Photosynthesis resilience to water stress in transgenic sweet potato expressing both Cu/Zn superoxide dismutase and ascorbate peroxidase
Two strains,Cu/Zn SOD and APX gene transferred sweet potato (TS) and nontransgenic sweet potato (Ipomoea batatas L. Yuimi) (NT), were used as experimental materials to study the effects of water stress induced by PEG 6 000 and rewatering on the antioxiditive system and photosynthetic characteristics. Results showed that the activity of SOD of TS was 20％ higher than that of NT after 24 h water stressed,and the activities of SOD of TS and NT both decreased after plant rewatering from water stress. Under water stress,the activity of ascorbate Peroxidase (APX) in TS increased initially and then decreased,whereas in NT the activity of APX Decreased initially and then increased. After 12 h rewatering, the activity of APX of TS was 50％ higher than that of NT. Under water stress induced by PEG for 0 h, 12 h and 24 h,the ascorbic acid (AsA) content in TS was significantly higher than that in NT (p< 0. 05). At the beginning of the water stress,net photosynthetic rate (Pn) decreased in both TS and NT. When stress became longer,Pn in TS increased,but did not change in NT. After 36 h stress, Pn in TS is 50％ higher than that in NT After 12 h rewatering,Pn in TS was 100％ higher than that in NT. After 36 h water stress,intercellular CO-2 concentration (Ci) in NT was 40％ higher than that in TS. These results suggested that SOD was the key enzyme under water stress and APX was much more active under rewatering. It is clear that the antioxidative system of this transgenic sweet potato had a strong ability to protect and recover the photosynthetic system from draught.
ascorbate peroxidase ascorbic acid antioxidative defense system carotenoid Cu/Zn superoxide dismutase photosynthesis transgenic sweetpotato
DENG Xi-ping LI Jian-Mei XU Bing-cheng KWAK Sang-soo
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A & F Unive State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A & F Unive Korea Research Institute of Bioscience and biotechnology,Daejeon 305-806,Korea
国际会议
徐州
英文
332-339
2010-11-27（万方平台首次上网日期，不代表论文的发表时间）