Leaf anatomy and ultrastructure of the North American marine angiosperm Phyllospadix (Zosteraceae)

1995 ◽  
Vol 73 (6) ◽  
pp. 827-842 ◽  
Author(s):  
John Kuo ◽  
Joan G. Stewart
Keyword(s):  
Vascular Bundle ◽  
North American ◽  
Cell Walls ◽  
Bundle Sheath ◽  
Epidermal Cells ◽  
The North ◽  
Bundle Sheath Cells ◽  
Parenchyma Cells ◽  
Sieve Tubes ◽  
Anatomy And Ultrastructure

The leaf anatomy and ultrastructure of the North American Phyllospadix species P. serrulatus Rupt. ex Aschers., P. scouleri Hook, and P. torreyi Watson are described. The unique anatomical and ultrastructural features of these species are compared with those of other seagrasses and their possible functional significance is discussed. All three species have ultrastructures similar to those in other members of the family Zosteracae. Subcuticular cavities, wall ingrowths, and numerous mitochondria and chloroplasts with well-developed grana are present in the blade epidermal cells and the adaxial sheath epidermal cells, indicating that these cells may play a major role in photosynthesis, osmoregulation, and absorption. Plasmodesmata are present occasionally between adjacent epidermal cells, and also between epidermal and mesophyll cells, suggesting that solutes can be transferred symplastically between these tissues. The vascular bundle sheath cells are not easy to recognize, as cell walls are thin and not suberized. The phloem contains both normal and nacreous-walled sieve tubes that may be functional. The walls of the phloem parenchyma cells facing nacreous-walled sieve tubes possess weak wall ingrowths, leading to speculation that these parenchyma cells may play an important role in solute translocation. The absence of suberin lamella in bundle sheath cells and the presence of a small xylem element in each vascular bundle suggest that the water flow in xylem elements in these seagrasses may be limited and that water is taken directly from the water column by leaf epidermal cells and is transported apoplastically along cell walls. The three North American Phyllospadix species can be separated by anatomical characters such as number of vascular bundles, the shape of epidermal cells in both transverse sectional and surface views, and the distribution of fibre bundles. It is proposed that P. serrulatus is taxonomically more closely related to the Japanese P. iwatensis Makino than to P. scouleri and P. torreyi and that there is no detectable hybrid species occurring between P. scouleri and P. torreyi. Key words: anatomy, ultrastructure, seagrasses, Phyllospadix, North America.

scholarly journals Leaf anatomy and carbon isotope composition in Coffea species related to photosynthetic pathway

2003 ◽  
Vol 15 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Maria Luiza Carvalho Carelli ◽  
Rachel Benetti Queiroz-Voltan ◽  
Joel Irineu Fahl ◽  
Paulo César Ocheuze Trivelin
Keyword(s):  
Carbon Isotope ◽  
Vascular Bundle ◽  
Leaf Anatomy ◽  
Isotope Composition ◽  
Bundle Sheath ◽  
Carbon Isotope Composition ◽  
Photosynthetic Pathway ◽  
Spongy Parenchyma ◽  
Bundle Sheath Cells ◽  
Parenchyma Cells

Possible presence of vascular bundle sheath cells and its relation to photosynthetic pathway, leaf anatomy and carbon isotope composition (delta13C) were examined in six species of genus Coffea: C. arabica (cvs. Catuaí Vermelho, Mundo Novo, Bourbon Vermelho and Icatu Amarelo), C. canephora (cvs. Apoatã and Guarini), C. liberica, C. dewevrei, C. salvatrix and C. stenophylla. In all genotypes, the vascular bundle was surrounded by a layer of cells with numerous chloroplasts in a centrifugal position. Visually no differences could be seen between the spongy parenchyma cells and the bundle sheath cells, neither in size nor in chloroplast number. The leaf delta13C values ranged between a maximum of - 26.2 ‰ in C. salvatrix and a minimum of -29.7 ‰ in C. liberica. A strong correlation (r = 0.972, p = 0.001) between delta13C and anatomical characteristics was observed in coffee species. C. salvatrix exhibited the highest delta13C values and the most compact mesophyll, with more palisade and spongy parenchyma cells in contact with the vascular bundle sheath.

