Nuclear variations and tapetum polyploidy related to pollen grain development in Passiflora L. (Passifloraceae).

Autor: Parteka LM; Programa de Pós-Graduação em Biologia Evolutiva, Universidade Estadual do Centro-Oeste (UNICENTRO), Guarapuava, Paraná, Brazil.; Laboratório de Citogenética e Diversidade Vegetal, CCB, Departamento de Biologia Geral, Universidade Estadual de Londrina-UEL, Londrina, Paraná, Brazil.; Laboratório de Botânica Estrutural, Universidade Estadual do Centro-Oeste (UNICENTRO), Guarapuava, Paraná, Brazil., Mariath JEA; Laboratório de Anatomia Vegetal (LAVeg), IB, Departamento de Botânica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil., Vanzela ALL; Laboratório de Citogenética e Diversidade Vegetal, CCB, Departamento de Biologia Geral, Universidade Estadual de Londrina-UEL, Londrina, Paraná, Brazil., Silvério A; Programa de Pós-Graduação em Biologia Evolutiva, Universidade Estadual do Centro-Oeste (UNICENTRO), Guarapuava, Paraná, Brazil.; Laboratório de Botânica Estrutural, Universidade Estadual do Centro-Oeste (UNICENTRO), Guarapuava, Paraná, Brazil.
Jazyk: angličtina
Zdroj: Cell biology international [Cell Biol Int] 2022 Mar; Vol. 46 (3), pp. 462-474. Date of Electronic Publication: 2022 Jan 09.
DOI: 10.1002/cbin.11748
Abstrakt: Tapetal cells comprise an anther tissue fundamental to pollen grain development. They are associated with endoreduplication events, which culminate in polyploid and multinucleated cells, high metabolic activity, and different organelle arrangements to support all the development of the pollen grains. Passiflora species present a secretory tapetum, with diversity in the number and size of nuclei. Tapetal cells undergo numerous changes in a short period of development when compared to the plant's life span. To improve our knowledge of tapetum development, tests assessing ploidy levels, anatomy, cytochemistry, transmission electron microscopy, flow cytometry, as well as conventional and molecular cytogenetics were used in Passiflora actinia and P. elegans. The current data show striking differences in nuclear organisation during tapetal cell development, including mono to quadrinucleate cells, and ploidy levels from 2n to 32n. One of the most peculiar features was the atypical behaviour of the endoplasmic reticulum (ER), which accumulated in the cell border, similar to a 'cER', as well as large dictyosomes. This endomembrane configuration may be related to the tapetum nutritional network and secretion of compounds at the end of meiosis. Another atypical feature of the ER was the formation of an invagination to establish 'binucleated' polyploid cells. This membrane projection appears when the nuclei form two lobes, as well as when it organises a nucleoplasmic reticulum. These data demonstrate that there are important ultrastructural changes in tapetal cells, including organelle arrangements, ploidy levels, and nuclear activity, common to P. actinia and P. elegans, but different from the plant model A. thaliana.
(© 2021 International Federation for Cell Biology.)
Databáze: MEDLINE
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