Akimasa Watanabe1,2, Jun Minagawa3,4. 1. Division of Environmental Photobiology, National Institute for Basic Biology, Nishigo-naka 38, Myodaiji, Okazaki, 444-8585, Japan. 2. Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, 444-8585, Japan. 3. Division of Environmental Photobiology, National Institute for Basic Biology, Nishigo-naka 38, Myodaiji, Okazaki, 444-8585, Japan. minagawa@nibb.ac.jp. 4. Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, 444-8585, Japan. minagawa@nibb.ac.jp.
Abstract
MAIN CONCLUSION: The supramolecular organization of the photosystem supercomplexes in the green alga Chlorella sorokiniana belonging to Trebouxiophyceae are essentially the same as those of Chlamydomonas reinhardtii belonging to Chlorophyceae. The photosynthetic conversion of light energy into chemical energy is performed by photosystems II and I (PSII and PSI) embedded within the thylakoid membranes. In plants and green algae, PSII and PSI comprise the core complex and light-harvesting complexes (LHCII and LHCI), forming PSII-LHCII and PSI-LHCI supercomplexes, respectively. The structural information about photosystem supercomplexes of green algae has been limited to chlorophytic algae. Here, to obtain an insight into the evolution of Chlorophyta, we determined the supramolecular organization of the PSII-LHCII and PSI-LHCI supercomplexes from the freshwater green alga Chlorella sorokiniana, which belongs to Trebouxiophyceae. The obtained results showed that the supramolecular organizations of the photosystem supercomplexes in C. sorokiniana were essentially the same as those of the model green alga C. reinhardtii, which belongs to Chlorophyceae, namely PSII-LHCII supercomplex formed the C2S2M2L2 configuration and PSI-LHCI supercomplex was associated with 10 LHCI subunits.
MAIN CONCLUSION: The supramolecular organization of the photosystem supercomplexes in the green alga Chlorella sorokiniana belonging to Trebouxiophyceae are essentially the same as those of Chlamydomonas reinhardtii belonging to Chlorophyceae. The photosynthetic conversion of light energy into chemical energy is performed by photosystems II and I (PSII and PSI) embedded within the thylakoid membranes. In plants and green algae, PSII and PSI comprise the core complex and light-harvesting complexes (LHCII and LHCI), forming PSII-LHCII and PSI-LHCI supercomplexes, respectively. The structural information about photosystem supercomplexes of green algae has been limited to chlorophytic algae. Here, to obtain an insight into the evolution of Chlorophyta, we determined the supramolecular organization of the PSII-LHCII and PSI-LHCI supercomplexes from the freshwater green alga Chlorella sorokiniana, which belongs to Trebouxiophyceae. The obtained results showed that the supramolecular organizations of the photosystem supercomplexes in C. sorokiniana were essentially the same as those of the model green alga C. reinhardtii, which belongs to Chlorophyceae, namely PSII-LHCII supercomplex formed the C2S2M2L2 configuration and PSI-LHCI supercomplex was associated with 10 LHCI subunits.
Entities:
Keywords:
EM; Evolution; Green algae; Photosynthesis
Authors: Caterina Gerotto; Andrea Trotta; Azfar Ali Bajwa; Tomas Morosinotto; Eva-Mari Aro Journal: Plant Physiol Date: 2022-08-29 Impact factor: 8.005