Effects of Shading on the Anatomy and Ultrastructure of the Leaf Mesophyll and Vascular Bundles of Itchgrass (Rottboellia exaltata)

Weed Science ◽  
1980 ◽  
Vol 28 (2) ◽  
pp. 216-224 ◽  
Author(s):  
Rex N. Paul ◽  
David T. Patterson
Keyword(s):  
Cell Walls ◽  
Membrane Integrity ◽  
Bundle Sheath ◽  
Vascular Bundles ◽  
Photosynthetic Pathway ◽  
Leaf Mesophyll ◽  
Structural Relationships ◽  
Bundle Sheath Cells ◽  
Shading Effects ◽  
Anatomy And Ultrastructure

A study of the C4plant itchgrass (Rottboellia exaltataL.f.) grown under 100%, 60%, 25% and 2% sunlight revealed differences in the anatomy and cytology of the foliar mesophyll and vascular bundles associated with shading. In the bundle sheath, shading caused a reduction in thickness of the cell walls, shrinkage of plastids, rearrangement of plastid thylakoids, a reduction in starch deposits and vacuolization of the cytoplasm. In general, plastids and mitochondria retained membrane integrity but underwent stromal deterioration. Shading effects on cytoplasm were similar for mesophyll and bundle sheath cells. Mesophyll chloroplasts lost starch grains and the peripheral reticulum tended to decrease with greater shading. Grana were well developed at all irradiances, although the chloroplasts themselves decreased in size with shading. Movement of mesophyll chloroplasts away from bundle sheath-mesophyll borders was pronounced at 60% sunlight and was progressively greater at the two lower irradiances. These observations suggest that the structural relationships thought to be necessary for the intercellular transfer of C4acids and the functioning of the C4photosynthetic pathway were disrupted by shading.

Comparison of photosynthetic carbon reduction (Kranz) cells having different ontogenetic origins in the C4 NADP – malic enzyme grass Arundinella hirta

1990 ◽  
Vol 68 (6) ◽  
pp. 1222-1232 ◽  
Author(s):  
Nancy G. Dengler ◽  
Ronald E. Dengler ◽  
Douglas J. Grenville
Keyword(s):  
Cell Walls ◽  
Vascular Tissue ◽  
Cell Types ◽  
Bundle Sheath ◽  
Carbon Reduction ◽  
Bundle Sheath Cells ◽  
Photosynthetic Carbon ◽  
Arundinella Hirta ◽  
Photosynthetic Carbon Reduction ◽  
Sheath Cells

The C4 grass Arundinella hirta is characterized by unusual leaf blade anatomy: photosynthetic carbon reduction takes place both within the chlorenchymatous bundle sheath cells of the longitudinal veins and within longitudinal strands of "distinctive cells" that form part of the leaf mesophyll and are often completely isolated from vascular tissue. Although they are equivalent physiologically, these two cell types have different ontogenetic origins: bundle sheath cells are delimited from procambium early in leaf development, whereas distinctive cells differentiate from ground meristem at a later developmental stage. Although the two cell types share numerous cytological features (large chloroplasts with reduced grana, thick cell walls with a suberin lamella), we also found significant differences in cell lengths, length to width ratios, cell cross-sectional areas, organelle numbers per cell cross section, phenol content of the cell walls, and numbers of pit fields in the longitudinal cell walls. The size and shape of bundle sheath cells are likely a direct consequence of procambial origin. The thicker walls of bundle sheath cells (in major veins) and their greater lignification may reflect the inductive effect of cell differentiation in the proximity of sclerenchyma and vascular tissues. Differences between major and minor vein bundle sheath cells may reflect differences in the timing of initiation of procambial strands. Our analysis of cell wall characteristics has also shown the presence of numerous primary pit fields in the transverse walls between adjacent distinctive cells in a file; plasmodesmata in these pit fields form a pathway for longitudinal symplastic transport not previously known to exist.

scholarly journals Arabidopsis leaf hydraulic conductance is regulated by xylem-sap pH, controlled, in turn, by a P-type H+-ATPase of vascular bundle sheath cells

2017 ◽  
Author(s):  
Yael Grunwald ◽  
Noa Wigoda ◽  
Nir Sade ◽  
Adi Yaaran ◽  
Tanmayee Torne ◽  
...  
Keyword(s):  
Proton Pump ◽  
Vascular Bundle ◽  
Xylem Sap ◽  
Hydraulic Conductance ◽  
Bundle Sheath ◽  
List Type ◽  
Mesophyll Cells ◽  
Leaf Hydraulic Conductance ◽  
Bundle Sheath Cells ◽  
Sheath Cells

