采用叶绿素荧光分析技术探讨了温度、p H、光强对水华优势种倪氏拟多甲藻光合活性的影响。结果表明,倪氏拟多甲藻光系统Ⅱ的量子产量Y(Ⅱ)和最大光化学效率(F_v/F_m)随温度(7.5—20.0℃)升高而显著增加(P<0.05),在低温下电子传递速...采用叶绿素荧光分析技术探讨了温度、p H、光强对水华优势种倪氏拟多甲藻光合活性的影响。结果表明,倪氏拟多甲藻光系统Ⅱ的量子产量Y(Ⅱ)和最大光化学效率(F_v/F_m)随温度(7.5—20.0℃)升高而显著增加(P<0.05),在低温下电子传递速率未受阻,细胞在7.5—20.0℃内均有高光合活性;10.0℃下的光合活性随p H增大先升高后降低,峰值出现在p H 7.3时,光合活性顺序为:弱碱性>中性>酸性;快速叶绿素荧光动力学曲线分析显示p H 7.3下的光合活性为典型OJIP曲线,其他p H下PSⅡ反应中心、电子受体库受损,显示该藻适应较窄的p H范围,p H7.0—8.0内是其适宜的条件;快速光响应曲线显示其半饱和光强E_k为385.52μmol photons/(m^2·s),表明其具有高光饱和点,耐受高光强。研究表明藻细胞光合活性对温度和光强变化有较强适应性,对p H的变化敏感,弱碱性条件是其光合作用的适宜条件;低温时细胞通过环式电子链提高光化学效率,降低高光强可能带来的光损伤;弱酸性(p H 5.0)会同时损伤其光系统Ⅰ和光系统Ⅱ,造成其光化学效率的显著下降;倪氏拟多甲藻在低温和高光强下的独特光合特性使其在春季淡水水体中占据竞争优势,是其形成水华的内在原因。展开更多
Surfactants are widely used in the purification and research of structure and function of the protein complexes in photosynthetic membrane. To elucidate the mechanism of interaction between surfactants and photosystem...Surfactants are widely used in the purification and research of structure and function of the protein complexes in photosynthetic membrane. To elucidate the mechanism of interaction between surfactants and photosystem Ⅰ (PSⅠ), effects of two typical surfactants, Triton X_100 and sodium dodecyl sulfate (SDS) on PSⅠ, were studied at different concentrations. The results were: SDS led to the reduction of apparent absorption intensity and blue shift of absorption peaks; while Triton X_100 led to the decrease of apparent absorption intensity in red region and blue shift of the peak, but to the increase of apparent absorption intensity in blue region. The fourth derivative spectra show that the longwavelength (669 nm and 683 nm) absorbing chlorophyll a was affected greatly and their relative changes of absorbance were axially symmetrical. The presence of surfactant could make the long wavelength fluorescence emission decrease greatly and a new fluorescence peak appeared around 680 nm, it was obvious that the surfactant interceded the transfer of excitation energy from antenna pigments to reaction center. The surfactants might affect the microenvironment of proteins, even the structure of PSⅠ protein subunits and hence changed the binding status of pigments with protein subunits, or the pigments might be released from the subunits. All of these might affect the absorption and the transfer of excitation energy.展开更多
[Objective] To investigate the effects of different ozone concentrations （30, 60, 80, 100 and 120 μg/L） on the physiological and biochemical characteristics of M9T337, so as to provide theoretical basis for breedin...[Objective] To investigate the effects of different ozone concentrations （30, 60, 80, 100 and 120 μg/L） on the physiological and biochemical characteristics of M9T337, so as to provide theoretical basis for breeding anti-ozone dwarfing root- stocks. [Method] The effects of different concentrations of ozone on chlorophyll con- tent, antioxidant enzyme activity, malondialdehyde （MDA） and soluble protein content of M9T337 were studied by potting dwarfing rootstock M9T337 as test material. [Result] With the increase of ozone concentration, the content of chlorophyll in M9T337 leaves decreased gradually. The activity of SOD （superoxide dismutase） and CAT （catalase） increased first and then decreased, while POD （Peroxidase） ac- tivity and MDA （malondialdehyde） content were gradually increased. [Conclusion] The comprehensive analysis of the indicators indicated that the potted M9T337 could tolerate the low concentration （〈80 μg/L） ozone stress in the short time （〈3 h）, and it would cause serious injury to M9T337 when the ozone concentration ex- ceeded 80 μg/L.展开更多
By measuring wetland plants chlorophyll content,malondialdehyde(MDA) content and superoxide dismutase(SOD) enzyme activity,the changes of wetland plant physiological characeristics under different power strength were ...By measuring wetland plants chlorophyll content,malondialdehyde(MDA) content and superoxide dismutase(SOD) enzyme activity,the changes of wetland plant physiological characeristics under different power strength were studied,and the mechanism of electric field on plant physiological characteristics was analyzed to provide a theoretical basis for the pollutant removal ability strengthening of artificial wetland under electricfield.The results showed that compared with the control plants,low-intensity-voltage(1 V and 3 V) had no significant effect on the normal physiological and biochemical indexes of the plants,and the growth trend was better than the control group;with the voltage increasing,plant chlorophyll content,MDA content and SOD activity were greatly affected,indicating that plants were under strong oxidative stress,and the growth was damaged.Therefore,a suitable electric field could enhance the sewage treatment effect of constructed wetland.展开更多
