Both structural and immunogold EM studies have also been carried to identify the storage PVCs in developing tobacco seeds and mungbean cotyledons. Biochemically, storage PVCs in both developing tobacco seeds and mungbean cotyledons were labeled by VSRAt-1, S2 (globulin-like proteins), BiP and DIP antibodies. Structurally, storage PVCs in developing tobacco seeds, sized about 200 nm diameter, contain wavy limiting membrane with electron-dense core and periphery translucent outer layer with internal vesicles. In contrast, storage PVCs in mungbean cotyledon, sized about 400 nm diameter, contain electron-dense and translucent area located adjacent to each other. / Further drug treatments studies demonstrated that the lytic PVCs/MVBs in tobacco BY-2 cells were distinct from the storage PVCs in seed cells. BFA and wortmannin treatments respectively caused the lytic PVCs in tobacco BY-2 cells to become aggregate and vacuolated, whereas the storage PVCs in seed cells remained unchanged in response to treatments of these drugs. Therefore, the storage PVCs in developing seeds are biochemically distinct from the lytic PVCs in tobacco BY-2 cells. / Plant cells contain both lytic vacuole and protein storage vacuole. Prevacuolar compartments (PVCs) are membrane-bounded organelles mediating protein trafficking between the Golgi apparatus and vacuoles in the plant secretory pathways. Multivesicular bodies (MVBs) have recently identified as the lytic PVCs in tobacco BY-2 cells. However, little is known about the dynamics of the lytic PVCs. In addition, the existence and identity of PVCs for protein storage vacuole (termed storage PVCs in this study) remain unknown. / This thesis research addressed two important biological questions: the dynamics of the lytic PVCs and the identity of the storage PVCs in plant cells. Towards this goal, I have demonstrated that the Golgi apparatus and the lytic PVCs, marked by YFP fusion reporters in transgenic tobacco BY-2 cells, have different sensitivity to brefeldin A (BFA) treatments. BFA at high concentrations (50 to 100 microg/mL) caused both YFP-marked Golgi stacks and lytic PVCs to form aggregates in a dosage-dependent and time-dependent manner. Confocal immunofluorescence and immunogold EM studies with specific organelle antibody markers further demonstrated that BFA-induced aggregates derived from the lytic PVCs were distinct from but physically associated with the Golgi aggregates. Thus, the BFA effects on the secretory organelles have been extended to the lytic PVCs. / Tse, Yu Chung. / "September 2007." / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4521. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 156-164). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_344148 |
| Date | January 2007 |
| Contributors | Tse, Yu Chung., Chinese University of Hong Kong Graduate School. Division of Biology. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, theses |
| Format | electronic resource, microform, microfiche, 1 online resource (xix, 164 p. : ill.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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