The responses of photosynthesis of phosphoenopyruvate carboxylase (PEPC), pyrurate dikinase (PPDK), NADP-malic enzyme (NADP-ME) and PPDK+PEPC transgenic rice (Oryza saltiva L.) plant to light, temperature, CO 2 and t...The responses of photosynthesis of phosphoenopyruvate carboxylase (PEPC), pyrurate dikinase (PPDK), NADP-malic enzyme (NADP-ME) and PPDK+PEPC transgenic rice (Oryza saltiva L.) plant to light, temperature, CO 2 and the characteristics of chlorophyll fluorescence under photoinhibition conditions were studied. The results were as follows: 1. The light-saturated photosynthetic rates of transgenic rice plants were higher than that of wild type, in which the light-saturated point of PEPC and PPDK+PEPC transgenic rice plants was 200 μmol·m -2·s -1 higher than that of untransformed rice and the light-saturated photosynthetic rates were 51.6% and 58.5% respectively. The carboxylation efficiency of PEPC transgenic rice plant increased by 49.3% and the CO 2 compensation point decreased by 26.2% than that of untransformed rice. Under high temperature (35 ℃), the photosynthetic rate of PEPC transgenic rice plant was higher over 17.5% than that of untransformed rice. 2. On the 8th day after photoinhibition treatment, the PSⅡ photochemical efficiency (F v/F m) and photochemical quenching (qP) of PEPC and PPDK+PEPC transgenic rice plants decreased by about 20%-30% while the non-photochemical quenching (qN) increased by approximately 30%. But F v/F m and qP of untransformed rice decreased by over 50% while qN increased by less than 10%. The result suggested that transgenic rice plants were more tolerant to photoinhibition.展开更多
To compare the transformation effects of two different forms （cDNA in monocotyledonous plant Echinochloa crusgalli, DNA in monocotyledonous plant Zea mays） of phosphoenolpyruvate carboxylase （PEPC） gene （Ppc） on...To compare the transformation effects of two different forms （cDNA in monocotyledonous plant Echinochloa crusgalli, DNA in monocotyledonous plant Zea mays） of phosphoenolpyruvate carboxylase （PEPC） gene （Ppc） on the growth of transgenic dicotyledonous plant, Agrobacterium-mediated transformation of Ppc genes into Nicotiana tabacum were carried out. Transgenic leaf plates and differentiated seedling leaves were verified by GUS histochemistry, PCR, and RT-PCR. Results showed that transgenic N. tabacum with Ppc-cDNA of E. crusgalli had relatively strong differentiation ability. However, N. tabacum after transformation of complete DNA sequence of Ppc genes in Z mays had relatively poor ability of growth. The differentiated green seedlings had the phenomenon of yellowing; and photosynthesis ability of leaves was poor. This might be caused by the misidentification and wrong splicing in transcription. This indicated that the expression rate of monocotyledonous complete DNA might be reduced in the monocotyledonous cells with relatively far genetic distances. Detection results of showed that Pn in most transgenic N. tabacum with Ppc-cDNA of E. crusgalli was was higher than that in control, which preliminarily proved that PEPC of monocotyledonous plant E. crusgalli had certain regulatory effects on photosynthesis of N. tabacum.展开更多
[ Objective] The aim of this study was to introduce Phosphoenolpyruvate Carboxylase （PEPCase） gene into common wheat Linyou 145. [ Method] With the material of common wheat Linyou 145, Phosphoenolpyruvate Carboxyla...[ Objective] The aim of this study was to introduce Phosphoenolpyruvate Carboxylase （PEPCase） gene into common wheat Linyou 145. [ Method] With the material of common wheat Linyou 145, Phosphoenolpyruvate Carboxylase （PEPCase） gene was introduced into wheat embryo callus by the agrobacterium-mediated transformation system, and then analyzed through successive selection with selective medium con- taing gygrornycin to detect the gene at the molecular level. [Result] The hyg-resistant plants were obtained, and GUS histochemical staining showed the leaf of resistant plants was stained dark blue. The target bands appeared in PCR analysis. [ Conclusion] Phosphoenolpyruvate Car- boxylase （PEPCase） gene has been primarily introduced into the recipient material.展开更多
Objective To investigate the effect and mechanism of the antihyperglycemic agent metformin on the expression of phosphoenolpyruvate carboxykinase (PEPCK) gene in hepatocytes and to determine whether the effects of me...Objective To investigate the effect and mechanism of the antihyperglycemic agent metformin on the expression of phosphoenolpyruvate carboxykinase (PEPCK) gene in hepatocytes and to determine whether the effects of metformin in hepatocytes are transmitted throughout the known insulin signaling pathways Methods Confluent H4IIE rat heptoma cells were cultured for 16 h with 0 1 mmol/L metformin either in absence or presence of 0 1 nmol/L insulin, and then stimulated with various agents The expression of PEPCK gene was examined by Northern blot analysis Results Therapeutic concentrations of metformin significantly inhibited basal PEPCK mRNA expression and also decreased cAMP and dexamethasone induced PEPCK gene expression through interaction with insulin In the presence of insulin signaling pathway inhibitors wortmannin and UO126, metformin reduced PEPCK mRNA levels, but wortmannin