When the first fully expanded leaf of wheat ( Triticum aestivum L.) seedlings with two leaves were treated with different concentrations (0.05, 0.10, 0.20 and 0.50 mmol/L) of nitric oxide donor, sodium nitroprusside (...When the first fully expanded leaf of wheat ( Triticum aestivum L.) seedlings with two leaves were treated with different concentrations (0.05, 0.10, 0.20 and 0.50 mmol/L) of nitric oxide donor, sodium nitroprusside (SNP), the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) were reduced by the lower concentrations (0.05, 0.10 and 0.20 mmol/L), but enhanced by the higher concentration of SNP (0.50 mmol/L). The protective effect of 0.10 mmol/L SNP was the most obvious. Furthermore, the treatment with 0.10 mmol/L SNP on the above seedlings until the fourth leaves were fully expanded attenuated the accumulation of H2O2, superoxide anion radical (O-2(-)) and MDA, also counteracted the degradation of chlorophyll and soluble proteins, especally Rubisco, both leading to the effective delay of aging process in wheat leaves. The effects of different SNP concentrations (0.05, 0.10, 0.20, 0.50, 1.00 and 5.00 mmol/L) also displayed a dual role in an aging experiment of chloroplasts in vitro, one of which, 0.2 mmol/L SNP treatment, protected the membrane structure and attenuated the degradation of Rubisco effectively. Based on the present results, it was inferred that lower concentrations of nitric oxide (NO) might play a role in delaying aging process in wheat leaves, i.e., might attribute to decrease the level of reactive oxygen species (ROS) and the alleviation of further oxidative damage caused by ROS.展开更多
The relationship between hydrogen peroxide (H 2O 2) and endopeptidase(EP) in wheat ( Triticum aestivum L. cv. Yanmai 158) leaves was studied during natural and artificial aging. Rapid accumulation of endogeno...The relationship between hydrogen peroxide (H 2O 2) and endopeptidase(EP) in wheat ( Triticum aestivum L. cv. Yanmai 158) leaves was studied during natural and artificial aging. Rapid accumulation of endogenous H 2O 2 and marked increase of EP activity were observed during the later phase of aging. A new EP isozyme with higher activity was detected by electrophoresis on polyacrylamide gels containing denatured heamoglobin. With the increase of exogenous H 2O 2, the activity of EP increased at first and then decreased.展开更多
[Objective] This study aimed to explore the effects of water and fertilizer regulation on the function of leaves in the filling stage. [Method] Six hybrid rice vari- eties including prematurely aged types and non-prem...[Objective] This study aimed to explore the effects of water and fertilizer regulation on the function of leaves in the filling stage. [Method] Six hybrid rice vari- eties including prematurely aged types and non-prematurely aged ones were selected as experimental materials. Limiting water treatment (with soil water potential of about -25 kpa) and increasing nitrogen treatment (additional 10% of granular nitrogen fertiliz- er in addition to limiting water treatment) were applied after heading to analyse the rates of aging and physiological responses of anti-aging in different hybrid rice vari- eties under water deficit and increased nitrogen conditions taking regular water and fertilizer as control. [Result] The results showed that water deficit accelerated the leaf senescence, and prematurely aged types-'Zhongyou838', 'Tianyou998' and 'Long- ping601 '-were more markedly affected by water deficit, of which the rates of chloro- phyll degradation were 6%-8% higher compared to that in another three hybrids. In- creasing nitrogen treatment raised chlorophyll content and slowed down its degrada- tion. Water deficit caused the increase of abscisic acid (ABA) content to obviously varying degrees in leaves of six hybried rice varieties. Responses of ABA content in six hybried rice varieties to increased nitrogen fertilizer were not consistent. Except in 'Zhongyou838', ABA content in the other five hybrids had varying degrees of in- crease. The responses of the activity of antioxidant enzymes in different hybried rice varieties were inconsistent. In response to increased nitrogen fertilizer in combination with water deficit, the activity of each antioxidant enzyme changed differently. Water deficit enhanced the accumulation of malondialdehyde (MDA) in leaves of each hybrid rice. The correlation analysis showed that chlorophyll content was extremely signifi- cantly positively correlated to the resistance of each antioxidant enzyme; SOD activity in leaves also positively related to ABA content. [Conclusion] The rate of leaf aging, physiological activity of anti-aging, and response to water deficit varied in different hy- bried rice varieties. The activity of antioxidant enzymes were not all induced to improve by ABA. SOD activity can be an indicator of resistance to stress. Increasing nitrogen ap- plication significantly postponed leave senescence in the late growth stage of rice.展开更多
