Samara development of black maple (Acer saccharum ssp. nigrum) with emphasis on the wing

1991 ◽  
Vol 69 (6) ◽  
pp. 1349-1360 ◽  
Author(s):  
Carol Jacobs Peck ◽  
Nels R. Lersten
Keyword(s):  
Acer Saccharum ◽  
Late Summer ◽  
Vascular Bundles ◽  
Short Fibers ◽  
Ground Tissue ◽  
Dorsal Ridge ◽  
Cell Layers ◽  
Oriented Parallel ◽  
Reticulate Venation ◽  
Lateral Orientation

Black maple (Acer saccharum Marsh, ssp. nigrum (Michx. f.) Desm.) carpels are initiated in late summer and over winter as paired, hood-shaped primordia with a naked megasporangium on each inrolled margin. The biloculate ovary develops from the lower portion of the primordium. The mature pericarp, about 30 cells thick, includes (i) the exocarp: outer epidermis and one to three layers of thick-walled hypodermal cells; (ii) the mesocarp: about 20 cells thick with reticulate venation and an innermost crystalliferous layer; and (iii) the endocarp: five to eight layers of short fibers oriented parallel to the locule surface. The samara wing arises from the dorsal ridge of the carpel primordium. The wing blade is approximately 10 cell layers thick with unifacial anatomy. Vascular bundles from opposite sides of the carpel alternate within the wing, thus xylem and phloem are oriented oppositely in adjacent bundles. The chlorenchymatous ground tissue ranges from compact subepidermal cells to elongated spongy cells, with increasing lateral orientation of cell arms in the mid-lamina. These central cells become sclerified, forming curved, branched fibers that buttress the vascular framework. Wing development and structure suggest early photosynthetic activity, which declines as sclerification and drying progress. Key words: Acer saccharum, anatomy, development, fruit, maple, samara.

DEVELOPMENTAL STUDIES OF THE APPLE FRUIT IN THE VARIETIES McINTOSH RED AND WAGENER: II. AN ANALYSIS OF DEVELOPMENT

1941 ◽  
Vol 19c (10) ◽  
pp. 371-382 ◽  
Author(s):  
Mary MacArthur ◽  
R. H. Wetmore
Keyword(s):  
Cell Division ◽  
Cell Size ◽  
Fruit Size ◽  
Apple Fruit ◽  
Vascular Bundles ◽  
Developmental Studies ◽  
Cell Enlargement ◽  
Ground Tissue ◽  
Fundamental Pattern

Growth in the various tissues of the fruit of a McIntosh Red and a Wagener tree, both self-pollinated, is compared. For several days succeeding pollination no increase in fruit size is apparent. Fertilization is followed by general cell division and cell enlargement. The period of cell division varies with the tissue and with the variety. Final cell size is reached first by the cells of those tissues near the centre of the apple. Impressed upon the fundamental pattern of growth is the localized activity of the primary vascular bundles, the cambia of which add cells to the ground tissue. Angulation in the Wagener is accentuated by this activity. With the exception of cells of the epidermis, final cell size is approximately equal in comparable regions of the two varieties. Differences in regional extent are due to differences in numbers of cells in that region.

scholarly journals Development of successive cambia and wood structure in stem of Rivea hypocriteriformis (Convolvulaceae)

2016 ◽  
Vol 61 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Kishore S. Rajput
Keyword(s):  
Secondary Xylem ◽  
Monsoon Season ◽  
Secondary Growth ◽  
Vascular Bundles ◽  
Growth Rings ◽  
Successive Cambia ◽  
Initial Stage ◽  
Ray Cells ◽  
Cell Layers ◽  
Ray Parenchyma Cells

Abstract This study examined the formation of successive rings of cambia in Rivea hypocriteriformis Choisy (Convolvulaceae). The mature stem is composed of four to five rings of xylem alternating with phloem. Successive cambia originate as smaller and larger segments; union and anastomosing of small cambial segments often leads to the formation of discontinuous rings. In the initial stage of growth, several vascular bundles interconnect to form the first ring of vascular cambium. The cambium remains functional for one complete season and becomes dormant during summer; a new ring of cambium is completed prior to the subsequent monsoon season and sprouting of new leaves. Successive cambia are initiated from the pericyclic parenchyma situated three to four cell layers outside of the protophloem. Functionally, all the successive cambia are bidirectional and produce secondary xylem centripetally and phloem centrifugally. The secondary xylem is diffuse-porous, with indistinct growth rings and consisting of wide fibriform vessels, fibre tracheids, and axial and ray parenchyma cells. The xylem rays are uni- to multiseriate and heterocellular. The multiseriate rays contain lignified marginal ray cells and thin-walled, unlignified central cells. The central ray cells also show accumulations of starch and druses. Discrete strands of intraxylary phloem occur at the periphery of the pith, and additional intraxylary phloem develops from adjacent cells as secondary growth progresses. Earlier-formed phloem shows heavy accumulation of callose, followed by its compaction. The development of successive cambia is correlated with extension growth and with the phenology of the plant.

