Energy transfer from phycobilisomes to photosystem I at room temperature

Avratanu Biswas; Parveen Akhtar; Petar H Lambrev; Ivo H M van Stokkum

doi:10.3389/fpls.2023.1300532

Energy transfer from phycobilisomes to photosystem I at room temperature

Front Plant Sci. 2024 Jan 8:14:1300532. doi: 10.3389/fpls.2023.1300532. eCollection 2023.

Authors

Avratanu Biswas^{1

2

3}, Parveen Akhtar², Petar H Lambrev², Ivo H M van Stokkum¹

Affiliations

¹ Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.
² Insitute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary.
³ Doctoral School of Biology, University of Szeged, Szeged, Hungary.

Abstract

The phycobilisomes function as the primary light-harvesting antennae in cyanobacteria and red algae, effectively harvesting and transferring excitation energy to both photosystems. Here we investigate the direct energy transfer route from the phycobilisomes to photosystem I at room temperature in a mutant of the cyanobacterium Synechocystis sp. PCC 6803 that lacks photosystem II. The excitation dynamics are studied by picosecond time-resolved fluorescence measurements in combination with global and target analysis. Global analysis revealed several fast equilibration time scales and a decay of the equilibrated system with a time constant of ≈220 ps. From simultaneous target analysis of measurements with two different excitations of 400 nm (chlorophyll a) and 580 nm (phycobilisomes) a transfer rate of 42 ns^-1 from the terminal emitter of the phycobilisome to photosystem I was estimated.

Keywords: energy transfer (ET); global analysis (GA); photosystem I (PSI); phycobilisomes (PBs); target analysis.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by grants from the National Research, Development and Innovation Fund (NKFI FK-139067 to PA and ANN-144012 and 2018-1.2.1-NKP-2018-00009 to PL) and the Hungarian Research Network (SA-76/2021 to PA). The research leading to these results has received funding from LASERLAB-EUROPE (grant agreement no. 871124, European Union’s Horizon 2020 research and innovation program).