An S-like RNase cDNA had been isolated from common wheat (Triticum aestivum L). The transcription of WRN1 mRNA was down-regulated by natural- and dark-induced senescence. But it was not senile-tissue-specific. As the ...An S-like RNase cDNA had been isolated from common wheat (Triticum aestivum L). The transcription of WRN1 mRNA was down-regulated by natural- and dark-induced senescence. But it was not senile-tissue-specific. As the two key histidine residues were replaced, WRN1 may not be active as RNase. Southern blotting analysis showed that WRN1 exists as one of a small gene family in common wheat genome.展开更多
The characterization of senescence-associated endopeptidase (EP) isoenzymes in wheat (Triticum aestivum L. cv. Yangmai 158) leaves during dark-induced senescence was performed. It was found that there was much higher ...The characterization of senescence-associated endopeptidase (EP) isoenzymes in wheat (Triticum aestivum L. cv. Yangmai 158) leaves during dark-induced senescence was performed. It was found that there was much higher endoproteolytic activity in dark-induced wheat leaves than in control. Six endopeptidase isoenzymes (EP1-EP6) were identified by natural gradient-polyacrylamide gel electrophoresis (PAGE) co-polymerized gelatin in the gel, five of which (EP1, EP2, EP4, EP5 and EP6) were only detected in senescing leaves. Treatment with 6-benzyl aminopurine (6-BA) delayed the expression of these EP isoenzymes and abscisic acid (ABA) accelerated it. The activity of EP3 could be detected at a wider range of pH and temperature levels while EP4, EP5 and EP 6 could be only detected at pH 4-5 and 30 -45 degreesC, EP1 and EP2 at pH 3-5 and 30-45 degreesC. All of the EP isoenzymes showed high thermal stability, especially EP3, EP5 and EP6 which still had activitiy even by incubation at 55 degreesC for 1 h. By using different class-specific inhibitors, EP1 and EP2 were characterized as metal-dependent cysteine-proteases, EP4 as a serine-protease.展开更多
[Objective] The pattern of leaves senescence was studied to provide reference for the planting technology and breeding rice cultivars resistant to premature senescence. [Method] Six hybrid rice cultivars were cultivat...[Objective] The pattern of leaves senescence was studied to provide reference for the planting technology and breeding rice cultivars resistant to premature senescence. [Method] Six hybrid rice cultivars were cultivated under limited and conventional irrigation managements; after the heading of rice, the root activities, nitrogen content in leaves, chlorophyll content (SPAD value), net photosynthetic rate and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) were determined. [Result] The rhythms in attenuation of xylem sap flow rate, leaf nitrogen content, chlorophyll content (SPAD value) and net photosynthetic rate of different rice cultivars were significantly different in attenuation starting time, attenuation frequency and attenuation range. Physiological indexes of different cultivars responded inconsistently to water shortage. Extremely significantly positive correlations were found between the decline rates of chlorophyll content and leaf nitrogen content and xylem sap flow rate of roots, the photosynthetic rate and chlorophyll content. The changes in activities of SOD, CAT and POD were different, and responded to water shortage differently in different cultivars. The change dynamic of leaf nitrogen content and chlorophyll content was positively related with the activity dynamic of SOD and CAT. The change dynamic of leaf nitrogen content and chlorophyll content was negatively related with the malondialdehyde (MDA) content. The difference in the attenuation rhythm of physiological indexes of leaves and response to water shortage of different hybrid rice cultivars were related to genotype difference. Increasing roots activities and protecting enzyme activities of leaves benefit to defer attenuation of chlorophyll content and nitrogen content of leaves and to keep stronger photosynthetic function. [Conclusion] The senescence resistance of rice is a combined result of genotype differences and physiological response to environment.展开更多
Leaf senescence is often caused by water deficit and the chimeric gene PSA612-1PT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, ...Leaf senescence is often caused by water deficit and the chimeric gene PSA612-1PT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, carotenoids, soluble protein and thiobarbituric acid reactive substance (TBARS) and antioxidant enzymes activities were investigated during leaf senescence of PSA612-1PT modified gerbera induced by osmotic stress compared with the control plant (wild type). Leaf discs were incubated in 20%, 40% (w/v) polyethylene glycol (PEG) 6 000 nutrient solution for 20 h under continuous light [ 130 μmol/(m^2·s)]. The results showed that the contents of chlorophylls, carotenoids and soluble protein were decreased by osmotic stress with the decrease being more pronounced at 40% PEG, but that, at the same PEG concentration the decrease in the transgenic plants was significantly lower than that in the control plant. The activities of superoxide dismutase (SOD), catalases (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and dehydroascorbate reductase (DHAR) were stimulated by PEG treatment. However, the increases were higher in PSA612-IPT transgenic plants than in the control plants, particularly at 40% PEG treatment. Lipid peroxidation (TBARS content) was increased by PEG treatment with the increase being much lower in transgenic plant than in the control plant. It could be concluded that the increases in the activities ofantioxidant enzymes including SOD, CAT, APX, GPX and DHAR were responsible for the delay of leaf senescence induced by osmotic stress.展开更多
P SAG12 _ IPT gene was introduced into an elite rice (Oryza sativa L. ssp. indica ) restorer line Minghui 63 through Agrobacterium _mediated transformation method. Out of 61 independent transgenic plants ...P SAG12 _ IPT gene was introduced into an elite rice (Oryza sativa L. ssp. indica ) restorer line Minghui 63 through Agrobacterium _mediated transformation method. Out of 61 independent transgenic plants obtained, a few acquired a recognizable phenotype in which leave senescence was delayed to a great degree. The results of field plot test on two homozygous transgenic lines indicated: (1) the stay_green ability of transgenic plants was significantly improved; (2) both the seed_setting rate and the number of panicles per plant of transgenic plants were significantly increased compared with that of the non_transgenic plants of Minghui 63; and (3) the plant height of transgenic plants was significantly reduced.展开更多
The process of endowment insurance system plan as a whole is an important step of old-age insurance system reform in our country. At present, the process of endowment insurance system plan as a whole's process etxcou...The process of endowment insurance system plan as a whole is an important step of old-age insurance system reform in our country. At present, the process of endowment insurance system plan as a whole's process etxcountered bottlenecks. Come to the conclusion after analysis, the basic old-age insurance system across the country plan as a whole facing same questions, such as the regional income is different, the regional replacement rate of endowment insurance system is different, the "fragmentation" phenomenon of regional endowment insurance system, impact both fairness and efficiency of the basic endowment insurance system.展开更多
OBJECTIVE: To investigate the involvement of growth arrest specific 5(GAS5), a long non-coding RNA, in the anti-hepatic fibrosis process induced by Dahuang Zhechong pill(DHZCP) in rats.METHODS: Thirty adult rats were ...OBJECTIVE: To investigate the involvement of growth arrest specific 5(GAS5), a long non-coding RNA, in the anti-hepatic fibrosis process induced by Dahuang Zhechong pill(DHZCP) in rats.METHODS: Thirty adult rats were divided into three groups, including a control group, a CCl4-induced fibrosis group and a DHZCP-treated fibrosis group. Hematoxylin-eosin and Masson staining were used for histopathological study. Serum enzymes, cytokines and cell proliferation were assayed using commercially available kits. A GAS5 lenti-virus vector was constructed to further investigate the role of GAS5 in the anti-hepatic fibrosis effect of DHZCP in rats.RESULTS: Our results revealed that the proliferation of hepatic stellate cells cultured in serum derived from rats treated with DHZCP was significantly decreased, compared with cells treated with serum from the untreated rats. DHZCP alleviated the CCl4-induced hepatic fibrosis. Additionally, DHZCP can restore the expression of GAS5,which was significantly decreased in the CCl4-induced group, and markedly suppress the expression of p-p38 and p-Erk induced by CCl4, but not p-Jnk. Cell proliferation was significantly arrested when cells overexpressed GAS5. Thus,DHZCP can inhibit the expression of p-p38 and p-Erk, while GAS5 can only inhibit the expression of p-Erk.CONCLUSIONS: DHZCP can alleviate hepatic fibrosis by increasing the expression of GAS5 to suppress p-Erk and regulating other factors to inhibit p-p38.展开更多
Nutrient resorption is a crucial mechanism for plant nutrient conservation,but most previous studies did not consider the leaf-mass loss during senescence due to lack of measured data.This would lead to an underestima...Nutrient resorption is a crucial mechanism for plant nutrient conservation,but most previous studies did not consider the leaf-mass loss during senescence due to lack of measured data.This would lead to an underestimation of nutrient resorption efficiency(NuRE),or calculating NuRE of various species based on the average mass loss at plant-functional-group level in the literature,thus affecting its accuracy.Here we measured the leaf-mass loss to correct NuRE with the species-specific mass loss correction factor(MLCF),so as to foster a more accurate calculation of the nutrient fluxes within and between plants and the soil.Green leaves and senesced leaves were collected from 35 dominant woody plants in northern China.Mass of green and senesced leaves were measured to calculate the MLCF at species level.The MLCF was reported for each of the 35 dominant woody plants in northern China.These species averagely lost 17%of the green-leaf mass during leaf senescence,but varied greatly from 1.3%to 36.8%mass loss across the 35 species,or 11.7%to 19.6%loss across the functional types.Accordingly,the MLCF varied from 0.632 to 0.987 across the 35 species with an average value 0.832.The NuRE corrected with MLCF was remarkably increased on the whole(e.g.both the average nitrogen and phosphorus NuRE became about 9%higher,or more accurate),compared with the uncorrected ones,especially in the case of low resorption efficiencies.Our field data provide reliable references for the MLCF of plants in related regions at both species and functional-type levels,and are expected to promote more accurate calculations of NuRE.展开更多
Objective:To discuss the curative effect of the dynamic hip system blade (DHS-blade) on the treatment of femoral neck fractures in elderly patients with osteoporosis.Methods:A retrospective study was conducted to ...Objective:To discuss the curative effect of the dynamic hip system blade (DHS-blade) on the treatment of femoral neck fractures in elderly patients with osteoporosis.Methods:A retrospective study was conducted to analyse the clinical data of 60 elderly patients with osteoporosis who had been treated for femoral neck fractures with DHS-blade in our department between September 2012 and February 2014.There were 22 males and 38 females with a mean age of (66.8±3.2) years.According to the Singh Index Classification,all the patients' Singh index was below level 3.The Harris criterion and function recovery after operation were analysed.Results:All patients were followed up for 12-17 months (mean 14 months).No femoral head necrosis,femoral neck shortening,internal fixation loosening or backing out of the nails occurred.Bone nonunion was found in one case and he had a good recovery after total hip arthroplasty.The time for fracture healing ranged from 3-6 months (average 3.5 months).According to Harris criterion,35 cases were rated as excellent,22 good,2 fair and 1 poor.The Harris scale was significantly improved from 28.46±2.35 preoperatively to 91.98±3.26 at 6 months postoperatively (P<0.05).Conclusion:DHS-blade,being minimally invasive,allowing earlier postoperative exercise and avoiding the complications elicited by traditional internal fixation,is advisable for treatment of femoral neck fractured patients with osteoporosis.展开更多
The class III homeodomain-leucine zipper(HD-Zip III)gene family plays important roles in plant growth and development,including regulation of apical embryo patterning,embryonic shoot meristem formation,leaf polarity,v...The class III homeodomain-leucine zipper(HD-Zip III)gene family plays important roles in plant growth and development,including regulation of apical embryo patterning,embryonic shoot meristem formation,leaf polarity,vascular development,and meristem function,with a particularly crucial function in leaf development.Although HD-Zip III members are highly conserved in land plants,previous studies,such as genetic analyses based on multiple mutants in Arabidopsis and other plants,suggest that various HD-Zip III family genes have evolved with distinct functions and pleiotropic effects on plant growth and development.In this study,we analyzed a HD-Zip III member,OsHox33,and demonstrated that it plays an important role in age-dependent leaf senescence in rice.We constructed two specific RNAi vectors derived from the 5′-end region and 3′-UTR of OsHox33 to knockdown its expression.Transgenic plants harboring either RNAi construct displayed similar phenotypes of precocious leaf senescence symptoms,suggesting that knockdown of OsHox33 accelerates leaf senescence in rice.pOsHox33::GUS fusion expression and RT-PCR revealed that OsHox33 is highly expressed in young organs,especially in young meristems such as shoot apical meristems,intercalary meristems,and young callus.In addition,real-time PCR indicated that OsHox33 was more highly expressed in young leaves than in old leaves.To further investigate OsHox33 function,we analyzed chloroplast ultrastructure in different-aged leaves of RNAi plants,and found that OsHox33 knockdown accelerated chloroplast degradation,which is consistent with RNAi phenotypes.Finally,real-time PCR studies showed that OsHox33 can regulate the expression of GS1 and GS2,two senescence-associated genes.Taken together,the work presented here provides new insights into the function of HD-Zip III members in plants.展开更多
文摘When the first fully expanded leaf of wheat ( Triticum aestivum L.) seedlings with two leaves were treated with different concentrations (0.05, 0.10, 0.20 and 0.50 mmol/L) of nitric oxide donor, sodium nitroprusside (SNP), the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) were reduced by the lower concentrations (0.05, 0.10 and 0.20 mmol/L), but enhanced by the higher concentration of SNP (0.50 mmol/L). The protective effect of 0.10 mmol/L SNP was the most obvious. Furthermore, the treatment with 0.10 mmol/L SNP on the above seedlings until the fourth leaves were fully expanded attenuated the accumulation of H2O2, superoxide anion radical (O-2(-)) and MDA, also counteracted the degradation of chlorophyll and soluble proteins, especally Rubisco, both leading to the effective delay of aging process in wheat leaves. The effects of different SNP concentrations (0.05, 0.10, 0.20, 0.50, 1.00 and 5.00 mmol/L) also displayed a dual role in an aging experiment of chloroplasts in vitro, one of which, 0.2 mmol/L SNP treatment, protected the membrane structure and attenuated the degradation of Rubisco effectively. Based on the present results, it was inferred that lower concentrations of nitric oxide (NO) might play a role in delaying aging process in wheat leaves, i.e., might attribute to decrease the level of reactive oxygen species (ROS) and the alleviation of further oxidative damage caused by ROS.
文摘The relationship between hydrogen peroxide (H 2O 2) and endopeptidase(EP) in wheat ( Triticum aestivum L. cv. Yanmai 158) leaves was studied during natural and artificial aging. Rapid accumulation of endogenous H 2O 2 and marked increase of EP activity were observed during the later phase of aging. A new EP isozyme with higher activity was detected by electrophoresis on polyacrylamide gels containing denatured heamoglobin. With the increase of exogenous H 2O 2, the activity of EP increased at first and then decreased.
基金Supported by the National Natural Science Foundation of China(30860137)the Research Fund of Department of Education of Jiangxi Province(GJJ09168)~~
文摘[Objective] This study aimed to explore the effects of water and fertilizer regulation on the function of leaves in the filling stage. [Method] Six hybrid rice vari- eties including prematurely aged types and non-prematurely aged ones were selected as experimental materials. Limiting water treatment (with soil water potential of about -25 kpa) and increasing nitrogen treatment (additional 10% of granular nitrogen fertiliz- er in addition to limiting water treatment) were applied after heading to analyse the rates of aging and physiological responses of anti-aging in different hybrid rice vari- eties under water deficit and increased nitrogen conditions taking regular water and fertilizer as control. [Result] The results showed that water deficit accelerated the leaf senescence, and prematurely aged types-'Zhongyou838', 'Tianyou998' and 'Long- ping601 '-were more markedly affected by water deficit, of which the rates of chloro- phyll degradation were 6%-8% higher compared to that in another three hybrids. In- creasing nitrogen treatment raised chlorophyll content and slowed down its degrada- tion. Water deficit caused the increase of abscisic acid (ABA) content to obviously varying degrees in leaves of six hybried rice varieties. Responses of ABA content in six hybried rice varieties to increased nitrogen fertilizer were not consistent. Except in 'Zhongyou838', ABA content in the other five hybrids had varying degrees of in- crease. The responses of the activity of antioxidant enzymes in different hybried rice varieties were inconsistent. In response to increased nitrogen fertilizer in combination with water deficit, the activity of each antioxidant enzyme changed differently. Water deficit enhanced the accumulation of malondialdehyde (MDA) in leaves of each hybrid rice. The correlation analysis showed that chlorophyll content was extremely signifi- cantly positively correlated to the resistance of each antioxidant enzyme; SOD activity in leaves also positively related to ABA content. [Conclusion] The rate of leaf aging, physiological activity of anti-aging, and response to water deficit varied in different hy- bried rice varieties. The activity of antioxidant enzymes were not all induced to improve by ABA. SOD activity can be an indicator of resistance to stress. Increasing nitrogen ap- plication significantly postponed leave senescence in the late growth stage of rice.
