The effect of lanthanum （Ⅲ） on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation（UV-B：280~320 nm）at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydropon...The effect of lanthanum （Ⅲ） on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation（UV-B：280~320 nm）at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydroponics in the laboratory.Plasmolemma permeability and contents of malonadialdehyde（MDA）,hydrogen peroxide（H2O2）,and proline gradually increased during the imposition of UV-B radiation and subsequently decreased during recovery from UV-B stress.The dynamic tendency of catalase（CAT）activity was similar to that of the above four indices.The activity of peroxidase（POD）initially increased,then remained at a high level,and finally dropped steeply when soybean seedlings were exposed to a low dosage of UV-B radiation.However,POD activity rose throughout and declined slightly on the eleventh day when soybean seedlings were stressed by a high dosage.With the addition of La （Ⅲ） of 20 mg·L-1,the rising tendency of plasmolemma permeability and contents of MDA,H2O2,and proline were slowed down during the stress period,whereas the declining speed was accelerated during the recovery period.The activities of CAT and POD were higher than those without La （Ⅲ） in all experiments.It suggested that the regulative effect of La （Ⅲ） on antioxidant enzymes such as CAT and POD could strengthen their capacities to scavenge reactive oxygen species（ROS）,decrease contents of MDA and proline,and maintain normal plasmolemma permeability.Further more,the protective potential of La （Ⅲ） was better under low UV-B radiation than under a high one.展开更多
Under artificially-simulated complex salt-alkali stress, the levels of active oxygen metabolism in roots were studied using three-year-old cutting seedlings of Spiraea × bumalda ‘Gold Mound＇ and Spiraea × ...Under artificially-simulated complex salt-alkali stress, the levels of active oxygen metabolism in roots were studied using three-year-old cutting seedlings of Spiraea × bumalda ‘Gold Mound＇ and Spiraea × bumalda ‘Gold Flame＇. The present study aimed at exploring the antioxidant capacity in roots of spiraeas and revealing their adaptability to salt-alkali stress. Results indicate that the oxygen free radicals contents, electrolyte leakage rates and MDA contents in roots of Spiraea × bumalda ＇Gold Mound＇ and Spiraea × bumalda ＇Gold Flame＇ show an increasing tendency with the increases of the salinity and pH value, whereas the activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） all increased firstly and then decreased. With the increase in intensity of salt-alkali stress, the CAT activity in roots of Spiraea × bumalda ‘Gold Flame＇ is higher and the increasing extents in the oxygen free radicals contents, electrolyte leakage rates as well as MDA contents are lower compared with Spiraea × bumalda ‘Gold Mound＇, indicating that Spiraea × bumalda ‘Gold Flame＇ has a stronger antioxidant capacity.展开更多
Peach fruits [Prumus persica （L.） Batsch, cv. Yuhuasanhao] were used as materials to investigate the changes of reactive oxygen species （ROS） and related enzymes in mitochondria respiration during storage and then...Peach fruits [Prumus persica （L.） Batsch, cv. Yuhuasanhao] were used as materials to investigate the changes of reactive oxygen species （ROS） and related enzymes in mitochondria respiration during storage and then their influence on senescence of harvested Peach fruits was studied. The results showed that low temperature （5℃） strongly inhibited the reduction of firmness and the increase in respiration rate. During storage at ambient temperature （20℃）, ROS had a cumulative process while malondialdehye （MDA） content continued to increase in associated with enhanced membrane lipid peroxidation. Lipoxygenase （LOX） activity was strongly inhibited under the low temperature condition. The activities of succinic dehydrogenase （SDH）, cytochrome C oxidase （CCO）, and Ca^2＋-ATPase declined to a certain extent at ambient temperature, while they showed higher activities at low temperature, which may be related to lower membrane lipid peroxidation at low temperature. Higher Ca^2＋ content at ambient temperature may be responsible for impairment of mitochondrial function, thus, leading to fruit senescence. The results showed that under low temperature condition, the low accumulation of ROS and the low level of membrane lipid peroxidation could maintain the function of mitochondria that would help to delay the senescence of peach fruits. These suggested a close relationship existed between ROS metabolism and mitochondrial respiration. It can be inferred that the low temperature helps to delay senescence of peach fruits via suppression of ROS and related enzymes, maintain better homeostasis of Ca^2＋ in mitochondria and thus better mitochondrial functions.展开更多