A greenhouse culture experiment was used to evaluate the effects of antimony(Sb)stress on Ficus tikoua(F.tikoua).Theresults showed that the growth of F.tikoua leaves was significantly inhibited when Sb concentration w...A greenhouse culture experiment was used to evaluate the effects of antimony(Sb)stress on Ficus tikoua(F.tikoua).Theresults showed that the growth of F.tikoua leaves was significantly inhibited when Sb concentration was higher than30μmol/L,andno significantly inhibitory effect of Sb on the roots and stems of F.tikoua was found in all the treatments,implying that leaves weremore sensitive to Sb toxicity than roots and stems.Antimony concentration in the roots was higher than that in the stems and leaves.To reduce reactive oxygen species(ROS)level in the F.tikoua,the activities of superoxide dismutase(SOD),peroxidase(POD)andcatalase(CAT)increased with Sb treatments,but the SOD and CAT were more early active than POD.Although the decrease ofchlorophyll content with high Sb treatments(450μmol/L)was observed at the end of the experiments,the positive impact onchlorophyll content was observed with all the Sb treatments at the early period.No significant difference of the maximum quantumefficiency of PSII and quantum yield of PSII electron transport values with different Sb treatments was observed at the end of thisexperiment,suggesting that the photosynthesis was not inhibited with Sb concentration below450μmol/L.The results implied acertain tolerance to Sb stress for F.tikoua.This meets the essential condition for utilization in Sb contamination environments.展开更多
In order to effectively reduce the chlorophyll content in flue-cured tobacco, improve the overall quality of tobacco leaves, chlorophyllase gene was cloned from Arabidopsis thaliana. After the expression of the expres...In order to effectively reduce the chlorophyll content in flue-cured tobacco, improve the overall quality of tobacco leaves, chlorophyllase gene was cloned from Arabidopsis thaliana. After the expression of the expression vector in E. coil, the recombinant engineering strain was obtained. Afterwards, IPTG （isopropy-β-D-thiogalactopyranoside）was used to induce the goal protein, and the chlorophyllase activity of the recombinant engineering strain was measured, so as to investigate its degradation effect on the chlorophyll in the extracts of tobacco leaves. The results were as follows： （1） the amplified chlorophyllase gene At- CLH1 constructed the expression vector pET28a-AtCLH1 successfully, obtaining the recombinant engineering strain; （2） induced under 30 ℃ for 22 h, the strain could well express the recombinant protein AtCLH1 with 0.5 mmol/L IPTG, and the molecular weight was about 35 kDa; （3） the strain showed good chlorophyllase producing capability, and the activity of the produced chlorophyllase could reach up to 24.9 U/mL, which could degrade the chlorophyll in tobacco extract and had a good application prospect in improving the quality of low quality tobacco; （4） based on the results of orthogonal test, the enzyme extract from the strain was added to the tobacco leaf surface, which could make the degradation rate of chlorophyll in the tobacco leaf reach 17.06% under the temperature of 37 ℃ at the humidity of 75% for 48 h; （5） after treated by the enzyme liquid, the test tobacco showed increase in the content of aromatic substances, enhancement of tobacco fragrance quality and amount, significant decrease of offensive odor and irritation, significant improvement of agreeable aftertaste, making the overall sensory quality of the tobacco leaf significantly improved.展开更多