文摘An S-like RNase cDNA had been isolated from common wheat (Triticum aestivum L). The transcription of WRN1 mRNA was down-regulated by natural- and dark-induced senescence. But it was not senile-tissue-specific. As the two key histidine residues were replaced, WRN1 may not be active as RNase. Southern blotting analysis showed that WRN1 exists as one of a small gene family in common wheat genome.
文摘The characterization of senescence-associated endopeptidase (EP) isoenzymes in wheat (Triticum aestivum L. cv. Yangmai 158) leaves during dark-induced senescence was performed. It was found that there was much higher endoproteolytic activity in dark-induced wheat leaves than in control. Six endopeptidase isoenzymes (EP1-EP6) were identified by natural gradient-polyacrylamide gel electrophoresis (PAGE) co-polymerized gelatin in the gel, five of which (EP1, EP2, EP4, EP5 and EP6) were only detected in senescing leaves. Treatment with 6-benzyl aminopurine (6-BA) delayed the expression of these EP isoenzymes and abscisic acid (ABA) accelerated it. The activity of EP3 could be detected at a wider range of pH and temperature levels while EP4, EP5 and EP 6 could be only detected at pH 4-5 and 30 -45 degreesC, EP1 and EP2 at pH 3-5 and 30-45 degreesC. All of the EP isoenzymes showed high thermal stability, especially EP3, EP5 and EP6 which still had activitiy even by incubation at 55 degreesC for 1 h. By using different class-specific inhibitors, EP1 and EP2 were characterized as metal-dependent cysteine-proteases, EP4 as a serine-protease.
基金Supported by National Natural Science Foundation of China(30860137)the Fund from the Education Department of Jiangxi Province(GJJ09168)~~
文摘[Objective] The pattern of leaves senescence was studied to provide reference for the planting technology and breeding rice cultivars resistant to premature senescence. [Method] Six hybrid rice cultivars were cultivated under limited and conventional irrigation managements; after the heading of rice, the root activities, nitrogen content in leaves, chlorophyll content (SPAD value), net photosynthetic rate and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) were determined. [Result] The rhythms in attenuation of xylem sap flow rate, leaf nitrogen content, chlorophyll content (SPAD value) and net photosynthetic rate of different rice cultivars were significantly different in attenuation starting time, attenuation frequency and attenuation range. Physiological indexes of different cultivars responded inconsistently to water shortage. Extremely significantly positive correlations were found between the decline rates of chlorophyll content and leaf nitrogen content and xylem sap flow rate of roots, the photosynthetic rate and chlorophyll content. The changes in activities of SOD, CAT and POD were different, and responded to water shortage differently in different cultivars. The change dynamic of leaf nitrogen content and chlorophyll content was positively related with the activity dynamic of SOD and CAT. The change dynamic of leaf nitrogen content and chlorophyll content was negatively related with the malondialdehyde (MDA) content. The difference in the attenuation rhythm of physiological indexes of leaves and response to water shortage of different hybrid rice cultivars were related to genotype difference. Increasing roots activities and protecting enzyme activities of leaves benefit to defer attenuation of chlorophyll content and nitrogen content of leaves and to keep stronger photosynthetic function. [Conclusion] The senescence resistance of rice is a combined result of genotype differences and physiological response to environment.