The objective of the present study was to gain better insight into the physiological mechanisms on the effects of copper （Cu） on photosynthesis and active oxygen metabolism in three-colored amaranth plant （Amaranth...The objective of the present study was to gain better insight into the physiological mechanisms on the effects of copper （Cu） on photosynthesis and active oxygen metabolism in three-colored amaranth plant （Amaranthus tricolor）. Three- colored amaranth seedlings were subjected to different Cu levels in soils during the entire experimental period. The parameters of growth, photosynthesis, mineral elements contents, and active oxygen metabolism were investigated using plant physiological methods. The results showed that 2.0 and 4.0 mmol Cu kg^-1 treatments decreased the whole plant biomass to 91 and 73% of the control, respectively. The net photosynthetic rate （Pn） and the stomatal conductance （gs） were similarly reduced in the third leaves of three-colored amaranth seedlings treated with 2.0 and 4.0 mmol Cu kg^-1 soil, respectively. None of the investigated Cu levels decreased the internal CO2 concentration （Ci）. The effect of Cu on the potential efficiency of photosystem Ⅱ （Fv/Fm） was negligible, whereas the effect of Cu on the PS Ⅱ quantum efficiency （ΦPS Ⅱ） after plant adaptation in actinic irradiation was more noticeable. On the other hand, decreases in water percentage, contents of photosynthetic pigments and mineral elements including Fe, K, and Mg, and significant increase in the Cu content were observed in the third leaves of Cu-treated plants. Superoxide dismutase （SOD） and peroxidase （POD） activities as well as the proline （Pro） content significantly increased in the third leaves of the three-colored amaranth seedlings treated with 2.0 and 4.0 mmol Cu kg^-1 soil, while catalase （CAT） and ascorbate peroxidase （APX） activities as well as the contents of carotenoid （Car）, glutathione （GSH）, and ascorbic acid （AsA） decreased, and accompanied by the increases in the contents of hydrogen peroxide （H2O2）, superoxide anion （O2^-）, and malondialdehyde （MDA）, and electrolyte leakage. As a result of the imbalance of active oxygen metabolism, Pn and ΦPS Ⅱ decreased, and peroxidization enhanced under levels of 2.0 and 4.0 mmol Cu kg^-1 soil. Finally, the growth of three-colored amaranth plant was significantly inhibited.展开更多
基金Project supported by the National Natural Science Foundation of China(30570323)the Foundation of State Developingand Reforming Committee(IFZ20051210)
文摘The effect of lanthanum （Ⅲ） on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation（UV-B：280~320 nm）at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydroponics in the laboratory.Plasmolemma permeability and contents of malonadialdehyde（MDA）,hydrogen peroxide（H2O2）,and proline gradually increased during the imposition of UV-B radiation and subsequently decreased during recovery from UV-B stress.The dynamic tendency of catalase（CAT）activity was similar to that of the above four indices.The activity of peroxidase（POD）initially increased,then remained at a high level,and finally dropped steeply when soybean seedlings were exposed to a low dosage of UV-B radiation.However,POD activity rose throughout and declined slightly on the eleventh day when soybean seedlings were stressed by a high dosage.With the addition of La （Ⅲ） of 20 mg·L-1,the rising tendency of plasmolemma permeability and contents of MDA,H2O2,and proline were slowed down during the stress period,whereas the declining speed was accelerated during the recovery period.The activities of CAT and POD were higher than those without La （Ⅲ） in all experiments.It suggested that the regulative effect of La （Ⅲ） on antioxidant enzymes such as CAT and POD could strengthen their capacities to scavenge reactive oxygen species（ROS）,decrease contents of MDA and proline,and maintain normal plasmolemma permeability.Further more,the protective potential of La （Ⅲ） was better under low UV-B radiation than under a high one.
基金supported by Innovation Team Project of Northeast Agricultural University of P. R. China (CXZ004-3)Science Foundation of Heilongjiang Province (C2007-16)
文摘Under artificially-simulated complex salt-alkali stress, the levels of active oxygen metabolism in roots were studied using three-year-old cutting seedlings of Spiraea × bumalda ‘Gold Mound＇ and Spiraea × bumalda ‘Gold Flame＇. The present study aimed at exploring the antioxidant capacity in roots of spiraeas and revealing their adaptability to salt-alkali stress. Results indicate that the oxygen free radicals contents, electrolyte leakage rates and MDA contents in roots of Spiraea × bumalda ＇Gold Mound＇ and Spiraea × bumalda ＇Gold Flame＇ show an increasing tendency with the increases of the salinity and pH value, whereas the activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） all increased firstly and then decreased. With the increase in intensity of salt-alkali stress, the CAT activity in roots of Spiraea × bumalda ‘Gold Flame＇ is higher and the increasing extents in the oxygen free radicals contents, electrolyte leakage rates as well as MDA contents are lower compared with Spiraea × bumalda ‘Gold Mound＇, indicating that Spiraea × bumalda ‘Gold Flame＇ has a stronger antioxidant capacity.
