Senescence Arrest of Endopolyploid Cells Renders Senescence into One Mechanism for Positive Tumorigenesis

Abstract The induction and regeneration of protocorm-like bodies (PLBs) is a morphogenetic pathway widely used for orchid micropropagation. As endopolyploidy, i.e., the coexistence of cells with different ploidy levels, is a common feature in orchid tissues, a natural question arises when using somatic tissues as explants for orchid micropropagation: does endopolyploidy in explants affect the cytogenetic stability of regenerated plantlets? To answer this question, Epidendrum fulgens was used as a model plant, and flow cytometry (FC) was used to analyze endopolyploidy in pollinia, petals, labella, leaf bases, leaf tips, root tips, protocorms bases and protocorms apexes, which were subsequently used as explants for PLB induction and plant regeneration. The ploidy screening showed contrasting ploidy patterns in the samples. Endopolyploidy was detected in all tissues, with C-values ranging from 1C to 16C. Protocorm bases and root tips presented the highest proportion of endopolyploidy, while petals and protocorm apexes showed the lowest proportion. Flower parts presented high oxidation for PLB induction and pollinia failed to produce PLB or callus. The highest induction rate was observed at 10 µM TDZ, with 92%, 22%, and 0.92% for protocorm bases, leaves, and root tips, respectively. Plantlets were more easily regenerated from PLBs induced from protocorm bases than from leaves and roots. Doubled ploidy levels were registered in a proportion of 11% and 33% for PLB-regenerated plantlets obtained from protocorm bases and leaf bases, respectively, which was not directly associated with the proportion of endopolyploid cells or cycle value of explants.

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Salinity Has no Effect on Polysomatic Pattern in Seedlings of Trifolium pratense and T. repens

Acta Biologica Cracoviensia s Botanica ◽

10.1515/abcsb-2017-0005 ◽

2017 ◽

Vol 59 (1) ◽

pp. 55-65 ◽

Cited By ~ 1

Author(s):

Valéria Kocová ◽

Dominika Bubanová ◽

Albert Rákai ◽

Vladislav Kolarčik ◽

Pavol Mártonfi

Keyword(s):

Cell Cycle ◽

Trifolium Pratense ◽

Genetic Material ◽

Genetic Trait ◽

Ploidy Levels ◽

Treatment Groups ◽

Pasture Legumes ◽

A Cell ◽

Endopolyploid Cells ◽

Adaptation To Salinity

AbstractEndopolyploidy is a condition of a cell containing reduplicated genetic material in its nucleus. Cells with the nuclei of different ploidy levels are often present within a single polysomatic organism. Endoreduplication is thus a modified cell cycle that omits cytokinesis and leads to chromatin replication in the endopolyploid cells. This study aimed to research the effect of salinity on endopolyploidy ofTrifolium pratenseandT. repens. Both species are important pasture legumes and belong to the genusFabaceaewith the well documented endopolyploidy occurence. Endopolyploidy levels in the seedlings treated with 0, 30, 60, 90 and 120 mM NaCl were investigated by flow cytometry. The seedling organs were evaluated during three ontogeny stages. The cytometric data plotted on a histogram showed the presence of 2C-16C nuclei inT. pratenseand 2C-8C inT. repens. The hypothesis that salinity induces additional endocycles was not confirmed. Our results show that the distribution of nuclei among ploidy levels does not differ markedly between the treatment groups and the control ones. Additionally, only minor changes were observed among the endoreduplication indexes (EI) of plant organs after exposure to various salt concentrations. Endopolyploidy patterns within the salt-treated seedlings during ontogeny are similar to the controls. We suggest that endopolyploidy inTrifoliumspecies is a conserved genetic trait, rather than an adaptation to salinity stress. The analyses of the roots ofT. pratenseat stage III show that with the increased concentrations of NaCl the length of roots decreased, but no evident changes in endopolyploidy occured.

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Spatial and Temporal Patterns of Endopolyploidy in Mosses

Genes ◽

10.3390/genes12010027 ◽

2020 ◽

Vol 12 (1) ◽

pp. 27

Author(s):

Marianna Paľová ◽

Dajana Ručová ◽

Michal Goga ◽

Vladislav Kolarčik

Keyword(s):

