Physiological indices related to the efficiency (F-v/F-m) of light energy conversion in PS II and the peroxidation of membrane lipid were measured in leaves of Oryza sativa L. sp. indica rice cv. 'Shanyou 63' ...Physiological indices related to the efficiency (F-v/F-m) of light energy conversion in PS II and the peroxidation of membrane lipid were measured in leaves of Oryza sativa L. sp. indica rice cv. 'Shanyou 63' and sp. japonica rice cv. '9516'' under different temperatures and fight intensities for 4 days. No changes in F-v/F-m and membrane lipid peroxidation product (MDA) were observed, so neither photoinhibition nor photooxidation happened in both rice cultivars under moderate temperature and medium light intensity. However, F-v/F-m dropped obviously with no change in MDA contents, and photoinhibition appeared in indica rice cv. 'Shanyou 63' under medium temperature and strong light intensity. Furthermore, both photoinhibition and photooxidation were observed in two rice cultivars under chilling temperature and strong light intensity. Experiments with inhibitors under chilling temperature and strong light intensity showed that indica rice had a decrease in DI protein content and SOD activity, and the extent of inhibition of xanthophyll. cycle and nonphotochemical quenching (qN) was larger, and a higher level of MDA was observed. The photoinhibition and photooxidation in indica rice were more distinct as compared with japonica rice. The authors suggested that PS II light energy conversion efficiency (F-v/F-m) and membrane lipid peroxidation were the key indices for the detection of photooxidation.展开更多
A 9-week feeding trial in floating freshwater cages(1.0 m×1.0 m×2.0 m) was conducted to study the effects of different dietary levels of protein and starch on growth,body composition,and gene expression of e...A 9-week feeding trial in floating freshwater cages(1.0 m×1.0 m×2.0 m) was conducted to study the effects of different dietary levels of protein and starch on growth,body composition,and gene expression of enzymes in common carp,Cyprinus carpio(mean body weight,36.12±1.18 g) to evaluate the protein-sparing effect of dietary carbohydrate.Four diets were formulated with corn starch as the carbohydrate source to obtain corn starch levels of 6.5%,13%,19.5%,or 26%and protein levels of 30.5%,28.2%,26.4%,and 24.2%.The results showed no differences in growth performance of fish fed the diets with different protein and corn starch levels,but body composition and glucose metabolic enzyme activity of carp were significantly affected by the different diets(P<0.05).Weight gain,specific growth rate,and the feed conversion ratio were not different in fish fed the different dietary treatments.Protein efficiency ratio increased significantly as corn starch level increased(P<0.05).Whole-body crude lipid composition increased with increasing dietary corn starch level(P<0.05).Glucokinase(GK),hexokinase,and pyruvate kinase(PK) activities increased significantly with increasing dietary corn starch level(P<0.05),whereas glucose-6-phosphate(G6Pase) activity decreased with increasing dietary corn starch level(P<0.05).GK gene expression was significantly higher in fish fed the high-corn starch diet than those fed the low-corn starch diet(P<0.05).G6 pase gene expression tended to decrease with increasing starch level(P>0.05).In summary,the results indicate a protein-sparing effect by substituting carbohydrate in the diet of common carp.展开更多
文摘Physiological indices related to the efficiency (F-v/F-m) of light energy conversion in PS II and the peroxidation of membrane lipid were measured in leaves of Oryza sativa L. sp. indica rice cv. 'Shanyou 63' and sp. japonica rice cv. '9516'' under different temperatures and fight intensities for 4 days. No changes in F-v/F-m and membrane lipid peroxidation product (MDA) were observed, so neither photoinhibition nor photooxidation happened in both rice cultivars under moderate temperature and medium light intensity. However, F-v/F-m dropped obviously with no change in MDA contents, and photoinhibition appeared in indica rice cv. 'Shanyou 63' under medium temperature and strong light intensity. Furthermore, both photoinhibition and photooxidation were observed in two rice cultivars under chilling temperature and strong light intensity. Experiments with inhibitors under chilling temperature and strong light intensity showed that indica rice had a decrease in DI protein content and SOD activity, and the extent of inhibition of xanthophyll. cycle and nonphotochemical quenching (qN) was larger, and a higher level of MDA was observed. The photoinhibition and photooxidation in indica rice were more distinct as compared with japonica rice. The authors suggested that PS II light energy conversion efficiency (F-v/F-m) and membrane lipid peroxidation were the key indices for the detection of photooxidation.
基金Supported by the Key Technology R&D Program of Tianjin(No.13ZCZDNC00900)the Tianjin Research Program of Application Foundation and Advanced Technology(No.14JCQNJC15100)+2 种基金the Tianjin Innovative Research Team(No.TD12-5018)the Tianjin Key Laboratory of Animal and Plant Resistancethe National Natural Science Foundation of China(No.31402313)
文摘A 9-week feeding trial in floating freshwater cages(1.0 m×1.0 m×2.0 m) was conducted to study the effects of different dietary levels of protein and starch on growth,body composition,and gene expression of enzymes in common carp,Cyprinus carpio(mean body weight,36.12±1.18 g) to evaluate the protein-sparing effect of dietary carbohydrate.Four diets were formulated with corn starch as the carbohydrate source to obtain corn starch levels of 6.5%,13%,19.5%,or 26%and protein levels of 30.5%,28.2%,26.4%,and 24.2%.The results showed no differences in growth performance of fish fed the diets with different protein and corn starch levels,but body composition and glucose metabolic enzyme activity of carp were significantly affected by the different diets(P<0.05).Weight gain,specific growth rate,and the feed conversion ratio were not different in fish fed the different dietary treatments.Protein efficiency ratio increased significantly as corn starch level increased(P<0.05).Whole-body crude lipid composition increased with increasing dietary corn starch level(P<0.05).Glucokinase(GK),hexokinase,and pyruvate kinase(PK) activities increased significantly with increasing dietary corn starch level(P<0.05),whereas glucose-6-phosphate(G6Pase) activity decreased with increasing dietary corn starch level(P<0.05).GK gene expression was significantly higher in fish fed the high-corn starch diet than those fed the low-corn starch diet(P<0.05).G6 pase gene expression tended to decrease with increasing starch level(P>0.05).In summary,the results indicate a protein-sparing effect by substituting carbohydrate in the diet of common carp.
