Fine Structure of Petunia Pollen Grain and Pollen Tube

Sassen, M. M. A.

doi:10.1111/j.1438-8677.1964.tb00150.x

Cited by 125 publications

(64 citation statements)

References 18 publications

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“…The nuclear invaginations found in onion epidermal cells are unlike the various small nuclear invaginations and nuclear vacuoles primarily associated with meiotic plant cells (Sassen, 1964;Aldrich and Vasil, 1970;Dickinson and Bell, 1970, 1972; Sheffield et al, 1979;Karasawa and Ueda, 1983;Sangwan, 1986;Li and Dickinson, 1987). Furthermore, because the structures in onion contain a cytoplasmic core, they are unlike the nuclear reticulum found in Lilium ovary placental cells, in which only the inner membrane of the nuclear envelope invaginates, so that the centers of these invaginations are continuous with the lumen of the ER rather than the cytoplasm (Singh and Walles, 1995;Singh et al, 1998).…”

Section: Nuclear Invaginations In Onion Are Similar To Structures Seementioning

confidence: 99%

Plant Nuclei Can Contain Extensive Grooves and Invaginations [W]

et al. 2000

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Plant cells can exhibit highly complex nuclear organization. Through dye-labeling experiments in untransformed onion epidermal and tobacco culture cells and through the expression of green fluorescent protein targeted to either the nucleus or the lumen of the endoplasmic reticulum/nuclear envelope in these cells, we have visualized deep grooves and invaginations into the large nuclei of these cells. In onion, these structures, which are similar to invaginations seen in some animal cells, form tubular or planelike infoldings of the nuclear envelope. Both grooves and invaginations are stable structures, and both have cytoplasmic cores containing actin bundles that can support cytoplasmic streaming. In dividing tobacco cells, invaginations seem to form during cell division, possibly from strands of the endoplasmic reticulum trapped in the reforming nucleus. The substantial increase in nuclear surface area resulting from these grooves and invaginations, their apparent preference for association with nucleoli, and the presence in them of actin bundles that support vesicle motility suggest that the structures might function both in mRNA export from the nucleus and in protein import from the cytoplasm to the nucleus. INTRODUCTIONAlthough cellular function often requires maximization of surface area relative to volume, notably in organelles such as the endoplasmic reticulum (ER) and Golgi apparatus, traditional representations of the nucleus depict a rounded structure with little internal organization. Recently, however, the nuclei of animal cells have been found to show considerable spatial and structural organization at the chromosomal level. The discrete and comparatively stable territories that chromosomes occupy within the nucleus are separated by interchromosomal domains through which transcribed RNA and other macromolecules can diffuse (reviewed in Lamond and Earnshaw, 1998). Animal nuclei also sometimes deviate from the characteristic rounded shape. Deviations include a folded, grooved, or notched surface (Majno et al., 1969) and tubular invaginations. Electron microscopy has shown that these nuclear invaginations can penetrate deep into the nucleus and confirmed the presence of the double membrane of the nuclear envelope (Ellenberg et al., 1997;Fricker et al., 1997;Clubb and Locke, 1998). However, revelation of the full nature of nuclear invaginations in living animal cells has required confocal microscopy of fluorescent dyes (Fricker et al., 1997;Lui et al., 1998aLui et al., , 1998b or green fluorescent protein (GFP) fusion proteins targeted to the nuclear envelope (Ellenberg et al., 1997;Broers et al., 1999). The number and nature of invaginations vary from cell type to cell type, ranging from simple invaginations to intricate branched structures that can penetrate into and through the nucleus. Invaginations often associate with nucleoli (Fricker et al., 1997) and appear to be stable (Ellenberg et al., 1997;Broers et al., 1999). Nuclear grooves and invaginations substantially increase the surface area of the ...

