Pleopeltis pleopeltifolia (Polypodiopsida, Polypodiaceae), a poikilochlorophyllous desiccation-tolerant fern: anatomical, biochemical and physiological responses during water stress

2014 ◽  
Vol 62 (8) ◽  
pp. 647 ◽  
Author(s):  
Ana Paula Lorenzen Voytena ◽  
Bruno Degaspari Minardi ◽  
José Bonomi Barufi ◽  
Marisa Santos ◽  
Áurea Maria Randi
Keyword(s):  
Cell Walls ◽  
Sugar Content ◽  
Longitudinal Direction ◽  
Photosynthetic Parameters ◽  
Palisade Parenchyma ◽  
Abaxial Surface ◽  
Adaxial Surface ◽  
Anomocytic Stomata ◽  
Relevant Role ◽  
Notable Increase

While many ferns have been described as desiccation tolerant (DT), few studies have reported on the mechanisms they use to survive cell desiccation. Among the species belonging to the genus Pleopeltis, P. pleopeltifolia (Raddi) Alston (Polypodiopsida, Polypodiaceae) is a DT species endemic to Brazil. So as to better characterise the mechanisms of desiccation tolerance in ferns, the present study aimed to analyse frond anatomy and physiological changes associated with desiccation and rehydration of P. pleopeltifolia. Fronds are dorsiventral, with uniseriate epidermis. The epidermal cells have various shapes, tending to stretch in the longitudinal direction of the frond. Anticlinal cell walls are sinuous, and periclinal cell walls are convex. Anomocytic stomata are restricted to the abaxial surface. Trichome-type scales are found on both sides of the frond and may play a relevant role in rehydration of this plant when water is available. The mesophyll of the frond consists of palisade parenchyma, tending to a bistratified adaxial surface and spongy parenchyma on abaxial surface. The cuticle on the adaxial surface is conspicuous, ensuring better control of internal water balance. For physiological analyses, sporophytes were subjected to desiccation for 0, 5, 10 and 15 days and rehydration for 1 day. Sporophytes showed a sharp decline in water content when kept without irrigation, reaching 9.6% after 15 days, in addition to wilting and frond rolling. A significant increase in sugar content in fronds was noticeable during desiccation, which may favour a possible osmotic adjustment and vitrification. A notable increase in proline content during rehydration was observed in fronds. During the five initial days of desiccation, the chlorophyll and carotenoid contents decreased abruptly, but after 1 day of rehydration, they had partly recovered. The photosynthetic parameters analysed by fluorescence of chlorophyll a ceased completely after 15 days of desiccation but they had recovered near to pre-desiccation levels after 1 day of rehydration.

scholarly journals Micromorphology of endemic Centaurea glaberrima subsp. divergens (Asteraceae)

2022 ◽  
Vol 81 (1) ◽  
Author(s):  
Milan Gavrilović ◽  
Pedja Janaćković
Keyword(s):  
Cell Walls ◽  
Glandular Trichomes ◽  
Pollen Grains ◽  
Involucral Bract ◽  
Epidermal Cells ◽  
Leaf Epidermis ◽  
Abaxial Surface ◽  
Reproductive Structures ◽  
Anomocytic Stomata ◽  
First Time

In this study, the micromorphology of the vegetative and reproductive structures of the endemic Centaurea glaberrima Tausch subsp. divergens (Vis.) Hayek (Asteraceae), using scanning electron microscope (SEM), is presented for the first time. Uniseriate whip-like non-glandular and biseriate glandular trichomes are found on the surface of all aboveground parts (stem, leaves, peduncles, involucral bract). On the adaxial leaf epidermis ribbed thickenings (striation pattern) of outer periclinal cell walls, slightly curved anticlinal cell walls and anomocytic stomata are noticed. Rugose abaxial surface with thorny protuberances of the involucral bract is documented. Corolla is glabrous with longitudinally parallel epidermal cells with distinct straight outline. Isopolar, radially symmetric and tricolporate microechinate pollen grains are seen. Short stylar hairs, without cuticular striations, are present along the outer sides of the style, while the inner sides (abaxial surface) constitute the papillate stigmatic surface. Microcharacters found in cypsela are as follows: slightly ribbed body; rotund base; lateral and concave insertion; short, unicellular curly acute trichomes; smooth epidermis; fine-sulcate ornamentation; rod shaped epidermal cells with short, obtuse end walls and straight anticlinal walls; poorly developed minutely dentate pericarp rim; and dimorphic pappus with bristles of different length and morphology, with pinnules restricted to the margins of the bristles. The results obtained contribute to knowledge about the micromorphology of the studied endemic species and provide features for its better identification. The taxonomic significance of the analyzed characters is discussed. Some well defined microcharacters of the studied species might have taxonomic value

