Gradual Response of Cyanobacterial Thylakoids to Acute High-Light Stress-Importance of Carotenoid Accumulation

0546702 - MBÚ 2022 RIV CH eng J - Journal Article
Canonico, Myriam - Konert, Grzegorz - Crepin, Aurelia - Šedivá, Barbora - Kaňa, Radek
Gradual Response of Cyanobacterial Thylakoids to Acute High-Light Stress-Importance of Carotenoid Accumulation.
Cells. Roč. 10, č. 8 (2021), č. článku 1916. E-ISSN 2073-4409
R&D Projects: GA ČR(CZ) GA19-11494S; GA MŠMT(CZ) ED2.1.00/19.0392
EU Projects: European Commission(CZ) 854126 - PhotoRedesign
Institutional support: RVO:61388971
Keywords : high light * thylakoid membrane * microdomains * carotenoids * photoprotection * Synechocystis * non-photochemical quenching * photoinhibition * photosystems
OECD category: Microbiology
Impact factor: 7.666, year: 2021
Method of publishing: Open access
https://www.mdpi.com/2073-4409/10/8/1916

Light plays an essential role in photosynthesis, however, its excess can cause damage to cellular components. Photosynthetic organisms thus developed a set of photoprotective mechanisms (e.g., non-photochemical quenching, photoinhibition) that can be studied by a classic biochemical and biophysical methods in cell suspension. Here, we combined these bulk methods with single-cell identification of microdomains in thylakoid membrane during high-light (HL) stress. We used Synechocystis sp. PCC 6803 cells with YFP tagged photosystem I. The single-cell data pointed to a three-phase response of cells to acute HL stress. We defined: (1) fast response phase (0-30 min), (2) intermediate phase (30-120 min), and (3) slow acclimation phase (120-360 min). During the first phase, cyanobacterial cells activated photoprotective mechanisms such as photoinhibition and non-photochemical quenching. Later on (during the second phase), we temporarily observed functional decoupling of phycobilisomes and sustained monomerization of photosystem II dimer. Simultaneously, cells also initiated accumulation of carotenoids, especially gamma-carotene, the main precursor of all carotenoids. In the last phase, in addition to gamma-carotene, we also observed accumulation of myxoxanthophyll and more even spatial distribution of photosystems and phycobilisomes between microdomains. We suggest that the overall carotenoid increase during HL stress could be involved either in the direct photoprotection (e.g., in ROS scavenging) and/or could play an additional role in maintaining optimal distribution of photosystems in thylakoid membrane to attain efficient photoprotection.
Permanent Link: http://hdl.handle.net/11104/0323104