AbstractThe leaf vascular bundle sheath cells (BSCs) that tightly envelop the leaf veins, are a selective and dynamic barrier to xylem-sap water and solutes radially entering the mesophyll cells. Under normal conditions, xylem-sap pH of <6 is presumably important for driving and regulating the transmembranal solute transport. Having discovered recently a differentially high expression of a BSCs proton pump, AHA2, we now test the hypothesis that it regulates this pH and leaf radial water fluxes.We monitored the xylem-sap pH in the veins of detached leaves of WT Arabidopsis, AHA mutants, and aha2 mutants complemented with AHA2 gene solely in BSCs. We tested an AHA inhibitor and stimulator, and different pH buffers. We monitored their impact on the xylem-sap pH and the whole leaf hydraulic conductance (Kleaf), and the effect of pH on the water osmotic permeability (Pf) of isolated BSCs protoplasts.Our results demonstrated that AHA2 is necessary for xylem-sap acidification, and in turn, for elevating Kleaf. Conversely, knocking out AHA2 alkalinized the xylem-sap. Also, elevating xylem sap pH to 7.5 reduced Kleaf and elevating external pH to 7.5 decreased the BSCs Pf.All these demonstrate a causative link between AHA2 activity in BSCs and leaf radial water conductance.One-sentence summaryBundle-sheath cells can control the leaf hydraulic conductance by proton-pump-regulated xylem sap pH

Localization of cadmium in granules within differentiating and mature root cells

1987 ◽  
Vol 65 (4) ◽  
pp. 643-646 ◽  
Author(s):  
W. E. Rauser ◽  
C. A. Ackerley
Keyword(s):  
Zea Mays ◽  
Cell Walls ◽  
Zea Mays L ◽  
Epidermal Cells ◽  
Root Cells ◽  
Dense Granules ◽  
Parenchyma Cells ◽  
Undifferentiated Cells ◽  
Mature Root

Cadmium was found in electron-dense granules inside root parenchyma cells of Agrostis gigantea Roth and of Zea mays L. (maize) exposed to 3 mmol m−3 CdSO4. Cadmium-bearing granules were found in the cytoplasm and vacuoles of differentiating and mature cells and in nuclei of undifferentiated cells. Cadmium-bearing granules were absent from cell walls and epidermal cells. In addition to Cd, the electron-dense granules contained variable proportions of Ca, Fe, Ni, P, Pb, and Zn.

Leaf ultrastructure in species of Gomphrena and Pfaffia (Amaranthaceae)

1984 ◽  
Vol 62 (4) ◽  
pp. 812-817 ◽  
Author(s):  
Maria Emília Estelita-Teixeira ◽  
Walter Handro
Keyword(s):  
Vascular Bundle ◽  
Bundle Sheath ◽  
Chloroplast Structure ◽  
Leaf Ultrastructure ◽  
Mesophyll Cells ◽  
Lamellar System ◽  
Kranz Anatomy ◽  
Companion Cells ◽  
Bundle Sheath Cells ◽  
Vascular Parenchyma

Ultrastructural aspects, especially the organization of chloroplasts and their distribution, were studied in leaves of three species of Gomphrena (G. macrocephala, G. prostrata, and G. decipiens) presenting "Kranz anatomy," and in Pfaffia jubata, without that characteristic. In Gomphrena spp. the distribution of chloroplasts according to the complexity of their lamellar system seems to follow a gradient: most of the chloroplasts in the bundle sheath cells have poorly developed grana but some of them, in the cell side opposite to the vascular bundle, may present conspicuous grana. A similar situation occurs in "Kranz mesophyll cells," but in this case grana are more developed. Finally, chloroplasts in "non-Kranz mesophyll cells" have the more developed grana. In P. jubata no differences occur in chloroplast structure, all of them showing well-organized grana. Chloroplasts with well-developed grana were found in vascular parenchyma and in companion cells of Gomphrena spp. and P. jubata.

