PT  - JOURNAL ARTICLE
AU  - MATTILA, H.
AU  - HAVURINNE, V.
AU  - ANTAL, T.
AU  - TYYSTJÄRVI, E.
TI  - Evaluation of visible-light wavelengths that reduce or oxidize  the plastoquinone pool in green algae with the activated F&lt;sub&gt;0&lt;/sub&gt; rise method
DP  - 2022 Dec 21
TA  - Photosynthetica
PG  - 529--538
VI  - 60
IP  - 4
AID - 10.32615/ps.2022.049
IS  - 03003604
AB  - We recently developed a chlorophyll a fluorescence method (activated F&lt;sub&gt;0&lt;/sub&gt; 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 F&lt;sub&gt;0&lt;/sub&gt; rise, suggesting that PSII/PSI absorption ratio is conserved from higher plants to green algae. F&lt;sub&gt;0&lt;/sub&gt; rise was weak in a strain of C. reinhardtii,  C. sorokiniana, and E. oleoabundans. Interestingly, another C. reinhardtii strain exhibited a strong F&lt;sub&gt;0&lt;/sub&gt; 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 F&lt;sub&gt;0&lt;/sub&gt; rise, presumably by oxidizing the plastoquinone pool during pre-illumination. The activity of plastid terminal oxidase, in turn, diminished the F&lt;sub&gt;0&lt;/sub&gt; rise, but to a small degree.