scholarly journals The Regulation of Photosynthetic Electron Transport during Nutrient Deprivation in Chlamydomonas reinhardtii

1998 ◽  
Vol 117 (1) ◽  
pp. 129-139 ◽  
Author(s):  
Dennis D. Wykoff ◽  
John P. Davies ◽  
Anastasios Melis ◽  
Arthur R. Grossman
Keyword(s):  
Electron Transport ◽  
Chlamydomonas Reinhardtii ◽  
Photosynthetic Electron Transport ◽  
Nutrient Deprivation

scholarly journals Metabolic control of acclimation to nutrient deprivation dependent on polyphosphate synthesis

2020 ◽  
Vol 6 (40) ◽  
pp. eabb5351
Author(s):  
E. Sanz-Luque ◽  
S. Saroussi ◽  
W. Huang ◽  
N. Akkawi ◽  
A. R. Grossman
Keyword(s):  
Electron Transport ◽  
Metabolic Control ◽  
Stress Responses ◽  
Physiological Function ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Nutrient Deprivation ◽  
Transcriptional Level ◽  
Sulfur Deprivation ◽  
Cellular Stress Responses

Polyphosphate, an energy-rich polymer conserved in all kingdoms of life, is integral to many cellular stress responses, including nutrient deprivation, and yet, the mechanisms that underlie its biological roles are not well understood. In this work, we elucidate the physiological function of this polymer in the acclimation of the model alga Chlamydomonas reinhardtii to nutrient deprivation. Our data reveal that polyphosphate synthesis is vital to control cellular adenosine 5′-triphosphate homeostasis and maintain both respiratory and photosynthetic electron transport upon sulfur deprivation. Using both genetic and pharmacological approaches, we show that electron flow in the energy-generating organelles is essential to induce and sustain acclimation to sulfur deprivation at the transcriptional level. These previously unidentified links among polyphosphate synthesis, photosynthetic and respiratory electron flow, and the acclimation of cells to nutrient deprivation could unveil the mechanism by which polyphosphate helps organisms cope with a myriad of stress conditions in a fluctuating environment.

A staining method for the detection of impaired photosynthetic electron transport in green algae strains

1983 ◽  
Vol 3 (4) ◽  
pp. 367-371
Author(s):  
Jacques Dauta
Keyword(s):  
Electron Transport ◽  
Chlamydomonas Reinhardtii ◽  
Green Algae ◽  
Electron Transport Chain ◽  
Staining Method ◽  
Agar Medium ◽  
Photosynthetic Electron Transport ◽  
Photosynthetic Electron Transport Chain ◽  
Transport Chain ◽  
Different Parts

The utilization of strain CW 15 of Chlamydomonas reinhardtii enables the biochemical staining test for characterizing ad efective photosynthetic electron-transport chain on colonies grown on agar medium. It may be used in order to screen for mutants specifically blocked in different parts of the transport chain.

Superoxide-and Ethane-Formation in Subchloroplast Particles: Catalysis by Pyridinium Derivatives

1980 ◽  
Vol 35 (9-10) ◽  
pp. 770-775 ◽  
Author(s):  
E. F. Elstner ◽  
H. P. Fischer ◽  
W. Osswald ◽  
G. Kwiatkowski
Keyword(s):  
Electron Transport ◽  
Photosystem I ◽  
Photosynthetic Electron Transport ◽  
Redox Potentials ◽  
Light Reaction ◽  
Pyridinium Bromide ◽  
Superoxide Formation ◽  
Fatty Acid Peroxidation ◽  
Chlorophyll Bleaching ◽  
Ethane Formation

Abstract Oxygen reduction by chloroplast lamellae is catalyzed by low potential redox dyes with E′0 values between -0 .3 8 V and -0 .6 V. Compounds of E′0 values of -0 .6 7 V and lower are inactive. In subchloroplast particles with an active photosystem I but devoid of photosynthetic electron transport between the two photosystems, the active redox compounds enhance chlorophyll bleaching, superoxide formation and ethane production independent on exogenous substrates or electron donors. The activities of these compounds decrease with decreasing redox potential, with one exception: 1-methyl-4,4′-bipyridini urn bromide with an E′0 value of lower -1 V (and thus no electron acceptor of photosystem I in chloroplast lamellae with intact electron transport) stimulates light dependent superoxide formation and unsaturated fatty acid peroxidation in sub­ chloroplast particles, maximal rates appearing after almost complete chlorophyll bleaching. Since this activity is not visible with compounds with redox potentials below -0 .6 V lacking the nitrogen atom at the 1-position of the pyridinium substituent, we assume that 1 -methyl-4,4′-bi-pyridinium bromide is “activated” by a yet unknown light reaction.

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