Flow Cytometry ◽

Temporal Distribution ◽

Temporal Patterns ◽

Spatial And Temporal Distribution ◽

Spatial And Temporal Patterns ◽

Ploidy Levels ◽

Moss Species ◽

Plant Kingdom ◽

Plant Groups ◽

Endopolyploid Cells

Somatic polyploidy or endopolyploidy is common in the plant kingdom; it ensures growth and allows adaptation to the environment. It is present in the majority of plant groups, including mosses. Endopolyploidy had only been previously studied in about 65 moss species, which represents less than 1% of known mosses. We analyzed 11 selected moss species to determine the spatial and temporal distribution of endopolyploidy using flow cytometry to identify patterns in ploidy levels among gametophytes and sporophytes. All of the studied mosses possessed cells with various ploidy levels in gametophytes, and four of six species investigated in sporophytic stage had endopolyploid sporophytes. The proportion of endopolyploid cells varied among organs, parts of gametophytes and sporophytes, and ontogenetic stages. Higher ploidy levels were seen in basal parts of gametophytes and sporophytes than in apical parts. Slight changes in ploidy levels were observed during ontogenesis in cultivated mosses; the youngest (apical) parts of thalli tend to have lower levels of endopolyploidy. Differences between parts of cauloid and phylloids of Plagiomnium ellipticum and Polytrichum formosum were also documented; proximal parts had higher levels of endopolyploidy than distal parts. Endopolyploidy is spatially and temporally differentiated in the gametophytes of endopolyploid mosses and follows a pattern similar to that seen in angiosperms.

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Endopolyploid cells produced after severe genotoxic damage have the potential to repair DNA double strand breaks

Journal of Cell Science ◽

10.1242/jcs.00740 ◽

2003 ◽

Vol 116 (20) ◽

pp. 4095-4106 ◽

Cited By ~ 52

Author(s):

A. Ivanov

Keyword(s):

Double Strand Breaks ◽

Dna Double Strand Breaks ◽

Strand Breaks ◽

Genotoxic Damage ◽

Endopolyploid Cells

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Miniature genomes and endopolyploidy in cladoceran crustaceans

Genome ◽

10.1139/g89-552 ◽

1989 ◽

Vol 32 (6) ◽

pp. 1048-1053 ◽

Cited By ~ 28

Author(s):

Margaret J. Beaton ◽

Paul D. N. Hebert

Keyword(s):

Genome Size ◽

Dna Content ◽

Daphnia Pulex ◽

The Body ◽

Haploid Genome ◽

Important Process ◽

Ploidy Levels ◽

Somatic Tissues ◽

Scanning Microdensitometry ◽

Endopolyploid Cells

The haploid genome sizes (0.37 and 0.47 pg) of two members of the cladoceran crustacean genus Daphnia rank among the smallest known for Crustacea. An examination of cladoceran somatic tissues by scanning microdensitometry revealed abundant endopolyploidy in both species. Although cells in the labrum possessed the highest DNA content (1024C), endopolyploid cells (4–512C) were widely distributed throughout the body. Daphnia pulex and D. magna exhibited similar ploidy levels in most tissues, but differences between the two species were noted in the epidermis and labrum. The prevalence of polyploid nuclei suggests that endopolyploidy is an important process in organisms whose genomes have been miniaturized by nucleotypic selection.Key words: somatic polyploidy, genome size, Daphnia, ploidy shifts, macroevolution.

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The Tomato Guanylate-Binding Protein SlGBP1 Enables Fruit Tissue Differentiation by Maintaining Endopolyploid Cells in a Non-Proliferative State

The Plant Cell ◽

10.1105/tpc.20.00245 ◽

2020 ◽

Vol 32 (10) ◽

pp. 3188-3205

Author(s):

Constance Musseau ◽

Joana Jorly ◽

Stéphanie Gadin ◽

Iben Sørensen ◽

Catherine Deborde ◽

...

Keyword(s):

Binding Protein ◽

Tissue Differentiation ◽

Fruit Tissue ◽

Endopolyploid Cells ◽

Guanylate Binding Protein

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Sucrose synthase isozyme SUS1 in the maize root cap is preferentially localized in the endopolyploid outer cells

Canadian Journal of Botany ◽

10.1139/b03-143 ◽

2004 ◽

Vol 82 (1) ◽

pp. 96-103 ◽

Cited By ~ 4

Author(s):

Aleš Kladnik ◽

Barbara Vilhar ◽

Prem S Chourey ◽

Marina Dermastia

Keyword(s):

Zea Mays ◽

Sucrose Synthase ◽

Nuclear Dna ◽

Zea Mays L ◽

Nuclear Dna Content ◽

Image Cytometry ◽

Root Cap ◽

Dna Amount ◽

The Relationship ◽

Endopolyploid Cells

The structure of the maize (Zea mays L.) root cap was studied to quantitatively evaluate the relationship among the size of the cells, their endopolyploidy level, and the abundance of the sucrose synthase isozyme SUS1. Median longitudinal root cap sections were analysed using immunolocalization, quantitative DNA staining, and image cytometry. Both the immunolocalization signal for the SUS1 protein and the endopolyploidy level increased from calyptrogen towards the root cap periphery and were thus the highest in the outer cells. These cells had a nuclear DNA content of mostly 8C or higher and the largest volumes of all root cap cells. The high amount of SUS1 protein in the outer, endopolyploid cells suggests an association between endoreduplication and the abundance of this enzyme. The outer cells are involved in mucilage production; hence, there is a possibility that sucrose synthase provides monosaccharide precursors for mucilage synthesis.Key words: nuclear DNA amount, endoreduplication, immunolocalization, image cytometry, Zea mays L.

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