Before the external symptoms appear in the young leaves, virus particles are found in mature sieve elements and undergo changes in distribution and numbers such that a multiplication of the virus is indicated.
Tubular and fibrillar components of mature and differentiating sieve elements.
definitive callose: usually massive deposits in sieve elements at cessation or interruption of translocation in the sieve element.
phloem: principal food-conducting tissue of the vascular plant; composed of sieve elements, various kinds of parenchyma cells, fibers, and sclereids.
P-protein: phloem protein formerly called "slime"; in cells of seed plants, most commonly in sieve elements.
1957) had brought the once controversial matter of plasmolyzability of the sieve element into relation with other concepts concerning the connection between structure and function in the conduit of the phloem tissue.
The main topics of research at UC Santa Barbara, as at UC Davis, were the structure and development of the phloem tissue, especially the sieve element, and the appearance and fate of the virus in plant cells.
When the bodies are formed, the sieve element is still an immature but complete cell containing a nucleus and other organelles and having a vacuole that is delimited by a tonoplast membrane.
Fixation of images of sieve element plastids in Beta.
A crystaline inclusion in sieve element nuclei of Amsinckia II.