scholarly journals Differential Colonization of Tomato Roots by Nonpathogenic and Pathogenic Fusarium oxysporum Strains May Influence Fusarium Wilt Control

2001 ◽  
Vol 91 (5) ◽  
pp. 449-456 ◽  
Author(s):  
Jian R. Bao ◽  
George Lazarovits
Keyword(s):  
Fusarium Oxysporum ◽  
Pathogenic Fungus ◽  
Root Surface ◽  
Histochemical Staining ◽  
Gus Activity ◽  
Vascular Bundles ◽  
Interaction Sites ◽  
Inoculation Density ◽  
Tomato Roots ◽  
Cell Layers

Histochemical staining, β-glucuronidase (GUS) activity, or placing roots on agar were methods used to characterize interactions between the pathogenic fungus, Fusarium oxysporum f. sp. lycopersici, and the nonpathogenic biocontrol F. oxysporum strain 70T01 with respect to colonization behaviors, interaction sites, and population densities on tomato roots. Mycelia of strain 70T01, a genetic transformant expressing stable GUS activity, hygromycin B resistance, and effective disease control, were localized in epidermal and cortex cell layers of tomato roots in a discontinuous and uneven pattern. In contrast, mycelia of F. oxysporum f. sp. lycopersici were found in the vascular bundles. Thus, direct interactions between the two fungi likely happen in the root surface cell layers. Colonization density of strain 70T01 was related to the inoculation density but decreased with distance from the inoculation site. Host defense reactions, including increased cell wall thickness or papilla deposits, were adjacent to 70T01 hyphae. Experiments done in soil showed that strain 70T01 densities in roots were highest at inoculation zones and barely detectable for root segments more than 2 cm away from the inoculation sites. F. oxysporum f. sp. lycopersici densities were lowest at 70T01 inoculation zones and highest (>10 times) where strain 70T01 was not directly applied. Newly elongating roots where strain 70T01 did not reach were available for infection by the pathogen. The higher strain 70T01 density was always found when the plants were simultaneously infected by F. oxysporum f. sp. lycopersici, suggesting that F. oxysporum f. sp. lycopersici has as much influence in predisposing the plant to colonization by strain 70T01 as strain 70T01 has on providing disease protection against the pathogen.

Permineralized monocotyledons from the Middle Eocene Princeton chert (Allenby Formation) of British Columbia: Alismataceae

1989 ◽  
Vol 67 (9) ◽  
pp. 2636-2645 ◽  
Author(s):  
Diane M. Erwin ◽  
Ruth A. Stockey
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Vascular Bundles ◽  
Western North America ◽  
Ground Tissue ◽  
Abaxial Surface ◽  
Parenchyma Cells ◽  
In Series ◽  
Thin Walled ◽  
Tannin Cells

One small monocotyledon petiole, 1.8 × 1.5 mm wide, has been recovered from the Princeton chert in the Middle Eocene Allenby Formation, British Columbia. The petiole, rectangular in transverse outline, shows approximately 36 circular to oval-shaped vascular bundles within aerenchymatous ground tissue that includes tannin cells. The epidermis is underlain by a discontinuous hypodermis of thick-walled, pitted cells. Vascular bundles are in five series: (I) a median U-shaped arc of 11 – 13 bundles; (II) an abaxial arc of 6 bundles located below the main arc; (III) two short abaxial arcs of 3 bundles each; (IV) 2 bundles just below the abaxial surface; and (V) an adaxial series of 7 bundles that show an inverse orientation to those bundles in series I–IV. Larger bundles are collateral, with a protoxylem lacuna encircled by a ring of 9 – 14 thin-walled parenchyma cells, a relatively well-developed phloem strand, and one to three thin-walled metaxylem elements. Based on bundle arrangement, orientation, and morphology, the fossil petiole most closely resembles those of the Butomaceae and Alismataceae. This new species, Heleophyton helobiaeoides Erwin and Stockey gen. et sp.nov., in the Princeton chert flora, documents the presence of the Alismataceae in the Middle Eocene of western North America and provides further evidence that the locality represents an ancient aquatic ecosystem.

scholarly journals Symplastic signaling instructs cell division, cell expansion, and cell polarity in the ground tissue of Arabidopsis thaliana roots

2016 ◽  
Vol 113 (41) ◽  
pp. 11621-11626 ◽  
Author(s):  
Shuang Wu ◽  
Ruthsabel O’Lexy ◽  
Meizhi Xu ◽  
Yi Sang ◽  
Xu Chen ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Polarity ◽  
Cell Expansion ◽  
Growth And Development ◽  
Cell Communication ◽  
Intercellular Signaling ◽  
Ground Tissue ◽  
Cell Layers ◽  
Division Cell ◽  
Multicellular Organisms

