摘要
Due to 4f electron characteristics and alternation valence, cerium involved in an oxidation-reduction reaction in plant, closely relating to photosynthesis. Our studies proved that cerium could promote photosynthesis and greatly improve spinach growth. However, the mechanism of promoting energy transfer and conversion by cerium remains unclear. Here we reported that the effects of Ce^3＋ on energy transfer and oxygen evolution in photosystem Ⅱ （PS Ⅱ ） isolated from spinach, which was related to 4f electron characteristics and alternation valence in Ce molecule. The methods of absorption spectrum, fluorescence spectrum were used in the research. Results showed that Ce^3＋ treatment at low concentration could suitably change PS Ⅱ mieroenvironment, increase the absorbance of visible light, improve the energy transfer among amino acids within PS Ⅱ protein-pigment complex, and accelerate energy transport from tyrosine residue to chlorophyll a. In summary, the photochemical activity of PS Ⅱ （fluorescence quantum yield） and its oxygen evolving rate were enhanced by Ce^3＋.
Due to 4f electron characteristics and alternation valence, cerium involved in an oxidation-reduction reaction in plant, closely relating to photosynthesis. Our studies proved that cerium could promote photosynthesis and greatly improve spinach growth. However, the mechanism of promoting energy transfer and conversion by cerium remains unclear. Here we reported that the effects of Ce^3＋ on energy transfer and oxygen evolution in photosystem Ⅱ （PS Ⅱ ） isolated from spinach, which was related to 4f electron characteristics and alternation valence in Ce molecule. The methods of absorption spectrum, fluorescence spectrum were used in the research. Results showed that Ce^3＋ treatment at low concentration could suitably change PS Ⅱ mieroenvironment, increase the absorbance of visible light, improve the energy transfer among amino acids within PS Ⅱ protein-pigment complex, and accelerate energy transport from tyrosine residue to chlorophyll a. In summary, the photochemical activity of PS Ⅱ （fluorescence quantum yield） and its oxygen evolving rate were enhanced by Ce^3＋.
基金
Project supported by the National Natural Science Foundation of China (20671067, 30470150)
