PT Journal AU MATTILA, H HAVURINNE, V ANTAL, T TYYSTJARVI, E TI Evaluation of visible-light wavelengths that reduce or oxidize the plastoquinone pool in green algae with the activated F0 rise method SO Photosynthetica PY 2022 BP 529 EP 538 VL 60 IS 4 DI 10.32615/ps.2022.049 WP https://ps.ueb.cas.cz/artkey/phs-202204-0006.php DE Chlamydomonas; chlorophyll fluorescence; far-red acclimation; FlvB protein; Scenedesmus. SN 03003604 AB We recently developed a chlorophyll a fluorescence method (activated F0 rise) for estimating if a light wavelength preferably excites PSI or PSII in plants. Here, the method was tested in green microalgae: Scenedesmus quadricauda, Scenedesmus ecornis, Scenedesmus fuscus, Chlamydomonas reinhardtii, Chlorella sorokiniana, and Ettlia oleoabundans. The Scenedesmus species displayed a plant-like action spectra of F0 rise, suggesting that PSII/PSI absorption ratio is conserved from higher plants to green algae. F0 rise was weak in a strain of C. reinhardtii, C. sorokiniana, and E. oleoabundans. Interestingly, another C. reinhardtii strain exhibited a strong F0 rise. The result indicates that the same illumination can lead to different redox states of the plastoquinone pool in different algae. Flavodiiron activity enhanced the F0 rise, presumably by oxidizing the plastoquinone pool during pre-illumination. The activity of plastid terminal oxidase, in turn, diminished the F0 rise, but to a small degree. ER