文摘Leaf senescence is often caused by water deficit and the chimeric gene PSA612-1PT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, carotenoids, soluble protein and thiobarbituric acid reactive substance (TBARS) and antioxidant enzymes activities were investigated during leaf senescence of PSA612-1PT modified gerbera induced by osmotic stress compared with the control plant (wild type). Leaf discs were incubated in 20%, 40% (w/v) polyethylene glycol (PEG) 6 000 nutrient solution for 20 h under continuous light [ 130 μmol/(m^2·s)]. The results showed that the contents of chlorophylls, carotenoids and soluble protein were decreased by osmotic stress with the decrease being more pronounced at 40% PEG, but that, at the same PEG concentration the decrease in the transgenic plants was significantly lower than that in the control plant. The activities of superoxide dismutase (SOD), catalases (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and dehydroascorbate reductase (DHAR) were stimulated by PEG treatment. However, the increases were higher in PSA612-IPT transgenic plants than in the control plants, particularly at 40% PEG treatment. Lipid peroxidation (TBARS content) was increased by PEG treatment with the increase being much lower in transgenic plant than in the control plant. It could be concluded that the increases in the activities ofantioxidant enzymes including SOD, CAT, APX, GPX and DHAR were responsible for the delay of leaf senescence induced by osmotic stress.
文摘P SAG12 _ IPT gene was introduced into an elite rice (Oryza sativa L. ssp. indica ) restorer line Minghui 63 through Agrobacterium _mediated transformation method. Out of 61 independent transgenic plants obtained, a few acquired a recognizable phenotype in which leave senescence was delayed to a great degree. The results of field plot test on two homozygous transgenic lines indicated: (1) the stay_green ability of transgenic plants was significantly improved; (2) both the seed_setting rate and the number of panicles per plant of transgenic plants were significantly increased compared with that of the non_transgenic plants of Minghui 63; and (3) the plant height of transgenic plants was significantly reduced.
文摘The process of endowment insurance system plan as a whole is an important step of old-age insurance system reform in our country. At present, the process of endowment insurance system plan as a whole's process etxcountered bottlenecks. Come to the conclusion after analysis, the basic old-age insurance system across the country plan as a whole facing same questions, such as the regional income is different, the regional replacement rate of endowment insurance system is different, the "fragmentation" phenomenon of regional endowment insurance system, impact both fairness and efficiency of the basic endowment insurance system.
基金Supported by National Natural Science Foundation of China:Research on Molecular Mechanism of Anti Liver Fibrosis of Dahuang Zhecong pill Targeting on NADPH Oxidase Signal Network(No.81473473)Science Technology and Innovation Commission of Shenzhen Municipality:the Role of Lnc RNA GAS5 on the Anti-hepatic Fibrosis of Dahuang Zhechong pill(No.JCYJ201604281732-52471)
文摘OBJECTIVE: To investigate the involvement of growth arrest specific 5(GAS5), a long non-coding RNA, in the anti-hepatic fibrosis process induced by Dahuang Zhechong pill(DHZCP) in rats.METHODS: Thirty adult rats were divided into three groups, including a control group, a CCl4-induced fibrosis group and a DHZCP-treated fibrosis group. Hematoxylin-eosin and Masson staining were used for histopathological study. Serum enzymes, cytokines and cell proliferation were assayed using commercially available kits. A GAS5 lenti-virus vector was constructed to further investigate the role of GAS5 in the anti-hepatic fibrosis effect of DHZCP in rats.RESULTS: Our results revealed that the proliferation of hepatic stellate cells cultured in serum derived from rats treated with DHZCP was significantly decreased, compared with cells treated with serum from the untreated rats. DHZCP alleviated the CCl4-induced hepatic fibrosis. Additionally, DHZCP can restore the expression of GAS5,which was significantly decreased in the CCl4-induced group, and markedly suppress the expression of p-p38 and p-Erk induced by CCl4, but not p-Jnk. Cell proliferation was significantly arrested when cells overexpressed GAS5. Thus,DHZCP can inhibit the expression of p-p38 and p-Erk, while GAS5 can only inhibit the expression of p-Erk.CONCLUSIONS: DHZCP can alleviate hepatic fibrosis by increasing the expression of GAS5 to suppress p-Erk and regulating other factors to inhibit p-p38.
基金TheNational Key Researchand Development Program of China(2018YFC0507204)"Strategic Priority Research Program"of the Chinese Academy of Sciences(XDA26040202)the National Natural Science Foundation of China(41473068).
