and Zelleromyces versicaulus but which is absent in symmetric spores of Z. sculptisporus, Martellia subochracea, and Gymnomyces yubaensis. A continuum in spore morphology from truly symmetric to asymmetric is evident in spores from individual sporocarps of many species of the Russulales. The variation in spore symmetry and spore surface ornamentation has clouded taxonomic concepts in the Russulales. Systematically, development of orthotropic and heterotropic spores has been regarded as two distinct end points of evolution, when they are likely terms describing degrees of the same phenomenon. The current circumscription of families and genera in the Russulales based on spore symmetry, therefore, appears to be artificial.

Spore wall development in Sphagnum lescurii

1982 ◽  
Vol 60 (11) ◽  
pp. 2394-2409 ◽  
Author(s):  
Roy Curtiss Brown ◽  
Betty E. Lemmon ◽  
Zane B. Carothers
Keyword(s):  
Plasma Membrane ◽  
Outer Layer ◽  
Mature Spore ◽  
Outer Wall ◽  
Spore Wall ◽  
Spore Surface ◽  
Proximal Surface ◽  
Complex Development ◽  
Surface Ornamentation ◽  
Cortical System

The spore wall of Sphagnum is unique in the Bryophyta. The Sphagnum spore exine consists of two layers: an inner, lamellate layer (A layer) and a thick, homogenous, outer layer (B layer). The exine of other mosses consists of only the outermost homogenous layer and, at most, a thin ill-defined opaque layer. During development of the A-layer exine and the intine, a cortical system of evenly spaced microtubules underlies the plasma membrane. The ontogeny of the wall layers is not strictly centripetal. The A-layer exine develops evenly around the young spore immediately after cytokinesis. As the intine is deposited centripetally inside it, the homogenous B-layer exine is deposited outside the first-formed A layer. The B layer is responsible for the primary sculpturing of the spore surface. The mature spore is covered by an outermost perine, which is responsible for secondary surface ornamentation. A trilaesurate aperture develops on the proximal surface of each spore after deposition of the A layer. Ridges of the laesurae develop as a result of deposition of thick areas of intine. The ridges are eventually covered by the outer wall layers, whereas the fissure is covered only by the A layer and a very thin B-layer exine. The complex development of the trilaesurate aperture is evidence that the structure is not merely a mechanically induced "trilete mark" or "scar" resulting from compression of tetrahedrally arranged spores within a sporocyte wall.

scholarly journals On the spore ornamentation of the microsoroid ferns (microsoroideae, polypodiaceae)

2020 ◽  
Author(s):  
Chi-Chuan Chen ◽  
Ho-Yih Liu ◽  
Cheng-Wei Chen ◽  
Harald Schneider ◽  
Jaakko Hyvönen
Keyword(s):  
Ancestral State ◽  
Spore Morphology ◽  
Spore Surface ◽  
Old World ◽  
Spore Ornamentation ◽  
The Third ◽  
Surface Ornamentation ◽  
Ancestral States ◽  
Phylogenetic Hypotheses ◽  
Five Tribes

AbstractMicrosoroideae is the third largest of the six subfamilies of Polypodiaceae, containing over 180 species. These ferns are widely distributed in the tropical and subtropical regions of the Old World and Oceania. We documented the spore ornamentation and integrated these data into the latest phylogenetic hypotheses, including a sampling of 100 taxa representing each of 17 major lineages of microsoroid ferns. This enabled us to reconstruct the ancestral states of the spore morphology. The results show verrucate ornamentation as an ancestral state for Goniophlebieae and Lecanoptereae, globular for Microsoreae, and rugulate surface for Lepisoreae. In addition, spore ornamentation can be used to distinguish certain clades of the microsoroid ferns. Among all five tribes, Lecanoptereae show most diversity in spore surface ornamentation.

Spore morphology of some Orthotrichaceae Arn. species (Bryophyta) from Turkey

2018 ◽  
Vol 44 (4) ◽  
pp. 499-506 ◽  
Author(s):  
Filiz Savaroglu
Keyword(s):  
Spore Morphology ◽  
Habitat Types ◽  
Moss Species ◽  
Spore Size ◽  
Taxonomic Relationships ◽  
The Family ◽  
Ecological Implications ◽  
Spore Walls ◽  
Surface Ornamentation

The spores of Orthotrichum lyellii Hook & Taylor, O. speciosum Nees, O. affine Schrad. ex Brid., O. rupestre Schleich. ex Schwagr., O. anomalum Hedw. and O. cupulatum Hoffm. ex Brid. showed the apertural region consists of a leptoma in their spores. Two spore types are characterized by their surface ornamentation, reflecting the species’ taxonomic relationships. The spore shape of all the species is spheroid. The spore size ranged from 7 to 23 μm in the genus Orthotrichum. While the surface ornamentation is verrucate in O. speciosum and O. affine, it is gemmate in O. lyellii, O. rupestre, O. anomalum and O. cupulatum. The spore walls of the family Orthotrichaceae include sclerine (the distinction between exine and perine might be difficult to define) and intine. The examined moss species belong to two habitat types: corticolous and saxicolous. The taxonomic and ecological implications of the genus Orthotrichum were discussed on the basis of its spore morphology.

