scholarly journals Starch Degradation in Synchronously Grown Chlamydomonas reinhardtii and Characterization of the Amylase

1984 ◽  
Vol 74 (3) ◽  
pp. 459-463 ◽  
Author(s):  
Carolyn Levi ◽  
Martin Gibbs
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Starch Degradation

Mutants of Chlamydomonas reinhardtii Deficient in Mitochondrial Complex I: Characterization of Two Mutations Affecting the nd1 Coding Sequence

Genetics ◽  
2001 ◽  
Vol 158 (3) ◽  
pp. 1051-1060
Author(s):  
Claire Remacle ◽  
Denis Baurain ◽  
Pierre Cardol ◽  
René F Matagne
Keyword(s):  
Mitochondrial Genome ◽  
Chlamydomonas Reinhardtii ◽  
Complex I ◽  
Slow Growth ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Sequencing Analysis ◽  
Mitochondrial Complex ◽  
Genetical Analysis ◽  
Complex I Activity

Abstract The mitochondrial rotenone-sensitive NADH:ubiquinone oxidoreductase (complex I) comprises more than 30 subunits, the majority of which are encoded by the nucleus. In Chlamydomonas reinhardtii, only five components of complex I are coded for by mitochondrial genes. Three mutants deprived of complex I activity and displaying slow growth in the dark were isolated after mutagenic treatment with acriflavine. A genetical analysis demonstrated that two mutations (dum20 and dum25) affect the mitochondrial genome whereas the third mutation (dn26) is of nuclear origin. Recombinational analyses showed that dum20 and dum25 are closely linked on the genetic map of the mitochondrial genome and could affect the nd1 gene. A sequencing analysis confirmed this conclusion: dum20 is a deletion of one T at codon 243 of nd1; dum25 corresponds to a 6-bp deletion that eliminates two amino acids located in a very conserved hydrophilic segment of the protein.

Non-photochemical quenching of chlorophyll a fluorescence: early history and characterization of two xanthophyll-cycle mutants of Chlamydomonas reinhardtii

2002 ◽  
Vol 29 (10) ◽  
pp. 1141 ◽  
Author(s):  
Govindjee ◽  
Manfredo J. Seufferheld
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Oxygen Evolution ◽  
Xanthophyll Cycle ◽  
Photochemical Quenching ◽  
Chl A ◽  
Fluorescence Transient ◽  
Chl A Fluorescence ◽  
Non Photochemical Quenching

This paper deals first with the early, although incomplete, history of photoinhibition, of 'non-QA-related chlorophyll (Chl) a fluorescence changes', and the xanthophyll cycle that preceded the discovery of the correlation between non-photochemical quenching of Chl a fluorescence (NPQ) and conversion of violaxanthin to zeaxanthin. It includes the crucial observation that the fluorescence intensity quenching, when plants are exposed to excess light, is indeed due to a change in the quantum yield of fluorescence. The history ends with a novel turn in the direction of research — isolation and characterization of NPQ xanthophyll-cycle mutants of Chlamydomonas reinhardtii Dangeard and Arabidopsis thaliana (L.) Heynh., blocked in conversion of violaxanthin to zeaxanthin, and zeaxanthin to violaxanthin, respectively. In the second part of the paper, we extend the characterization of two of these mutants (npq1, which accumulates violaxanthin, and npq2, which accumulates zeaxanthin) through parallel measurements on growth, and several assays of PSII function: oxygen evolution, Chl a fluorescence transient (the Kautsky effect), the two-electron gate function of PSII, the back reactions around PSII, and measurements of NPQ by pulse-amplitude modulation (PAM 2000) fluorimeter. We show that, in the npq2 mutant, Chl a fluorescence is quenched both in the absence and presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). However, no differences are observed in functioning of the electron-acceptor side of PSII — both the two-electron gate and the back reactions are unchanged. In addition, the role of protons in fluorescence quenching during the 'P-to-S' fluorescence transient was confirmed by the effect of nigericin in decreasing this quenching effect. Also, the absence of zeaxanthin in the npq1 mutant leads to reduced oxygen evolution at high light intensity, suggesting another protective role of this carotenoid. The available data not only support the current model of NPQ that includes roles for both pH and the xanthophylls, but also are consistent with additional protective roles of zeaxanthin. However, this paper emphasizes that we still lack sufficient understanding of the different parts of NPQ, and that the precise mechanisms of photoprotection in the alga Chlamydomonas may not be the same as those in higher plants.

Characterization of photoreactivation-deficient mutants of Chlamydomonas reinhardtii

1991 ◽  
Vol 139 (1-4) ◽  
pp. 207-211 ◽  
Author(s):  
Eva Miadoková ◽  
Svetlana Podstavková ◽  
Daniel Vlček ◽  
Mária Šimonová
Keyword(s):  
Chlamydomonas Reinhardtii

scholarly journals Characterization of Chlamydomonas reinhardtii phosphatidylglycerophosphate synthase in Synechocystis sp. PCC 6803

2015 ◽  
Vol 6 ◽  
Author(s):  
Chun-Hsien Hung ◽  
Kaichiro Endo ◽  
Koichi Kobayashi ◽  
Yuki Nakamura ◽  
Hajime Wada
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Synechocystis Sp ◽  
Pcc 6803

scholarly journals Production and characterization of algae extract from Chlamydomonas reinhardtii

2014 ◽  
Vol 17 (1) ◽  
pp. 14-18 ◽  
Author(s):  
Weston Kightlinger ◽  
Kai Chen ◽  
Azadeh Pourmir ◽  
Daniel W. Crunkleton ◽  
Geoffrey L. Price ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii
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