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Presence of state transitions in the cryptophyte alga Guillardia theta.

Cheregi O, Kotabová E, Prášil O, Schröder WP, Kaňa R, Funk C - J. Exp. Bot. (2015)

Bottom Line: These state transitions were triggered by blue light absorbed by the membrane integrated chlorophyll a/c antennae, and green light absorbed by the lumenal biliproteins was ineffective.It is proposed that state transitions in G. theta are induced by small re-arrangements of the intrinsic antennae proteins, resulting in their coupling/uncoupling to the photosystems in state 1 or state 2, respectively.G. theta therefore represents a chromalveolate algae able to perform state transitions.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Umeå University, SE-90187 Umeå, Sweden.

No MeSH data available.


Low temperature (77 K) fluorescence emission of G. theta cells after excitation of phycoerythrin at 530nm. The spectra were normalized to the maximal phycoerythrin emission at 590nm. Displayed curves are an average of three measurements. (A) Spectra measured at different culture ages after 20min dark adaptation. (B) Average spectra obtained of the cultures in logarithmic phase (Days 2 and 4), either were dark-adapted for 20min (black curve) or exposed to low white light (2 µmol photons m−2 s−1) for 10min (grey curve). (C) Deconvoluted spectrum obtained of G. theta cells in logarithmic growth phase (Day 2), dark adapted for 20min. The four main fluorescence emission maxima (F576, F589, F607, and F644) are indicated.
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Figure 3: Low temperature (77 K) fluorescence emission of G. theta cells after excitation of phycoerythrin at 530nm. The spectra were normalized to the maximal phycoerythrin emission at 590nm. Displayed curves are an average of three measurements. (A) Spectra measured at different culture ages after 20min dark adaptation. (B) Average spectra obtained of the cultures in logarithmic phase (Days 2 and 4), either were dark-adapted for 20min (black curve) or exposed to low white light (2 µmol photons m−2 s−1) for 10min (grey curve). (C) Deconvoluted spectrum obtained of G. theta cells in logarithmic growth phase (Day 2), dark adapted for 20min. The four main fluorescence emission maxima (F576, F589, F607, and F644) are indicated.

Mentions: Changes in the functional organization of phycoerythrin (PE) in G. theta cells were analysed by low temperature (77 K) fluorescence emission spectra (Fig. 3). De-convoluted spectra of dark adapted cells in the early logarithmic growth phase revealed two main PE emission bands, F576 and F589, and two additional minor bands, F607 and F644 (Fig. 3C). F576 almost disappeared in the stationary phase (Fig. 3A), while the fluorescence bands at 694nm (PSII) and 705nm (PSI) increased, indicating that F576 PE is energetically stronger coupled to PSII and PSI during the stationary growth phase. Interestingly, the largest F576 emission was observed in young cells that were dark adapted for 20min, fluorescence emission decreased in cells adapted to low white light (Fig. 3B).


Presence of state transitions in the cryptophyte alga Guillardia theta.

Cheregi O, Kotabová E, Prášil O, Schröder WP, Kaňa R, Funk C - J. Exp. Bot. (2015)

Low temperature (77 K) fluorescence emission of G. theta cells after excitation of phycoerythrin at 530nm. The spectra were normalized to the maximal phycoerythrin emission at 590nm. Displayed curves are an average of three measurements. (A) Spectra measured at different culture ages after 20min dark adaptation. (B) Average spectra obtained of the cultures in logarithmic phase (Days 2 and 4), either were dark-adapted for 20min (black curve) or exposed to low white light (2 µmol photons m−2 s−1) for 10min (grey curve). (C) Deconvoluted spectrum obtained of G. theta cells in logarithmic growth phase (Day 2), dark adapted for 20min. The four main fluorescence emission maxima (F576, F589, F607, and F644) are indicated.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4588893&req=5

Figure 3: Low temperature (77 K) fluorescence emission of G. theta cells after excitation of phycoerythrin at 530nm. The spectra were normalized to the maximal phycoerythrin emission at 590nm. Displayed curves are an average of three measurements. (A) Spectra measured at different culture ages after 20min dark adaptation. (B) Average spectra obtained of the cultures in logarithmic phase (Days 2 and 4), either were dark-adapted for 20min (black curve) or exposed to low white light (2 µmol photons m−2 s−1) for 10min (grey curve). (C) Deconvoluted spectrum obtained of G. theta cells in logarithmic growth phase (Day 2), dark adapted for 20min. The four main fluorescence emission maxima (F576, F589, F607, and F644) are indicated.
Mentions: Changes in the functional organization of phycoerythrin (PE) in G. theta cells were analysed by low temperature (77 K) fluorescence emission spectra (Fig. 3). De-convoluted spectra of dark adapted cells in the early logarithmic growth phase revealed two main PE emission bands, F576 and F589, and two additional minor bands, F607 and F644 (Fig. 3C). F576 almost disappeared in the stationary phase (Fig. 3A), while the fluorescence bands at 694nm (PSII) and 705nm (PSI) increased, indicating that F576 PE is energetically stronger coupled to PSII and PSI during the stationary growth phase. Interestingly, the largest F576 emission was observed in young cells that were dark adapted for 20min, fluorescence emission decreased in cells adapted to low white light (Fig. 3B).

Bottom Line: These state transitions were triggered by blue light absorbed by the membrane integrated chlorophyll a/c antennae, and green light absorbed by the lumenal biliproteins was ineffective.It is proposed that state transitions in G. theta are induced by small re-arrangements of the intrinsic antennae proteins, resulting in their coupling/uncoupling to the photosystems in state 1 or state 2, respectively.G. theta therefore represents a chromalveolate algae able to perform state transitions.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Umeå University, SE-90187 Umeå, Sweden.

No MeSH data available.