Structural Analysis of Water-Storage Tissue in Leaves of Sansevieria (Agavaceae)

1988 ◽  
Vol 149 (3) ◽  
pp. 260-274 ◽  
Author(s):  
Alan L. Koller ◽  
Thomas L. Rost
Keyword(s):  
Structural Analysis ◽  
Water Storage ◽  
Storage Tissue

scholarly journals Is Pteropyrum a pathway to C4 evolution in Polygonaceae? An integrative approach to the taxonomy and anatomy of Pteropyrum (C3), an immediate relative of Calligonum (C4)

2019 ◽  
Vol 192 (2) ◽  
pp. 369-400 ◽  
Author(s):  
Moslem Doostmohammadi ◽  
Maryam Malekmohammadi ◽  
Morteza Djamali ◽  
Hossein Akhani
Keyword(s):  
Pollen Morphology ◽  
Water Storage ◽  
Integrative Approach ◽  
Herbarium Specimens ◽  
Similar Species ◽  
High Plasticity ◽  
Storage Tissue ◽  
Mesophyll Cells ◽  
Distribution Maps ◽  
Mesophyll Tissue

Abstract Pteropyrum is a small genus of Polygonaceae with four species from the arid regions of Iran and adjacent countries. Pteropyrum spp. are not precisely delimitated and are difficult to identify because of their high plasticity in morphological characters. Pteropyrum (C3) has a close affinity to Calligonum (C4) and is therefore a suitable case for C4 evolutionary studies. We investigated the morphology and micromorphology (including pollen morphology) of Pteropyrum and elucidated the phylogenetic relationships with Atraphaxis and Calligonum using nuclear ITS sequences. Characteristics of the photosynthetic tissues such as volume and number of layers of primary carbon assimilation tissues (PCA) and photosynthetic carbon reduction tissue (PCR) were studied. In addition, the leaf and cotyledon anatomical characters of Pteropyrum (C3), Atraphaxis (C3) and Calligonum (C4), and their δ 13C values were compared to look for evolutionary changes in assimilating organs. The molecular phylogenetic tree identifies two strongly supported clades in Pteropyrum and its close relationship with Calligonum, confirming previous studies. Some morphologically similar species belong to different clades, which is probably due to convergent evolution and homoplasy. Leaf anatomical studies show that Atraphaxis has a multilayered mesophyll tissue, whereas Calligonum has one-layered mesophyll cells. The volume and layer number of mesophyll tissue cells decreases, whereas water storage tissue area significantly increases from Atraphaxis to Pteropyrum and Calligonum. This phenomenon confirms previous studies in other lineages with C4 salsoloid anatomy that have evolved through increasing of water storage tissue and succulence of assimilating organs. In the taxonomic part of the paper, a key to identification of accepted taxa of Pteropyrum, description of species and distribution maps are presented based on numerous herbarium specimens and our own rich collections from the field. Four new species are described based on a combination of morphology of seedlings and mature plants, pollen morphology and molecular data. A subspecific classification is suggested to show morpho-geographical variation of Pteropyrum aucheri s.l.

Photosynthetic and anatomical characteristics in the C4–crassulacean acid metabolism-cycling plant Portulaca grandiflora

2002 ◽  
Vol 29 (6) ◽  
pp. 763 ◽  
Author(s):  
Lonnie J. Guralnick ◽  
Gerald Edwards ◽  
Maurice S. B. Ku ◽  
Brandon Hockema ◽  
Vince Franceschi
Keyword(s):  
Water Stress ◽  
Crassulacean Acid Metabolism ◽  
Carbon Fixation ◽  
Acid Metabolism ◽  
Water Storage ◽  
Diurnal Fluctuation ◽  
Carbon Gain ◽  
O2 Evolution ◽  
Storage Tissue ◽  
Portulaca Grandiflora

This paper originates from a presentation at the IIIrd International Congress on Crassulacean Acid Metabolism, Cape Tribulation, Queensland, Australia, August 2001. Portulaca grandiflora (Lind.) is a succulent species with C4 photosynthesis and crassulacean acid metabolism (CAM) cycling in leaves, and CAM-idling type photosynthesis in stems. We investigated the level and localization of carbon fixation enzymes and photosynthetic activity of leaves and stems of P. grandiflora under well-watered and drought conditions. As CAM activity increased during water stress, the leaf water-storage tissue collapsed, presumably transferring water to the bundle sheath and mesophyll cells, and so maintaining the C4 photosynthetic pathway. Tissue prints indicated an increase in phosphoenolpyruvate carboxylase (PEPC) in the water-storage tissue of leaves and the cortex of stems. Immunoblot analyses after 10 d of water stress showed that leaves had a slight decrease in the proteins of the C4-CAM pathway, while at the same time a new isoform of NADP-malic enzyme (NADP-ME) appeared. In contrast, the stem showed increases in proteins of the CAM pathway when water stressed. Under water stress, diurnal fluctuation in acidity in leaves was not accompanied by a net gain or loss of CO2 at night, and there was sustained, but decreased, fixation of CO2 during the day, characteristic of CAM cycling. High gross rates of O2 evolution were maintained during the day under water stress, suggesting induction of alternative electron sinks. With induced diurnal fluctuations in acidity in stems, there was no net carbon gain during the day or night. These results demonstrate, for the first time, that the stem of P. grandiflora is an inducible CAM-idling tissue. Our results also indicate that the C4 and CAM pathways operate independently of one another in P. grandiflora.