Structural aspects of the leaves of seven species of Portulaca growing in Hawaii

1990 ◽  
Vol 68 (8) ◽  
pp. 1803-1811 ◽  
Author(s):  
InSun Kim ◽  
David G. Fisher
Keyword(s):  
Bundle Sheath ◽  
Portulaca Oleracea ◽  
Mesophyll Cells ◽  
Peripheral Reticulum ◽  
Bundle Sheath Cells ◽  
Group A ◽  
Group B ◽  
Anatomy And Ultrastructure ◽  
Structural Aspects ◽  
Sheath Cells

Seven species of Portulaca growing in Hawaii can be divided into two groups based on the morphology, anatomy, and ultrastructure of their leaves. Portulaca oleracea, P. molokiniensis, P. lutea, forming group A, have spatulate to obovate leaves, paradermal minor veins, and mesophyll cells that completely encircle the minor veins. The chloroplasts in their bundle sheath cells are larger than those in the mesophyll cells and have well-developed grana and reduced peripheral reticulum. Bundle sheath mitochondria are larger and more numerous than those in the mesophyll, and chloroplasts in the mesophyll cells have well-developed grana and peripheral reticulum. Portulaca pilosa, P. villosa, P. sclerocarpa, and P. "ulupalakua," forming group B, have lanceolate to oblong–oblanceolate leaves, peripheral minor veins, and incomplete wreaths of mesophyll cells. The choroplasts in their bundle sheath cells are about the same size as those in the mesophyll and have reduced grana and well-developed peripheral reticulum. The bundle sheath mitochondria are about the same in size and number as those in the mesophyll, and the mesophyll chloroplasts have well-developed grana and reduced peripheral reticulum. Groups A and B may be equivalent, respectively, to types ii and i of R. C. Carolin, S. W. L. Jacobs, and M. Vesk (Aust. J. Bot. 26: 683–698, 1978) and to coronary subtypes B and A of E. V. Voznesenskaya and Y. V. Gamalei (Bot. Zh. Leningrad, 71: 1291–1306, 1986), which constitute groupings of Portulaca species studied by those authors.

A scanning electron microscope study of the spores and selected peristomes of the North American Encalyptaceae (Musci)

1974 ◽  
Vol 52 (8) ◽  
pp. 1973-1981 ◽  
Author(s):  
Dale H. Vitt ◽  
Catherine D. Hamilton
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
North American ◽  
Cell Walls ◽  
Electron Microscope Study ◽  
Spore Morphology ◽  
Scanning Electron Microscope Study ◽  
Whole Cells ◽  
The North ◽  
Scanning Electron

The eight North American species of Encalypta can be readily distinguished on the basis of spore morphology as viewed in the scanning electron microscope. Descriptions are given of the spores of each species as well as those of Bryobrittonia pellucida. Although the spores of Bryobrittonia closely resemble those of Encalypta procera, Bryobrittonia is easily distinguished from all Encalypta species in having mammillose leaf cells. Based on spore polarity and ornamentation, Encalypta can be divided into three groups, these closely approximating groupings that have been proposed on the basis of peristome characteristics. Of the three peristomes examined, that of E. longicolla appears to consist of whole cells, that of E. brevicolla of both whole cells and cell walls, while the peristome of E. rhaptocarpa consists of cell walls only.

Foliar anatomy of the subfamily Myrtoideae (Myrtaceae)

2009 ◽  
Vol 57 (2) ◽  
pp. 148 ◽  
Author(s):  
C. M. V. Cardoso ◽  
S. L. Proença ◽  
M. G. Sajo
Keyword(s):  
Vascular Bundle ◽  
Vascular System ◽  
Diagnostic Value ◽  
Bundle Sheath ◽  
Epidermal Cells ◽  
Vascular Bundles ◽  
Palisade Parenchyma ◽  
Surface Features ◽  
Foliar Anatomy ◽  
Secretory Cavities

The foliar structure of 44 species of Myrtoideae Nied. (Myrtaceae) was described to characterise the anatomy of the leaves in this subfamily and also to recognise particular features in each genus and/or subtribe. In the present study, nine genera of the subtribe Myrtinae, five genera of the subtribe Myrciinae and eight genera of the subtribe Eugeniinae were examined. All of them have dorsiventral and hypostomatic leaves, with stomata slightly protruded in relation to other epidermal cells; the leaves also present secretory cavities, idioblasts containing druses and vascular bundles with phloem on both adaxial and abaxial sides. Some surface features have diagnostic value for all genera of these three subtribes, such as the percentage of palisade parenchyma, the presence or absence of an adaxial hypodermis, the occurrence of an extension to the vascular bundle sheath, and the shape and position of the vascular system of the midrib. These features are described for each of the species studied and the results are discussed in a taxonomical context.

Sign in / Sign up

Export Citation Format

Share Document