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] This study aimed to investigate the changes in activity of POD and CAT in wheat during generation period under drought stress. [Method] Four wheat cultivars, including Yunong 51, Zhoumai 22, Jimai 19 and H...[Objective] This study aimed to investigate the changes in activity of POD and CAT in wheat during generation period under drought stress. [Method] Four wheat cultivars, including Yunong 51, Zhoumai 22, Jimai 19 and Huaimai 22, were selected as experimental materials and cultured under drought stress simulated by different concentrations of PEG6000, to determine the activity of POD and CAT. [Result] POD and CAT activity in wheat during generation period increased gradual y under stress of 5% and 15% PEG6000 from 0 to 120 h; POD and CAT activity in wheat under stress of 15% PEG6000 increased more compared with that under stress of 5% PEG6000; POD and CAT activity in wheat under stress of 25% and 35% PEG6000 increased first and then decreased. Stress duration significantly af-fected the activity of POD and CAT in wheat during generation period. [Conclusion] This study provided theoretical references for breeding drought-tolerant wheat.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
Due to its strong and effective insecticidal properties, transgenic Bt+CpTI cotton has witnessed an expanding planting area in recent years, and the impact of its cultivation on soil ecosystem becomes an important pa...Due to its strong and effective insecticidal properties, transgenic Bt+CpTI cotton has witnessed an expanding planting area in recent years, and the impact of its cultivation on soil ecosystem becomes an important part of environmental risk assessment. Using transgenic Bt+CpTI cotton sGK321 and its parental homologous conventional cotton Shiyuan 321 as the study objects, a comparative analysis was conducted on the changes in enzyme activities (urease, alkaline phosphatase, and catalase) of the rhizosphere soil and changes in the number of culturable microor-ganisms (bacteria, fungi, and actinomycetes) at different growth stages (seedling stage, budding stage, flower and bol stage, and bol opening stage) of sGK321 and Shiyuan 321 under the condition of 13 years field plantings. The results showed that, the populations of bacteria, fungi, and actinomycete and the soil enzyme activi-ties of urease, alkaline phosphatase and catalase had a similar variation trend along with the cotton growing process for transgenic cotton and conventional cotton. Some occasional and inconsistent effects on soil enzyme activities and soil fungi composi-tion in the rhizosphere soil of transgenic Bt+CpTI cotton were found at the seedling stage, budding stage, flower and bol stage as compared with that of conventional cotton. The amount of bacteria and actinomycetes were not significantly different during a certain stage; however, the activities of urease, catalase, alkaline phos-phatase, also with the number of fungi were significantly different, e.g. the urease activities at seedling stage, the alkaline phosphatase at seedling and budding stages, and the soil culturable fungi at flower and bol stage were less than that of conven-tional cotton, while the soil alkaline phosphatase activities at flower and bol stage were higher. Cluster analysis showed that soil enzyme activities and microbial popu-lation changed mainly along the growth processes, suffering little from the planting of transgenic Bt+CpTI cotton.展开更多
[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved re...[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved recently were taken as materials and relationship of plant characters including bud living rate and moth- er stem emergence rate of ratoon rice before harvest was explored, based on relat- ed data. [Result] The shorter rice with lower harvesting index is the main character of high emergence rate for first cropping rice; decline of plant height and increase of ear-bearing percentage would improve emergence of regenerative seedlings. [Conclusion] The research provided scientific reference for breeding of rice cultivars with high regenerative capacity.展开更多
Double staining flow cytometry was performed using 7-amino actinomycin D and 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate,to detect the level fluctuation of reactive oxygen species (ROS) during the cel...Double staining flow cytometry was performed using 7-amino actinomycin D and 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate,to detect the level fluctuation of reactive oxygen species (ROS) during the cell cycle of normal NB4 cells. Our results showed that NB4 cells possessed higher level of ROS in G2/M phase than in G1 and S phases. Double staining flow cytometry,with TdT mediated dUTP nick end labeling (Tunel) and propidium iodide (PI),indicated that As2O3 (2 μM) could induce apoptosis in NB4 cells prevailingly from G2/M phase,and this efficacy was enhanced upon co-administration of 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) (2.5 μM) which could produce the endogenous ROS. These results suggested that different ROS level in different cell cycle phases of NB4 cells might determin the selective induction of G2/M apoptosis and the cells' susceptibility to apoptosis by As2O3.展开更多
Many flaviviruses are significant human pathogens causing considerable disease burdens,including encephalitis and hemorrhagic fever,in the regions in which they are endemic.A paucity of treatments for flaviviral infec...Many flaviviruses are significant human pathogens causing considerable disease burdens,including encephalitis and hemorrhagic fever,in the regions in which they are endemic.A paucity of treatments for flaviviral infections has driven interest in drug development targeting proteins essential to flavivirus replication,such as the viral protease.During viral replication,the flavivirus genome is translated as a single polyprotein precursor,which must be cleaved into individual proteins by a complex of the viral protease,NS3,and its cofactor,NS2B.Because this cleavage is an obligate step of the viral life-cycle,the flavivirus protease is an attractive target for antiviral drug development.In this review,we will survey recent drug development studies targeting the NS3 active site,as well as studies targeting an NS2B/NS3interaction site determined from flavivirus protease crystal structures.展开更多
Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicid...Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicidal activity of 5 kinds of Chinese herbs extracts and the compound solution of Avermectin,with strong contact toxicity effect indoor,was systematically studied and investigated the affection on the root-knot nematode parasitized on the cucumber seeding stage. It is found that under the premise of no influence on root growth of cucumber,extracts from Picrorhiza scrophulariiflora and Punica granatum showed strong prevention and nematicidal activity,and had the similar efficacy of Avermectin; while the extracts from Cibotium barometz,Aucklandia lappa Decne and Fructus cnidii showed low nematicidal activity and various degrees inhibition effect on plant growth.展开更多
Plasma membrane (PM) Ca2+-ATPase activity in poplar apical bud meristematic cells during short-day (SD)-induced dormancy development was examined by a cerium precipitation EM-cytochemical method. Ca2+-ATPase activ...Plasma membrane (PM) Ca2+-ATPase activity in poplar apical bud meristematic cells during short-day (SD)-induced dormancy development was examined by a cerium precipitation EM-cytochemical method. Ca2+-ATPase activity, indicated by the status of cerium phosphate precipitated grains, was localized mainly on the interior face (cytoplasmic side) of the PM when plants were grown under long days and reached a deep dormancy. A few reaction products were also observed on the nuclear envelope.When plant buds were developing dormancy after 28 to 42 d of SD exposure, almost no reaction products were present on the interior face of the PM. In contrast, a large number of cerium phosphate precipitated grains were distributed on the exterior face of the PM. After 70 d of SD exposure, when buds had developed a deep dormancy, the reaction products of Ca2+-ATPase activity again appeared on the interior face of the PM. The results seemed suggesting that two kinds of Ca2+-ATPases may be present on the PM during the SD-induced dormancy in poplar.One is the Ca2+-punlping ATPase, which is located on the interior face of the PM, for maintaining and restoring the Ca2+homeostasis. The other might be an ecto-Ca2+-ATPase, which is located on the exterior face of the PM, for the exocytosis of cell wall materials as suggested by the fact of the cell wall thickening during the dormancy developlnent in poplar.展开更多
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 Natural Science Fund of Education Department of Anhui Province(KJ2012B188)General Science and Research Program of Suzhou College(2011yyb13)~~
文摘[Objective] This study aimed to investigate the changes in activity of POD and CAT in wheat during generation period under drought stress. [Method] Four wheat cultivars, including Yunong 51, Zhoumai 22, Jimai 19 and Huaimai 22, were selected as experimental materials and cultured under drought stress simulated by different concentrations of PEG6000, to determine the activity of POD and CAT. [Result] POD and CAT activity in wheat during generation period increased gradual y under stress of 5% and 15% PEG6000 from 0 to 120 h; POD and CAT activity in wheat under stress of 15% PEG6000 increased more compared with that under stress of 5% PEG6000; POD and CAT activity in wheat under stress of 25% and 35% PEG6000 increased first and then decreased. Stress duration significantly af-fected the activity of POD and CAT in wheat during generation period. [Conclusion] This study provided theoretical references for breeding drought-tolerant wheat.
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Due to its strong and effective insecticidal properties, transgenic Bt+CpTI cotton has witnessed an expanding planting area in recent years, and the impact of its cultivation on soil ecosystem becomes an important part of environmental risk assessment. Using transgenic Bt+CpTI cotton sGK321 and its parental homologous conventional cotton Shiyuan 321 as the study objects, a comparative analysis was conducted on the changes in enzyme activities (urease, alkaline phosphatase, and catalase) of the rhizosphere soil and changes in the number of culturable microor-ganisms (bacteria, fungi, and actinomycetes) at different growth stages (seedling stage, budding stage, flower and bol stage, and bol opening stage) of sGK321 and Shiyuan 321 under the condition of 13 years field plantings. The results showed that, the populations of bacteria, fungi, and actinomycete and the soil enzyme activi-ties of urease, alkaline phosphatase and catalase had a similar variation trend along with the cotton growing process for transgenic cotton and conventional cotton. Some occasional and inconsistent effects on soil enzyme activities and soil fungi composi-tion in the rhizosphere soil of transgenic Bt+CpTI cotton were found at the seedling stage, budding stage, flower and bol stage as compared with that of conventional cotton. The amount of bacteria and actinomycetes were not significantly different during a certain stage; however, the activities of urease, catalase, alkaline phos-phatase, also with the number of fungi were significantly different, e.g. the urease activities at seedling stage, the alkaline phosphatase at seedling and budding stages, and the soil culturable fungi at flower and bol stage were less than that of conven-tional cotton, while the soil alkaline phosphatase activities at flower and bol stage were higher. Cluster analysis showed that soil enzyme activities and microbial popu-lation changed mainly along the growth processes, suffering little from the planting of transgenic Bt+CpTI cotton.
