The leafy stems of Sphagnum (Bryophyta) contain highly differentiated polarized cells with axial arrays of endoplasmic microtubules
Contrary to the long-held belief that, internal to the cortical sterome, the central region of Sphagnum stems comprises unspecialized parenchyma, the present light- and electron-microscope study has revealed that these cells in fact have a highly specialized cytoplasmic organization. Their key featu...
Veröffentlicht in: | The New phytologist. - 1979. - 140(1998), 3 vom: 18. Nov., Seite 567-579 |
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Format: | Online-Aufsatz |
Sprache: | English |
Veröffentlicht: |
1998
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Zugriff auf das übergeordnete Werk: | The New phytologist |
Schlagworte: | Journal Article Sphagnum cytoplasmic polarity microtubules plasmodesmata symplasmic transport |
Zusammenfassung: | Contrary to the long-held belief that, internal to the cortical sterome, the central region of Sphagnum stems comprises unspecialized parenchyma, the present light- and electron-microscope study has revealed that these cells in fact have a highly specialized cytoplasmic organization. Their key features are: (a) the absence of large central vacuoles; (b) a spindle-shaped nucleus positioned internally; (c) a prominent axial system of endoplasmic microtubules associated with the nucleus, mitochondria, pleomorphic vacuoles, and membrane-bounded tubules and vesicles; (d) a distinct cytoplasmic polarization, with the cellular region near the capitulum being richer in organelles than the basal region; and (e) a high frequency of plasmodesmata in the cross walls with an enlarged median region containing no discernible desmotubule. Such a distinctive combination of cytological features has been hitherto only described for putative food-conducting cells in bryoid mosses. The results introduce a major new character common to Sphagnum and bryoid mosses and strongly suggest that this cytological organization underlines cellular specialization in symplasmic transport |
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Beschreibung: | Date Revised 19.04.2021 published: Print Citation Status PubMed-not-MEDLINE |
ISSN: | 1469-8137 |
DOI: | 10.1111/j.1469-8137.1998.00298.x |