blocked inhibitory regulation of insulin on PEPCK gene expression Conclusion Metformin inhibits PEPCK gene expression via either an insulin independent or an interacting with insulin manner The results suggest that a possible mechanism by which metformin reduces gluconeogenesis could be associated with the inhibition of PEPCK gene expression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 responses of photosynthesis of phosphoenopyruvate carboxylase (PEPC), pyrurate dikinase (PPDK), NADP-malic enzyme (NADP-ME) and PPDK+PEPC transgenic rice (Oryza saltiva L.) plant to light, temperature, CO 2 and the characteristics of chlorophyll fluorescence under photoinhibition conditions were studied. The results were as follows: 1. The light-saturated photosynthetic rates of transgenic rice plants were higher than that of wild type, in which the light-saturated point of PEPC and PPDK+PEPC transgenic rice plants was 200 μmol·m -2·s -1 higher than that of untransformed rice and the light-saturated photosynthetic rates were 51.6% and 58.5% respectively. The carboxylation efficiency of PEPC transgenic rice plant increased by 49.3% and the CO 2 compensation point decreased by 26.2% than that of untransformed rice. Under high temperature (35 ℃), the photosynthetic rate of PEPC transgenic rice plant was higher over 17.5% than that of untransformed rice. 2. On the 8th day after photoinhibition treatment, the PSⅡ photochemical efficiency (F v/F m) and photochemical quenching (qP) of PEPC and PPDK+PEPC transgenic rice plants decreased by about 20%-30% while the non-photochemical quenching (qN) increased by approximately 30%. But F v/F m and qP of untransformed rice decreased by over 50% while qN increased by less than 10%. The result suggested that transgenic rice plants were more tolerant to photoinhibition.
基金Supported by the Innovation Project of Chinese Academy of Agricultural Sciences~~
文摘To compare the transformation effects of two different forms （cDNA in monocotyledonous plant Echinochloa crusgalli, DNA in monocotyledonous plant Zea mays） of phosphoenolpyruvate carboxylase （PEPC） gene （Ppc） on the growth of transgenic dicotyledonous plant, Agrobacterium-mediated transformation of Ppc genes into Nicotiana tabacum were carried out. Transgenic leaf plates and differentiated seedling leaves were verified by GUS histochemistry, PCR, and RT-PCR. Results showed that transgenic N. tabacum with Ppc-cDNA of E. crusgalli had relatively strong differentiation ability. However, N. tabacum after transformation of complete DNA sequence of Ppc genes in Z mays had relatively poor ability of growth. The differentiated green seedlings had the phenomenon of yellowing; and photosynthesis ability of leaves was poor. This might be caused by the misidentification and wrong splicing in transcription. This indicated that the expression rate of monocotyledonous complete DNA might be reduced in the monocotyledonous cells with relatively far genetic distances. Detection results of showed that Pn in most transgenic N. tabacum with Ppc-cDNA of E. crusgalli was was higher than that in control, which preliminarily proved that PEPC of monocotyledonous plant E. crusgalli had certain regulatory effects on photosynthesis of N. tabacum.
文摘[ Objective] The aim of this study was to introduce Phosphoenolpyruvate Carboxylase （PEPCase） gene into common wheat Linyou 145. [ Method] With the material of common wheat Linyou 145, Phosphoenolpyruvate Carboxylase （PEPCase） gene was introduced into wheat embryo callus by the agrobacterium-mediated transformation system, and then analyzed through successive selection with selective medium con- taing gygrornycin to detect the gene at the molecular level. [Result] The hyg-resistant plants were obtained, and GUS histochemical staining showed the leaf of resistant plants was stained dark blue. The target bands appeared in PCR analysis. [ Conclusion] Phosphoenolpyruvate Car- boxylase （PEPCase） gene has been primarily introduced into the recipient material.
文摘Objective To investigate the effect and mechanism of the antihyperglycemic agent metformin on the expression of phosphoenolpyruvate carboxykinase (PEPCK) gene in hepatocytes and to determine whether the effects of metformin in hepatocytes are transmitted throughout the known insulin signaling pathways Methods Confluent H4IIE rat heptoma cells were cultured for 16 h with 0 1 mmol/L metformin either in absence or presence of 0 1 nmol/L insulin, and then stimulated with various agents The expression of PEPCK gene was examined by Northern blot analysis Results Therapeutic concentrations of metformin significantly inhibited basal PEPCK mRNA expression and also decreased cAMP and dexamethasone induced PEPCK gene expression through interaction with insulin In the presence of insulin signaling pathway inhibitors wortmannin and UO126, metformin reduced PEPCK mRNA levels, but wortmannin blocked inhibitory regulation of insulin on PEPCK gene expression Conclusion Metformin inhibits PEPCK gene expression via either an insulin independent or an interacting with insulin manner The results suggest that a possible mechanism by which metformin reduces gluconeogenesis could be associated with the inhibition of PEPCK gene expression
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.