The epidermis in Passerina/ (Thymelaeaceae): structure, function and taxonomic significance

Bothalia ◽  
2000 ◽  
Vol 30 (1) ◽  
pp. 69-86 ◽  
Author(s):  
C. L. Bredenkamp ◽  
A. E. Van Wyk
Keyword(s):  
Cell Walls ◽  
Mediterranean Climate ◽  
High Light Intensity ◽  
Epidermal Cells ◽  
Cell Orientation ◽  
Abaxial Surface ◽  
Epidermal Structure ◽  
Interspecific Differences ◽  
Epidermal Features ◽  
Structural Adaptations

Epidermal features were studied in all 17 species of Passerina, a genus endemic to southern Africa. Leaves in Passerina are inversely ericoid, the adaxial surface concave and the abaxial surface convex. Leaves are inversely dorsiventral and epistomatic. The adaxial epidermis is villous, with unicellular, uniseriate trichomes and relatively small thin-walled cells, promoting flexibility of leaf margins owing to turgor changes. In common with many other Thymelaeaceae, abaxial epidermal cells are large and tanniniferous with mucilaginous cell walls. The cuticle is adaxially thin, but abaxially well devel­oped, probably enabling the leaf to restrict water loss and to tolerate high light intensity and UV-B radiation. Epicuticular waxes, present in all species, comprise both soft and plate waxes. Epidermal structure proves to be taxonomically impor­tant at family, genus and species levels. Interspecific differences include arrangement of stomata and presence or absence of abaxial epidermal hair. Other diagnostic characters of the abaxial epidermal cells are arrangement,size and shape, cutic- ular ornamentation and presence or absence of wax platelets. Two groups of species on the basis of abaxial epidermal cell orientation are recognised. Many leaf epidermal features in Passerina are interpreted as structural adaptations to the Mediterranean climate of the Cape.

Leaf micromorphology of the Persicaria sect. Cephalophilon (Polygonaceae) and its systematic re-evaluation

Phytotaxa ◽  
2019 ◽  
Vol 391 (3) ◽  
pp. 167 ◽  
Author(s):  
MIN-JUNG KONG ◽  
SUK-PYO HONG
Keyword(s):  
Comparative Study ◽  
Cell Walls ◽  
Smooth Surface ◽  
Glandular Trichomes ◽  
Adaxial Side ◽  
Abaxial Side ◽  
Stomatal Size ◽  
Systematic Significance ◽  
Leaf Micromorphology ◽  
Anomocytic Stomata

A comparative study of the leaf microstructures of 19 taxa belonging to the Persicaria sect. Cephalophilon and related four Koenigia taxa was performed by LM and SEM to evaluate their systematic significance. Both amphistomatic and hypostomatic leaves were observed in the taxa studied. The stomatal size ranged from 17.04–41.96 × 13.41–37.30 μm, and stomata on the adaxial side were larger than those on the abaxial side in general. Anomocytic stomata occurred most commonly, but more than one type of stomata was observed on the same surface. Paracytic stomata was found in both Persicaria palmata and P. criopolitana. The epidermal cells usually have straight to sinuate anticlinal cell walls (ACW), and the ACW on the abaxial side of most taxa is much more undulated than that on the adaxial side. Cuticular striation was observed in most of the studied taxa, which was restricted to only the adaxial side. Two types of crystals were observed: druse and prismatic, and seven types of trichome were recognized: five types of non-glandular trichomes (stellate with smooth surface, multiseriate with either smooth or striated surface, and uniseriate with either smooth or papillose surface), and two types of glandular trichomes (peltate and long-stalked pilate). The leaf micromorphology in this study was categorized into five types based on the stomata, epidermis, crystal and trichome, as further systematic significance of the leaf epidermal characters within the P. sect. Cephalophilon are discussed. In addition, we propose a new taxonomic combination in the P. sect. Cephalophilon.

A new species and comparative morphology of Vesselowskya (Cunoniaceae)

2001 ◽  
Vol 14 (2) ◽  
pp. 175 ◽  
Author(s):  
Andrew C. Rozefelds ◽  
Richard W. Barnes ◽  
Belinda Pellow
Keyword(s):  
New Species ◽  
Cell Walls ◽  
New South ◽  
Comparative Morphology ◽  
Epidermal Cells ◽  
The Other ◽  
Abaxial Surface ◽  
South Wales ◽  
Central Column ◽  
A New Species

