2004-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/694284摘要：超氧自由基，是所有生物在正常有氧代謝過程中自然產生的活性氧分子，會造成氧化逆境，產生連鎖反應，破壞細胞，是老化及疾病的元兇。粒腺體因它是細胞內進行氧化作用產生能量的主要場所，推測有3至5 ％的氧會轉變形成超氧自由，是產生超氧自由基最主要地點，可利用超氧歧化脢 (superoxide dismutase, SOD) 以消除超氧自由基，使它們轉換成無害的水及氧氣。生物具有嚴密的調控機制來控制生長發育過程中體內活性氧分子的含量，以及因應氧化逆境所產生的大量活性氧分子。竹類生長快速的現象顯示其能具有特殊及有效的抗氧化系統，才能解除快速生長過程所造成的氧化逆境。本計畫將研究綠竹筍的抗氧化機制，探討竹筍在對抗快速生長的氧化逆境及採收後老化過程中所SOD所扮演的角色，以期能由增加竹筍的抗氧化能力解決此老化現象。選定抗氧化酵素中的首要酵素超氧歧化脢（superoxide dismutase, SOD），分析竹筍中SOD各同功脢，catalase 及peroxidase的活性表現情形，並探討CCS（copper chaperone for SOD）如何調控SOD活性表現。並選殖SOD基因，利用阿拉伯芥來<br> Abstract: Superoxide, a self-generated molecule during the oxidative metabolic process of cells, resulting in oxidative stress, leads to damages in proteins, lipids and DNA or cell death. Mitochondrion is the major site where 3 to 5 % of oxygen was reported to convert into superoxide. Superoxide dismutase (SOD) catalyzes the conversion of superoxide into oxygen and hydrogen peroxide. Organisms have precise regulatory systems to monitor superoxide concentration for appropriate release of oxidative stress during growth and development. Bamboo shoots grow very rapidly, indicating that it might have a special and efficient antioxidant system to release the stress when the energy is generated from mitochondria during cell division and elongation. In this study, antioxidative systems of green bamboo shoots will be studied to understand the role of SOD in fast growing and highly oxidative environments of bamboo shoots in hope that increasing antioxidative capacity can inhibit bamboo shoot senescence. SOD, the primary antioxidant enzyme, will be investigated, and how CCS (copper chaperone for SOD) protein regulate SOD activities will be studied. Catalase and peroxidase activities of green bamboo shoots during growth and development will be also analyzed. All SOD genes will be cloned and transformed into the Arabidopsis to study and identify their unique antioxidant activity, and be overexpressed in E. coli or yeast system to characterize the physiological and biochemical activities. The total antioxidant activities of the low-molecular-weight antioxidants of green bamboo shoots will be evaluated, and the main antioxidants will be purified and identified. After knowing enzymatic and non-enzymatic antioxidative systems, we will try to repress senescence of green bamboo shoots by transforming SOD gene to bamboo or by spraying antioxidants to bamboo shoots to maintain freshness after harvest. Research reports have also indicated that overexpression of the SOD gene in plants can provide tolerance against antioxidative stress.綠竹筍抗氧化酵素超氧歧化總抗氧化力抗氧化物Green bambooSODAntioxidant enzymeTotal antioxidant activityAntioxidant