scholarly journals Light-Harvesting Complex Protein LHCBM9 Is Critical for Photosystem II Activity and Hydrogen Production in Chlamydomonas reinhardtii

2014 ◽  
Vol 26 (4) ◽  
pp. 1598-1611 ◽  
Author(s):  
Sabrina Grewe ◽  
Matteo Ballottari ◽  
Marcelo Alcocer ◽  
Cosimo D’Andrea ◽  
Olga Blifernez-Klassen ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Photosystem Ii ◽  
Chlamydomonas Reinhardtii ◽  
Light Harvesting ◽  
Light Harvesting Complex ◽  
Complex Protein ◽  
Photosystem Ii Activity

scholarly journals Correlation between changes in light energy distribution and changes in thylakoid membrane polypeptide phosphorylation in Chlamydomonas reinhardtii.

1984 ◽  
Vol 98 (1) ◽  
pp. 1-7 ◽  
Author(s):  
F A Wollman ◽  
P Delepelaire
Keyword(s):  
Photosystem Ii ◽  
Chlamydomonas Reinhardtii ◽  
Redox State ◽  
Light Harvesting ◽  
Anaerobic Treatment ◽  
Intact Cells ◽  
Light Harvesting Complex ◽  
Plastoquinone Pool

We have used a new method to extensively modify the redox state of the plastoquinone pool in Chlamydomonas reinhardtii intact cells. This was achieved by an anaerobic treatment that inhibits the chlororespiratory pathway recently described by P. Bennoun (Proc. Natl. Acad. Sci. USA, 1982, 79:4352-4356). A state I (plus 3,4-dichlorophenyl-1,1-dimethylurea) leads to anaerobic state transition induced a decrease in the maximal fluorescence yield at room temperature and in the FPSII/FPSI ratio at 77 degrees K, which was three times larger than in a classical state I leads to state II transition. The fluorescence changes observed in vivo were similar in amplitude to those observed in vitro upon transfer to the light of dark-adapted, broken chloroplasts incubated in the presence of ATP. We then compared the phosphorylation pattern of thylakoid polypeptides in C. reinhardtii in vitro and in vivo using gamma-[32P]ATP and [32P]orthophosphate labeling, respectively. The same set of polypeptides, mainly light-harvesting complex polypeptides, was phosphorylated in both cases. We observed that this phosphorylation process is reversible and is mediated by the redox state of the plastoquinone pool in vivo as well as in vitro. Similar changes of even larger amplitude were observed with the F34 mutant intact cells lacking in photosystem II centers. The presence of the photosystem II centers is then not required for the occurrence of the plastoquinone-mediated phosphorylation of light-harvesting complex polypeptides.

scholarly journals Transcriptome for Photobiological Hydrogen Production Induced by Sulfur Deprivation in the Green Alga Chlamydomonas reinhardtii

2008 ◽  
Vol 7 (11) ◽  
pp. 1965-1979 ◽  
Author(s):  
Anh Vu Nguyen ◽  
Skye R. Thomas-Hall ◽  
Alizée Malnoë ◽  
Matthew Timmins ◽  
Jan H. Mussgnug ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Chlamydomonas Reinhardtii ◽  
Green Alga ◽  
Light Harvesting ◽  
Expression Profiles ◽  
Transcriptional Analysis ◽  
Sulfur Deprivation ◽  
Light Harvesting Complex ◽  
Sulfur Starvation ◽  
Reverse Transcription Pcr

ABSTRACT Photobiological hydrogen production using microalgae is being developed into a promising clean fuel stream for the future. In this study, microarray analyses were used to obtain global expression profiles of mRNA abundance in the green alga Chlamydomonas reinhardtii at different time points before the onset and during the course of sulfur-depleted hydrogen production. These studies were followed by real-time quantitative reverse transcription-PCR and protein analyses. The present work provides new insights into photosynthesis, sulfur acquisition strategies, and carbon metabolism-related gene expression during sulfur-induced hydrogen production. A general trend toward repression of transcripts encoding photosynthetic genes was observed. In contrast to all other LHCBM genes, the abundance of the LHCBM9 transcript (encoding a major light-harvesting polypeptide) and its protein was strongly elevated throughout the experiment. This suggests a major remodeling of the photosystem II light-harvesting complex as well as an important function of LHCBM9 under sulfur starvation and photobiological hydrogen production. This paper presents the first global transcriptional analysis of C. reinhardtii before, during, and after photobiological hydrogen production under sulfur deprivation.

scholarly journals Identification of parallel pH- and zeaxanthin-dependent quenching of excess energy in LHCSR3 in Chlamydomonas reinhardtii

2020 ◽  
Author(s):  
Julianne M. Troiano ◽  
Federico Perozeni ◽  
Raymundo Moya ◽  
Luca Zuliani ◽  
Kwangryul Baek ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Light Harvesting ◽  
Complex Stress ◽  
Excess Energy ◽  
Photochemical Quenching ◽  
Light Harvesting Complexes ◽  
Light Harvesting Complex ◽  
Non Photochemical Quenching

AbstractUnder high light conditions, oxygenic photosynthetic organisms avoid photodamage by thermally dissipating excess absorbed energy, which is called non-photochemical quenching (NPQ). In green algae, a chlorophyll and carotenoid-binding protein, light-harvesting complex stress-related (LHCSR3), detects excess energy via pH and serves as a quenching site. However, the mechanisms by which LHCSR3 functions have not been determined. Using a combined in vivo and in vitro approach, we identify two parallel yet distinct quenching processes, individually controlled by pH and carotenoid composition, and their likely molecular origin within LHCSR3 from Chlamydomonas reinhardtii. The pH-controlled quenching is removed within a mutant LHCSR3 that lacks the protonable residues responsible for sensing pH. Constitutive quenching in zeaxanthin-enriched systems demonstrates zeaxanthin-controlled quenching, which may be shared with other light-harvesting complexes. We show that both quenching processes prevent the formation of damaging reactive oxygen species, and thus provide distinct timescales and mechanisms of protection in a changing environment.

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