Anatomy of Wild Garlic Bulbs During and Subsequent to After-Ripening

Weed Science ◽  
1972 ◽  
Vol 20 (3) ◽  
pp. 233-237 ◽  
Author(s):  
J. F. Stritzke ◽  
E. J. Peters
Keyword(s):  
Cell Division ◽  
Microscopic Examination ◽  
Cell Elongation ◽  
Leaf Primordia ◽  
Root Primordia ◽  
Ripening Period ◽  
Shoot Primordia ◽  
Division Cell ◽  
Wild Garlic

Microscopic examination of central and soft offset bulbs of wild garlic(Allium vinealeL.) at senescence of the parent plants in May and June revealed embryonic plants with numerous root primordia and four or five shoot primordia. Hardshell bulbs and aerial bulblets contained only one or two root primordia and three leaf primordia. The embryonic plants of central, soft offset, and hardshell bulbs elongated slowly during the after-ripening period. Rapid cell division, cell elongation, and initiation of new leaves took place after termination of the after-ripening period in all but the dormant hardshell bulbs. In November, new hardshell bulbs could be seen at the base of plants developed from central and soft offset bulbs.

Leaf morphogenesis and growth in Cyperus eragrostis (Cyperaoeae)

1996 ◽  
Vol 74 (11) ◽  
pp. 1753-1765 ◽  
Author(s):  
Connie L. Soros ◽  
Nancy G. Dengler
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Leaf Development ◽  
Pulse Labelling ◽  
Leaf Morphogenesis ◽  
Calcofluor White ◽  
Basal Half ◽  
Mitotic Figures ◽  
Division Cell ◽  
Leaf Extension

We identified the zones of leaf extension, cell division, cell elongation, and cell differentiation in developing leaves of a sedge species, Cyperus eragrostis Lam. (Cyperaceae). The zone of leaf extension was located by measuring the separation between pinhole markers and by observing the staining pattern of Calcofluor White after pulse-labelling growing leaves. These observations were supported by determining growth rates of control and punctured leaves and by scanning electron and light microscopy of developing leaves. The location of the zone of cell division was assessed by enumerating mitotic figures, and the zone of cell elongation was established by measuring lengths of epidermal cells in cleared leaves. These studies indicated that the zone of leaf elongation is within the basal 10–15 mm of a leaf and that cell divisions are restricted to the basal 0.2–1 mm. Radial enlargement of internal tissues begins in the basal half of the elongation zone and cells are fully differentiated within a short distance above it. Expanding leaves can be divided into three zones: zone 1, a basal meristematic zone where cell division and some cell elongation occur; zone 2, a zone above the base where cells are elongating but cell division has ceased; and zone 3, a zone where elongation is complete and cells have reached their final length. This pattern of leaf development is similar to, but more condensed than, feat found in the related monocotyledonous family, the Poaceae. Keywords: Cyperus eragrostis, leaf development, leaf extension zone, Cyperaceae, cell enlargement.

scholarly journals Actin isovariant ACT7 regulates root meristem development in Arabidopsis through modulating auxin and ethylene responses

2021 ◽  
Author(s):  
Takahiro Numata ◽  
Kenji Sugita ◽  
Arifa Ahamed Rahman ◽  
Abidur Rahman
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Root Meristem ◽  
Primary Role ◽  
Arabidopsis Root ◽  
Meristem Development ◽  
Constant Cell ◽  
Division Cell ◽  
Auxin Efflux Carriers