The vegetative and reproductive morphology of Vesselowskya Pampanini, southern marara, is described and illustrated in detail. The variation within V. rubifolia (F.Muell.) Pampanini sens. lat. is shown to be greater than has previously been recognised, with the differences identified supporting the recognition of a new segregate species, V. venusta Rozefelds, R.W.Barnes and Pellow sp. nov. Vesselowskya venusta occurs in the Barrington Tops Plateau of New South Wales and differs from V. rubifolia in possessing hairs on the abaxial surface of the sepals and lacking both a prominent distal connective protrusion on the anthers and colleters at the base of the stipules. The two Vesselowskya species are dioecious with a vestigial ovary in staminate flowers and reduced stamens in pistillate flowers. Dioecy is more pronounced in Vesselowskya, than in some Weinmannia species, and in both genera is expressed through reduction in the size of the ovaries in staminate flowers, and stamens in pistillate flowers. Vesselowskya shares with the other genera in the tribe Cunonieae (Pancheria, Weinmannia and Cunonia), a central column in the fruits, and Cunonia-type stipules, but differs from these genera in having valvate aestivation, digitate leaves, craspedodromous secondary venation with secondary veins terminating at a tooth, tuft domatia along the midrib, adaxial epidermal cells with strongly sinuous cell walls and the absence of hydathodes.

Two new species of Graffenrieda (Melastomataceae, Merianieae) from the Amazon Rainforest

Phytotaxa ◽  
2016 ◽  
Vol 267 (1) ◽  
pp. 77 ◽  
Author(s):  
LAÍCE FERNANDA GOMES DE LIMA ◽  
JOSÉ FERNANDO ANDRADE BAUMGRATZ ◽  
EIMEAR NIC LUGHADHA ◽  
JOÃO UBIRATAN MOREIRA DOS SANTOS
Keyword(s):  
New Species ◽  
Conservation Status ◽  
The State ◽  
Amazon Rainforest ◽  
Similar Species ◽  
Abaxial Surface ◽  
Adaxial Surface ◽  
Two New Species

Two new species of Graffenrieda are described from the Amazon rainforest. Graffenrieda maturaca is characterized mainly by its leaves which are dull on the adaxial surface, chartaceous, narrowly elliptic to oblanceolate, and apparently uni-nerved, with only the median acrodromous vein evident. This species has been collected only at Serra de Maturacá, in the state of Amazonas, Brazil. Graffenrieda goldenbergii is distinguished mainly by the pulverulent, whitish, early caducous indumentum of the rachis, pedicel, hypanthium and calyx, by the abaxial surface of the leaves which is moderately lepidote, with trichomes ca. 0.2 mm diam., by the irregularly valvate calyx, and by the membranaceous, costate, not sulcate fruits. This species has been collected in the state of Acre, Brazil, and in the Province and District of Lama in Peru. Both species are illustrated, compared with similar species, and their conservation status is discussed.

scholarly journals Leaf anatomy changes related to physiological adaptations to flooding in Amazonian tree species

2009 ◽  
Vol 21 (4) ◽  
pp. 301-308 ◽  
Author(s):  
Ana Herrera ◽  
Marcia Escala ◽  
Elizabeth Rengifo
Keyword(s):  
Photosynthetic Rate ◽  
Tree Species ◽  
Cell Walls ◽  
Leaf Gas Exchange ◽  
Leaf Thickness ◽  
Palisade Parenchyma ◽  
Evergreen Species ◽  
Stomatal Size ◽  
Physiological Adaptations ◽  
Seasonally Flooded

In trees of the seasonally flooded forest of the Mapire River in Venezuela, early flooding induces a reversible diminution in leaf conductance and photosynthetic rate. With the aim of finding an anatomical explanation for the observed responses of leaf gas exchange, the characteristics of emerged leaves developed under drainage or after three months of flooding were examined in the tree species Acosmium nitens, Campsiandra laurifolia, Duroia fusifera, Eschweilera tenuifolia, Pouteria orinocoensis and Symmeria paniculata and in leaves developed only under flooding in Inga spuria and Tachigali davidsei. Anatomy was remarkably similar among species and families and consisted of a bi-layered palisade parenchyma, a 5-6-cell-thick spongy parenchyma and large whole-leaf thickness. Anatomy also resembled that of xerophytes or evergreen species by possessing thick cuticles, large epidermal cells, thickened anticlinal epidermal cell walls and an abundance of sclerenchyma. Leaves of flooded v. un-flooded trees were not qualitatively different. Specific leaf area resembled values of deciduous species in tropical dry forests. No quantitative differences were found between leaves developed in un-flooded and flooded trees, with the exception of a reduction in whole-leaf thickness of E. tenuifolia, P. orinocoensis and S. paniculata and a change in the contribution of palisade parenchyma to leaf thickness in E. tenuifolia. Both stomatal size and density in these exclusively hypostomatous species remained unaffected by flooding. A decrease under flooding in whole-leaf thickness may have resulted in an increase in mesophyll conductance and therefore photosynthetic rate.

