The tobacco RuBPcase was purified by the method of (NH 4) 2SO 4 precipitation and Sephadex G 200 column chromatography. The effects of Ln 3+ on inhibition of RuBPcase activity were studied. The results show t...The tobacco RuBPcase was purified by the method of (NH 4) 2SO 4 precipitation and Sephadex G 200 column chromatography. The effects of Ln 3+ on inhibition of RuBPcase activity were studied. The results show that the v max (maximum velocity) of RuBPcase does not change, but its k m (Michaelis constant) increases with a k i (inhibitor constant) when increasing the concentration of Ln 3+ in enzymatic reaction. It indicates that the inhibitory action of Ln 3+ on tobacco RuBPcase is a model of competitive inhibition with Mg 2+ . The k i of La 3+ , Ce 3+ and Gd 3+ is 26 3, 34 3 and 200 μmol·L -1 , respectively. Their inhibitory action on the RuBPcase is in the order of La 3+ >Ce 3+ Gd 3+ .展开更多
大豆（Glycine max L.cv.Bragg）种植在330或660ul/L CO2的室外、人工气候室。当植物50天龄时,通过逐渐减少每晚的灌溉施加干旱胁迫,结果植物在以后的白天萎蔫更早。第九天,由于盆里缺水,整个白天的CO2交换速率（CER）迅速减少,几乎为...大豆（Glycine max L.cv.Bragg）种植在330或660ul/L CO2的室外、人工气候室。当植物50天龄时,通过逐渐减少每晚的灌溉施加干旱胁迫,结果植物在以后的白天萎蔫更早。第九天,由于盆里缺水,整个白天的CO2交换速率（CER）迅速减少,几乎为零。高浓度的CO2和干旱胁迫减少(HCO3-/Mg2+-激活)总的可提的核酮糖-1,5一二磷酸（RuBP）羧化酶的活性,以叶绿素为单位表示。此外,当冠层CER值和叶片水势最低时,与相应的非胁迫处理比较,干旱胁迫使最初的（非激活的）RuBP羧化酶的活性减少了50%。展开更多
Ribulose-1, 5-bisphosphate carboxylase/oxygenase (EC 4, 1, 1, 39, abbreviation: RuBPcase)is a bifunction enzyme. Because of its properties in genetic function and structure, RuBPcase has been intensively studied. In t...Ribulose-1, 5-bisphosphate carboxylase/oxygenase (EC 4, 1, 1, 39, abbreviation: RuBPcase)is a bifunction enzyme. Because of its properties in genetic function and structure, RuBPcase has been intensively studied. In the absence of certain effective genetic markers for identifying hybrids, the analysis of the isoelectrofocusing pattern of RuBPcase has become a standard procedure to verify the nature of the hybrid plants.展开更多
The net CO2 assimilation rate, stomatal conductance, RuBPcase (ribulose 1,5-biphosphate carboxylose) activity, dry weight of aboveground and belowgroud part, plant height, the length and diameter of taproot ofPinus ko...The net CO2 assimilation rate, stomatal conductance, RuBPcase (ribulose 1,5-biphosphate carboxylose) activity, dry weight of aboveground and belowgroud part, plant height, the length and diameter of taproot ofPinus koraiensis seedlings were measured and analyzed after six-week exposure to elevated CO2 in an open-top chamber in Changbai Mountain of China from May to Oct. 1999. Seedlings were planted in four different conditions: on an open site, control chamber, 500 μL·L?1 and 700 μL·L?1 CO2 chambers. The results showed that the total biomass of the seedlings increased whereas stomatal conductance decreased. The physiological responses and growth to 500 μL·L?1 and 700 μL·L?1 CO2 varied greatly. The acclimation of photosynthesis was downward to 700 μL·L?1 CO2 but upward to 500 μL·L?1 CO2. The RuBPcase activity, chlorophyll and soluble sugar contents of the seedlings grown at 500 μL·L?1 CO2 were higher than that at 700 μL·L?1 CO2. The concentration 500 μL·L?1 CO2 enhanced the growth of aboveground part whereas 700 μL·L?1 CO2 allocated more carbon to belowground part. Elevated CO2 changed the carbon distribution pattern. The ecophysiological responses were significantly different between plants grown under 500 μL·L?1 CO2 and 700 μL·L?1 CO2.展开更多
It was proved that the nitrogen utilization efficiency(NUE) of rice (O. sativa L. )-is of difference among cultivars. In our study, the local rice cultivars Nantong Ludao, Huakegu, and Kugu were used as high NUE type,...It was proved that the nitrogen utilization efficiency(NUE) of rice (O. sativa L. )-is of difference among cultivars. In our study, the local rice cultivars Nantong Ludao, Huakegu, and Kugu were used as high NUE type, and modern cultivars Wuxiangqi 25, Zijingeng, and Wuxiangxian as low NUE one,展开更多
The green-tide-forming macroalga Ulva linza was profiled by transcriptome sequencing to ascertain whether the alga carries both C3 and C4 photosynthesis genes.The key enzymes involved in C4 metabolism including pyruva...The green-tide-forming macroalga Ulva linza was profiled by transcriptome sequencing to ascertain whether the alga carries both C3 and C4 photosynthesis genes.The key enzymes involved in C4 metabolism including pyruvate orthophosphate dikinase(PPDK),phosphoenolpyruvate carboxylase(PEPC),and phosphoenolpyruvate carboxykinase(PCK) were found.When measured under normal and different stress conditions,expression of rbcL was higher under normal conditions and lower under the adverse conditions,whereas that of PPDK was higher under some adverse conditions,namely desiccation,high salinity,and low salinity.Both ribulose-1,5-biphosphate carboxylase(RuBPCase) and PPDK were found to play a role in carbon fixation,with significantly higher PPDK activity across the stress conditions.These results suggest that elevated PPDK activity alters carbon metabolism in U.linza leading to partial operation of the C4 carbon metabolism,a pathway that,under stress conditions,probably contributes to the hardy character of U.linza and thus to its wide distribution.展开更多
文摘The tobacco RuBPcase was purified by the method of (NH 4) 2SO 4 precipitation and Sephadex G 200 column chromatography. The effects of Ln 3+ on inhibition of RuBPcase activity were studied. The results show that the v max (maximum velocity) of RuBPcase does not change, but its k m (Michaelis constant) increases with a k i (inhibitor constant) when increasing the concentration of Ln 3+ in enzymatic reaction. It indicates that the inhibitory action of Ln 3+ on tobacco RuBPcase is a model of competitive inhibition with Mg 2+ . The k i of La 3+ , Ce 3+ and Gd 3+ is 26 3, 34 3 and 200 μmol·L -1 , respectively. Their inhibitory action on the RuBPcase is in the order of La 3+ >Ce 3+ Gd 3+ .