Rice leaf color mutants play a great role in research about the formation and development of chloroplasts and the genetic mechanism of the chlorophyll （Chl） metabolism pathway, pgl3 is a rice leaf color mutant deriv...Rice leaf color mutants play a great role in research about the formation and development of chloroplasts and the genetic mechanism of the chlorophyll （Chl） metabolism pathway, pgl3 is a rice leaf color mutant derived from Xiushuil 1 （Oryza sativa L. spp. japonica）, treated with ethyl methane sulfonate （EMS）. The mutant exhibited a pale- green leaf （pg/） phenotype throughout the whole development as well as reduced grain quality. Map-based cloning of PGL3 revealed that it encodes the chloroplast signal recognition particle 43 kDa protein （cpSRP43）. PGL3 affected the Chl synthesis by regulating the expression levels of the Chl synthesis-associated genes. Considerable reactive oxygen species were accumulated in the leaves of pgl3, and the transcription levels of its scavenging genes were down- regulated, indicating that pgl3 can accelerate senescence. In addition, high temperatures could inhibit the plant＇s growth and facilitate the process of senescence in pgl3.展开更多
The effects of direct extracts of compost (DEC), aerated fermentation extracts of compost (AFEC) and non-aerated fermentation extracts of compost (NAFEC) on cucumber growth and the action mechanisms were evaluated bas...The effects of direct extracts of compost (DEC), aerated fermentation extracts of compost (AFEC) and non-aerated fermentation extracts of compost (NAFEC) on cucumber growth and the action mechanisms were evaluated based on the structure and activity analysis of humic-like substances. AFEC increased cucumber growth most significantly, followed by DEC and NAFEC, which was insignificant compared to the control treatment. Humic-like substances from compost extracts played an important role in promoting cucumber growth. Application of humic-like substances stimulated auxin-like activity and increased chlorophyll content and nitrogen accumulation in plants. The positive auxin-like activity of humic-like substances could be attributed to the relative distribution of special carbon groups, such as those with a large amount of peptidic and carbohydratic groups or with a low content of phenolic groups. In conclusion, the best growth promotion by application of AFEC was mainly attributed to the humic-like substances in the AFEC.展开更多
文摘采用叶绿素荧光分析技术探讨了温度、p H、光强对水华优势种倪氏拟多甲藻光合活性的影响。结果表明,倪氏拟多甲藻光系统Ⅱ的量子产量Y(Ⅱ)和最大光化学效率(F_v/F_m)随温度(7.5—20.0℃)升高而显著增加(P<0.05),在低温下电子传递速率未受阻,细胞在7.5—20.0℃内均有高光合活性;10.0℃下的光合活性随p H增大先升高后降低,峰值出现在p H 7.3时,光合活性顺序为:弱碱性>中性>酸性;快速叶绿素荧光动力学曲线分析显示p H 7.3下的光合活性为典型OJIP曲线,其他p H下PSⅡ反应中心、电子受体库受损,显示该藻适应较窄的p H范围,p H7.0—8.0内是其适宜的条件;快速光响应曲线显示其半饱和光强E_k为385.52μmol photons/(m^2·s),表明其具有高光饱和点,耐受高光强。研究表明藻细胞光合活性对温度和光强变化有较强适应性,对p H的变化敏感,弱碱性条件是其光合作用的适宜条件;低温时细胞通过环式电子链提高光化学效率,降低高光强可能带来的光损伤;弱酸性(p H 5.0)会同时损伤其光系统Ⅰ和光系统Ⅱ,造成其光化学效率的显著下降;倪氏拟多甲藻在低温和高光强下的独特光合特性使其在春季淡水水体中占据竞争优势,是其形成水华的内在原因。
文摘Surfactants are widely used in the purification and research of structure and function of the protein complexes in photosynthetic membrane. To elucidate the mechanism of interaction between surfactants and photosystem Ⅰ (PSⅠ), effects of two typical surfactants, Triton X_100 and sodium dodecyl sulfate (SDS) on PSⅠ, were studied at different concentrations. The results were: SDS led to the reduction of apparent absorption intensity and blue shift of absorption peaks; while Triton X_100 led to the decrease of apparent absorption intensity in red region and blue shift of the peak, but to the increase of apparent absorption intensity in blue region. The fourth derivative spectra show that the longwavelength (669 nm and 683 nm) absorbing chlorophyll a was affected greatly and their relative changes of absorbance were axially symmetrical. The presence of surfactant could make the long wavelength fluorescence emission decrease greatly and a new fluorescence peak appeared around 680 nm, it was obvious that the surfactant interceded the transfer of excitation energy from antenna pigments to reaction center. The surfactants might affect the microenvironment of proteins, even the structure of PSⅠ protein subunits and hence changed the binding status of pigments with protein subunits, or the pigments might be released from the subunits. All of these might affect the absorption and the transfer of excitation energy.