scholarly journals EFFECT OF SURFACTANTS ON UPTAKE OF GIBBERELLIN A3 BY SOUR CHERRY LEAVES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1167d-1167
Author(s):  
Moritz Knoche ◽  
Martin J. Bukovac
Keyword(s):  
Field Experiments ◽  
Biological Response ◽  
Sour Cherry ◽  
Flower Initiation ◽  
Abaxial Surface ◽  
Adaxial Surface ◽  
Response Data ◽  
Time Period ◽  
Order Of Magnitude ◽  
Spur Formation

Gibberellin A3 (GA) applied to virus-infected sour cherry (Prunus cerasus L., `Montmorency') trees inhibits flower initiation and promotes spur formation. However, response to a given dose may vary. Differential foliar absorption has been suggested as a major source of this variation. Therefore, we studied if surfactants would reduce variation in GA absorption. Uptake through the abaxial surface exceeded that through the adaxial surface by about one order of magnitude (adaxial surface 1.1 vs 7.8% in 1988, 0.7 vs 16.6% in 1989). GA uptake was markedly affected by surfactants. Over a 24-hr uptake period, Activator 90 and Ortho X-77 were most effective (abaxial surface 38.3 and 37.4% in 1989), whereas Regulaid did not affect GA uptake. L-77 significantly depressed absorption (abaxial surface 9.1% in 1989). In addition to the level of uptake, surfactants also changed GA absorption kinetics. Penetration increased linearly over a 96-hr time period when Regulaid was included. However, with Ortho X-77, uptake was rapid initially but levelled off within 96 hr. These findings will be discussed in relation to biological response data obtained in the field experiments.

scholarly journals The permeability of microwave treated wood for distilled water

2008 ◽  
Vol 56 (1) ◽  
pp. 137-142 ◽  
Author(s):  
Lukáš Merenda ◽  
Jiří Holan
Keyword(s):  
Microwave Radiation ◽  
Cell Walls ◽  
Wood Property ◽  
Treated Wood ◽  
Longitudinal Direction ◽  
Water Molecules ◽  
Low Permeability ◽  
Growing Up ◽  
Wood Impregnation ◽  
The One

Permeability of wood is a wood property which strongly affects a process of drying wood, as well as steaming, boiling and wood impregnation. The low permeability of the most industry treated wood causes investigating the ways which increase the permeability of wood. The one of the considered methods is drying of wood with the aid microwave radiation which causes rotation and friction of water molecules, thus the temperature and the pressure inside the wood are growing up. As a result of raised pressure are crackled cell walls which makes the wood structure more permeable in transverse direction, but in longitudinal direction the wood speciemens treated with microwave radiation don’t analyse differences in the permeability in comparison with unmodified wood.

Morphological investigation of glandular hairs on Drosera capensis leaves with an ultrastructural study of the sessile glands

Botany ◽  
2013 ◽  
Vol 91 (4) ◽  
pp. 234-241 ◽  
Author(s):  
Yougasphree Naidoo ◽  
Samia Heneidak
Keyword(s):  
Cell Walls ◽  
Morphological Investigation ◽  
Adaxial Surface ◽  
Glandular Hairs ◽  
Red Hair ◽  
Leaf Surfaces ◽  
Radial Cell ◽  
Electron And Light Microscopy ◽  
First Time ◽  
Mucilage Secretion

Electron and light microscopy were employed to elucidate the types of glandular hairs on Drosera capensis L. leaves. Eight types of stalked and sessile hairs were found. One type of long-stalked red hair is present only along the margin of the adaxial surface of the leaf, and five types of short-stalked hairs exist mainly on the central part of the adaxial surface of the leaf. Two types of sessile glands are abundantly distributed on both the adaxial and abaxial leaf surfaces. The sessile glands of two head cells are described for the first time in D. capensis, and the sessile glands of four head cells are illustrated for the first time in the genus Drosera. The presence of a secretion from the two head cells of the sessile glands and the dark large vesicles inside them suggests a secretory function. Numerous wall ingrowths are present in the outer tangential and radial cell walls of the head cells of the sessile glands, increasing the surface area to facilitate mucilage secretion.

scholarly journals The Sugar Content of Cell Walls and Intercellular Spaces in Sugar-Cane Stems and its Relation to Sugar Transport

1965 ◽  
Vol 18 (5) ◽  
pp. 959 ◽  
Author(s):  
JS Hawker
Keyword(s):  
Aqueous Phase ◽  
Sugar Cane ◽  
Cell Walls ◽  
Sugar Content ◽  
Sugar Transport ◽  
Intercellular Spaces ◽  
Parenchyma Cells ◽  
Storage Parenchyma

In sugar-cane stems which contain large amounts of sucrose the concentration of sucrose in the volume external to the vacuoles was found to approach the concentration present in the vacuoles (20%). It was shown that this sucrose is situated mainly in the aqueous phase of the cell walls and intercellular spaces of the storage parenchyma cells.

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