Results 241 to 250 of about 17,918 (286)

Endoplasmic reticulum in the sieve element of Cucurbita

Journal of Ultrastructure Research, 1968
The endoplasmic reticulum (ER) in immature sieve elements of Cucurbita maxima Duchesne resembles that of other types of nucleate cells in morphology and distribution. In mature sieve elements the ER assumes two forms. One of these is represented by a network closely applied to the plasma membrane lining the cell wall.
K, Esau, J, Cronshaw
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A reevaluation of extruded nucleoli in sieve elements

Journal of Ultrastructure Research, 1970
Immature and mature sieve elements of Populus deltoides, Quercus alba, Salix nigra, Tilia americana, and Rhus glabra were examined with light and electron microscopes. Sieve elements of the first four species contain persistent spherical inclusions similar to those heretofore interpreted as extruded nucleoli.
B P, Deshpande, R F, Evert
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Lignified sieve elements in the wheat leaf

Planta, 1974
Sieve elements with thick, lignified walls are identified in the longitudinal bundles of the wheat leaf and appear to be functional. They are also present in several festucoid grasses but appear to be absent from the panicoid grasses examined.
J, Kuo, T P, O'Brien
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On the occurrence of nuclei in mature sieve elements

Planta, 1970
The secondary phloem of 3 species of the Taxodiaceae and 13 species of woody dicotyledons was examined for the occurrence of nuclei in mature sieve elements. Nuclei were found in all mature sieve cells of Metasequoia glyptostroboides, Sequoia sempervirens and Taxodium distichum, and in some mature sieve-tube members in 12 of the 13 species of woody ...
R F, Event, J D, Davis, C M, Tucker, F J, Alfieri   +3 more
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Removing the nucleus in sieve elements

Science, 2014
Cellular remodeling to develop phloem cells orchestrates degradation of the cell’s nucleus.
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CALLOSE SUBSTANCE IN SIEVE ELEMENTS

American Journal of Botany, 1964
The secondary phloem of 6 species of woody dicotyledons was examined for the occurrence of callose on the sieve plates of active sieve elements. Fluorescence and bright‐field staining methods were used to detect callose. Tissue from the 6 species was killed and fixed in each of 5 solutions. Some tissue of each species was submerged
Ray F. Evert, William F. Derr
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Sieve–element characters

Nordic Journal of Botany, 1981
Of all the ultrastructural features recognized within sieve elements their specific plastids provide the most successful characters in seed plant systematics. Sieve–element plastids are classified into subtypes and forms according to their protein and starch contents. Presently 26 different forms grouped into six subtypes within the two basic types (S–
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Strands in Sections of Sieve Elements Cut in a Cryostat

Nature New Biology, 1971
Observations of these strands are consistent with the idea of trans-cellular strands of cytoplasm in sieve tubes.
P, Jarvis, R, Thaine
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Sieve element pores in Nicotiana pith culture

Journal of Ultrastructure Research, 1970
Sieve elements were induced to form in cultured pith cylinders of Nicotiana tabacum L. (var. Wisconsin 38). Both xylem and phloem differentiate in isolated nodules at the periphery of the cylinders. The mature sieve elements closely resemble sieve elements in intact plants but are more irregular in shape and usually not highly elongated.
R, Anderson, J, Cronshaw
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Microtubules in differentiating sieve elements of Gossypium hirsutum

Journal of Ultrastructure Research, 1982
Changes in distribution, orientation, and abundance of microtubules (MT) in relation to sieve element differentiation in root protophloem and stem and midvein metaphloem of Gossypium hirsutum were studied at the ultrastructural level. Depending on their stage of differentiation the sieve elements were divided into four previously characterized groups ...
J, Thorsch, K, Esau
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