scholarly journals Tradescantia bracteata pollen in vitro: pollen tubes development and mitosis

2015 ◽  
Vol 46 (4) ◽  
pp. 587-598 ◽  
Author(s):  
E. Lewandowska ◽  
M. Charzyńska
Keyword(s):  
Pollen Tube ◽  
Generative Cell ◽  
Metaphase Plate ◽  
Pollen Grains ◽  
Neutral Red ◽  
Generative Nucleus ◽  
Mitotic Spindles ◽  
Germinating Pollen ◽  
Vacuolar System

About 90 per cent of <i>Tradescantia bracteata</i> pollen germinates <i>in vitro</i> after 15 min. Mitosis starts in the pollen tube after about 3 h. The mitotic trans-formations of chromosomes within the generative nucleus are not synchronized. They involve succesively the linearly arranged chromosomes in the elongated generative nucleus. In metaphase the chromosomes are arranged tandem-like linearly along the pollen tube. The chromatides translocate in anaphase from various distances to the poles in a plane parallel to the metaphase plate. This suggests that chromosomes have individual mitotic spindles and that coordination of the chromosome transformations in the generative cell is much less strict than in a typical somatic mitosis. Starch is the storage material of pollen grains. In the vegetative cytoplasm of mature pollen grains minute reddish-orange vesicular structures are visible after staining with neutral red. They do not fuse with the vacuoles proper arising in germinating pollen grains to form the vacuolar system of the pollen tube.

scholarly journals The mechanics of mitosis in the pollen-tube of Tulipa

1936 ◽  
Vol 121 (822) ◽  
pp. 207-220 ◽  
Keyword(s):  
Pollen Tube ◽  
Higher Plants ◽  
Generative Cell ◽  
Metaphase Plate ◽  
Cell Plate ◽  
Usual Method ◽  
Generative Nucleus ◽  
A Cell ◽  
Marked Cell

The division of the generative nucleus in the pollen-tube of the higher plants has been studied by several authors, with results differing widely from one another even when concerned with the same genus. For example, Koernicke (1906), Welsford (1914), and O’Mara (1933) have investigated various species of Lilium . Koernicke and Welsford describe the formation of a definite though narrow metaphase plate, while O’Mara, in spite of his illustration (fig. 9), is of the opinion that there is no such regular congression owing to the narrowness of the tube. Trankowsky (1930) finds a metaphase plate in Hemerocallis , the pollen-tube of which is wide in comparison with the size of the spindle, but not in Galanthus or Convallaria . Wulff’s (1933) observations are weakened by his confusing anaphase with pro-metaphase, and centric with nucleolar constrictions. A further point at issue is whether the generative cell divides by constriction or by the formation of a cell-plate, the more usual method in the higher plants. Koernicke illustrates a well marked cell-plate, but Wulff and others are of the opinion that division is by constriction.

Generative cell mitosis in pollen tubes of Nicotiana tabacum: Ultrastructure and 3-D reconstruction

1992 ◽  
Vol 50 (1) ◽  
pp. 848-849
Author(s):  
Hong-Shi Yu ◽  
S. D. Russell
Keyword(s):  
Pollen Tube ◽  
Generative Cell ◽  
Three Dimensional ◽  
Metaphase Plate ◽  
Preprophase Band ◽  
Mitotic Division ◽  
Mitotic Apparatus ◽  
Cell Mitosis

In bicellular pollen, the two sperm cells are formed by mitotic division of the generative cell (GC) in the pollen tube. This division is characterized by several unique features, including: lack of a preprophase band (PPB), absence of a metaphase plate, absence of normal spindle formation, and irregular patterns of cytokinesis. Purportedly, this is the result of spatial constraints within the pollen tube, which in vivo may be as narrow as 3 μm (as in Nicotiana) and slightly wider in vitro.Immunofluorescence studies of GC mitosis have been published in the last five years2−7, but only one incomplete ultrastructural report on GC division in vitro is available. This study is the first using three-dimensional (3-D) techniques to reconstruct the mitotic apparatus of the GC in vivo.

