Influence of Pinocytosis and Membrane Specializations on Pollen Wall Form
作者:
J.R. Rowley,
J.J. Flynn,
Anita Dunbar,
S. Nilsson,
期刊:
Grana
(Taylor Available online 1970)
卷期:
Volume 10,
issue 1
页码: 3-12
ISSN:0017-3134
年代: 1970
DOI:10.1080/00173137009429851
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
Three features of developing pollen grains may facilitate the uptake of materials: (1) tubules (∼ 10 nm in diameter) at the surface of the exine, (2) wall tubules (7–18 nm in diameter), and (3) channels through the exine (irregular in shape, but generally between 50 and 300 nm in diameter). The tubules ofAegicerasoccur in tufts on the surface of the exine and extend from the exine to the tapetal cell surface. A glycocalyx (1,2-glycols and acidic groups) is associated with the tubules, and we suggest that the tubules and glycocalyx may be a specialization of a unit membrane on the exine surface. The wall tubules ofNupharare found in the outer part of the exine and extend from the nexine-2 to the tectum, including the tips of spines. Evaginations of the plasma membrane penetrate the exine of young microspores ofEpilobiumand their trails remain as channels in the mature exine. We show that lanthanum nitrate can pass directly through the substance, not only the channels, of the exine in microspores ofEpilobium.
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