基金Supported by the National Natural Science Foundation of China[(CN)(31572091)]the Natural Science Foundation of Shandong Province(ZR2015CQ016)~~
文摘[Objective] To investigate the effects of different ozone concentrations （30, 60, 80, 100 and 120 μg/L） on the physiological and biochemical characteristics of M9T337, so as to provide theoretical basis for breeding anti-ozone dwarfing root- stocks. [Method] The effects of different concentrations of ozone on chlorophyll con- tent, antioxidant enzyme activity, malondialdehyde （MDA） and soluble protein content of M9T337 were studied by potting dwarfing rootstock M9T337 as test material. [Result] With the increase of ozone concentration, the content of chlorophyll in M9T337 leaves decreased gradually. The activity of SOD （superoxide dismutase） and CAT （catalase） increased first and then decreased, while POD （Peroxidase） ac- tivity and MDA （malondialdehyde） content were gradually increased. [Conclusion] The comprehensive analysis of the indicators indicated that the potted M9T337 could tolerate the low concentration （〈80 μg/L） ozone stress in the short time （〈3 h）, and it would cause serious injury to M9T337 when the ozone concentration ex- ceeded 80 μg/L.
基金Supported by Natural Science Foundation of Shanghai(10ZR1400300 )Central University Special Foundation of Basic Research and Operating expenses+1 种基金Creative Group Foundation of the National Natural Science Foundation of China (50721006)Key Discipline construction Project of Shanghai (B604)~~
文摘By measuring wetland plants chlorophyll content,malondialdehyde(MDA) content and superoxide dismutase(SOD) enzyme activity,the changes of wetland plant physiological characeristics under different power strength were studied,and the mechanism of electric field on plant physiological characteristics was analyzed to provide a theoretical basis for the pollutant removal ability strengthening of artificial wetland under electricfield.The results showed that compared with the control plants,low-intensity-voltage(1 V and 3 V) had no significant effect on the normal physiological and biochemical indexes of the plants,and the growth trend was better than the control group;with the voltage increasing,plant chlorophyll content,MDA content and SOD activity were greatly affected,indicating that plants were under strong oxidative stress,and the growth was damaged.Therefore,a suitable electric field could enhance the sewage treatment effect of constructed wetland.
基金Project(2012GS430203-1)supported by Science and Technology Program for Public Wellbeing,China
文摘A greenhouse culture experiment was used to evaluate the effects of antimony(Sb)stress on Ficus tikoua(F.tikoua).Theresults showed that the growth of F.tikoua leaves was significantly inhibited when Sb concentration was higher than30μmol/L,andno significantly inhibitory effect of Sb on the roots and stems of F.tikoua was found in all the treatments,implying that leaves weremore sensitive to Sb toxicity than roots and stems.Antimony concentration in the roots was higher than that in the stems and leaves.To reduce reactive oxygen species(ROS)level in the F.tikoua,the activities of superoxide dismutase(SOD),peroxidase(POD)andcatalase(CAT)increased with Sb treatments,but the SOD and CAT were more early active than POD.Although the decrease ofchlorophyll content with high Sb treatments(450μmol/L)was observed at the end of the experiments,the positive impact onchlorophyll content was observed with all the Sb treatments at the early period.No significant difference of the maximum quantumefficiency of PSII and quantum yield of PSII electron transport values with different Sb treatments was observed at the end of thisexperiment,suggesting that the photosynthesis was not inhibited with Sb concentration below450μmol/L.The results implied acertain tolerance to Sb stress for F.tikoua.This meets the essential condition for utilization in Sb contamination environments.