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Section: Nuclear Invaginations In Onion Are Similar To Structures Seementioning

confidence: 99%

Plant Nuclei Can Contain Extensive Grooves and Invaginations [W]

et al. 2000

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“…We therefore used an isotropic material model to describe the pole region (domain 1; Figure 2D). In the shank, cellulose microfibrils display a preferential orientation oblique to the growth axis (O'Kelley and Carr, 1954;Sassen, 1964;Aouar et al, 2010). It is unknown exactly how microfibrils are oriented in the regions of the apical dome located between pole and shank.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

“…(2) Does the cell wall need to possess mechanical anisotropy in its plane? The second question arises from the observation that cellulose microfibrils are present in the apical region of pollen tubes (Sassen, 1964); thus, a biochemical basis for putative anisotropy exists.…”

Section: Identification Of Crucial Parametersmentioning

confidence: 99%

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Finite Element Model of Polar Growth in Pollen Tubes

et al. 2010

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Cellular protuberance formation in walled cells requires the local deformation of the wall and its polar expansion. In many cells, protuberance elongation proceeds by tip growth, a growth mechanism shared by pollen tubes, root hairs, and fungal hyphae. We established a biomechanical model of tip growth in walled cells using the finite element technique. We aimed to identify the requirements for spatial distribution of mechanical properties in the cell wall that would allow the generation of cellular shapes that agree with experimental observations. We based our structural model on the parameterized description of a tip-growing cell that allows the manipulation of cell size, shape, cell wall thickness, and local mechanical properties. The mechanical load was applied in the form of hydrostatic pressure. We used two validation methods to compare different simulations based on cellular shape and the displacement of surface markers. We compared the resulting optimal distribution of cell mechanical properties with the spatial distribution of biochemical cell wall components in pollen tubes and found remarkable agreement between the gradient in mechanical properties and the distribution of deesterified pectin. Use of the finite element method for the modeling of nonuniform growth events in walled cells opens future perspectives for its application to complex cellular morphogenesis in plants.

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“…But ultrastructural studies about pollen tubes are very rare. Initial studies have been done in Petunia (Solanaceae) (Sassen 1964), (Cresti and Van Went 1976) and Lilium longiflorum (Liliaceae) (Rosen et al 1964). Few reports have appeared in 1980s, concerning the fine structure of the pollen tubes in Lycopersicum peruvianum (Solanaceae) (Cresti et al 1977), (Cresti et al 1980), Prunus avium (Rosaceae) (Cresti et al 1979), (Uwate and Lin 1980), Prunus sp.…”

Section: Introductionmentioning

confidence: 99%

Ultrastructural features of Mimulus aurantiacus (Scrophulariaceae) pollen tubes in vivo

Ekici

Dane

Olgun

2009

An. Acad. Bras. Ciênc.

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The aim of this study is to give information on ultrastructure of in vivo pollen tubes of Mimulus aurantiacus which were collected from the Botanical Garden of the University of California at Berkeley. Materials were prepared according to electron microscopy methods and examined under Zeiss electron microscope. Four zones were examined in the pollen tubes of Mimulus aurantiacus. Apical zone: Mitochondria, smooth endoplasmic reticulum, rough endoplasmic reticulum, dictyosomes and secretory vesicles were observed. Subapical zone: This area contained abundant rough endoplasmic reticulum and occasionally some smooth endoplasmic reticulum. The polysomes, mitochondria, proplastids that contain starch, small vacuoles and a few lipid bodies were detected. Nuclear zone: Both generative and vegetative cell nuclei lie in this zone. The vegetative cell nucleus was large and long. Rough endoplasmic reticulum, mitochondria, ribosomes, dictyosomes, and amyloplasts that are rich of starch were observed. Vacuolation and plug formation zone: Cytoplasm of the tubes was full of large vacuoles. Few organelles such as mitochondria, dictyosome and rough endoplasmic reticulum were detected along their periphery.

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Fine Structure of Petunia Pollen Grain and Pollen Tube

Cited by 125 publications

References 18 publications

Plant Nuclei Can Contain Extensive Grooves and Invaginations [W]

Plant Nuclei Can Contain Extensive Grooves and Invaginations [W]

Finite Element Model of Polar Growth in Pollen Tubes

Ultrastructural features of Mimulus aurantiacus (Scrophulariaceae) pollen tubes in vivo

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