Ady3p Links Spindle Pole Body Function to Spore Wall Synthesis in Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 160 (4) ◽  
pp. 1439-1450
Author(s):  
Mark E Nickas ◽  
Aaron M Neiman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
De Novo ◽  
Spindle Pole Body ◽  
Leading Edge ◽  
Spindle Pole ◽  
Spore Wall ◽  
Pole Body ◽  
Prospore Membrane ◽  
Sporulation Efficiency ◽  
Spore Walls

Abstract Spore formation in Saccharomyces cerevisiae requires the de novo synthesis of prospore membranes and spore walls. Ady3p has been identified as an interaction partner for Mpc70p/Spo21p, a meiosis-specific component of the outer plaque of the spindle pole body (SPB) that is required for prospore membrane formation, and for Don1p, which forms a ring-like structure at the leading edge of the prospore membrane during meiosis II. ADY3 expression has been shown to be induced in midsporulation. We report here that Ady3p interacts with additional components of the outer and central plaques of the SPB in the two-hybrid assay. Cells that lack ADY3 display a decrease in sporulation efficiency, and most ady3Δ/ady3Δ asci that do form contain fewer than four spores. The sporulation defect in ady3Δ/ady3Δ cells is due to a failure to synthesize spore wall polymers. Ady3p forms ring-like structures around meiosis II spindles that colocalize with those formed by Don1p, and Don1p rings are absent during meiosis II in ady3Δ/ady3Δ cells. In mpc70Δ/mpc70Δ cells, Ady3p remains associated with SPBs during meiosis II. Our results suggest that Ady3p mediates assembly of the Don1p-containing structure at the leading edge of the prospore membrane via interaction with components of the SPB and that this structure is involved in spore wall formation.

scholarly journals Reactive oxygen species are required for spore-wall formation in Physcomitrella patens

Botany ◽  
2020 ◽  
Vol 98 (10) ◽  
pp. 575-587
Author(s):  
Fazle Rabbi ◽  
Karen S. Renzaglia ◽  
Neil W. Ashton ◽  
Dae-Yeon Suh
Keyword(s):  
Reactive Oxygen Species ◽  
Physcomitrella Patens ◽  
Reactive Oxygen ◽  
Spore Wall ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Normal Wall ◽  
Spore Walls ◽  
Ros Scavenger ◽  
Spine Structure

A robust spore wall was a key requirement for terrestrialization by early plants. Sporopollenin in spore and pollen grain walls is thought to be polymerized and cross-linked to other macromolecular components, partly through oxidative processes involving H2O2. Therefore, we investigated effects of scavengers of reactive oxygen species (ROS) on the formation of spore walls in the moss Physcomitrella patens (Hedw.) Bruch, Schimp & W. Gümbel. Exposure of sporophytes, containing spores in the process of forming walls, to ascorbate, dimethylthiourea, or 4-hydroxy-TEMPO prevented normal wall development in a dose, chemical, and stage-dependent manner. Mature spores, exposed while developing to a ROS scavenger, burst when mounted in water on a flat slide under a coverslip (a phenomenon we named “augmented osmolysis” because they did not burst in phosphate-buffered saline or in water on a depression slide). Additionally, the walls of exposed spores were more susceptible to alkaline hydrolysis than those of the control spores, and some were characterized by discontinuities in the exine, anomalies in perine spine structure, abnormal intine and aperture, and occasionally, wall shedding. Our data support the involvement of oxidative cross-linking in spore-wall development, including sporopollenin polymerization or deposition, as well as a role for ROS in intine/aperture development.

