Excitation energy transfer and trapping in Photosystem I of the green alga Bryopsis corticulans.

ABSTRACT: Photosystem I (PSI) from the siphonous green alga Bryopsis corticulans carries ten subunits of Light-Harvesting Complex I (LHCI) that enlarge its absorption cross-section yet must still deliver excitations rapidly to the P₇₀₀ reaction center. Here we investigate the light-harvesting function of PSI-LHCI, the excitation energy transfer within the supercomplex and how it affects the overall photochemical trapping lifetime. We performed picosecond time-resolved fluorescence spectroscopy at room temperature and 77 K and femtosecond transient absorption spectroscopy on purified PSI-LHCI supercomplex. Ultrafast spectroscopy showed that spectral equilibration in the antenna occurs mainly in the first 1 ps after excitation and is virtually complete within 10 ps. Nonetheless, the fluores

SUBMITTER: Akhtar P 

PROVIDER: S-EPMC12644198 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature