Nature of the guard cell wall in leaf stomata of three Ophioglossum species

1975 ◽  
Vol 53 (16) ◽  
pp. 1698-1711 ◽  
Author(s):  
R. L. Peterson ◽  
M. S. Firminger ◽  
L. A. Dobrindt
Keyword(s):  
Cell Wall ◽  
Guard Cell ◽  
Cell Walls ◽  
Guard Cells ◽  
Aniline Blue ◽  
Phenolic Substance ◽  
Polarization Microscopy ◽  
Leaf Tissues ◽  
Stomatal Guard Cells ◽  
Staining Techniques

A β-1,3-glucan which has characteristics of callose was identified as a component of the cell wall in stomatal guard cells in three species of the fern, Ophioglossum. This identification was made by the fluorochrome properties of callose when stained with aqueous solutions of aniline blue. Controls involved both the effect of solutions of different pH on autofluorescence of guard cell walls and the extraction of leaf tissues with β-1,3-glucanases before staining with aniline blue. An electron-translucent region between the plasmalemma and the cell wall proper was observed with the electron microscope and corresponded in position with the areas that fluoresced after aniline blue staining.Other components of the guard cell wall identified included cellulose, which was identified by staining techniques, polarization microscopy, and electron microscopy; and a phenolic substance identified by a number of staining reactions. The cell wall failed to stain with a number of reagents for the identification of lignin.

Guard cell ontogeny in leaf stomata of the fern Ophioglossum petiolatum

1978 ◽  
Vol 56 (22) ◽  
pp. 2836-2852 ◽  
Author(s):  
R. L. Peterson ◽  
Sarah Hambleton
Keyword(s):  
Cell Wall ◽  
Epidermal Cell ◽  
Guard Cell ◽  
Cell Walls ◽  
Middle Lamella ◽  
Guard Cells ◽  
Aniline Blue ◽  
Blue Staining ◽  
Starch Grains ◽  
Common Cell

Guard cells in Ophioglossum petiolatum leaves are initiated by a single division of a stomatal initial with no subsidiary cells being formed. The stomatal initials have few vacuoles, plastids with little starch, and a large nucleus with much heterochromatin and prominent nucleoli. Young guard cells are similar cytologically to stomatal initials; their common cell walls are thin and traversed by plasmodesmata. Plasmodesmata are also present within guard cell and adjacent epidermal cell walls. With increasing age, guard cells develop a lenticular thickening in the median portion of the common cell walls, larger vacuoles, and plastids with several starch grains. Numerous microtubules are present near the thickening wall which also has an electron-translucent region between the cell wall and the plasmalemma. Many dictyosomes and mitochondria are present in the cytoplasm. Older guard cells become more vacuolated, with some of the vacuoles containing fibrillar or dense deposits. Plastids become very large as a result of storing several large starch grains. In the thickened portion of the cell walls, the middle lamella and some of the adjacent cell wall appear to be degraded during stomatal pore formation. Mature guard cells are highly vacuolated and have very thick electron-dense cell walls without plasmodesmata. Fluorescence microscopy following aniline blue staining shows that aniline blue positive materials are present around and within the thickened portion of the cell walls, at the junction of guard cells with epidermal cells, and as distinct spots in guard cell and epidermal cell walls during the early stages of ontogeny. Mature guard cells, however, lack the distinct fluorescent spots, which are interpreted as plasmodesmata, in their walls.

scholarly journals Submicroscopical Features of Leaves of Xyris Species

2001 ◽  
Vol 44 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Maria das Graças Sajo ◽  
Silvia Rodrigues Machado
Keyword(s):  
Electron Microscope ◽  
Cell Walls ◽  
Guard Cells ◽  
Leaf Ultrastructure ◽  
Mesophyll Cells ◽  
Transmission Electron ◽  
Inner Surface ◽  
Stomatal Guard Cells ◽  
Adaptative Significance ◽  
Scanning Electron

The leaf ultrastructure of five Xyris species were examined using scanning electron microscope (SEM), transmission electron microscope (TEM) and histochemical methods. All studied leaves show some features in epidermis and mesophyll, which were of considerable adaptative significance to drought stress. Such features included the occurrence of a pectic layer on the stomatal guard cells and the presence of a network of pectic compounds in the cuticle. Pectic compunds were also in abundance in lamellated walls of the mesophyll cells and on the inner surface of the sclerified cell walls of the vascular bundle sheaths. There were also specialized chlorenchymatous "peg cells" in the mesophyll and drops of phenolic compounds inside the epidermal cells.

Ultrastructural observations on guard cells of Vicia faba and Allium porrum

1972 ◽  
Vol 50 (6) ◽  
pp. 1405-1413 ◽  
Author(s):  
W. G. Allaway ◽  
George Setterfield
Keyword(s):  
Vicia Faba ◽  
Small Groups ◽  
Guard Cell ◽  
Cell Walls ◽  
Guard Cells ◽  
Cell Physiology ◽  
Allium Porrum ◽  
Starch Granules ◽  
Mesophyll Cells ◽  
Guard Cell Chloroplasts

Stomata of Vicia faba and Allium porrum were examined in thin section with the electron microscope. Guard cells contained numerous mitochondria, few plastids, and relatively small vacuoles traversed by many strands of cytoplasm. Spherosomes were often observed but were variable in occurrence. Endoplasmic reticulum and dictyosomes were present, although not well developed. Scattered microtubules were present at the periphery of the cells. Microbodies were very rarely observed in guard cells and no plasmodesmata were ever seen in the guard cell walls. Plastids were small and irregular in outline in guard cells of both species. Guard cell plastids of V. faba contained abundant large starch granules. In both species thylakoids were few and grana were small in comparison with mesophyll plastids. The inner of the two bounding membranes of guard cell chloroplasts was extensively invaginated, forming a peripheral reticulum. This was not observed in mesophyll plastids of these species. Small groups of microtubule-like structures were often observed in V. faba guard cell plastids; microtubule-like structures were less frequent in A. porrum plastids, and were not in groups. The structures described are compared with those of other epidermal cells and mesophyll cells, and are discussed in relation to guard cell physiology.

Ca2+ signalling in stomatal guard cells

2000 ◽  
Vol 28 (4) ◽  
pp. 476-481 ◽  
Author(s):  
M. R. McAinsh ◽  
J. E. Gray ◽  
A. M. Hetherington ◽  
C. P. Leckie ◽  
C. Ng
Keyword(s):  
Signal Transduction ◽  
Guard Cell ◽  
Signal Transduction Pathway ◽  
Guard Cells ◽  
Stomatal Opening ◽  
Cell Turgor ◽  
Stomatal Guard Cells ◽  
External Stimuli ◽  
Spatial And Temporal Characteristics

Ca2+ is a ubiquitous second messenger in the signal transduction pathway(s) by which stomatal guard cells respond to external stimuli. Increases in guard-cell cytosolic free Ca2+ concentration ([Ca2+]cyt) have been observed in response to stimuli that cause both stomatal opening and closure. In addition, several important components of Ca2+-based signalling pathways have been identified in guard cells, including the cADP-ribose and phospholipase C/Ins(1,4,5)P3-mediated Ca2+-mobilizing pathways. The central role of stimulus-induced increases in [Ca2+]cyt in guard-cell signal transduction has been clearly demonstrated in experiments examining the effects of modulating increases in [Ca2+]cyt on alterations in guard-cell turgor or the activity of ion channels that act as effectors in the guard-cell turgor response. In addition, the paradox that Ca2+ is involved in the transduction of signals that result in opposite end responses (stomatal opening and closure) might be accounted for by the generation of stimulus-specific Ca2+ signatures, such that increases in [Ca2+]cyt exhibit unique spatial and temporal characteristics.

scholarly journals Silicon-Induced Cell Wall Fortification of Rice Leaves: A Possible Cellular Mechanism of Enhanced Host Resistance to Blast

2002 ◽  
Vol 92 (10) ◽  
pp. 1095-1103 ◽  
Author(s):  
Sang Gyu Kim ◽  
Ki Woo Kim ◽  
Eun Woo Park ◽  
Doil Choi
Keyword(s):  
Cell Wall ◽  
Epidermal Cell ◽  
Host Resistance ◽  
Cell Walls ◽  
Leaf Surface ◽  
Leaf Blast ◽  
X Ray ◽  
Silicon Accumulation ◽  
Stomatal Guard Cells ◽  
Rice Leaves

Locations of silicon accumulation in rice leaves and its possible association with resistance to rice blast were investigated by electron microscopy and X-ray microanalysis. A blast-susceptible cultivar, Jinmi, and a partially resistant cultivar, Hwaseong, were grown under a hydroponic culture system with modified Yoshida's nutrient solution containing 0, 50, 100, and 200 ppm of silicon. Electron-dense silicon layers were frequently found beneath the cuticle in epidermal cell walls of silicon-treated plants. Increasing levels of silicon were detected in the outer regions of epidermal cell walls. Silicon was present mainly in epidermal cell walls, middle lamellae, and intercellular spaces within subepidermal tissues. Furthermore, silicon was prevalent throughout the leaf surface, with relatively small deposition on stomatal guard cells in silicon-treated plants. Silicon accumulation and epidermal cell wall thickness in leaves were greater in cv. Jinmi than in cv. Hwaseong. However, the thickness ratios of the silicon layers to epidermal cell walls were greater in cv. Hwaseong (53.25 to 93.28%) than in cv. Jinmi (36.58 to 66.54%). Leaf blast severity was lower in cv. Hwaseong than in cv. Jinmi and was significantly reduced in silicon-treated plants of both cultivars. These results suggest that silicon-induced cell wall fortification of rice leaves may be closely associated with enhanced host resistance to blast.

scholarly journals Eukaryotic lipid metabolic pathway is essential for functional chloroplasts and CO2 and light responses in Arabidopsis guard cells

2018 ◽  
Vol 115 (36) ◽  
pp. 9038-9043 ◽  
Author(s):  
Juntaro Negi ◽  
Shintaro Munemasa ◽  
Boseok Song ◽  
Ryosuke Tadakuma ◽  
Mayumi Fujita ◽  
...  
Keyword(s):  
Metabolic Pathway ◽  
Guard Cell ◽  
Membrane Lipids ◽  
Stomatal Closure ◽  
Guard Cells ◽  
Land Plant ◽  
In The Wild ◽  
Stomatal Guard Cells ◽  
Guard Cell Chloroplasts ◽  
And Function

Stomatal guard cells develop unique chloroplasts in land plant species. However, the developmental mechanisms and function of chloroplasts in guard cells remain unclear. In seed plants, chloroplast membrane lipids are synthesized via two pathways: the prokaryotic and eukaryotic pathways. Here we report the central contribution of endoplasmic reticulum (ER)-derived chloroplast lipids, which are synthesized through the eukaryotic lipid metabolic pathway, in the development of functional guard cell chloroplasts. We gained insight into this pathway by isolating and examining an Arabidopsis mutant, gles1 (green less stomata 1), which had achlorophyllous stomatal guard cells and impaired stomatal responses to CO2 and light. The GLES1 gene encodes a small glycine-rich protein, which is a putative regulatory component of the trigalactosyldiacylglycerol (TGD) protein complex that mediates ER-to-chloroplast lipid transport via the eukaryotic pathway. Lipidomic analysis revealed that in the wild type, the prokaryotic pathway is dysfunctional, specifically in guard cells, whereas in gles1 guard cells, the eukaryotic pathway is also abrogated. CO2-induced stomatal closing and activation of guard cell S-type anion channels that drive stomatal closure were disrupted in gles1 guard cells. In conclusion, the eukaryotic lipid pathway plays an essential role in the development of a sensing/signaling machinery for CO2 and light in guard cell chloroplasts.

In vitro expression of resistance responses to Seiridium species in micropropagated shoots of Cupressus sempervirens and Chamaecyparis lawsoniana

1997 ◽  
Vol 75 (7) ◽  
pp. 1103-1109 ◽  
Author(s):  
K. A. Spanos ◽  
A. Pirrie ◽  
S. Woodward
Keyword(s):  
Cell Walls ◽  
Guard Cells ◽  
Cupressus Sempervirens ◽  
Fungal Hyphae ◽  
In Vitro Inoculation ◽  
Host Tree Species ◽  
Stomatal Guard Cells ◽  
Seiridium Cardinale ◽  
Chamaecyparis Lawsoniana

Wounded and nonwounded micropropagated shoots of Cupressus sempervirens and Chamaecyparis lawsoniana were inoculated in vitro with the canker-causing pathogens Seiridium cardinale (Wag.) Sutton & Gibson, Seiridium cupressi (Guba) Boeswinkel and Seiridium unicorne (Cke & Ell.) Sutton. Seiridium cardinale was significantly more pathogenic on Cupressus sempervirens than on Chamaecyparis lawsoniana (Murr.) Parlatore, irrespective of the presence of wounds on the shoots. On wounded shoots, both S. cupressi and S. unicorne caused significantly larger lesions on Chamaecyparis lawsoniana than on Cupressus sempervirens by 20 days after inoculation. Superficial wounding of shoots prior to inoculation caused a significant increase in the lengths of lesions and numbers of shoots girdled by the pathogens on both hosts. These results broadly correlate with known virulence of the three pathogens on these two host tree species in field and glasshouse tests. Using histological methods, penetration of fungal hyphae through stomatal pores of both shoots and leaves into the substomatal cavity and the mesophyll space was observed. Penetration directly through the cuticle was also seen. Defence-related responses, including accumulation of oxidized polyphenols compounds and deposition of lignin and suberin in cell walls, were detected in inoculated tissues. These responses occurred predominantly in the epidermis, including stomatal guard cells, and the hypodermis and were particularly marked in Chamaecyparis lawsoniana inoculated with S. cardinale. The possible utility of these methods in the study and detection of host genotypes resistant to Seiridium spp. is discussed. Key words: Seiridium, Cupressus, Chamaecyparis, micropropagation, in vitro inoculation, defence.

scholarly journals Diversity in the organisation and lignification of tension wood fibre walls – A review

IAWA Journal ◽  
2017 ◽  
Vol 38 (2) ◽  
pp. 245-265 ◽  
Author(s):  
Barbara Ghislain ◽  
Bruno Clair
Keyword(s):  
Cell Wall ◽  
Tensile Stress ◽  
Cell Walls ◽  
Tension Wood ◽  
Anatomical Structure ◽  
Wood Fibre ◽  
Tropical Species ◽  
Wood Fibres ◽  
Staining Techniques

Tension wood, a tissue developed by angiosperm trees to actively recover their verticality, has long been defined by the presence of an unlignified cellulosic inner layer in the cell wall of fibres, called the G-layer. Although it was known that some species have no G-layer, the definition was appropriate since it enabled easy detection of tension wood zones using various staining techniques for either cellulose or lignin. For several years now, irrespective of its anatomical structure, tension wood has been defined by its high mechanical internal tensile stress. This definition enables screening of the diversity of cell walls in tension wood fibres. Recent results obtained in tropical species with tension wood with a delay in the lignification of the G-layer opened our eyes to the effective presence of large amounts of lignin in the G-layer of some species. This led us to review older literature mentioning the presence of lignin deposits in the G-layer and give them credit. Advances in the knowledge of tension wood fibres allow us to reconsider some previous classifications of the diversity in the organisation of the fibre walls of the tension wood.

scholarly journals SCALE FORMATION IN CHRYSOPHYCEAN ALGAE

1970 ◽  
Vol 45 (2) ◽  
pp. 246-271 ◽  
Author(s):  
R. Malcolm Brown ◽  
Werner W. Franke ◽  
Hans Kleinig ◽  
Heinz Falk ◽  
Peter Sitte
Keyword(s):  
Cell Wall ◽  
Cross Sections ◽  
Cell Walls ◽  
Present Finding ◽  
Alkaline Treatment ◽  
Cellulose Synthesis ◽  
Proton Resonance ◽  
Histochemical Tests ◽  
Zoospore Formation ◽  
Staining Techniques

The cell wall of the marine chrysophycean alga Pleurochrysis scherfellii is composed of distinct wall fragments embedded in a gelatinous mass. The latter is a polysaccharide of pectic character which is rich in galactose and ribose. These wall fragments are identified as scales. They have been isolated and purified from the vegetative mother cell walls after zoospore formation. Their ultrastructure is described in an electron microscope study combining sectioning, freeze-etch, and negative staining techniques. The scales consist of a layer of concentrically arranged microfibrils (ribbons with cross-sections of 12 to 25 x 25 to 40 A) and underlying radial fibrils of similar dimensions. Such a network-plate is densely coated with particles which are assumed to be identical to the pectic component. The microfibrils are resistant to strong alkaline treatment and have been identified as cellulose by different methods, including sugar analysis after total hydrolysis, proton resonance spectroscopical examination (NMR spectroscopy) of the benzoylated product, and diverse histochemical tests. The formation and secretion of the scales can be followed along the maturing Golgi cisternae starting from a pronounced dilated "polymerization center" as a completely intracisternal process which ends in the exocytotic extrusion of the scales. The scales reveal the very same ultrastructure within the Golgi cisternae as they do in the cell wall. The present finding represents the first evidence on cellulose formation by the Golgi apparatus and is discussed in relation to a basic scheme for cellulose synthesis in plant cells in general.

II. On the origin of parasitism in fungi

1905 ◽  
Vol 197 (225-238) ◽  
pp. 7-24 ◽  
Keyword(s):  
Cell Wall ◽  
Host Plant ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Germ Tube ◽  
Guard Cells ◽  
Suitable Host ◽  
Parasitic Fungi ◽  
Germ Tubes ◽  
Gain Access

Respecting the various modes by which parasitic fungi gain access to the interior of the host-plant, much is known. De Bary (1) demonstrated that the germ-tubes of secidiospores and uredospores enter solely through the stomata, whereas germ-tubes of teleutospores, and also those of various other parasites, enter by piercing the walls of the epidermal cells, or of the guard-cells of the stomata. Other fungi gain an entrance sometimes by a stoma, sometimes by piercing the wall of an epidermal cell. The same author also observed that the zoospores of Cytopus and of Peronospora umbelliferarum , when deposited on the leaf of a suitable host-plant, germinate and the germ-tube enters a stoma, whereas when germination takes place in water the germ-tubes soon die. Marshall Ward has shown (2) that in the case of a species of Botrytis an entrance into the host-plant through the cell-walls of the epidermis is effected by means of the secretion of a ferment by the tip of the germ-tube, whereby the substance of the cell-wall is softened.

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