State transitions, photosystem stoichiometry adjustment and non-photochemical quenching in cyanobacterial cells acclimated to light absorbed by photosystem I or photosystem II.

摘要: Cells of the cyanobacterium Synechococcus 6301 were grown in yellow light absorbed primarily by phycobilisome (PBS) light-harvesting antenna photosystem II (PS II), and red chlorophyll and, therefore, I I). Chromatic acclimation cells produced a higher phycocyanin/chlorophyll ratio PBS-PS II/PS under PS I-light. State 1-state 2 transitions demonstrated as changes yield fluorescence both cell types. The amplitude state was substantially lower II-light cells, suggesting specific attenuation superimposed non-photochemical quenching excitation. 77 K emission spectra each type 1 suggested that regulate excitation energy transfer from to reaction centre are distinct stoichiometry adjustments. kinetics adjustment appearance process measured upon switching I-light II-light, vice versa. Photosystem complete within about 48 h, while occurred 25 h. It is proposed there at least three phenomena exerting effects on rate absorption utilization two photoreactions: transitions; adjustment; quenching. relationship between these processes discussed.