By immumolabeling and electronmicroscopy, the subcellular localization of GmPAP3 has been proved to be mainly localized in mitochondria, a primary site for ROS production. Ectopic expression of GmPAP3 in transgenic tobacco BY-2 cells mimicked the protective effects exhibited by the antioxidant ascorbic acid by: (1) increase the percentage of cells with active mitochondria; (2) reduce the percentage of dead cells; and (3) lower the accumulation of ROS under NaCl and osmotic stress treatments. However, when ectopically express a truncated GmPAP3 with the mitochondria transit peptide removed, such protective effect was not observed. This provides evidences on the significance of mitochondria localization to the physiological function of GmPAP3. In addition, when GmPAP3 transgenic Arabidopsis thaliana seedlings were subjected to NaCl, osmotic stress, and oxidative stress treatments, the growth performance of the transgenic lines was significantly better than the wild type. To summarize, these studies has demonstrate that the mitochondrial localized GmPAP3 may play a role in stress tolerance by enhancing ROS scavenging. / Mitochondrion is one of the major sites for the production of reactive oxygen species (ROS). Abiotic stresses such as salinity and osmotic stress can cause oxidative damage to organelle membranes due to excess accumulation of ROS. The inducibility of GmPAP3 gene expression by salinity and oxidative stresses and the putative mitochondrial localization of GmPAP3 prompt us to further investigate the possible physiological roles of GmPAP3 under abiotic stress-induced oxidative stress. / My Ph.D. study has been focused on the detailed functional analysis of the GmPAP3 gene. The objectives of my research include: (i) to verified the subcellular localization of GmPAP3; (ii) to investigate the physiological functions of GmPAP3 under NaC1 and osmotic stress in both cellular level and in planta level. and (iii) to examine the significance of mitochondria] localization of GmPAP3 in relationship to its protective roles. / Purple acid phosphatases (PAPs) represent a diverse group of acid phosphatases in animals and plants. While the mammalian PAPs were found to be related to Reactive Oxygen Species (ROS) evolution in important physiological functions, the roles of plant PAPs remain largely unknown. / Recently, we have isolated a novel PAP-like gene (GmPAP3) from soybean that is induced by NaC1 and oxidative stresses. Subcellular localization prediction programs suggested that GmPAP3 may be a novel PAP that localized in mitochondria. Most other PAPs are extracellularly located and membrane localization of PAPs was only verified in a few cases. / by Li, Wing Yen Francisca. / "December 2009." / Adviser: Lam Hon-Ming. / Source: Dissertation Abstracts International, Volume: 72-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 123-134). / 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 Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_344474 |
| Date | January 2010 |
| Contributors | Li, Wing Yen Francisca., Chinese University of Hong Kong Graduate School. Division of Life Sciences. |
| 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 (xv, 144 leaves : 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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