Photoadaptation in the green alga Spongiochloris sp. A three-fluorometer study

Title:

Photoadaptation in the green alga Spongiochloris sp. A three-fluorometer study

Creator:

Koblížek, M., Ciscato, M., Komenda, J., Kopecký, J., Šiffel, P., and Masojídek, J.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:3b45a46c-a609-4ee1-b1b2-300afb30705a
uuid:3b45a46c-a609-4ee1-b1b2-300afb30705a
issn:0300-3604
doi:10.1023/A:1007120424769

Subject:

chlorophyll fluorescence, photochemical yield, non-photochemical quenching, connectivity, and electron transport rate

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

The dark-adapted cells of the green alga Spongiochloris sp. were exposed to "white light" of 1000 µmol(photon) m-2 s-1 for 2 h and then dark adapted for 1.5 h. Changes of photochemical activities during photoadaptation were followed by measurement of chlorophyll (Chl) fluorescence kinetics, 77 K emission spectra, photosynthetic oxygen evolution, and pigment composition. We observed a build-up of slowly-relaxing non-photochemical quenching which led to a decrease of the Fv/Fm parameter and the connectivity. In contrast to the depression of Fv/Fm (35 %) and the rise of non-photochemical quenching (∼ 1.6), we observed an increase in effective absorption cross-section (20 %), Hill reaction (30 %), photosynthetic oxygen evolution (80 %), and electron transport rate estimated from the Chl fluorescence analysis (80 %). We showed an inconsistency in the presently used interpretation schemes, and ascribe the discrepancy between the increase of effective absorption cross-section and the photosynthetic activities on one side and the effective non-photochemical quenching on the other side to the build-up of a quenching mechanism which dissipates energy in closed reaction centres. Such a type of quenching changes the ratio between thermal dissipation and fluorescence without any effect on photochemical yield. In this case the Fv/Fm ratio cannot be used as a measure of the maximum photochemical yield of PS2. and M. Koblížek ... [et al.].

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

307-323

Source:

Photosynthetica | 1999 Volume:37 | Number:2

Harvested from:

CDK

Metadata only:

false