Cell-to-cell communication is essential for the development and patterning of multicellular organisms. In plants, plasmodesmata (PD) provide direct routes for intercellular signaling. However, the role that PD-mediated signaling plays in plant development has not been fully investigated. To gain a comprehensive view of the role that symplastic signaling plays in Arabidopsis thaliana, we have taken advantage of a synthetic allele of CALLOSE SYNTHASE3 (icals3m) that inducibly disrupts cell-to-cell communication specifically at PD. Our results show that loss of symplastic signaling to and from the endodermis has very significant effects on the root, including an increase in the number of cell layers in the root and a misspecification of stele cells, as well as ground tissue. Surprisingly, loss of endodermal signaling also results in a loss of anisotropic elongation in all cells within the root, similar to what is seen in radially swollen mutants. Our results suggest that symplastic signals to and from the endodermis are critical in the coordinated growth and development of the root.

scholarly journals Macro and microscopic characters of Maerua oblongifolia (Forssk.) A. Rich leaf

2020 ◽  
pp. 182-186
Author(s):  
G. Prabhakar ◽  
K. Shailaja ◽  
P. Kamalakar
Keyword(s):  
Diabetes Mellitus ◽  
Vascular Bundle ◽  
Transverse Section ◽  
Lower Limbs ◽  
Vascular Bundles ◽  
Skin Infections ◽  
Ground Tissue ◽  
Abdominal Colic ◽  
The Family ◽  
Powder Analysis

The paper deals with a detailed investigation on the leaves of Maerua oblongifolia (Forssk.) A. Rich. which includes it’s morphological, anatomical and powder analysis. It is a low woody bushy under-shrub belonging to the family Capparaceae. The leaves are used in treatment of as fever, ear ache, stomach ache, skin infections, urinary calculii, diabetes mellitus, epilepsy, rigidity in lower limbs, and abdominal colic. The leaf amphistomatic, with mostly anamocytic, few tetracytic stomata. In transverse section of leaf is ribbed on either sides at midvein, epidermis one layered. Mesophyll differentiated into palisade and spongy tissues. Ground tissue of midvein differentiated into palisade, collenchyma and parenchyma. The midvien consists of one large oval shaped vascular bundles arranged are at the centre. Petiole in transverse section is circular adaxially small, grooved at centre and epidermis is having one layered, a single circular vascular bundle present at the centre, vascular bundle is enclosed by endodermis. The powder microscopic and organoleptic characters are also presented in this study. This study would helps as an appropriate source for authentification of the present studied drug.  

A dominant mutation in the maize homeobox gene, Knotted-1, causes its ectopic expression in leaf cells with altered fates

Development ◽  
1992 ◽  
Vol 116 (1) ◽  
pp. 21-30 ◽  
Author(s):  
L.G. Smith ◽  
B. Greene ◽  
B. Veit ◽  
S. Hake
Keyword(s):  
Leaf Development ◽  
Early Stage ◽  
Ectopic Expression ◽  
Homeobox Gene ◽  
Vascular Bundles ◽  
Ground Tissue ◽  
Wild Type ◽  
Dominant Mutation ◽  
Coding Regions ◽  
Undifferentiated Cells

Dominant mutations of the Knotted-1 (Kn1) homeobox gene of maize alter the differentiation and growth of cells associated with leaf veins. By analyzing Kn1 transcripts and KN1 protein, we show that the gene is not expressed at high levels during the development of wild-type leaves. Instead, Kn1 is expressed in apical meristems of vegetative and floral shoots, and is downregulated as leaves and floral organs are initiated. Kn1 is also expressed in relatively undifferentiated cells within developing vascular bundles, as well as ground tissue, in immature, unelongated axes of wild-type vegetative and floral shoots. In Kn1-N2 mutant plants, quantitative, but not qualitative differences are apparent in Kn1 transcripts and KN1 protein, consistent with previous observations that dominant Kn1 mutations map to non-coding regions of the gene. Kn1 is expressed ectopically in vascular bundles within developing mutant leaves in a pattern that correlates with the phenotypic alterations produced by the Kn1-N2 mutation. Thus, Kn1 apparently alters the fates of leaf cells in which it is ectopically expressed from an early stage of leaf development. Based on these observations, we hypothesize that Kn1 functions in its wild-type context as a regulator of cell determination.