Meristem, which sustains a reservoir of niche cells at its apex, is the most functionally dynamic part in a plant body. The shaping of the meristem requires constant cell division and cell elongation, that are regulated by hormones and cell cytoskeletal components, actin. Although the roles of hormones in regulating meristem development have been extensively studied, the role of actin in this process is still elusive. Using the single and double mutants of the vegetative class actin, we demonstrate that ACT7 plays a primary role in regulating the root meristem development. In absence of ACT7, but not ACT8 and ACT2, cellular depolymerization of actin is observed. Consistently, act7 mutant shows reduced cell division, cell elongation and meristem length. Intracellular distribution and trafficking of auxin transport proteins in the actin mutants revealed that ACT7 specifically functions in root meristem to facilitate the trafficking of auxin efflux carriers PIN1 and PIN2, and consequently the transport of auxin. Compared with act7, act7act8 double mutant shows slightly enhanced phenotypic response and altered intracellular trafficking. The altered distribution of auxin in act7 and act7act8 affects the roots response to ethylene but not to cytokinin. Collectively, our results suggest that Arabidopsis root meristem development is primarily controlled through actin isovariant ACT7 mediated modulation of auxin-ethylene response.

The cytological effects of myxin on Escherichia coli

1969 ◽  
Vol 15 (7) ◽  
pp. 707-711 ◽  
Author(s):  
I. L. Stevenson
Keyword(s):  
Escherichia Coli ◽  
Plasma Membrane ◽  
Cell Division ◽  
Cell Surface ◽  
Microscopic Examination ◽  
Cell Elongation ◽  
Nuclear Bodies ◽  
Abnormal Development ◽  
Macromolecular Synthesis ◽  
Apparent Effect

When actively growing cells of Escherichia coli 15T− were treated with the new antibiotic myxin, the effects produced by the antibiotic varied, depending on the concentration. With a concentration of 1 μg/ml, the action was bacteriostatic for the first 60 min exposure. Cell division was inhibited but there was no apparent effect on macromolecular synthesis as evidenced by the formation of filamentous cells. At higher concentrations (3 and 5 μg/ml), myxin was bactericidal although some cell elongation occurred at the 3 μg/ml level. Microscopic examination of cells treated with 3 and 5 μg/ml for 30–45 min indicated the presence of vacuolated areas which thin section studies revealed as intracellular ramifications of the plasma membrane. Protoplasts of cells grown in the presence of 5 μg/ml myxin were enlarged or rapidly lysed even after as little as 15 min exposure. Myxin has no effect on the cell surface of control protoplasts. No abnormal development of the plasma membrane was noted in the elongated cells formed in the presence of 1 μg/ml myxin. Except for the lack of septation during the first 60 min, the filamentous forms appeared normal with well-defined nuclear bodies distributed throughout the cell.

scholarly journals Patterns of Cell Division, Cell Differentiation and Cell Elongation in Epidermis and Cortex of Arabidopsis pedicels in the Wild Type and in erecta

PLoS ONE ◽  
2012 ◽  
Vol 7 (9) ◽  
pp. e46262 ◽  
Author(s):  
Mark G. R. Bundy ◽  
Olivia A. Thompson ◽  
Matthew T. Sieger ◽  
Elena D. Shpak
Keyword(s):  
Cell Division ◽  
Cell Differentiation ◽  
Cell Elongation ◽  
Wild Type ◽  
In The Wild ◽  
Division Cell

Cell division, cell elongation and the co-ordination of crystallin gene expression during lens morphogenesis in the rat

Development ◽  
1978 ◽  
Vol 45 (1) ◽  
pp. 271-281
Author(s):  
J. W. McAvoy
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Posterior Part ◽  
Temporal And Spatial Distribution ◽  
Alpha Crystallin ◽  
Pit Cells ◽  
Specific Proteins ◽  
Lens Vesicle ◽  
Temporal And Spatial ◽  
Division Cell

A quantitative analysis of cell division and cell elongation was carried out during lens morphogenesis in the rat. At 13 days of development elongating cells in the posterior part of the lens vesicle (presumptive fibre cells) have a lower mitotic activity than cells in the anterior vesicle. By 14 days these elongating cells do not divide. Thus at 14 days of development the lens can be separated into two compartments; a proliferation compartment in the anterior lens and an elongation compartment in the posterior lens. The three main groups of lens-specific proteins, α-,β- and γ-crystallins, were localized by immunofiuorescence. Alpha-crystallin is the first crystallin to be detected and is localized in some lens pit cells at 12 days of development. By 14 days all lens cells contain α-crystallin. Beta- and β-crystallins are detected later at 12½ days and are localized in some cells situated primarily in the posterior part of the lens vesicle. At later stages of development these crystallins are restricted to cells of the elongation compartment, i.e. presumptive fibre and fibre cells. Possible mechanisms that govern the temporal and spatial distribution of crystallins are discussed.

