Claim · model-written summary
In Cucurbita phloem, Nuclei and ribosomes disappear before breakdown of the tonoplast.
- Taxon
- Cucurbita maxima
Cucurbita maximat0 - Outcome
- Nuclei and ribosomese0
Not reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleTreatmentComparatorSettingDirectionValueQualifier
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nuclei and ribosomes disappear before breakdown of the tonoplast”
t0“young internodes of Cucurbita maxima”
Title
Another View of the Ultrastructure of Cucurbita Phloem
RAY F. EVERT; LIDIJA MURMANIS; IRVING B. SACHS Annals of Botany 1966. doi:10.1093/oxfordjournals.aob.a084097
Other claims from this paper (18)
- Observation In Cucurbita phloem, Phloem parenchyma cells are highly vacuolated and contain nuclei, endoplasmic reticulum, ribosomes, mitochondria, chloro-plasts, and occasional dictyosomes.
- Observation In Cucurbita phloem, the most distinctive features of companion cells are their extremely dense cytoplasm, low degree of vacuolation, lack of chloroplasts, and numerous sieve-element connexions.
- Observation In Cucurbita phloem, Companion cells contain plastids with few internal membranes.
- Observation In Cucurbita phloem, At maturity the enucleate sieve element is lined by a plasmalemma, one or more cistema-like layers of endoplasmic reticulum, and a membrane which apparently delimits the parietal layer of cytoplasm from a large central cavity.
- Observation In Cucurbita phloem, the central cavity is traversed by numerous strands, which run from cell to cell through the pores of sieve plates and lateral sieve areas, and which are derived ontogenetically from the slime bodies of immature cells.
- Observation In Cucurbita phloem, Numerous normal-appearing mitochondria are present in the parietal layer of cytoplasm.
- Observation In Cucurbita phloem, The pores of sieve plates and lateral sieve areas are lined with cytoplasm.
- Observation In Cucurbita phloem, The ultrastructural details of young sieve elements differ little from those of other young nucleate cells.
- Observation In Cucurbita phloem, During sieve-element development, the sieve element increases in vacuolation.
- Observation In Cucurbita phloem, slime bodies develop in the cytoplasm.
- Observation In Cucurbita phloem, these bodies often exhibit a double-layered limiting membrane.
- Observation In Cucurbita phloem, the slime bodies increase in size and the parietal layer of cytoplasm becomes very narrow.
- Observation In Cucurbita phloem, the slime bodies begin to disperse and their contents fuse.
- Observation In Cucurbita phloem, The initiation of slime-body dispersal more or less coincides with perforation of the pore sites.
- Observation In Cucurbita phloem, many pores are traversed by slime early in their development.
- Observation In Cucurbita phloem, Before slime-body dispersal, all dictyosomes and associated vesicles disappear from the cytoplasm.
- Observation In Cucurbita phloem, the tonoplast diappears and the slime becomes distributed throughout the central cavity in the form of strands.
- Observation In Cucurbita phloem, Sieve elements are connected with companion cells and parenchyma cells by plasmodesmata.