at Google ScholarTitle data
Orlich, Gabriele ; Komor, Ewald:
Phloem loading in ricinus cotyledons : sucrose pathways via the mesophyll and the apoplasm.
In: Planta.
Vol. 187
(1992)
Issue 4
.
- pp. 460-474.
ISSN 0032-0935
DOI: https://doi.org/10.1007/BF00199964
Abstract in another language
"Ricinus communis cv. Carmencita seedlings with their cotyledons incubated in sucrose solution and their hypocotyls cut to induce exudation of phloem sap, constitute a system of sucrose fluxes into and out of the cotyledons. This system was characterized with respect to quasi-steady-state conditions of sucrose uptake and export and then used to investigate the pathways of sucrose during phloem loading. The redistribution of C-14-labelled internal sucrose between the three ""compartments"", cotyledons (mesophyll), exudate (sieve tubes) and incubation medium (cell-wall space), was measured in the presence or absence of external non-labelled sucrose. It was found that mesophyll-derived labelled and external sucrose compete at uptake sites in the apoplasm. On the basis of the specific radioactivity of sucrose which reflects the proportionate intermixture of mesophyll-derived and external sucrose in the three ""compartments"", it was determined that about 50% of the sucrose exported is loaded directly from the apoplasm, while the other half takes the route via the mesophyll. It was confirmed that mesophyll-derived sucrose is released into the apoplasm, so that the existence of an indirect apoplasmic loading pathway is established. Calculations depending on the concentration gradients of labelled and non-labelled sucrose in the cell-wall space are presented to quantify tentatively the proportions of direct and indirect apoplasmic as well as symplasmic loading."
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Additional notes: | BAYCEER22543 |
| Institutions of the University: | Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Biology > Chair Plant Physiology Research Institutions > Research Centres > Bayreuth Center of Ecology and Environmental Research- BayCEER Faculties Faculties > Faculty of Biology, Chemistry and Earth Sciences Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Biology Research Institutions Research Institutions > Research Centres |
| Result of work at the UBT: | Yes |
| DDC Subjects: | 500 Science |
| Date Deposited: | 05 Feb 2016 07:23 |
| Last Modified: | 05 Feb 2016 07:23 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/30445 |