Far-red light photoacclimation (FaRLiP) in Synechococcus sp. PCC 7335. II.Characterization of phycobiliproteins produced during acclimation to far-red light.
Phycobilisomes (PBS) are antenna complexes that harvest light for photosystem (PS) I and PS II in cyanobacteria and some algae. A process known as far-red light photoacclimation (FaRLiP) occurs when some cyanobacteria are grown in far-red light (FRL). They synthesize chlorophylls d and f and remodel PS I, PS II, and PBS using subunits paralogous to those produced in white light. The FaRLiP strain, Leptolyngbya sp. JSC-1, replaces hemidiscoidal PBS with pentacylindrical cores, which are produced when cells are grown in red or white light, with PBS with bicylindrical cores when cells are grown in FRL. This study shows that the PBS of another FaRLiP strain, Synechococcus sp. PCC 7335, are not remodeled in cells grown in FRL. Instead, cells grown in FRL produce bicylindrical cores that uniquely contain the paralogous allophycocyanin subunits encoded in the FaRLiP cluster, and these bicylindrical cores coexist with red-light-type PBS with tricylindrical cores. The bicylindrical cores have absorption maxima at 650 and 711 nm and a low-temperature fluorescence emission maximum at 730 nm. They contain ApcE2:ApcF:ApcD3:ApcD2:ApcD5:ApcB2 in the approximate ratio 2:2:4:6:12:22, and a structural model is proposed. Time course experiments showed that bicylindrical cores were detectable about 48 h after cells were transferred from RL to FRL and that synthesis of red-light-type PBS continued throughout a 21-day growth period. When considered in comparison with results for other FaRLiP cyanobacteria, the results here show that acclimation responses to FRL can differ considerably among FaRLiP cyanobacteria.
403C Althouse Laboratory, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA.|Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
Ming-Yang
MY
Ho
403C Althouse Laboratory, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
Fei
F
Gan
403C Althouse Laboratory, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
Gaozhong
G
Shen
403C Althouse Laboratory, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA. dab14@psu.edu.|Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, PA, 16802, USA. dab14@psu.edu.|Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, 59717, USA. dab14@psu.edu.
Donald A
http://orcid.org/0000-0003-2782-5988
DA
Bryant
D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D008027:Light; D046529:Microscopy, Electron, Transmission; D052979:Phycobiliproteins / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D046940:Synechococcus / Q000378:metabolism / Q000502:physiology*
D001426:Bacterial Proteins; D052979:Phycobiliproteins
Chlorophyll f; Cyanobacteria; Far-red light; Photoacclimation; Photosynthesis