cover image: Photosynthetic antenna : biogenesis, function and regulation

Photosynthetic antenna : biogenesis, function and regulation

24 Nov 2023

Photosynthesis is the biological process that converts light into chemical energy. It occurs within the chloroplasts of plant cells. Inside these organelles, light energy is absorbed by chlorophyll antennas (light-harvesting complexes or LHC), composed of proteins and pigments, chlorophylls and carotenoids. While chloroplasts possess their own genome, most of the genes have been transferred to the nucleus, thus implying the presence of an efficient protein import and assembly machinery within this organelle. The functioning of the photosynthetic apparatus is also finely regulated, particularly to prevent damage that could be caused by excess light energy. The aim of this thesis was to investigate how the synthesis and assembly processes of photosynthetic antennas and the photoprotective and acclimation responses to changes in light conditions, to further characterize their interactions. In this study, we have collected some observations concerning the synchronization of the two biosynthesis pathways, chlorophyll and LHC proteins, within the chloroplast. Understanding this synchronization will be crucial in order to understand how organisms adapt to natural variations in light intensity. We used the eukaryotic microalga Chlamydomonas reinhardtii as a biological model for its exceptional genetic features. For instance, the analysis of mutants has demonstrated the significance of proteins like cpSRP43 and ALB3.1 in the biogenesis of photosynthetic antennae while also suggesting an alternative pathway. A genetic analysis has precisely identified unexpected genomic rearrangements in a mutant strain of Chlamydomonas commonly used for studies on Chlamydomonas’ acclimation to environmental changes. Finally, we have uncovered the significance of a new genetic context –which is yet to be dissected- that specifies the variable properties of the main photoprotection mechanism in this microalgae.

Authors

Sandrine Bujaldon

Organizations mentioned

Bibliographic Reference
Sandrine Bujaldon. Les antennes photosynthétiques chez Chlamydomonas reinhardtii : biogénèse, fonction et régulation. Physiologie [q-bio.TO]. Sorbonne Université, 2023. Français. ⟨NNT : 2023SORUS346⟩. ⟨tel-04336988⟩
HAL Collection
['CNRS - Centre national de la recherche scientifique', 'STAR - Dépôt national des thèses électroniques', 'Biologie du chloroplaste et perception de la lumière chez les micro-algues', 'Sorbonne Université', 'Sorbonne Université 01/01/2018', 'Thèses de Sorbonne Université', 'Faculté des Sciences de Sorbonne Université', 'Sorbonne Université - Texte Intégral', 'Alliance Sorbonne Université', "Productions de l'UMR7141"]
HAL Identifier
4336988
Laboratory
Biologie du chloroplaste et perception de la lumière chez les micro-algues
Published in
France

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