Leymus chinensis seedlings were treated with 0.05--10 mmol/L vitamin E under osmotic stress in the presence of polyethylene glycol（PEG） as the stress reagent. The effects of the different concentrations of exogenous...Leymus chinensis seedlings were treated with 0.05--10 mmol/L vitamin E under osmotic stress in the presence of polyethylene glycol（PEG） as the stress reagent. The effects of the different concentrations of exogenous vitamin E on the activities of SOD, POD and free proline, and the MDA contents under drought stress were examined so as to ascertain the mechanism of Leymus chinensis resistance to drought stress and explore the possible preventive measures. The results indicate that the activities of SOD and POD decreased but the free proline and MDA contents increased as drought stress was accentuated, showing an enhancement of oxidative stress that may cause a decline in membrane stabilization. However, the activities of SOD and POD and the free proline content increased, whereas the MDA content reduced in Leymus chinensis pretreated with vitamin E in comparison with that of the control. This indicates that exogenous vitamin E enhanced the antioxidation of Leymus chinensis seedlings. It suggests that cytomembrane can be protected from damage by increasing the free proline content and the activities of SOD and POD that result in enhancing the drought resistance of Leymus chinensis seedlings.展开更多
Membrane lipid peroxidation and protective enzyme activity in leaves of low-phosphorus-tolerant rice cultivars Dalidao and Liantangzao 3, and low-phosphorus-sensitive cultivars Huzhanqi and Xinsanbaili were studied un...Membrane lipid peroxidation and protective enzyme activity in leaves of low-phosphorus-tolerant rice cultivars Dalidao and Liantangzao 3, and low-phosphorus-sensitive cultivars Huzhanqi and Xinsanbaili were studied under low phosphorus stress with sandy culture. Results indicated that low-phosphorus stress aggravated the membrane lipid peroxidation in rice leaves, and it was more severe in low-phosphorus-sensitive cultivars than that in low-phosphorus-tolerant eultivars. During the period of low-phosphorus stress, the activities of SOD, CAT and POD maintained relatively stable in low-phosphorustolerant cultivars, whereas those increased obviously at early stage and subsequently decreased rapidly in the low-phosphorus-sensitive cultivars, suggesting that the absolute activities of protective enzymes had no relation with the low-phosphorus stress, while the changing trend was reverse.展开更多
Four varieties of winter wheat with different return green rates were used to analyze the plasma membrane stability and the factors that affect winter wheat in the frigid region during winter. The removal of reactive ...Four varieties of winter wheat with different return green rates were used to analyze the plasma membrane stability and the factors that affect winter wheat in the frigid region during winter. The removal of reactive oxygen species, the degree of plasma membrane impairment, water composition and content, and the changes in cell viability in the crowns, which contain the growing point, were studied during the period from cold acclimation to the deep freezing. The results showed that electrical conductivity which reflects the degree of plasma membrane damaged under low temperature was significantly correlated with the free water and the total water content. The malondialdehyde （MDA） content, which reflects the degree of membrane peroxidation, was very significantly correlated with superoxide dismutase （SOD）, peroxidase, and ascorbic acid. During the deep freezing period, the SOD activity and glutathione （GSH） content of the winter wheat varieties were relative to their cold resistance. During this period, the MDA stability, SOD, GSH, and the total water and the free water content might be used to identify the cold resistance of winter wheat varieties.展开更多
文摘Leymus chinensis seedlings were treated with 0.05--10 mmol/L vitamin E under osmotic stress in the presence of polyethylene glycol（PEG） as the stress reagent. The effects of the different concentrations of exogenous vitamin E on the activities of SOD, POD and free proline, and the MDA contents under drought stress were examined so as to ascertain the mechanism of Leymus chinensis resistance to drought stress and explore the possible preventive measures. The results indicate that the activities of SOD and POD decreased but the free proline and MDA contents increased as drought stress was accentuated, showing an enhancement of oxidative stress that may cause a decline in membrane stabilization. However, the activities of SOD and POD and the free proline content increased, whereas the MDA content reduced in Leymus chinensis pretreated with vitamin E in comparison with that of the control. This indicates that exogenous vitamin E enhanced the antioxidation of Leymus chinensis seedlings. It suggests that cytomembrane can be protected from damage by increasing the free proline content and the activities of SOD and POD that result in enhancing the drought resistance of Leymus chinensis seedlings.
文摘Membrane lipid peroxidation and protective enzyme activity in leaves of low-phosphorus-tolerant rice cultivars Dalidao and Liantangzao 3, and low-phosphorus-sensitive cultivars Huzhanqi and Xinsanbaili were studied under low phosphorus stress with sandy culture. Results indicated that low-phosphorus stress aggravated the membrane lipid peroxidation in rice leaves, and it was more severe in low-phosphorus-sensitive cultivars than that in low-phosphorus-tolerant eultivars. During the period of low-phosphorus stress, the activities of SOD, CAT and POD maintained relatively stable in low-phosphorustolerant cultivars, whereas those increased obviously at early stage and subsequently decreased rapidly in the low-phosphorus-sensitive cultivars, suggesting that the absolute activities of protective enzymes had no relation with the low-phosphorus stress, while the changing trend was reverse.
基金Supported by the Postdoctoral Science Foundation of Heilongjiang Province(2010RCB17)Doctoral Research Startup Foundation of Northeast Agricultural University(LBH-Z10266)+2 种基金New Rural Project of Heilongjiang Provincial Department of EducationProject of Education Department in Heilongjiang Province(12521035)Postgraduate Innovation Project of Education Department in Heilongjiang Province (YJSCX2012-036HLJ)
文摘Four varieties of winter wheat with different return green rates were used to analyze the plasma membrane stability and the factors that affect winter wheat in the frigid region during winter. The removal of reactive oxygen species, the degree of plasma membrane impairment, water composition and content, and the changes in cell viability in the crowns, which contain the growing point, were studied during the period from cold acclimation to the deep freezing. The results showed that electrical conductivity which reflects the degree of plasma membrane damaged under low temperature was significantly correlated with the free water and the total water content. The malondialdehyde （MDA） content, which reflects the degree of membrane peroxidation, was very significantly correlated with superoxide dismutase （SOD）, peroxidase, and ascorbic acid. During the deep freezing period, the SOD activity and glutathione （GSH） content of the winter wheat varieties were relative to their cold resistance. During this period, the MDA stability, SOD, GSH, and the total water and the free water content might be used to identify the cold resistance of winter wheat varieties.
