English  |  正體中文  |  简体中文  |  Items with full text/Total items : 43312/67235
Visitors : 2108532      Online Users : 19
RC Version 5.0 © Powered By DSPACE, MIT. Enhanced by NTU/NCHU Library IR team.

Please use this identifier to cite or link to this item: http://nchuir.lib.nchu.edu.tw/handle/309270000/154612

標題: 離層酸促進水稻幼苗葉片老化之生理研究
Physiological studies on the abscisic acid-induced senescence of rice seedling leaves
作者: 黃思惇
Huang, Sih-Dun
Contributors: 許奕婷
農藝學系所
關鍵字: 離層酸;葉片老化;氧化逆境;氮素代謝;醣類訊號
abscisic acid;leaf senescence;oxidative stress;nitrogen metabolism;sugars signalling
日期: 2013
Issue Date: 2013-11-21 11:05:39 (UTC+8)
Publisher: 農藝學系所
摘要: 本論文主要探討離層酸 (abscisic acid,ABA) 促進水稻台中在來一號 (Oryza sativa L. cv. Taichung Native 1, TCN1) 三葉齡幼苗葉片老化之生理反應。老化葉片中malondialdehyde (MDA)、H2O2 (hydrogen peroxide) 和GSSG (oxidized glutathione) 增加,ASC (reduced ascorbate) 減少,但抗氧化酵素GR (glutathione reductase)、APX (ascorbate peroxidase) 比活性會有所提高,顯示葉片老化的原因可能為氧化逆境的產生。而在氮素代謝方面,ABA處理會促進蛋白酶 (protease) 活性與比活性,造成第二葉游離銨根 (NH4+) 增加。Glutamine synthase活性降低,但NADH-Glutamine dehydrogenase 和NADP-isocitrate dehydrogenase 活性抑制程度則較不明顯,顯示ABA主要是透過抑制GS活性進而促使葉片老化。此外,ABA 能誘導葉片澱粉提早降解而使游離醣類增加,並促使 HXK (hexokinase)活性和比活性增加,顯示葉片老化與醣類訊號相關。這些結果說明ABA會誘導氧化逆境產生並干擾氮素和醣類代謝促使葉片老化。
Abstract
Rice (Oryza sativa L., cv. Taichung Native 1, TCN1) seedlings were used to investigate the abscisic acid-induced leaf senescence. Increased MDA (malondialdehyde), H2O2 (hydrogen peroxide), GSSG (oxidized glutathione) contents and reduced ASC (ascorbate) contents were observed in senescenced leaves. Activities of antioxidant enzymes such as GR (glutathione reductase) and APX (ascorbate peroxidase) were induced in senescence leaves. These data suggest that the ABA induced leaves senescence may cause from oxidative stress. Furthemore, ABA also induced protease activity and increased ammonia ions concentration. In contrast, glutamine synthase (GS) activity was reduced in senescenced leaves. But the NADH‐GDH (NADH-glutamine dehydrogenase) and NADP‐ICDH (NADP-isocitrate dehydrogenase) activities were unaffected. It shows that ABA mainly repressed the GS activity rather than inhibited NADH‐GDH GDH and NADP‐ICDH activity.
Besides, ABA accelerated the starch degradations and increased the soluble sugars contents in senescence leaves, and induced HXK (hexokinase) activity. These results indicated that abscisic acid-induced senescence of leaves may due to oxidative stress and unbalances between nitrogen and sugars metabolism.
Appears in Collections:[依資料類型分類] 碩博士論文

Files in This Item:

File SizeFormat
index.html0KbHTML128View/Open


 


學術資源

著作權聲明

本網站為收錄中興大學學術著作及學術產出,已積極向著作權人取得全文授權,並盡力防止侵害著作權人之權益。如仍發現本網站之數位內容有侵害著作權人權益情事者,請權利人通知本網站維護人員,將盡速為您處理。

本網站之數位內容為國立中興大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用。

聯絡網站維護人員:wyhuang@nchu.edu.tw,04-22840290 # 412。

DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU/NCHU Library IR team Copyright ©   - Feedback