Photoprotective strategies in the motile cryptophyte alga Rhodomonas salina-role of non-photochemical quenching, ions, photoinhibition, and cell motility

0517919 - MBÚ 2020 RIV NL eng J - Journal Article
Kaňa, Radek - Kotabová, Eva - Šedivá, Barbora - Kuthanová Trsková, Eliška
Photoprotective strategies in the motile cryptophyte alga Rhodomonas salina-role of non-photochemical quenching, ions, photoinhibition, and cell motility.
Folia Microbiologica. Roč. 64, 5 SI (2019), s. 691-703. ISSN 0015-5632. E-ISSN 1874-9356
R&D Projects: GA MŠMT(CZ) LO1416; GA MŠMT(CZ) ED2.1.00/19.0392; GA ČR(CZ) GA16-10088S
Institutional support: RVO:61388971
Keywords : light-harvesting complex * transthylakoid proton gradient * photosystem-ii
OECD category: Microbiology
Impact factor: 1.730, year: 2019
Method of publishing: Limited access
https://link.springer.com/article/10.1007%2Fs12223-019-00742-y

We explored photoprotective strategies in a cryptophyte alga Rhodomonas salina. This cryptophytic alga represents phototrophs where chlorophyll a/c antennas in thylakoids are combined with additional light-harvesting system formed by phycobiliproteins in the chloroplast lumen. The fastest response to excessive irradiation is induction of non-photochemical quenching (NPQ). The maximal NPQ appears already after 20 s of excessive irradiation. This initial phase of NPQ is sensitive to Ca2+ channel inhibitor (diltiazem) and disappears, also, in the presence of non-actin, an ionophore for monovalent cations. The prolonged exposure to high light of R. salina cells causes photoinhibition of photosystem II (PSII) that can be further enhanced when Ca2+ fluxes are inhibited by diltiazem. The light-induced reduction in PSII photochemical activity is smaller when compared with immotile diatom Phaeodactylum tricornutum. We explain this as a result of their different photoprotective strategies. Besides the protective role of NPQ, the motile R. salina also minimizes high light exposure by increased cell velocity by almost 25% percent (25% from 82 to 104 mu m/s). We suggest that motility of algal cells might have a photoprotective role at high light because algal cell rotation around longitudinal axes changes continual irradiation to periodically fluctuating light.
Permanent Link: http://hdl.handle.net/11104/0303157