Pericarp micromorphology and dehydration characteristics of Quercus suber L. acorns

2000 ◽  
Vol 10 (3) ◽  
pp. 401-407 ◽  
Author(s):  
Eduardo Sobrino-Vesperinas ◽  
Ana Belén Viviani
Keyword(s):  
Water Loss ◽  
External Surface ◽  
Quercus Suber ◽  
Vascular Bundles ◽  
Palisade Layer ◽  
Intercellular Spaces ◽  
Cell Layers ◽  
Poorly Differentiated ◽  
Xylem Elements ◽  
The Mean

AbstractThe aim of the present study was to examine the micromorphology of the cork-oak (Quercus suber) acorn and to evaluate the efficiency of the pericarp as a barrier to water loss. When the desiccation curve obtained at 25 ± 1°C and 62% RH for physiologically mature acorns collected from the tree was compared with that corresponding to fully ripe acorns which had been shed, the latter showed a slightly lower rate of water loss. A marked reduction in the mean rate of water loss was recorded for intact acorns compared with those from which the pericarp had been removed. The external surface and transverse sections of the pericarp from both mature and fully ripe acorns were examined by scanning electron microscopy. Two zones presenting morphological and micromorphological differences were identified: an area including the point of attachment to the cupule and an apical zone covering the embryo. The microstructure of the pericarp showed an external thick cuticle and a single external palisade layer of closely packed cells with no intercellular spaces. Underlying this layer, there was a further parenchymatous layer of poorly differentiated, roughly isodiametric cells. The pericarp in the cupular zone consisted of only this undifferentiated layer between the two epidermal cell layers and contained vascular bundles with many xylem elements.

Localization of amylase activity in cotyledons of germinated mung bean seeds

1991 ◽  
Vol 69 (7) ◽  
pp. 1501-1506 ◽  
Author(s):  
Yasuko Kaneko ◽  
Hisashi Matsushima ◽  
Yukio Morohashi
Keyword(s):  
Key Words ◽  
Seed Coat ◽  
Vigna Radiata ◽  
Mung Bean ◽  
Amylase Activity ◽  
The Other ◽  
Vascular Bundles ◽  
Starch Granules ◽  
Developmental Patterns ◽  
Cell Layers

Developmental patterns of amylase activity in mung bean (Vigna radiata) cotyledons were observed by histochemical methods. In axis-attached cotyledons, the development of amylase activity and the decompostion of starch grains occurred first in cells located farthest from vascular bundles, and 3 days after imbibition, starch granules appeared to remain intact only in two to three cell layers around the vascular bundles. In axis-detached cotyledons, on the other hand, no conspicuous change in amylolytic activity was detected. When cotyledons were allowed to imbibe water through the surface not covered by the seed coat, amylase activity developed, even if they were detached from the axis. However, the developmental patterns of the activity were quite different from those with attached cotyledons; high amylase activity was detected in the cell layers beneath the epidermis of the surface not covered by the seed coat. These histochemical observations are related to previous results of biochemical experiments. Key words: amylase development, cotyledons, germination, histochemistry, mung bean, Vigna radiata.

The rediscovery of Billburttia vaginoides, with notes on the morphology, anatomy, traditional uses and conservation status of the genus Billburttia (Apieae, Apiaceae)

Phytotaxa ◽  
2017 ◽  
Vol 321 (3) ◽  
pp. 265
Author(s):  
STÉPHAN R. RAKOTONANDRASANA ◽  
ALEXEI A. OSKOLSKI ◽  
PATRICIA M. TILNEY ◽  
EKATERINA L. KOTINA ◽  
BEN-ERIK VAN WYK
Keyword(s):  
Conservation Status ◽  
Field Studies ◽  
Vascular Bundles ◽  
Organic Crystals ◽  
Ground Tissue ◽  
Complete Understanding ◽  
X Ray ◽  
Traditional Uses ◽  
Secretory Canals ◽  
Shrubby Species

Recent field studies of the hitherto poorly known Madagascar-endemic genus Billburttia, including the rediscovery of the rare B. vaginoides, have resulted in a more complete understanding of the morphology, anatomy, ethnobotany and conservation status of the two aromatic shrubby species from Central Madagascar. Billburttia capensoides is relatively common and occurs in rocky places from Andringitra to Arivonimamo, while B. vaginoides is a rare species known only from around the Akaratra massif. The two species can easily be distinguished from one another by their habit (erect or spreading branches) and leaflet shape (obovate to linear-elliptic or filiform-linear). The leaves have numerous secretory canals; organic crystals occur in the epidermis, ground tissue and vascular bundles. Studies of fresh fruits confirmed the lack of wings, the position of the vascular bundles in the tips of the ribs and especially the reported presence of unusual acicular crystals in sheaf-like and spherical aggregates (not only in the epidermis, but also in groups close to the epidermis and around the vascular bundles). X-ray microanalysis showed that the crystals do not contain calcium, only carbon and oxygen, indicating that they are organic and precipitate during drying or fixation in alcohol. Updated descriptions of the morphology and anatomy are presented, together with a key to the species and notes on their traditional uses, conservation status and known geographical distributions. 

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