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Photosystem II antenna complexes CP26 and CP29 are essential for nonphotochemical quenching in Chlamydomonas reinhardtii
Author(s) -
Cazzaniga Stefano,
Kim Minjae,
Bellamoli Francesco,
Jeong Jooyoen,
Lee Sangmuk,
Perozeni Federico,
Pompa Andrea,
Jin EonSeon,
Ballottari Matteo
Publication year - 2020
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.13680
Subject(s) - photosystem ii , chlamydomonas reinhardtii , photochemistry , photoprotection , photosystem , photosystem i , chemistry , photosynthesis , biophysics , light harvesting complex , light harvesting complexes of green plants , p700 , chlorophyll fluorescence , non photochemical quenching , biology , biochemistry , mutant , gene
Photosystems must balance between light harvesting to fuel the photosynthetic process for CO 2 fixation and mitigating the risk of photodamage due to absorption of light energy in excess. Eukaryotic photosynthetic organisms evolved an array of pigment‐binding proteins called light harvesting complexes constituting the external antenna system in the photosystems, where both light harvesting and activation of photoprotective mechanisms occur. In this work, the balancing role of CP29 and CP26 photosystem II antenna subunits was investigated in Chlamydomonas reinhardtii using CRISPR‐Cas9 technology to obtain single and double mutants depleted of monomeric antennas. Absence of CP26 and CP29 impaired both photosynthetic efficiency and photoprotection: Excitation energy transfer from external antenna to reaction centre was reduced, and state transitions were completely impaired. Moreover, differently from higher plants, photosystem II monomeric antenna proteins resulted to be essential for photoprotective thermal dissipation of excitation energy by nonphotochemical quenching.