Bicarbonate protects the water-oxidizing complex of photosystem II against thermoinactivation in intact Chlamydomonas reinhardtii cells

被引:0
作者
S. K. Zharmukhamedov
G. N. Shirshikova
Z. V. Maevskaya
T. M. Antropova
V. V. Klimov
机构
[1] Russian Academy of Sciences,Institute of Basic Problems of Biology
来源
Russian Journal of Plant Physiology | 2007年 / 54卷
关键词
Chlamydomonas reinhardtii; photosystem II; water-oxidizing complex; bicarbonate; thermoinactivation; photosynthesis;
D O I
暂无
中图分类号
学科分类号
摘要
Currently available data about bicarbonate (BC) action on the Mn-containing water-oxidizing complex (WOC) of the photosystem II (PSII) were obtained almost solely in vitro, e.g. on subchloroplast membrane fragments enriched with PSII. To investigate the in vivo BC effect on the PSII donor side, we used the method of dark thermoinactivation of intact Chlamydomonas reinhardtii cells. Photosynthetic activity of PSII was measured as photoinduced changes in the PSII chlorophyll fluorescence yield and as the rate of photosynthetic oxygen evolution. To exclude a “direct” effect of the absence of BC on the PSII activity, before measurements of the photosynthetic activity, the concentration of BC in all samples was equalized by addition of NaHCO3 to each of them (except for those that contained 5 mM of NaHCO3 during thermoinactivation) to reach the final concentration of 5 mM. This allowed registering only so-called “irreversible” (i.e., not reversible by subsequent addition of BC) effect of the absence of BC during thermoinactivation. It was shown that, if 5 mM NaHCO3 was added to the medium before thermoinactivation, the rate of inactivation of the PSII donor side was lower than in BC-depleted medium 1.5-to 2-fold. The obtained results are interpreted as an indication that BC protects the donor side of PSII against thermoinactivation in vivo, in intact C. reinhardtii cells. This proves the correctness of the earlier proposition that BC is an integral constituent of the Mn-containing water-oxidizing complex of PSII.
引用
收藏
页码:302 / 308
页数:6
相关论文
共 92 条
[1]  
Warburg O.(1958)Hill-Reaktionen Z. Naturforsch. 13b 509-514
[2]  
Krippahl G.(1973)Bicarbonate Ion as a Critical Factor in Photosynthetic Oxygen Evolution Plant Physiol. 52 119-123
[3]  
Stemler A.(1979)Isotope Ratios in Photosynthetic Oxygen Biochim. Biophys. Acta 548 287-295
[4]  
Govindjee H.(1980)Inhibition of Photosystem 2 by Formate: Possible Evidence for a Direct Role of Bicarbonate in Photosynthetic Oxygen Evolution Biochim. Biophys. Acta 593 103-112
[5]  
Metzner K.(1975)A New Site of Bicarbonate Effect in Photosystem II of Photosynthesis: Evidence from Chlorophyll Fluorescence Transients in Spinach Chloroplasts Biochim. Biophys. Acta 387 403-408
[6]  
Fischer O.(1978)Bicarbonate Effects on the Electron Flow in Isolated Broken Chloroplasts Biochim. Biophys. Acta 505 183-213
[7]  
Balzen A.(1990)Formation by NO of Nitrosyl Adducts of Redox Components of the Photosystem II Reaction Center: 2. Evidence that HCO Biochim. Biophys. Acta 1015 141-149
[8]  
Stemler T.(1995)/CO Biochemistry 34 16 288-16 297
[9]  
Wydrzynski J.J.S.(1995) Binds to the Acceptor-Side Non-Heme Iron FEBS Lett. 363 251-255
[10]  
Govindjee B.A.(1995)Bicarbonate Binding to the Non-Heme Iron of Photosystem II Investigated by Fourier Transform Infrared Difference Spectroscopy and Photosynth. Res. 46 219-225