文摘Nutrient resorption is a crucial mechanism for plant nutrient conservation,but most previous studies did not consider the leaf-mass loss during senescence due to lack of measured data.This would lead to an underestimation of nutrient resorption efficiency(NuRE),or calculating NuRE of various species based on the average mass loss at plant-functional-group level in the literature,thus affecting its accuracy.Here we measured the leaf-mass loss to correct NuRE with the species-specific mass loss correction factor(MLCF),so as to foster a more accurate calculation of the nutrient fluxes within and between plants and the soil.Green leaves and senesced leaves were collected from 35 dominant woody plants in northern China.Mass of green and senesced leaves were measured to calculate the MLCF at species level.The MLCF was reported for each of the 35 dominant woody plants in northern China.These species averagely lost 17%of the green-leaf mass during leaf senescence,but varied greatly from 1.3%to 36.8%mass loss across the 35 species,or 11.7%to 19.6%loss across the functional types.Accordingly,the MLCF varied from 0.632 to 0.987 across the 35 species with an average value 0.832.The NuRE corrected with MLCF was remarkably increased on the whole(e.g.both the average nitrogen and phosphorus NuRE became about 9%higher,or more accurate),compared with the uncorrected ones,especially in the case of low resorption efficiencies.Our field data provide reliable references for the MLCF of plants in related regions at both species and functional-type levels,and are expected to promote more accurate calculations of NuRE.
文摘Objective:To discuss the curative effect of the dynamic hip system blade (DHS-blade) on the treatment of femoral neck fractures in elderly patients with osteoporosis.Methods:A retrospective study was conducted to analyse the clinical data of 60 elderly patients with osteoporosis who had been treated for femoral neck fractures with DHS-blade in our department between September 2012 and February 2014.There were 22 males and 38 females with a mean age of (66.8±3.2) years.According to the Singh Index Classification,all the patients' Singh index was below level 3.The Harris criterion and function recovery after operation were analysed.Results:All patients were followed up for 12-17 months (mean 14 months).No femoral head necrosis,femoral neck shortening,internal fixation loosening or backing out of the nails occurred.Bone nonunion was found in one case and he had a good recovery after total hip arthroplasty.The time for fracture healing ranged from 3-6 months (average 3.5 months).According to Harris criterion,35 cases were rated as excellent,22 good,2 fair and 1 poor.The Harris scale was significantly improved from 28.46±2.35 preoperatively to 91.98±3.26 at 6 months postoperatively (P<0.05).Conclusion:DHS-blade,being minimally invasive,allowing earlier postoperative exercise and avoiding the complications elicited by traditional internal fixation,is advisable for treatment of femoral neck fractured patients with osteoporosis.
基金supported by the National Natural Science Foundation of China(31171515)the Tianjin Natural Science Foundation of China(11JCZDJC17900)the Knowledge Innovation and Training Program of Tianjin,Tianjin Municipal Education Commission(2013-1-2015-12)
文摘The class III homeodomain-leucine zipper(HD-Zip III)gene family plays important roles in plant growth and development,including regulation of apical embryo patterning,embryonic shoot meristem formation,leaf polarity,vascular development,and meristem function,with a particularly crucial function in leaf development.Although HD-Zip III members are highly conserved in land plants,previous studies,such as genetic analyses based on multiple mutants in Arabidopsis and other plants,suggest that various HD-Zip III family genes have evolved with distinct functions and pleiotropic effects on plant growth and development.In this study,we analyzed a HD-Zip III member,OsHox33,and demonstrated that it plays an important role in age-dependent leaf senescence in rice.We constructed two specific RNAi vectors derived from the 5′-end region and 3′-UTR of OsHox33 to knockdown its expression.Transgenic plants harboring either RNAi construct displayed similar phenotypes of precocious leaf senescence symptoms,suggesting that knockdown of OsHox33 accelerates leaf senescence in rice.pOsHox33::GUS fusion expression and RT-PCR revealed that OsHox33 is highly expressed in young organs,especially in young meristems such as shoot apical meristems,intercalary meristems,and young callus.In addition,real-time PCR indicated that OsHox33 was more highly expressed in young leaves than in old leaves.To further investigate OsHox33 function,we analyzed chloroplast ultrastructure in different-aged leaves of RNAi plants,and found that OsHox33 knockdown accelerated chloroplast degradation,which is consistent with RNAi phenotypes.Finally,real-time PCR studies showed that OsHox33 can regulate the expression of GS1 and GS2,two senescence-associated genes.Taken together,the work presented here provides new insights into the function of HD-Zip III members in plants.