HEAT-INDUCED CHANGES IN THE EFFICIENCY OF P700 PHOTO-OXIDATION IN PEA CHLOROPLAST MEMBRANES

被引：27
作者：
IVANOV, AG
VELITCHKOVA, MY
机构：
[1] Bulgarian Academy of Sciences, Central Laboratory of Biophysics, 1113 Sofia, Acad. G. Bonchev Str.
来源：
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY | 1990年 / 4卷 / 03期
关键词：
77 K fluorescence; chloroplast structure; ESR spectroscopy; glutaraldehyde; heat stress; P700;
D O I：
10.1016/1011-1344(90)85036-V
中图分类号：
Q5 [生物化学]; Q7 [分子生物学];
学科分类号：
071010 ; 081704 ;
摘要：
The influence of short-time heat stress (5 min at 50 °C) on the photo-oxidation of the reaction center pigment of photosystem I (P700) under continuous illumination of pea chloroplasts was studied. It was found that heating leads to a considerable increase in P700+, measured by the amplitude of the electron spin resonance signal I. Fluorescence emission spectra (77 K) of heat-treated chloroplasts indicate an enhancement of spillover. Photosystem II activity (H2O-2,6-dichlorophenolindophenol) is strongly inhibited at heat-stressed chloroplasts. Low light intensity measurements showed a higher rate of light-induced oxidation of P700, related to an increase in the photosystem I absorption cross-section. The data are discussed with respect to the heat-induced structural reorganization of membrane pigment-protein complexes. © 1990.
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页码：307 / 320
页数：14
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