Pollen germination of Larix sibirica (Siberian larch) in vitro

1970 ◽  
Vol 48 (2) ◽  
pp. 213-215 ◽  
Author(s):  
Ronghui Ho ◽  
Glenn E. Rouse
Keyword(s):  
Pollen Tube ◽  
Pollen Germination ◽  
Generative Cell ◽  
Siberian Larch ◽  
Pollen Grains ◽  
The Body ◽  
Stalk Cell ◽  
Body Cell

Mature pollen grains of Siberian larch were successfully germinated in vitro for the first time. Mature grains, containing two prothallial cells, a generative cell, and a tube cell, were incubated in stock solution B for periods up to 5 days. At the 2-day stage, the generative cell had divided into a stalk cell and body cell. In 5 days, the body nucleus had divided into two male nuclei contained within the body cell. Pollen germination was limited to elongation of the intine towards the distal pole, accompanied by a splitting of the exine, but without any suggestion of the formation of a pollen tube. This supports the suggestion of previous studies in vivo on other species of Larix pollen that a pollen tube does not form before the pollen grain reaches the nucellus of the ovule.

scholarly journals 3H-thymidyne incorporation into the microspores and pollen grains nuclei in excised Tradescantia stamens

2015 ◽  
Vol 47 (1–2) ◽  
pp. 163-172 ◽  
Author(s):  
Maria Charzyńska ◽  
Joanna Maleszka
Keyword(s):  
Dna Synthesis ◽  
Generative Cell ◽  
Pollen Grains ◽  
Vegetative Nucleus ◽  
Generative Nucleus ◽  
Tetrad Stage ◽  
Pollen Grain Wall ◽  
Medium Culture

The development of microspores and pollen grains lasts in <i>Tradescantia bracteata in vivo</i> from the tetrad stage to pollen shedding about 14 days. This including 7 days of the microspore life cycle. In stamens excised and placed on a medium the microspores and pollen grains develop normally for at least 3 days. <sup>3</sup>H-thymidine is added into medium culture. DNA synthesis m the microspore nucleus is demonstrated 6 days after tetrad formation so at the end of microspore interphase. During synthesis the nucleus lies at one end of the long axis of the vacuolated microspore. Synthesis ends before migration of the nucleus to the proximal pole of the microspore where mitosis begins. Incorporation of <sup>3</sup>H-thymidine into the generative nucleus is noted in two-celled pollen grains as early as about 24h after the end of microspore division. During DNA synthesis the generative cell is rounded and is still adjacent to the pollen grain wall. DNA synthesis ends before separation of the generative cell from the sporoderm, before the generative nucleus starts to elongate. <sup>3</sup>H-thymidine is not incorporated into the vegetative nucleus in stamens developing <i>in vitro</i>.

scholarly journals Prunus necrotic ringspot virus Early Invasion and Its Effects on Apricot Pollen Grain Performance

2007 ◽  
Vol 97 (8) ◽  
pp. 892-899 ◽  
Author(s):  
Khalid Amari ◽  
Lorenzo Burgos ◽  
Vicente Pallas ◽  
María Amelia Sanchez-Pina
Keyword(s):  
Developmental Stages ◽  
Generative Cell ◽  
Pollen Grains ◽  
Growth Zone ◽  
Pollen Tubes ◽  
Climatic Conditions ◽  
Pollen Grain ◽  
Ringspot Virus ◽  
Prunus Necrotic Ringspot Virus

The route of infection and the pattern of distribution of Prunus necrotic ringspot virus (PNRSV) in apricot pollen were studied. PNRSV was detected both within and on the surface of infected pollen grains. The virus invaded pollen during its early developmental stages, being detected in pollen mother cells. It was distributed uniformly within the cytoplasm of uni- and bicellular pollen grains and infected the generative cell. In mature pollen grains, characterized by their triangular shape, the virus was located mainly at the apertures, suggesting that PNRSV distribution follows the same pattern as the cellular components required for pollen tube germination and cell wall tube synthesis. PNRSV also was localized inside pollen tubes, especially in the growth zone. In vitro experiments demonstrated that infection with PNRSV decreases the germination percentage of pollen grains by more than half and delays the growth of pollen tubes by ≈24 h. However, although PNRSV infection affected apricot pollen grain performance during germination, the presence of the virus did not completely prevent fertilization, because the infected apricot pollen tubes, once germinated, were able to reach the apricot embryo sacs, which, in the climatic conditions of southeastern Spain, mature later than in other climates. Thus, infected pollen still could play an important role in the vertical transmission of PNRSV in apricot.

scholarly journals Impact of Manganese on Pollen Germination and Tube Growth in Lily