文摘大豆（Glycine max L.cv.Bragg）种植在330或660ul/L CO2的室外、人工气候室。当植物50天龄时,通过逐渐减少每晚的灌溉施加干旱胁迫,结果植物在以后的白天萎蔫更早。第九天,由于盆里缺水,整个白天的CO2交换速率（CER）迅速减少,几乎为零。高浓度的CO2和干旱胁迫减少(HCO3-/Mg2+-激活)总的可提的核酮糖-1,5一二磷酸（RuBP）羧化酶的活性,以叶绿素为单位表示。此外,当冠层CER值和叶片水势最低时,与相应的非胁迫处理比较,干旱胁迫使最初的（非激活的）RuBP羧化酶的活性减少了50%。
文摘Ribulose-1, 5-bisphosphate carboxylase/oxygenase (EC 4, 1, 1, 39, abbreviation: RuBPcase)is a bifunction enzyme. Because of its properties in genetic function and structure, RuBPcase has been intensively studied. In the absence of certain effective genetic markers for identifying hybrids, the analysis of the isoelectrofocusing pattern of RuBPcase has become a standard procedure to verify the nature of the hybrid plants.
文摘The net CO2 assimilation rate, stomatal conductance, RuBPcase (ribulose 1,5-biphosphate carboxylose) activity, dry weight of aboveground and belowgroud part, plant height, the length and diameter of taproot ofPinus koraiensis seedlings were measured and analyzed after six-week exposure to elevated CO2 in an open-top chamber in Changbai Mountain of China from May to Oct. 1999. Seedlings were planted in four different conditions: on an open site, control chamber, 500 μL·L?1 and 700 μL·L?1 CO2 chambers. The results showed that the total biomass of the seedlings increased whereas stomatal conductance decreased. The physiological responses and growth to 500 μL·L?1 and 700 μL·L?1 CO2 varied greatly. The acclimation of photosynthesis was downward to 700 μL·L?1 CO2 but upward to 500 μL·L?1 CO2. The RuBPcase activity, chlorophyll and soluble sugar contents of the seedlings grown at 500 μL·L?1 CO2 were higher than that at 700 μL·L?1 CO2. The concentration 500 μL·L?1 CO2 enhanced the growth of aboveground part whereas 700 μL·L?1 CO2 allocated more carbon to belowground part. Elevated CO2 changed the carbon distribution pattern. The ecophysiological responses were significantly different between plants grown under 500 μL·L?1 CO2 and 700 μL·L?1 CO2.
文摘It was proved that the nitrogen utilization efficiency(NUE) of rice (O. sativa L. )-is of difference among cultivars. In our study, the local rice cultivars Nantong Ludao, Huakegu, and Kugu were used as high NUE type, and modern cultivars Wuxiangqi 25, Zijingeng, and Wuxiangxian as low NUE one,
基金supported by Shandong Science and Technology Plan Project (2011GHY11528)the Specialized Fund for the Basic Research Operating Expenses Program (20603022012004)+4 种基金National Natural Science Foundation of China (41176153)Natural Science Foundation of Shandong Province (2009ZRA02075)Qingdao Municipal Science and Technology Plan Project (11-3-1-5-hy)Qingdao Municipal Science and Technology Plan Project (10-3-4-11-1-jch)National Marine Public Welfare Research Project (200805069)
文摘The green-tide-forming macroalga Ulva linza was profiled by transcriptome sequencing to ascertain whether the alga carries both C3 and C4 photosynthesis genes.The key enzymes involved in C4 metabolism including pyruvate orthophosphate dikinase(PPDK),phosphoenolpyruvate carboxylase(PEPC),and phosphoenolpyruvate carboxykinase(PCK) were found.When measured under normal and different stress conditions,expression of rbcL was higher under normal conditions and lower under the adverse conditions,whereas that of PPDK was higher under some adverse conditions,namely desiccation,high salinity,and low salinity.Both ribulose-1,5-biphosphate carboxylase(RuBPCase) and PPDK were found to play a role in carbon fixation,with significantly higher PPDK activity across the stress conditions.These results suggest that elevated PPDK activity alters carbon metabolism in U.linza leading to partial operation of the C4 carbon metabolism,a pathway that,under stress conditions,probably contributes to the hardy character of U.linza and thus to its wide distribution.