基金Supported by Sichuan Financial and Engineering Foundation for the Young(2007QNJJ-020)Sichuan Cultivation Foundation for Academy leaders+3 种基金Sichuan Key Project of Rice BreedingConstruction of Rice Industry System in SouthwestNational Crop-harvesting ProjectSichuan Financial Promotion~~
文摘[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved recently were taken as materials and relationship of plant characters including bud living rate and moth- er stem emergence rate of ratoon rice before harvest was explored, based on relat- ed data. [Result] The shorter rice with lower harvesting index is the main character of high emergence rate for first cropping rice; decline of plant height and increase of ear-bearing percentage would improve emergence of regenerative seedlings. [Conclusion] The research provided scientific reference for breeding of rice cultivars with high regenerative capacity.
基金supported by research grants from National Natural Science Foundation of China(No.30170475)
文摘Double staining flow cytometry was performed using 7-amino actinomycin D and 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate,to detect the level fluctuation of reactive oxygen species (ROS) during the cell cycle of normal NB4 cells. Our results showed that NB4 cells possessed higher level of ROS in G2/M phase than in G1 and S phases. Double staining flow cytometry,with TdT mediated dUTP nick end labeling (Tunel) and propidium iodide (PI),indicated that As2O3 (2 μM) could induce apoptosis in NB4 cells prevailingly from G2/M phase,and this efficacy was enhanced upon co-administration of 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) (2.5 μM) which could produce the endogenous ROS. These results suggested that different ROS level in different cell cycle phases of NB4 cells might determin the selective induction of G2/M apoptosis and the cells' susceptibility to apoptosis by As2O3.
基金supported by grants(AI094335) from the National Institute of Health and from the Wadsworth Center Scientific Interaction Group
文摘Many flaviviruses are significant human pathogens causing considerable disease burdens,including encephalitis and hemorrhagic fever,in the regions in which they are endemic.A paucity of treatments for flaviviral infections has driven interest in drug development targeting proteins essential to flavivirus replication,such as the viral protease.During viral replication,the flavivirus genome is translated as a single polyprotein precursor,which must be cleaved into individual proteins by a complex of the viral protease,NS3,and its cofactor,NS2B.Because this cleavage is an obligate step of the viral life-cycle,the flavivirus protease is an attractive target for antiviral drug development.In this review,we will survey recent drug development studies targeting the NS3 active site,as well as studies targeting an NS2B/NS3interaction site determined from flavivirus protease crystal structures.
基金Supported by Science and Technology Project from Shaanxi Provincial Department of EducationMajor Scientific and Technological In-novation Project of Shaanxi Province (2009ZKC08-09 )Science and Technology Project of Wenzhou (H20080045)~~
文摘Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicidal activity of 5 kinds of Chinese herbs extracts and the compound solution of Avermectin,with strong contact toxicity effect indoor,was systematically studied and investigated the affection on the root-knot nematode parasitized on the cucumber seeding stage. It is found that under the premise of no influence on root growth of cucumber,extracts from Picrorhiza scrophulariiflora and Punica granatum showed strong prevention and nematicidal activity,and had the similar efficacy of Avermectin; while the extracts from Cibotium barometz,Aucklandia lappa Decne and Fructus cnidii showed low nematicidal activity and various degrees inhibition effect on plant growth.
文摘Plasma membrane (PM) Ca2+-ATPase activity in poplar apical bud meristematic cells during short-day (SD)-induced dormancy development was examined by a cerium precipitation EM-cytochemical method. Ca2+-ATPase activity, indicated by the status of cerium phosphate precipitated grains, was localized mainly on the interior face (cytoplasmic side) of the PM when plants were grown under long days and reached a deep dormancy. A few reaction products were also observed on the nuclear envelope.When plant buds were developing dormancy after 28 to 42 d of SD exposure, almost no reaction products were present on the interior face of the PM. In contrast, a large number of cerium phosphate precipitated grains were distributed on the exterior face of the PM. After 70 d of SD exposure, when buds had developed a deep dormancy, the reaction products of Ca2+-ATPase activity again appeared on the interior face of the PM. The results seemed suggesting that two kinds of Ca2+-ATPases may be present on the PM during the SD-induced dormancy in poplar.One is the Ca2+-punlping ATPase, which is located on the interior face of the PM, for maintaining and restoring the Ca2+homeostasis. The other might be an ecto-Ca2+-ATPase, which is located on the exterior face of the PM, for the exocytosis of cell wall materials as suggested by the fact of the cell wall thickening during the dormancy developlnent in poplar.