2021 ◽  
Vol 74 ◽  
Author(s):  
Thomas Sawidis ◽  
Gülriz Baycu ◽  
Elżbieta Weryszko-Chmielewska ◽  
Aneta Sulborska
Keyword(s):  
Pollen Tube ◽  
Pollen Germination ◽  
Surrounding Medium ◽  
Pollen Grains ◽  
Lilium Longiflorum ◽  
Tube Growth ◽  
Low Concentrations ◽  
Main Effect

Abstract In vitro culture of Lilium longiflorum pollen grains was carried out to determine the role of manganese in pollen germination and pollen tube growth. Pollen germination was adversely affected by the presence of manganese (>10 −8 M), whereas low concentrations (10 −12 –10 −10 M) stimulated the process. Manganese caused morphological anomalies during tube growth, characterized by irregular pollen tube thickening and swollen tips. The main effect was the anomalous cell wall formation at the tip, in which the presence of several organelles reduced the number of secretory vesicles. A loose network of fibrillar material and spherical aggregates, mostly in the tip region, was detected, and this material was progressively loosened into the surrounding medium. As a response to potential toxicity, the excess manganese was isolated in vacuoles, which formed an internal barrier against penetration of manganese to the tip area. Elevated manganese concentrations might affect plant reproduction, resulting in anomalies in gamete development. Consequently, the loss in genetic diversity and decreased fruit set ultimately lower yield.

scholarly journals Comparative analyses of angiosperm secretomes identify apoplastic pollen tube functions and novel secreted peptides

2020 ◽  
Author(s):  
María Flores-Tornero ◽  
Lele Wang ◽  
David Potěšil ◽  
Said Hafidh ◽  
Frank Vogler ◽  
...  
Keyword(s):  
Cell Wall ◽  
Pollen Tube ◽  
Turgor Pressure ◽  
Pollen Grains ◽  
Pollen Tubes ◽  
Secreted Proteins ◽  
Reproductive Tissues ◽  
Small Proteins ◽  
Secreted Peptides

Abstract Key message Analyses of secretomes of in vitro grown pollen tubes from Amborella, maize and tobacco identified many components of processes associated with the cell wall, signaling and metabolism as well as novel small secreted peptides. Abstract Flowering plants (angiosperms) generate pollen grains that germinate on the stigma and produce tubes to transport their sperm cells cargo deep into the maternal reproductive tissues toward the ovules for a double fertilization process. During their journey, pollen tubes secrete many proteins (secreted proteome or secretome) required, for example, for communication with the maternal reproductive tissues, to build a solid own cell wall that withstands their high turgor pressure while softening simultaneously maternal cell wall tissue. The composition and species specificity or family specificity of the pollen tube secretome is poorly understood. Here, we provide a suitable method to obtain the pollen tube secretome from in vitro grown pollen tubes of the basal angiosperm Amborella trichopoda (Amborella) and the Poaceae model maize. The previously published secretome of tobacco pollen tubes was used as an example of eudicotyledonous plants in this comparative study. The secretome of the three species is each strongly different compared to the respective protein composition of pollen grains and tubes. In Amborella and maize, about 40% proteins are secreted by the conventional “classic” pathway and 30% by unconventional pathways. The latter pathway is expanded in tobacco. Proteins enriched in the secretome are especially involved in functions associated with the cell wall, cell surface, energy and lipid metabolism, proteolysis and redox processes. Expansins, pectin methylesterase inhibitors and RALFs are enriched in maize, while tobacco secretes many proteins involved, for example, in proteolysis and signaling. While the majority of proteins detected in the secretome occur also in pollen grains and pollen tubes, and correlate in the number of mapped peptides with relative gene expression levels, some novel secreted small proteins were identified. Moreover, the identification of secreted proteins containing pro-peptides indicates that these are processed in the apoplast. In conclusion, we provide a proteome resource from three distinct angiosperm clades that can be utilized among others to study the localization, abundance and processing of known secreted proteins and help to identify novel pollen tube secreted proteins for functional studies.

scholarly journals In vitro germination and viability of pea pollen grains after application of organic nano-fertilizers

2017 ◽  
Vol 32 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Natalia Georgieva ◽  
Ivelina Nikolova ◽  
Valentin Kosev ◽  
Yordanka Naydenova
Keyword(s):  
Pollen Tube ◽  
Pollen Germination ◽  
Culture Media ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Pollen Grain ◽  
In Vitro Germination ◽  
Pisum Sativum L ◽  
Pollen Tube Elongation