基金Supported by the Planning Project for the Scientific Research and Technological Development of China Tobacco Henan Industrial Co.,Ltd.(ZW201435)
文摘In order to effectively reduce the chlorophyll content in flue-cured tobacco, improve the overall quality of tobacco leaves, chlorophyllase gene was cloned from Arabidopsis thaliana. After the expression of the expression vector in E. coil, the recombinant engineering strain was obtained. Afterwards, IPTG （isopropy-β-D-thiogalactopyranoside）was used to induce the goal protein, and the chlorophyllase activity of the recombinant engineering strain was measured, so as to investigate its degradation effect on the chlorophyll in the extracts of tobacco leaves. The results were as follows： （1） the amplified chlorophyllase gene At- CLH1 constructed the expression vector pET28a-AtCLH1 successfully, obtaining the recombinant engineering strain; （2） induced under 30 ℃ for 22 h, the strain could well express the recombinant protein AtCLH1 with 0.5 mmol/L IPTG, and the molecular weight was about 35 kDa; （3） the strain showed good chlorophyllase producing capability, and the activity of the produced chlorophyllase could reach up to 24.9 U/mL, which could degrade the chlorophyll in tobacco extract and had a good application prospect in improving the quality of low quality tobacco; （4） based on the results of orthogonal test, the enzyme extract from the strain was added to the tobacco leaf surface, which could make the degradation rate of chlorophyll in the tobacco leaf reach 17.06% under the temperature of 37 ℃ at the humidity of 75% for 48 h; （5） after treated by the enzyme liquid, the test tobacco showed increase in the content of aromatic substances, enhancement of tobacco fragrance quality and amount, significant decrease of offensive odor and irritation, significant improvement of agreeable aftertaste, making the overall sensory quality of the tobacco leaf significantly improved.
基金Project supported by the National Natural Science Foundation of China(No.31521064)the Chinese Academy of Agricultural Sciences(No.CAAS-ASTIP-201X-CNRRI)the Zhejiang Provincial Natural Science Foundation of China(Nos.LQ15C130001 and LY16C060003)
文摘Rice leaf color mutants play a great role in research about the formation and development of chloroplasts and the genetic mechanism of the chlorophyll （Chl） metabolism pathway, pgl3 is a rice leaf color mutant derived from Xiushuil 1 （Oryza sativa L. spp. japonica）, treated with ethyl methane sulfonate （EMS）. The mutant exhibited a pale- green leaf （pg/） phenotype throughout the whole development as well as reduced grain quality. Map-based cloning of PGL3 revealed that it encodes the chloroplast signal recognition particle 43 kDa protein （cpSRP43）. PGL3 affected the Chl synthesis by regulating the expression levels of the Chl synthesis-associated genes. Considerable reactive oxygen species were accumulated in the leaves of pgl3, and the transcription levels of its scavenging genes were down- regulated, indicating that pgl3 can accelerate senescence. In addition, high temperatures could inhibit the plant＇s growth and facilitate the process of senescence in pgl3.
基金Supported by the Ministry of Agriculture Public Benefit Research Foundation of China (No. 201103004)the National Key Technology R&D Program of China (No. 2010AA10Z401)
文摘The effects of direct extracts of compost (DEC), aerated fermentation extracts of compost (AFEC) and non-aerated fermentation extracts of compost (NAFEC) on cucumber growth and the action mechanisms were evaluated based on the structure and activity analysis of humic-like substances. AFEC increased cucumber growth most significantly, followed by DEC and NAFEC, which was insignificant compared to the control treatment. Humic-like substances from compost extracts played an important role in promoting cucumber growth. Application of humic-like substances stimulated auxin-like activity and increased chlorophyll content and nitrogen accumulation in plants. The positive auxin-like activity of humic-like substances could be attributed to the relative distribution of special carbon groups, such as those with a large amount of peptidic and carbohydratic groups or with a low content of phenolic groups. In conclusion, the best growth promotion by application of AFEC was mainly attributed to the humic-like substances in the AFEC.