Spore morphology of Selaginella (Selaginellaceae) from China and its systematic significance

Phytotaxa ◽  
2015 ◽  
Vol 237 (1) ◽  
pp. 1 ◽  
Author(s):  
Xin-Mao Zhou ◽  
Li-Jü Jiang ◽  
Liang Zhang ◽  
Xin-Fen Gao ◽  
Zhao-Rong He ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Morphological Characteristics ◽  
Spore Morphology ◽  
Systematic Significance ◽  
First Time ◽  
Scanning Electron

Using light microscope (LM) and scanning electron microscope (SEM), the megaspores and microspores of 77 samples representing ca. 70 species of Selaginella from China are observed. Combing previous studies, the spore morphology of nearly all documented Selaginella species from China were reviewed. Based on the morphological characteristics in megaspores and/or microspores, we divided the spores of Chinese species into 15 types and three types are further divided into various subtypes. Each type and subtype are described in detail and a key to the types and subtypes of spores is given. For the first time, the systematic significance of microspores of Selaginella are discussed, and the results indicate that microspores of Selaginella are significant in the systematics of Selaginella. Some important morphological characteristics in spores (e.g., color, micro-sculpture, size, etc.), often been neglected in previous studies, are introduced. Some spore-morphological synapomorphies of the clades and subclades, identified by recent molecular work (Zhou et al. 2015a), are well established. Using the spore morphology, the delimitation of some taxonomically difficult species in Selaginella is assessed.

Teliospore wall structure in Entorrhiza (Tilletiaceae) and its relationship to taxonomy of the genus

1992 ◽  
Vol 70 (10) ◽  
pp. 1964-1983 ◽  
Author(s):  
Brian A. Fineran ◽  
Judith M. Fineran
Keyword(s):  
Electron Microscopy ◽  
Outer Zone ◽  
Spore Wall ◽  
Wall Structure ◽  
Dense Matrix ◽  
Thin Sections ◽  
Transmission Electron ◽  
Layer 2 ◽  
Layer 4 ◽  
Freeze Etching

Spore wall organization in the five species of Entorrhiza (Ustilaginales) has been investigated using thin sections for transmission electron microscopy, supported by light and scanning electron microscopy and some freeze-etching. Material was examined from herbaria, specimens preserved in fixative, and fresh host tissue. The wall has four main layers, numbered 1–4 from the outside to inside of the wall; some layers are further differentiated into zones. Layer 1 in E. aschersoniana, E. caspaiyana, and E. caricicola has two zones: a broad outer zone 2 of dense matrix and a narrow inner zone 1 of less compacted material. Zone 1 is absent in E. cypericola. In E. scirpicola, layer 1 is represented by discontinuous longitudinal ridges. In all spores, layer 2 is composed of a homogeneous electron-dense matrix. Layer 1 in E. aschersoniana, E. casparyana, and E. caricicola is uniformly thick, but in E. cypericola it is broad with an irregular outer margin. In E. scirpicola, layer 2 is differentiated into a distinctive pattern of longitudinal ribs. In all spores of Entorrhiza, layer 3 is resolvable into fine lamellae, corresponding to the mosaic of striations seen after freeze-etching. Layer 3 in Entorrhiza is equivalent to the partition layer described in other Tilletiaceae. Layer 4 has the same organization in all the species, consisting of a very narrow zone 2 abutting layer 3 and a broad zone 1 that forms the rest of the layer. Based on wall structure, E. aschersoniana and E. casparyana represent the most closely related species, followed by E. caricicola, with E. cypericola more distant again. Entorrhiza scirpicola is considered the least related of the species; only its layers 3 and 4 resemble the other species. Key words: Entorrhiza, Tilletiaceae, spore wall ultrastructure, species relationships.

scholarly journals The fission yeast spore is coated by a proteinaceous surface layer comprising mainly Isp3

2014 ◽  
Vol 25 (10) ◽  
pp. 1549-1559 ◽  
Author(s):  
Kana Fukunishi ◽  
Kana Miyakubi ◽  
Mitsuko Hatanaka ◽  
Natsumi Otsuru ◽  
Aiko Hirata ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Digestive Enzymes ◽  
Spore Wall ◽  
Environmental Stresses ◽  
Dense Layer ◽  
Spore Coat ◽  
Spore Surface ◽  
Wild Type ◽  
Dormant Cell ◽  
Spore Coat Protein

The spore is a dormant cell that is resistant to various environmental stresses. As compared with the vegetative cell wall, the spore wall has a more extensive structure that confers resistance on spores. In the fission yeast Schizosaccharomyces pombe, the polysaccharides glucan and chitosan are major components of the spore wall; however, the structure of the spore surface remains unknown. We identify the spore coat protein Isp3/Meu4. The isp3 disruptant is viable and executes meiotic nuclear divisions as efficiently as the wild type, but isp3∆ spores show decreased tolerance to heat, digestive enzymes, and ethanol. Electron microscopy shows that an electron-dense layer is formed at the outermost region of the wild-type spore wall. This layer is not observed in isp3∆ spores. Furthermore, Isp3 is abundantly detected in this layer by immunoelectron microscopy. Thus Isp3 constitutes the spore coat, thereby conferring resistance to various environmental stresses.

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