Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Publication year range
1.
Biofizika ; 55(2): 252-8, 2010.
Article in Russian | MEDLINE | ID: mdl-20429278

ABSTRACT

The joint effects of 0.5 M NaCI and light of different intensities on the activity of the photosynthetic apparatus and ATP contents in cells of the katG- mutant of cyanobacterium Synechocystis sp. PCC 6803 have been studied. The mutant demonstrated a higher photoinhibition rate and a slower rate of recovery compared to the wild type, as it was shown by measurements of the CO2-dependent O2 production and delayed light emission of Chl a. The presence of 0.5 M NaCl in incubation medium induced the equal photoinhibition of the photosynthetic apparatus at I = 1200 microE m(-2) x (-1) in the mutant and wild-type cells. At I = 2400 microE m(-2) x c(-1), a stronger inhibition and a slower recovery of the photosynthetic apparatus activity in the kat- mutant than in wild-type cells was observed. The data obtained evidence an important role of catalase-peroxidase in the system of reparation of the photosynthetic apparatus damaged by high-intensty light, especially against the background of NaCI stress.


Subject(s)
Catalase/metabolism , Photosynthesis/drug effects , Sodium Chloride/pharmacology , Synechocystis/enzymology , Catalase/genetics , Mutation , Synechocystis/genetics , Synechocystis/growth & development
2.
Biofizika ; 52(2): 277-86, 2007.
Article in Russian | MEDLINE | ID: mdl-17477055

ABSTRACT

The damaging effect of oxidative stress inductors: methyl viologen, benzyl viologen, cumene hydroperoxide, H2O2, menadion, and high irradiance on the photosynthetic apparatus of cyanobacterium Synechocystis sp. PCC 6803 in cells of the wild type strain and the methyl viologen-resistant Prq20 mutant with the disrupted function of the regulatory gene prqR has been investigated by measuring the delayed fluorescence of chlorophyll a and the rate of CO2dependent -O2 gas exchange. It has been shown that the damage to the photosynthetic apparatus in the Prq20 mutant as compared with the wild type was less in the presence of methyl viologen and benzyl viologen. Reasons for the enhanced resistance of the photosynthetic apparatus in the mutant Prq20 to methyl viologen and benzyl viologen are discussed.


Subject(s)
Drug Resistance/genetics , Oxidants/pharmacology , Oxidative Stress , Photosynthetic Reaction Center Complex Proteins/drug effects , Synechocystis/drug effects , Bacterial Proteins/genetics , Benzyl Viologen/metabolism , Benzyl Viologen/pharmacology , Herbicides/pharmacology , Mutation , Oxidants/metabolism , Paraquat/pharmacology , Repressor Proteins/genetics , Synechocystis/genetics
4.
Biokhimiia ; 48(10): 1604-10, 1983 Oct.
Article in Russian | MEDLINE | ID: mdl-6357291

ABSTRACT

It was demonstrated that the decrease of the activity of photosystem II in agranal chloroplasts of bundle sheath cells of malate C4 plants is due to a loss of the chlorophyll-protein complex of this photosystem. This is paralleled with an increase in the relative amount of the chlorophyll--protein complex of photosystem I and a partial loss of the light-harvesting pigmentprotein complex. These two events may account for the high activity of photosystem I and for the low content of chlorophyll b in the plastids. The cumulative data are indicative of a close interrelationship between the granal state of the chloroplast membranes and the presence of the chlorophyll--protein complex of photosystem II.


Subject(s)
Chlorophyll/isolation & purification , Chlorophyta/metabolism , Plant Proteins/isolation & purification , Plants/metabolism , Chlorophyll/metabolism , Light-Harvesting Protein Complexes , Photosynthesis , Photosynthetic Reaction Center Complex Proteins , Photosystem I Protein Complex , Photosystem II Protein Complex , Plant Proteins/metabolism , Species Specificity
5.
Biokhimiia ; 48(9): 1421-8, 1983 Sep.
Article in Russian | MEDLINE | ID: mdl-6354277

ABSTRACT

Three types of mutants (pigment, non-photosynthesizing and pigment non-photosynthesizing ones) were used to identify the chlorophyll-containing bands in gel slices. The pigment mutants with an impaired light-harvesting chlorophyll a/b-protein complex possess photochemically active reaction centers of photosystems and are capable of phototrophic growth. Using these mutants, the heterogeneity of the chlorophyll-containing bands, LH2 and LH3, in gel slices and the dependence of LH2 on chlorophyll a-protein and that of LH3 on chlorophyll b-protein in the light-harvesting complex were established. The non-photosynthesizing mutants with an inactive photosystem I (or II) are devoid of antennae forms of chlorophyll a and are not capable of phototrophic growth. Using these mutants, it was demonstrated that in gel slices the chlorophyll-containing band, CPI, corresponds to the chlorophyll a-protein complex of photosystem I, while CPII to the chlorophyll a-protein complex of photosystem II. It was also found that the presence of the chlorophyll-containing band, LH0 (CPIa) in gel slices correlates with the preservation of the light-harvesting complex and is independent of photosystem I. The spectral properties of chlorophyll complexes in gel slices are not identical to those of native chlorophyll. It was assumed that chloroplasts contain at least 4 types of chlorophyll proteins that are controlled by independent genes.


Subject(s)
Chlamydomonas/metabolism , Chlorophyll/isolation & purification , Mutation , Plant Proteins/isolation & purification , Chlamydomonas/genetics , Chlorophyll/metabolism , Electrophoresis/methods , Light , Light-Harvesting Protein Complexes , Photosynthetic Reaction Center Complex Proteins , Photosystem I Protein Complex , Photosystem II Protein Complex , Plant Proteins/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...