Light transmission in window-leaved plants

1980 ◽  
Vol 58 (14) ◽  
pp. 1591-1600 ◽  
Author(s):  
Gerald A. Krulik
Keyword(s):  
Light Transmission ◽  
Incident Light ◽  
Water Storage ◽  
Soil Surface ◽  
Scanning Electron Micrographs ◽  
Light Penetration ◽  
Storage Tissue ◽  
Desert Regions ◽  
Succulent Plants ◽  
Highly Evolved

Window-leaved plants are succulent plants which possess areas of clear epidermis on their leaves. The underlying water storage tissue is transparent to allow light penetration to the internal chlorenchyma. The most highly evolved window-leaved plants with the most transparent tissue grow completely underground in desert regions. Only the rounded leaf tips are level with the soil surface and directly exposed to incident light. Light transmission curves were measured using live windows of five species of plants from three families (Liliaceae, Piperaceae, Mesembryanthemaceae). These results suggest that subterranean window leaves may be limited to a relatively short effective maximum length because of light absorption by the tissues involved. Scanning electron micrographs (SEM) of these plants show considerable differences in surface structure which may help to modulate incident light. Comparisons with related Mesembryanthemaceae illustrate that a complex series of adaptations have been developed to allow underground growth.

scholarly journals Presence of paratracheal water storage tissue does not alter vessel characters in cactus wood

1997 ◽  
Vol 84 (6) ◽  
pp. 815-822 ◽  
Author(s):  
James D. Mauseth ◽  
Brandon J. Plemons-Rodriguez
Keyword(s):  
Water Storage ◽  
Storage Tissue

scholarly journals Leaf anatomical adaptation of eighteen mangrove plant species from the Sundarbans in Bangladesh

2020 ◽  
Vol 49 (4) ◽  
pp. 903-911
Author(s):  
Parveen Rashid ◽  
Kishwar Jahan Shethi ◽  
Asfaque Ahmed
Keyword(s):  
Plant Species ◽  
Glandular Trichomes ◽  
Water Storage ◽  
Capillary Water ◽  
Storage Tissue ◽  
Mangrove Plant ◽  
Mesophyll Tissue ◽  
Anatomical Adaptations ◽  
Mesohaline Zone ◽  
Anatomical Adaptation

Investigation on leaf anatomical adaptation of 18 mangrove plant species was carried out. Among the 18 species 13 were dorsiventral and five were isobilateral type. All the species had special stomatal structure and variable cuticle layer to minimize transpiration. Most of the species had succulent leaves with leaf thickness ranging from around 232 to 1363 μm. As an indication of salt secretion, both glandular and non-glandular trichomes were observed in several species. Although presence of single to multilayered hypodermis might effectively function as water storage tissue, several studied mangrove plant species e.g. Cynometra ramiflora L., Phoenix paludosa Roxb., Pongamea pinnata (L.) Pierre, Sonneratia apetala Buch. - Ham., S. caseolaris (L.) Engl. and Xylocarpus moluccensis (Lamk.) M. Roem. showed complete absence of hypodermis. This might be due to moderate saline condition. In addition, marked terminal tracheids in mesophyll tissue of a number of species might help with capillary water storage within the leaf. To enhance mechanical support several species were found to develop considerable amount of diverse sclereids within the mesophyll tissue and surrounding vascular bundle. Although maximum anatomical adaptations are common for plants growing in saline habitat it may be suggested that these features were differentially developed in plants specifically grown in mesohaline zone.

Identification of water storage tissue in the stem of cowpea plant (Vigna unguliculata Walp) by neutron radiography

1999 ◽  
Vol 242 (2) ◽  
pp. 353-359 ◽  
Author(s):  
T. M. Nakanishi ◽  
K. Don-Jin ◽  
T. Kitamura ◽  
R. Ishii ◽  
M. Matsubayashi
Keyword(s):  
Neutron Radiography ◽  
Water Storage ◽  
Storage Tissue ◽  
Cowpea Plant

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

RNA polymerase: Preparation and structural analysis of helical polymers

1984 ◽  
Vol 42 ◽  
pp. 152-153
Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi
Keyword(s):  
Structural Analysis ◽  
Rna Polymerase ◽  
Molecular Level ◽  
X Ray Diffraction ◽  
Helical Polymers ◽  
X Ray ◽  
E Coli ◽  
The Past ◽  
Ordered Arrays ◽  
Low Ionic Strength

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.

Interpreting HVEM of muscle-cell impulse networks

1992 ◽  
Vol 50 (1) ◽  
pp. 126-127
Author(s):  
Paul DeCosta ◽  
Kyugon Cho ◽  
Stephen Shemlon ◽  
Heesung Jun ◽  
Stanley M. Dunn
Keyword(s):  
Structural Analysis ◽  
Muscle Cell ◽  
Electron Micrographs ◽  
Relative Size ◽  
Automatic Classification ◽  
Nerve Fibers ◽  
Analysis Algorithm ◽  
Structural Networks

Introduction: The analysis and interpretation of electron micrographs of cells and tissues, often requires the accurate extraction of structural networks, which either provide immediate 2D or 3D information, or from which the desired information can be inferred. The images of these structures contain lines and/or curves whose orientation, lengths, and intersections characterize the overall network.Some examples exist of studies that have been done in the analysis of networks of natural structures. In, Sebok and Roemer determine the complexity of nerve structures in an EM formed slide. Here the number of nodes that exist in the image describes how dense nerve fibers are in a particular region of the skin. Hildith proposes a network structural analysis algorithm for the automatic classification of chromosome spreads (type, relative size and orientation).

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