TY - JOUR
T1 - Light-harvesting complex stress-related proteins catalyze excess energy dissipation in both photosystems of Physcomitrella patens
AU - Pinnola, Alberta
AU - Cazzaniga, Stefano
AU - Alboresi, Alessandro
AU - Nevo, Reinat
AU - Levin-Zaidman, Smadar
AU - Reich, Ziv
AU - Bassi, Roberto
N1 - European Union [316427]; Italian Ministry of Agriculture, Food, and Forestry; Israel Science Foundation [1034/12]; Human Frontier Science Program [RGP0005/2013]; Carolito StiftungResearch was funded in part through the European Union Seventh Framework Programme for Research Project 316427, Environmental Acclimation of Photosynthesis, and the Italian Ministry of Agriculture, Food, and Forestry Project HYDROBIO. The immunoelectron microscopy studies were conducted at the Irving and Cherna Moskowitz Center for Nano and Bio-Nano Imaging at the Weizmann Institute of Science (WIS). Work performed at the WIS was funded by grants (to Z.R.) from the Israel Science Foundation (No. 1034/12), Human Frontier Science Program (RGP0005/2013), and Carolito Stiftung. Research was funded in part through the European Union Seventh Framework Programme for Research Project 316427, Environmental Acclimation of Photosynthesis, and the Italian Ministry of Agriculture, Food, and Forestry Project HYDROBIO. The immunoelectron microscopy studies were conducted at the Irving and Cherna Moskowitz Center for Nano and Bio-Nano Imaging at the Weizmann Institute of Science (WIS). Work performed at the WIS was funded by grants (to Z.R.) from the Israel Science Foundation (No. 1034/12), Human Frontier Science Program (RGP0005/2013), and Carolito Stiftung.
PY - 2015/11
Y1 - 2015/11
N2 - Two LHC-like proteins, Photosystem II Subunit S (PSBS) and Light-Harvesting Complex Stress-Related (LHCSR), are essential for triggering excess energy dissipation in chloroplasts of vascular plants and green algae, respectively. The mechanism of quenching was studied in Physcomitrella patens, an early divergent streptophyta (including green algae and land plants) in which both proteins are active. PSBS was localized in grana together with photosystem II (PSII), but LHCSR was located mainly in stroma-exposed membranes together with photosystem I (PSI), and its distribution did not change upon high-light treatment. The quenched conformation can be preserved by rapidly freezing the high-light-treated tissues in liquid nitrogen. When using green fluorescent protein as an internal standard, 77K fluorescence emission spectra on isolated chloroplasts allowed for independent assessment of PSI and PSII fluorescence yield. Results showed that both photosystems underwent quenching upon high-light treatment in the wild type in contrast to mutants depleted of LHCSR, which lacked PSI quenching. Due to the contribution of LHCII, P. patens had a PSI antenna size twice as large with respect to higher plants. Thus, LHCII, which is highly abundant in stroma membranes, appears to be the target of quenching by LHCSR.
AB - Two LHC-like proteins, Photosystem II Subunit S (PSBS) and Light-Harvesting Complex Stress-Related (LHCSR), are essential for triggering excess energy dissipation in chloroplasts of vascular plants and green algae, respectively. The mechanism of quenching was studied in Physcomitrella patens, an early divergent streptophyta (including green algae and land plants) in which both proteins are active. PSBS was localized in grana together with photosystem II (PSII), but LHCSR was located mainly in stroma-exposed membranes together with photosystem I (PSI), and its distribution did not change upon high-light treatment. The quenched conformation can be preserved by rapidly freezing the high-light-treated tissues in liquid nitrogen. When using green fluorescent protein as an internal standard, 77K fluorescence emission spectra on isolated chloroplasts allowed for independent assessment of PSI and PSII fluorescence yield. Results showed that both photosystems underwent quenching upon high-light treatment in the wild type in contrast to mutants depleted of LHCSR, which lacked PSI quenching. Due to the contribution of LHCII, P. patens had a PSI antenna size twice as large with respect to higher plants. Thus, LHCII, which is highly abundant in stroma membranes, appears to be the target of quenching by LHCSR.
UR - http://www.scopus.com/inward/record.url?scp=84949639293&partnerID=8YFLogxK
U2 - 10.1105/tpc.15.00443
DO - 10.1105/tpc.15.00443
M3 - مقالة
SN - 1040-4651
VL - 27
SP - 3213
EP - 3227
JO - Plant Cell
JF - Plant Cell
IS - 11
ER -