Morphogenetic studies on excised leaves of Osmunda cinnamomea: histological studies of leaf development in sterile nutrient culture

1970 ◽  
Vol 48 (6) ◽  
pp. 1005-1016 ◽  
Author(s):  
James D. Caponetti ◽  
T. A. Steeves
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Leaf Development ◽  
Culture Medium ◽  
Histological Study ◽  
Cell Number ◽  
Leaf Primordia ◽  
Mature Leaves ◽  
Stage Of Development ◽  
Nutrient Culture

Leaf primordia of Osmunda cinnamomea L. explanted to a culture medium of simple composition at the end of three of their five seasons of development, complete their normal morphogenetic sequence but produce mature leaves of greatly reduced size. A histological study of the ground tissues of the rachis of cultured leaves reveals that, at least in these tissues, the size reduction results from a diminished cell number rather than from reduced cell elongation. It is apparent that, at every stage of development, cell division is greatly curtailed and that cell elongation begins precociously. Nevertheless, the pattern of development, including the distribution of mitotic activity at critical stages in the morphogenesis of the leaf, is normal. It is concluded that the effects of isolation upon leaves at this stage of development are quantitative ones upon the extent and duration of cell division and cell elongation.

Far-red light stimulates internode elongation, cell division, cell elongation, and gibberellin levels in bean

1996 ◽  
Vol 74 (5) ◽  
pp. 743-752 ◽  
Author(s):  
Frederick D. Beall ◽  
Edward C. Yeung ◽  
Richard P. Pharis
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Red Light ◽  
Cell Labeling ◽  
Internode Elongation ◽  
Bean Plants ◽  
Gas Chromatography Mass Spectroscopy ◽  
Division Cell ◽  
Lower Magnitude

The contributions of cell division and cell elongation and the potential role of gibberellins in the far-red light stimulation of bean internode elongation were investigated. When bean plants, Phaseolus vulgaris cv. Kentucky Wonder, were grown in white light supplemented with far-red light a significant increase, up to threefold, in internode elongation was observed. Microscopic examination revealed that cell lengths were also increased but by a lower magnitude than internode length. Cell-labeling studies with [3H]thymidine showed that nuclei labeling was increased in internodes receiving supplemental far-red light. Thus far-red light induced increased internode elongation is a result of both increased cell elongation and increased cell division. Gibberellins A1, A20, A19, A44, and A4 and kaurenoic acid were identified in extracts of internode tissue by gas chromatography – mass spectroscopy using [2H2]-labeled internal standards for quantification. It thus appears that the early C-13 hydroxylation pathway is operative in the elongating internode. Endogenous GA1 and GA20 were approximately twofold higher in the first internodes of plants receiving supplemental far-red light. A comparison of the metabolism of exogenously supplied [2H2]GA19 suggested that GA turnover was greater in tissues exposed to supplemental far-red light. These results indicate that both cell division and elongation contribute to the enhanced elongation response of bean internodes to far-red light and that these processes are correlated with an increase in GA levels and (or) metabolism. Keywords: Phaseolus, gibberellins, phytochrome, far-red light.

scholarly journals Cell Elongation and Cell Death ofHelicobacter pyloriIs Modulated by the Disruption ofcdrA(Cell Division-Related Gene A)

2006 ◽  
Vol 50 (7) ◽  
pp. 487-497 ◽  
Author(s):  
Hiroaki Takeuchi ◽  
Teruko Nakazawa ◽  
Takeshi Okamoto ◽  
Mutsunori Shirai ◽  
Mitsuo Kimoto ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Division ◽  
Cell Elongation ◽  
Related Gene
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