Effects of Photosystem Ⅱ (PS Ⅱ) extrinsic polypeptides of oxygen-evolving complex and manganese clusters on PS Ⅱ carbonic anhydrase (CA) were studied with spinach PS Ⅱ membranes. The result supported that membrane...Effects of Photosystem Ⅱ (PS Ⅱ) extrinsic polypeptides of oxygen-evolving complex and manganese clusters on PS Ⅱ carbonic anhydrase (CA) were studied with spinach PS Ⅱ membranes. The result supported that membrane-bound CA is located in the donor side of PS Ⅱ. The extrinsic polypeptides played an important role of maintaining CA activity. After removing manganese clusters, oxygen evolution activity was inhibited, but PSⅡ-CA activity was unchanged. It was concluded that CA activity is independent of the presence of manganese clusters, and was not directly correlated with oxygen evolution activity.展开更多
The emission of microwave sulfur lamp is mainly composed of visible light. The sulfur lamp, producing little infrared radiation, has high efficiency, long duration of illumination and less energy consumption. In order...The emission of microwave sulfur lamp is mainly composed of visible light. The sulfur lamp, producing little infrared radiation, has high efficiency, long duration of illumination and less energy consumption. In order to probe the agricultural application of the lamp, experiments were carried out with wheat (cv. Yangmai 158) to emphatically study illuminating effects of xenon or sulfur lamp on tillering, jointing and net photosynthetic rate during tillering and jointing periods. Results indicated that there is almost no difference in net photosynthetic rate of wheat leaves growing under different lamps. Xenon lamp significantly advanced the time of jointing, decreased number of tillers, number of total leaves per plant and leaf size, as well as inhibited root growth. In contrast with xenon lamp, sulfur lamp evidently delays the time of heading and grain maturation, increased number of heads per plant, head length, total number of grains per plant, head weight and total grain weight per plant,展开更多
Photodynamics of peripheral antenna complexes,light-harvesting complex (LH2) of Rhodobacter (Rb) Sphaeroides 601,was studied using femtosecond pump-probe technique at different laser wavelengths. The obtained results ...Photodynamics of peripheral antenna complexes,light-harvesting complex (LH2) of Rhodobacter (Rb) Sphaeroides 601,was studied using femtosecond pump-probe technique at different laser wavelengths. The obtained results reveal dramatic dynamical evolutions within B800 and B850 absorption bands of antenna complexes LH2. At excitation wavelength around 835 nm,a sharp photobleaching signal was observed which was assigned to the contribution of the two-exciton state,which was further confirmed by the power dependence measurement. Rate equations with eight-level scheme were used to calculate the population evolution in LH2 and the transient dynamics under femtosecond pulse excitation. The research results prove that not only the transition from ground state to one-exciton state but also that from one-exciton state to two-exciton state contribute to the photodynamics of B850.展开更多
One electron paramagnetic resonance(EPR)signal,named SignalⅡslow,originates from the oxidized Tyrosine 160(Y_(D))of D2 polypeptide of photosystemⅡreaction center.After adding high concentration trichloroacetate(TCA)...One electron paramagnetic resonance(EPR)signal,named SignalⅡslow,originates from the oxidized Tyrosine 160(Y_(D))of D2 polypeptide of photosystemⅡreaction center.After adding high concentration trichloroacetate(TCA)to the Chlamydomonas reinhardtii thylakoid suspension.this signal was abolished in a minute.Treatment of TCA also removes a few of polypeptides,including three extrinsic polypeptides of oxygen-evolving complex,from the thylakoid membrane.Based upon the analysis of the microenvironment around YD with a three-dimensional model,it is indicated that relatively high hydrophobicity of this microenvironment may be the essential prerequisite for TCA to affect YD.It has been observed that TCA treatment also retards the decay of the Signal I,produced by the oxidized reaction center chlorophyll dimer(P700^(+))of photosys-tem I.展开更多
基金State Key Basic Research Development Plan (Grant No. G1998010100) and the National Natural Science Foundation of China (Grant No. 39770156).
文摘Effects of Photosystem Ⅱ (PS Ⅱ) extrinsic polypeptides of oxygen-evolving complex and manganese clusters on PS Ⅱ carbonic anhydrase (CA) were studied with spinach PS Ⅱ membranes. The result supported that membrane-bound CA is located in the donor side of PS Ⅱ. The extrinsic polypeptides played an important role of maintaining CA activity. After removing manganese clusters, oxygen evolution activity was inhibited, but PSⅡ-CA activity was unchanged. It was concluded that CA activity is independent of the presence of manganese clusters, and was not directly correlated with oxygen evolution activity.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 30170079)the State Key Basic Development Plan Programm (Grant No. G1998010100).
文摘The emission of microwave sulfur lamp is mainly composed of visible light. The sulfur lamp, producing little infrared radiation, has high efficiency, long duration of illumination and less energy consumption. In order to probe the agricultural application of the lamp, experiments were carried out with wheat (cv. Yangmai 158) to emphatically study illuminating effects of xenon or sulfur lamp on tillering, jointing and net photosynthetic rate during tillering and jointing periods. Results indicated that there is almost no difference in net photosynthetic rate of wheat leaves growing under different lamps. Xenon lamp significantly advanced the time of jointing, decreased number of tillers, number of total leaves per plant and leaf size, as well as inhibited root growth. In contrast with xenon lamp, sulfur lamp evidently delays the time of heading and grain maturation, increased number of heads per plant, head length, total number of grains per plant, head weight and total grain weight per plant,
基金the National Natural Science Foundation of China (Grant No.10674031)
文摘Photodynamics of peripheral antenna complexes,light-harvesting complex (LH2) of Rhodobacter (Rb) Sphaeroides 601,was studied using femtosecond pump-probe technique at different laser wavelengths. The obtained results reveal dramatic dynamical evolutions within B800 and B850 absorption bands of antenna complexes LH2. At excitation wavelength around 835 nm,a sharp photobleaching signal was observed which was assigned to the contribution of the two-exciton state,which was further confirmed by the power dependence measurement. Rate equations with eight-level scheme were used to calculate the population evolution in LH2 and the transient dynamics under femtosecond pulse excitation. The research results prove that not only the transition from ground state to one-exciton state but also that from one-exciton state to two-exciton state contribute to the photodynamics of B850.
基金This work was supported by the State Key Bausic Research and Developmen Plan(Grant No.G1998010100)the National Natural Science Foundation of China(Grant No.39730040).
文摘One electron paramagnetic resonance(EPR)signal,named SignalⅡslow,originates from the oxidized Tyrosine 160(Y_(D))of D2 polypeptide of photosystemⅡreaction center.After adding high concentration trichloroacetate(TCA)to the Chlamydomonas reinhardtii thylakoid suspension.this signal was abolished in a minute.Treatment of TCA also removes a few of polypeptides,including three extrinsic polypeptides of oxygen-evolving complex,from the thylakoid membrane.Based upon the analysis of the microenvironment around YD with a three-dimensional model,it is indicated that relatively high hydrophobicity of this microenvironment may be the essential prerequisite for TCA to affect YD.It has been observed that TCA treatment also retards the decay of the Signal I,produced by the oxidized reaction center chlorophyll dimer(P700^(+))of photosys-tem I.