The objective of this study was to evaluate the influence of two organic nanofertilizers, Lithovit and Nagro, on in vitro germination, pollen tube elongation and pollen grain viability of Pisum sativum L cv. Pleven 4. The effect of their application was high and exceeded data for the untreated control (44.2 and 47.23 % regarding pollen germination and pollen tube elongation, respectively), as well as the effect of the control organic algal fertilizer Biofa (17.5 and 27.9 %, respectively). Pollen grains were inoculated in four culture media. A medium containing 15% sucrose and 1% agar had the most stimulating impact on pea pollen grains. Pollen viability, evaluated by staining with 1% carmine, was within limits of 74.72-87.97%. The highest viability of pollen grains was demonstrated after the application of Nagro organic nano-fertlizer.

scholarly journals Metabolomic Analysis of Pollen Grains with Different Germination Abilities from Two Clones of Chinese Fir (Cunninghamia lanceolata (Lamb) Hook)

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3162 ◽  
Author(s):  
Seif Aldin Dawina Abdallah Fragallah ◽  
Pei Wang ◽  
Nuo Li ◽  
Yu Chen ◽  
Sizu Lin
Keyword(s):  
Pollen Germination ◽  
Early Stage ◽  
Pollen Grains ◽  
Chinese Fir ◽  
Tube Growth ◽  
Metabolomic Analysis ◽  
Factors Affecting ◽  
Germination Process ◽  
Germinating Pollen

Pollen grains produce certain metabolites, which can improve or inhibit germination and tube growth. Metabolomic analysis of germinating and growing Chinese fir pollen has not been reported. Therefore, this study aimed to analyse metabolites changes, content and expression in the germinating pollen of Chinese fir. To understand the metabolic differences, two clones from Chinese fir were selected. Metabolomics analyses were performed on three stages (1-, 24- and 48-h) during in vitro pollen germination. The metabolites profiles at different time points were analyzed by using liquid chromatography-mass spectrometry. The results showed that 171 peaks were screened; the corresponding differential metabolites of 121 peaks were classified into nine types of substances. The expression of metabolites showed significant differences across and between clones, and the variation was evident at all germination stages. The expression was obvious at the early stage of germination, which differed clearly from that of the late stage after pollen tube growth. Moreover, the metabolites were mainly enriched in 14 metabolic pathways. Pollen germination and tube growth and metabolites expressions changed per incubation time. Since this work is preliminary, we suggest further investigations to understand the relationship between the differential metabolites and pollen development, and factors affecting pollen germination process.

In vitro germination and pollen tube growth of maize (Zea mays) pollen. IX. Pollen source genotype and nonionic surfactant interactions

1980 ◽  
Vol 58 (5) ◽  
pp. 557-561 ◽  
Author(s):  
P. L. Pfahler ◽  
H. F. Linskens ◽  
M. Wilcox
Keyword(s):  
Pollen Tube ◽  
Calcium Nitrate ◽  
Pollen Grains ◽  
Tween 80 ◽  
Tube Length ◽  
In Vitro Germination ◽  
Sorbitan Monooleate ◽  
Germination Characteristics ◽  
Surfactant Effects

Because of their structure and active metabolic state, pollen grains are vulnerable to any agent in the in vitro germination medium. Surfactants are used in biological systems to reduce surface tension but are also known to produce subtle biochemical effects. This study investigated the effect of three nonionic surfactants on the germination characteristics of pollen grains from three pollen source genotypes. Pollen grains from three single cross hybrids (Wf9 × H55, K64 × K55, Ky228 × Ky226) were cultured on an artificial medium (15% sucrose, 0.6% bacto-agar, 0.03% calcium nitrate, 0.01% boric acid) supplemented with all possible combinations of three concentrations (10, 100, 1000 ppm, v/v) of the following surfactants: (i) Tween 80 (polyoxyethylene sorbitan monooleate); (ii) X-114 (alkyl phenoxypolyethoxy ethanol); and (iii) commercial sticker spreader (alkyl olefin aromatic polymers). A control containing no supplement was included. Over all genotypes, increasing concentrations of Tween 80 had the least effect on the germination characteristics measured (germination and ruptured percent, pollen tube length at 1, 2, and 3 h after inoculation) and X-114 had the greatest effect with no germination found above 10 ppm. For most of the germination characteristics, highly significant pollen source genotype X concentration interactions were found for each surfactant. The direction and magnitude of the surfactant effects depended on the surfactant, its concentration, the germination characteristic involved, and the pollen source genotype.

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