基金funded by the National Natural Science Fundation of China (30840016)the Natural Science Fundation of Jiangsu Province, China (BK 2010310)the Natural Science Fundation for Colleges and Universities in Jiangsu Province, China (10KJB550004)
文摘Peach fruits [Prumus persica （L.） Batsch, cv. Yuhuasanhao] were used as materials to investigate the changes of reactive oxygen species （ROS） and related enzymes in mitochondria respiration during storage and then their influence on senescence of harvested Peach fruits was studied. The results showed that low temperature （5℃） strongly inhibited the reduction of firmness and the increase in respiration rate. During storage at ambient temperature （20℃）, ROS had a cumulative process while malondialdehye （MDA） content continued to increase in associated with enhanced membrane lipid peroxidation. Lipoxygenase （LOX） activity was strongly inhibited under the low temperature condition. The activities of succinic dehydrogenase （SDH）, cytochrome C oxidase （CCO）, and Ca^2＋-ATPase declined to a certain extent at ambient temperature, while they showed higher activities at low temperature, which may be related to lower membrane lipid peroxidation at low temperature. Higher Ca^2＋ content at ambient temperature may be responsible for impairment of mitochondrial function, thus, leading to fruit senescence. The results showed that under low temperature condition, the low accumulation of ROS and the low level of membrane lipid peroxidation could maintain the function of mitochondria that would help to delay the senescence of peach fruits. These suggested a close relationship existed between ROS metabolism and mitochondrial respiration. It can be inferred that the low temperature helps to delay senescence of peach fruits via suppression of ROS and related enzymes, maintain better homeostasis of Ca^2＋ in mitochondria and thus better mitochondrial functions.
基金the Natural Science Foundation of Zhejiang Province, China （Y504256）.
文摘The objective of the present study was to gain better insight into the physiological mechanisms on the effects of copper （Cu） on photosynthesis and active oxygen metabolism in three-colored amaranth plant （Amaranthus tricolor）. Three- colored amaranth seedlings were subjected to different Cu levels in soils during the entire experimental period. The parameters of growth, photosynthesis, mineral elements contents, and active oxygen metabolism were investigated using plant physiological methods. The results showed that 2.0 and 4.0 mmol Cu kg^-1 treatments decreased the whole plant biomass to 91 and 73% of the control, respectively. The net photosynthetic rate （Pn） and the stomatal conductance （gs） were similarly reduced in the third leaves of three-colored amaranth seedlings treated with 2.0 and 4.0 mmol Cu kg^-1 soil, respectively. None of the investigated Cu levels decreased the internal CO2 concentration （Ci）. The effect of Cu on the potential efficiency of photosystem Ⅱ （Fv/Fm） was negligible, whereas the effect of Cu on the PS Ⅱ quantum efficiency （ΦPS Ⅱ） after plant adaptation in actinic irradiation was more noticeable. On the other hand, decreases in water percentage, contents of photosynthetic pigments and mineral elements including Fe, K, and Mg, and significant increase in the Cu content were observed in the third leaves of Cu-treated plants. Superoxide dismutase （SOD） and peroxidase （POD） activities as well as the proline （Pro） content significantly increased in the third leaves of the three-colored amaranth seedlings treated with 2.0 and 4.0 mmol Cu kg^-1 soil, while catalase （CAT） and ascorbate peroxidase （APX） activities as well as the contents of carotenoid （Car）, glutathione （GSH）, and ascorbic acid （AsA） decreased, and accompanied by the increases in the contents of hydrogen peroxide （H2O2）, superoxide anion （O2^-）, and malondialdehyde （MDA）, and electrolyte leakage. As a result of the imbalance of active oxygen metabolism, Pn and ΦPS Ⅱ decreased, and peroxidization enhanced under levels of 2.0 and 4.0 mmol Cu kg^-1 soil. Finally, the growth of three-colored amaranth plant was significantly inhibited.
